vvEPA
  United States
  Environmental Protection
  Agency
An Introduction to

Freshwater Mussels as

Biological Indicators


Including Accounts of Interior Basin,
Cumberlandian, and Atlantic Slope
Species

-------

-------
                                            EPA-260-R-08-015
                                              November 2008
         An Introduction  to
     Freshwater Mussels as
       Biological Indicators

   Including Accounts of Interior Basin,
Cumberlandian, and Atlantic Slope Species
                  Prepared by:
       Jeffrey D. Grabarkiewicz1 and Wayne S. Davis2

          1Ecological Survey and Design, LLC
              1517 W. Temperance Rd.
              Temperance, Ml 48182

         2U.S. Environmental Protection Agency
          Office of Environmental Information
        Office of Information Analysis and Access
              Washington, DC 20460
          U.S. Environmental Protection Agency
          Office of Environmental Information
        Office of Information Analysis and Access
              Washington, DC 20460
       Printed on chlorine free 100% recycled paper with
       100% post-consumer fiber using vegetable-based ink.

-------

-------
An Introduction to Freshwater Mussels as Biological Indicators
                 NOTICE

                 This document has been reviewed and approved in accordance
                 with U.S. Environmental Protection Agency policy. Mention
                 of trade names, products, or services does not convey and
                 should not be interpreted as conveying official EPA approval,
                 endorsement, or recommendation for use.

                 Funding was provided by the U.S. Environmental Protection
                 Agency under Contract # 68-C-04-006, Work Assignment #4-79
                 with the Great Lakes Environmental Center, Inc.

                 The appropriate citation for this report is:
                 Grabarkiewicz, J. and W. Davis. 2008. An introduction to
                   freshwater mussels as biological indicators. EPA-260-R-
                   08-015. U.S. Environmental Protection Agency, Office of
                   Environmental Information, Washington, DC.

                 The entire document can be downloaded from:
                       http://www.epa.gov/bioindicators/html/publications.html
                 ACKNOWLEDGEMENTS	

                 We would like to thank the many individuals who provided
                 manuscripts and papers for our review and reference. Thanks
                 also to the University of Michigan Museum of Zoology and the
                 Ohio State Museum of Biological Diversity for providing access
                 to their collections. Last, but certainly not least, thank you to
                 the reviewers who took the time to look over this document,
                 including Dr. Tom Augspurger, Dr. Chris Barnhart, Dr. Arthur
                 Bogan, Dr. Hans Gottgens, Edward Hammer, Tina Hendon, Dr.
                 Teresa Newton, Dr. Brenda Rashleigh, Brett Rodstrom,  and John
                 Tetzloff.

-------
           An Introduction to Freshwater Mussels as Biological Indicators
CONTENTS
Notice	v

Acknowledgements	v

Part One - Introduction and Indicator Use

Introduction	 1
Distribution and Conservation Status	 2
Freshwater Mussel Ecology	 4
Freshwater Mussel Reproduction	 6
Shell Morphology	 8
Sampling Freshwater Mussels	10
Freshwater Mussels as Biological Indicators	15
   Tolerance to Habitat Alteration	17
   Indicators of Biological Integrity	18
   Sensitivity to Toxic Contaminants	20
      Heavy metals	21
      Ammonia	25
      Chlorine	27
      Insecticides, Herbicides, and Fungicides	27
   Shells as Indicators	29

Part Two - Genus and Species Accounts

Genus Accounts
   Alasmidonta Say, 1818	31
   Epioblasma Rafinesque, 1831	34
   Fusconaia  Simpson, 1900	37
   Lampsilis Rafinesque, 1820	40
   Lasmigona  Rafinesque, 1831	44
   Pleurobema Rafinesque, 1819	47
   Quadrula Rafinesque, 1820	50

Species Accounts
   Mucket (Actinonaias ligamentina)	53
   Pheasantshell  (Actinonaias pectorosa)	54
   Dwarf Wedgemussel (Alasmidonta heterodon)	55
   Elktoe (Alasmidonta marginata)	56
   Threeridge (Amblema plicata)	57
                                       VI

-------
           An Introduction to Freshwater Mussels as Biological Indicators
CONTENTS (CON'T)
Species Accounts*
    Purple Wartyback (Cyclonaias tuberculata)	58
    Dromedary Pearlymussel (Dromus dromas)	59
    Eastern Elliptic (Elliptic complanata)	60
    Spike (Elliptic dilatata)	61
    Oyster Mussel (Epioblasma capsaeformis)	62
    Northern Riffleshell (Epioblasma tomlosa rangiana)	63
    Tubercled Blossom  (Epioblasma torulosa torulosa)	64
    Wabash Pigtoe (Fusconaia flava)	65
    Pink Mucket (Lampsilis abrupta)	66
    Plain Pocketbook (Lampsilis cardium)	67
    Wavyrayed Lampmussel (Lampsilis fasciola)	68
    Fat Mucket (Lampsilis siliquoidea)	69
    White Heelsplitter (Lasmigona complanata complanata)	70
    Flutedshell (Lasmigona costata)	71
    Black Sandshell (Ligumia recta)	72
    Cumberland Moccasinshell (Medionidus conradicus)	73
    Threehorn Wartyback (Obliquaria reflexa)	74
    Sheepnose (Plethobasus cyphyus)	75
    Clubshell  (Pleurobema clava)	76
    Ohio Pigtoe (Pleurobema cordatum)	77
    Round Pigtoe (Pleurobema sintoxia)	78
    Kidneyshell (Ptychobranchus fasciolaris)	79
    Fluted Kidneyshell (Ptychobranchus subtentum)	80
    Giant Floater (Pyganodon grandis)	81
    Rabbitsfoot (Quadrula cylindrica cylindrical	82
    Pimpleback (Quadrula pustulosa pustulosa)	83
    Mapleleaf (Quadrula quadrula)	84
    Creeper (Strophitus undulatus)	85
    Pistolgrip  (Tritogonia verrucosa)	86
    Rain bow (Villosa iris)	87

Conservation Status Table	88
Glossary	89
Literature Cited	90
             *Taxonomic Note: To  simplify the taxonomy of this guide, all
             names follow Turgeon et al. (1998). However, we recognize that
             this may not represent the most current taxonomic scheme.
                                         VII

-------
            An Introduction to Freshwater Mussels as Biological Indicators
FIGURES
Figure 1.  (Top) Total number of freshwater mussel species by state.
(Bottom) Percentage of imperiled freshwater mussel species by state	2
Figure 2.  Freshwater mussel faunal provinces	3
Figure 3.  Proportion of species at risk by plant and animal group	3
Figure 4.  Various beak sculptures	8
Figure 5.  Basic shell anatomy	8
Figure 6.  Basic shell orientation	9
Figure 7.  Inner soft tissue	9
Figure 8.  Hypothetical qualitative bridge survey.	12
Figure 9.  A systematic sampling design along 2 transects with 3 random starts	13
Figure 10. Hypothetical survey layout using the ORVET protocol	15
Figure 11. A listing of the most sensitive aquatic genera to copper
excluding freshwater mussels	23
Figure 12. A listing of the most sensitive aquatic genera to copper
including freshwater mussel taxa	23
Figure 13. A listing of the most sensitive aquatic genera to ammonia
excluding freshwater mussel taxa	25
Figure 14. A listing of the most sensitive aquatic genera to ammonia
including freshwater mussel taxa	26
Figure 15. External rings of the Ohio Pigtoe (Pleurobema cordatum)	29
                                          VIM

-------
            An Introduction to Freshwater Mussels as Biological Indicators
PHOTOGRAPHS
Photo 1. A Kidneyshell (Ptychobranchus fasciolaris) repositioning in the substrate	4
Photo 2. Small fishes, such as this Brindled Madtom (Noturus miurus), often take
shelter in the spent shells of freshwater mussels (Photo: Threeridge shell)	5
Photo 3. The Spike (Elliptic dilatata) blanketed in periphyton	5
Photo 4. Water pennies (Psephenidae sp.) grazing on a White Heelsplitter
shell (Lasmigona complanata complanata)	5
Photo 5. The mantle flap lure of the Plain  Pocketbook (Lampsilis cardium) 	6
Photo 6. The charged gills of the Plain Pocketbook (Lampsilis cardium)  	6
Photo 7. A 12 mm Rayed Bean (Villosa fabalis) attached to a small piece
of gravel via byssal threads	7
Photo 8. Clinch River, TN	10
Photo 9. Sampling a small creek with a view-bucket and snorkeling gear	10
Photo 10. Typical diving gear used by biologists searching for mussels	11
Photo 11. Mussel researcher utilizing an underwater viewer	11
Photo 12. Researcher sorting mussels for identification and measurement	11
Photo 13. Unionids collected during a qualitative survey.	12
Photo 14. Excavating  sediments within  a 0.25 m2 quadrat during a
quantitative survey. 	14
Photo 15. Excavating  sediments within  a 0.25 m2 quadrat during a
quantitative survey	14
Photo 16. The Green River, KY, home to 71 mussel species and 151
fish species	16
Photo 17. The Shelbyville dam, Duck River, TN	17
Photo 18. A researcher measures a mussel with a caliper to collect
demographic data	19
Photo 19. Swan Creek, OH, headwater habitat of the Slippershell
Mussel (Alasmidonta viridis)	31
Photo 20. Slippershell Mussel (Alasmidonta viridis), Swan Creek, OH	31
Photo 21. The Oyster Mussel (Epioblasma capsaeformis), Clinch River, TN	34
Photo 22. The Powell  River (TN, VA) was  historically home to several
species of Epioblasma, including the extinct Forkshell (Epioblasma lewisii)
and Acornshell (Epioblasma haysiana)	34
Photo 23. Roanoke River, VA, home to the Atlantic Pigtoe (Fusconaia masoni)	37
Photo 24. The Wabash Pigtoe (Fusconaia flava), Swan Creek, OH	38
                                          IX

-------
           An Introduction to Freshwater Mussels as Biological Indicators
PHOTOGRAPHS  (CON'T)
Photo 25. Streamline chubs (Erimystax dissimilis) foraging above a
Longsolid (Fusconaia subrotunda), French Creek, PA	38
Photo 26. Cumberland River, KY, home to the Ebonyshell (Fusconaia ebena),
Longsolid (Fusconaia subrotunda), and Wabash Pigtoe (Fusconaia flava)	39
Photo 27. Lake Michigan, home to the Plain Pocketbook (Lampsilis cardium)
and Fatmucket (Lampsilis siliquoidea)	41
Photo 28. In-situ mantle flap lure of the Wavyrayed Lampmussel	43
Photo 29. In-situ apertures of the Plain Pocketbook	43
Photo 30. The Flutedshell (Lasmigona costata) in French Creek, PA	45
Photo 31. Green River, KY, home to the Flutedshell (Lasmigona costata) and
White Heelsplitter (Lasmigona complanata complanata)	46
Photo 32. The Green River (KY), home of the federally endangered
Rough Pigtoe (Pleurobema plenum)	48
Photo 33. The federally endangered Clubshell (Pleurobema clava),
French Creek, PA	48
Photo 34. East Fork West Branch St. Joseph River, Ml, habitat of the
Clubshell (Pleurobema clava)	49
Photo 35. Rabbitsfoot (Quadrula cylindrica cylindrical, French Creek, PA	51
Photo 36. French Creek, PA, habitat of the  Rabbitsfoot (Quadrula cylindrica cylindrical	52
                   All photographs by Jeff Grabarkiewicz and Todd Crail

-------
           An Introduction to Freshwater Mussels as Biological Indicators
INTRODUCTION
While marine environments harbor the delicate beauty of the seahorse, coral reef, and
anemone, North American freshwater streams and lakes support a splendor all their own.
Freshwater mussels, also called pearly mussels, naiads, or clams, are a diverse group of
creatures that are both unassuming and inconspicuous. Most will not confound passersby
with oddities or evoke awe-inspired gasps from onlookers. In fact, many spend a good
deal of their life partially or wholly buried in stream sediments, detectable to only the most
astute observer. Yet, despite their mild manner and cryptic nature, evolution has bestowed
a great variety of these creatures on the North American continent. And we should
consider ourselves fortunate! Not only do these mussels possess a unique elegance and
beauty, but they also exhibit a dizzying array of adaptations and life history strategies.

As a group, freshwater mussels are differentiated from other bivalves by their unique life
cycle. This life cycle includes a parasitic larval stage that requires, in most cases, a fish
host to complete. Adult mussels can measure up to ten inches in length and, under certain
conditions,  live more than 100 years (Bauer 1987; Cummings and Mayer 1992).

From  an economic perspective, mussels have  been valued for their beauty, shell material,
and natural pearls for centuries. Unfortunately, this has also led to the overharvesting
of mussel resources. For example, during the mid-1800s, freshwater mussels were
commonly collected by people seeking fortune in the form of freshwater pearls. Following
a valuable discovery, successive collecting often led to the wholesale destruction of entire
mussel beds (Anthony and Downing 2001). The pearl button industry, founded during the
late 1800s, provides another example of overharvesting leading to resource depletion. This
industry created buttons from the durable shells of freshwater mussels. Thousands of tons
of shells were harvested  in Eastern North America from the late 1800s to the mid 1900s to
fuel the button industry. Coker et al. (1921) eloquently observed "equal as they were to the
vicissitudes of natural conditions, they were unable to withstand the unchecked ravages
of commercial fishery". Freshwater mussels continue to be an important  economic and
ecological resource (Anthony and Downing 2001, Pritchard 2001).

The primary purpose of this guide is to encourage the use of freshwater mussels for water
quality assessment and to briefly review their use as biological indicators and biomonitors.
This document is not intended as a "how to" manual or methods document, but as an
educational tool. It was designed and written with a wide audience in mind, including
academic institutions, natural resource managers, park naturalists, conservationists,
monitoring groups, environmental managers, and interested citizens. Several topics will
be examined in detail, including ecology, reproduction, indicator use, sensitivity to toxic
contaminants, survey methodologies. In addition,  species records are included with
pictures to assist in identification and indicator usage.

-------
           An Introduction to Freshwater Mussels as Biological Indicators
DISTRIBUTION  AND  CONSERVATION STATUS
                                                  Total Number
Freshwater mussels (Bivalvia: Unionoida) are distributed nearly worldwide, inhabiting
every continent on Earth except Antarctica. Approximately 780 species belonging to 140
genera have been identified, with species diversity maximized in the creeks,  rivers,  and
lakes of North America (Graf and Cummings 2007). Globally, six families of freshwater
mussels are known, although
only two occur in  North
America - the  Unionidae and
Margaritiferidae. The Unionidae
makeup the vast majority of the
North American fauna. Overall,
approximately 300 species
of mussels are found in the
U.S., with the highest species
richness found in  the Southeast
(Fig. 1) (Neves et al. 1997).
Various unionoid faunal
zones have been identified by
malacologists during the past
century (e.g. Simpson 1900;
van der Schalie and van der
Schalie 1950; Parmalee and
Began 1998; Abell et al. 2000).
This guide borrows from the
interpretation introduced by
Parmalee and Bogan (1998)
(Fig. 2). Faunal regions are
useful when attempting to
describe the distribution
patterns and evolutionary
characteristics of freshwater
mussels. For example, some
faunal provinces represent
areas of considerable
endemism, such as the
Ozarkian, Cumberlandian, and
Mobile Basin. Within these
regions, faunal "hotspots" occur
that support unionoid species
found nowhere else on Earth.
                                               Percentage Imperiled
                                                         (Source: LaRoe et al. 1995)
                              Figure 1: (Top) Total number of freshwater mussel species
                              by state. (Bottom) Percentage of imperiled freshwater mussel
                              species by state.

-------
            An Introduction to Freshwater Mussels as Biological Indicators
              (Source: Parmalee and Bogan (1998), The Freshwater Mussels of Tennessee.
              University of Tennessee Press. Permission granted by the authors.)
                           Northern Atlantic Slope
                           Southern Atlantic Slope
                           Interior Basin or
                           Mississippian
                           Cumberlandlan
                           Mobil Basin
                           Eastern Gulf Coast or
                           Apalachlcolan
                           Peninsular Florida
                           Ozarkian
                           Sablne
                           Central Texas
                           Rio Grande
                           Pacific
              Figure 2: Freshwater mussel faunal provinces.
While historically highly diverse
and abundant throughout a good
portion of the U.S., unionoids are
now one of the most imperiled
groups nationwide (Fig. 3).
Approximately 70% of the North
American fauna is in various
states of decline (Williams  et
al. 1993; Master et al. 2000;
NatureServe 2008). Sadly,  37
species are now presumed
extinct (Master et  al. 2000). This
decline is often attributed to
habitat destruction, water quality
degradation, damming,  exotic
species, and hydrologic changes
(Williams et al. 1993; Strayer et
al. 2004).


Crayfishes

Stoneflies

Freshwater Fishes

Amphibians

Flowering Plants






1 II 51%

QB 43%

1 13

1 1 369

1 1 1 33%

Gymnosperms H
I 24%

Ferns/Fern Allies I 
|| 22%

Tiger Beetles I I

Butterflies/Skippers

Reptiles

Dragonflies/Damselflies I 

Mammals
Birds rZ^^B
0% 10%
(Sou
19% P-, D

I1 19%  Critic
, 	 , .
|| 18%  lmPE
CH Vuln
HI

] 16%
14%
%
i
jmed/Poss
allylmper'
riled (G2)
arable (G3)
blyF-xtinct
ed(G1)

69%
(GX/GH)

20% 30% 40% 50% 60% 70%
Percent of Species
ce: Precious Heritage, TNC and NatureServe, 2000)
Figure 3: Proportion of species at risk by plant and animal
group.

-------
           An Introduction to Freshwater Mussels as Biological Indicators
FRESHWATER  MUSSEL ECOLOGY
Freshwater mussels play a number of important roles in aquatic ecosystems. As sedentary
suspension feeders, unionoids remove a variety of materials from the water column,
including sediment, organic matter, bacteria, and phytoplankton. Siphoned material is
either transferred to the mouth for digestion or sloughs off the gills and exits via the ventral
margin of the shell (pseudofeces). Digested material is either used as fuel for various
life processes or excreted as feces. The amount and rate of particulate matter removed
from the water column and subsequent deposition of waste is largely dependent on
temperature, particle concentration, flow regime, mussel size, and species (Vaughn and
Hakenkamp 2001). While the siphoning activities of mussels are often overlooked, they
provide an integral resource link between pelagic and benthic habitats (Nelepa et al. 1991;
Howard and Cuffey 2006).
Mussels also interact with stream sediments.
The burrowing behavior of unionids mixes
sediment pore water, releasing nutrients and
oxygenating substrates (Photo 1) (Vaughn
and Hakenkamp 2001). Particularly dense
assemblages of mussels may influence
substrate stability and provide nutrients and
microrefugia for benthic life (Vaughn and
Hakenkamp 2001; Zimmerman and de Szalay
2007).

Juvenile mussels have demonstrated the
ability to pedal feed by sweeping their foot
to collect food particles from sediments.
Studies conducted by Gatenby et al. (1996)
documented the importance of sediments
to the growth of juvenile Rainbow (Villosa
iris). Researchers reported increased shell
growth and survival rates when algal diets
were supplemented with a fine sediment
substratum.
                                          Photo 1:  A Kidneyshell (Ptychobranchus
                                          fasciolahs) repositioning in the substrate.

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Freshwater mussels also provide food
for a number of terrestrial and aquatic
species. Raccoons, muskrats, otters,
fishes, turtles, and birds all feed on
mussels. The cracked valves and
weathered remains of unionids often litter
gravel bars and floodplains, a testament
to the efficiency of terrestrial predators.
The spent valves of freshwater mussels
play a role in aquatic ecosystems as well.
Shells provide habitat for a variety of
life, including fish (Photo 2), periphyton
(Photo 3), crustaceans, molluscs,
and macroinvertebrates (Photo 4).
Additionally, the weathering and eventual
erosion of shell material recycles calcium
carbonate back to aquatic ecosystems.
Photo 2: Small fishes, such as this Brindled
Madtom (Noturus miurus), often take shelter
in the spent shells of freshwater mussels
(Photo: Threeridge shell).
 Photo 3: The Spike (Elliptic dilatata) blanketed
 in periphyton.
                                           Photo 4: Water pennies (Psephenidae sp.)
                                           grazing on a White Heelsplitter shell (Lasmigona
                                           complanata complanata).

-------
           An Introduction to Freshwater Mussels as Biological Indicators
FRESHWATER MUSSEL  REPRODUCTION
The reproductive characteristics and
processes found among the Unionoidea
are diverse, complex, and more than a
little intriguing. As a group, they exhibit
extraordinary variations in fecundity, brooding
tendencies, host specificity, and "luring"
techniques (Photo 5) (Walters 1995; Haag
and Warren 1999; Haag and Staton 2003;
Haag and Warren 2003).

While sexes are separate in most freshwater
mussels, hermaphroditic species have
been reported (van der Schalie 1970). The
reproductive process is initiated when an
upstream male releases sperm into the water
column and a downstream female collects it
via the incurrent aperture. Fertilization occurs
internally, with embryo development ensuing
within the marsupia (gill pouches) (Photo 6).
The resulting larvae, termed "glochidia," are
brooded by the female for a period of time
ranging from a few weeks to several months.
While some species use all four gills to brood
(e.g. Quadrula), others use only the outer gills
or specialized portions of the outer gills (e.g.
Lampsilis). Once released, glochidia are, for
the most part, obligate parasites that must
find a suitable host or perish.

With few exceptions, freshwater mussels
utilize freshwater and anadromous fishes
as hosts. While some mussel species have
proven capable of parasitizing a wide range
of fish hosts, others are seemingly more
specific. For example, laboratory host studies
                                          Photos 5 and 6: (Top) The mantle flap lure of the
                                          Plain Pocketbook (Lampsilis cardium). (Bottom)
                                          The charged gills of the Plain Pocketbook
                                          (Lampsilis cardium).

-------
           An Introduction to Freshwater Mussels as Biological Indicators
suggest that the Giant Floater (Pyganodon
grandis) may be capable of successfully
transforming on nearly 40 species (Walters
1994; Walters 1995). Conversely, Layzer et al.
(2003) exposed 18 species of fish (from six
families) to the glochidia of the Cumberland
Pigtoe (Pleurobema gibberum) and reported
just two species as suitable hosts. Glochidia
that successfully locate a host species attach to
the fins, skin, or gills. Once attached, glochidia
feed on host tissue and develop  anatomical
structures. After a period of time, the glochidia
excyst and drop off into the substrate or attach
to objects with byssal threads (Photo 7).
Photo 7: A 12 mm Rayed Bean (Villosa
fabalis) attached to a small piece of gravel via
byssal threads.
Freshwater mussels utilize a variety of structures and techniques to attract potential
host species. For example, several members of the genus Lampsilis display a mantle
flap lure (Photos 5 and 6) to entice various piscivorous hosts, including species such
the Largemouth Bass, Rock Bass, and Black Crappie. When the mantle lure is struck
by an unsuspecting fish, the female responds by expelling glochidia out of the excurrent
siphon and infecting the  potential host. The Fusconaia utilize a markedly different
strategy, packaging glochidia in capsule-like cases termed "conglutinates." After being
ejected into the water column, the conglutinates are fed on by fishes, initiating glochidial
attachment to the gills of potential host fishes. A few species have the ability to produce
"superconglutinates," gelatinous masses that are attached to the female mussel via
a mucus cord. The minnow-like masses "swim" back and forth in the current, and are
presumably preyed upon by species such  as the Smallmouth Bass (Haag and Warren
1997).
                                        7

-------
           An Introduction to Freshwater Mussels as Biological Indicators
SHELL MORPHOLOGY
In order to accurately identify freshwater
mussels, some basic knowledge of shell
morphology is required. While some species
have distinctive features that allow for instant
identification, others are much more cryptic. In
addition, young mussels often vary significantly
in shape, thickness, length, color, and inflation
when compared to older individuals. To
further complicate matters, the same species
may vary in appearance from watershed to
watershed, or even within the same watershed.
Perhaps the easiest (and most efficient) way
to become proficient with the identification of
mussels is to visit an established collection.
Many major universities maintain collections
of mollusks that are open to researchers
and interested naturalists by appointment.
Additionally, numerous regional and state
guides are now available at reasonable prices
(e.g. Oesch 1984; Cummings and Mayer 1992;
Parmalee and Bogan 1998; WDNR 2003).
                       elevated and
                       heavy ridges
double-looped
   ridges
                     coarse ridges
numerous wavy
   ridges 
                     fine ridges
                                            Figure 4: Various beak sculptures.
                  Figure 5: Basic shell anatomy.
                                       8

-------
An Introduction to Freshwater Mussels as Biological Indicators
        postero-
         dorsal
dorsal
antero-
dorsal
       posterior
                     anterior
       postero-
        ventral
ventral
 antero-
 ventral
      Figure 6: Basic shell orientation.
      Figure 7: Inner soft tissue.

-------
           An Introduction to Freshwater Mussels as Biological Indicators
 Photo 8: Clinch River, TN.
SAMPLING FRESHWATER MUSSELS
General Overview

Freshwater mussel sampling designs and techniques are largely dependent on the
resources available, sampling conditions, survey objectives, and prior knowledge of the
target population(s) (Strayer and Smith 2003). Surveys range from informal or qualitative
timed searches to intensive, quantitative designs aimed at providing precise population
estimates.

Survey area size and water depth play an
important role in determining sampling
techniques. For example, small, shallow
streams can often be effectively sampled with
little more than a view-bucket or mask and
snorkel (Photos 9 and 11). However, large
streams, rivers, and lakes usually require
SCUBA gear (Photo 10) or surface-supplied
air (SSA) systems. Biologists and commercial
divers utilize a widerange of SSA systems,
some of which are intended for recreational
purposes while others are designed for
deepwater diving. Hookah compressors
(recreational) are popular when surveying
small streams where the water is clean and
relatively shallow. Conversely, navigational channels often require the use of SCUBA
gear or commercial SSA dive stations. Commercial dive stations usually permit divers to
communicate with a topside dive supervisor as well as each other; thereby adding an  extra
degree of comfort and safety to dive operations. Commercial systems may also utilize a
"hardhat," a helmet that completely  encapsulates the head, protecting the ears and oral-
Photo 9: Sampling a small creek with a view-
bucket and snorkeling gear.
                                      10

-------
          An Introduction to Freshwater Mussels as Biological Indicators
Photo 10: Typical diving gear used
by biologists searching for mussels.
                              nasal passages
                              from contact
                              with the water
                              column. This may
                              be especially
                              important when
                              surveying in
                              contaminated
                              environments.

                              Sampling
                              conditions and
                              the habits of
                              freshwater
                              mussels can
                              make them difficult to detect. Detection is usually
                              related to substrate type, species, mussel length,
                              instream vegetation, and observer proficiency (Smith et
                              al. 2001 a). Mussel investigators often use their hands
                              to gently feel or disturb the substrate, a technique
                              informally termed "noodling." Noodling is effective when
                              searching for young mussels or species that burrow
                              deep into the substrate.
Photo 11: Mussel researcher utilizing an
underwater viewer.
                                Photo 12: Researcher sorting mussels for identification and
                                measurement.
                                        11

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Qualitative Searches

Qualitative searches are generally performed in a bounded area (such as 30m x 20m cell)
for a finite amount of time. Time is often expressed in person-minutes or person-hours
when multiple investigators survey the same area. Qualitative timed searches usually are
designed to optimize species detection without expending the effort required to derive
population estimates, calculate relative abundances, or detect statistically significant
changes in mussel populations over time. As such, qualitative searches are generally more
efficient for species detection than quadrat-based surveys where sediments are excavated
(Obermeyer 1998; Smith et al. 2001 a;
2001 b; Smith 2006).

       Example. Figure 8 provides a
       plan view example of a typical
       qualitative survey. In this study,  a
       small area near a bridge is being
       surveyed qualitatively by two
       malacologists. The survey design
       partitions the study area into 15m
       x 20m sampling units, which are
       delineated onsite using a variety
       of  markers. The investigators
       then survey each cell using
       snorkeling gear for 40 person-
       minutes, searching for mussels
       visually and factually. Assuming a
       search efficiency of 1 m2 /minute,
       an "effective sampling fraction"
       of  0.13 can be calculated (see
       Smith et al. 2001 a). Essentially,
       the effective sampling fraction is
       defined as the percentage of the
       cell that is thoroughly searched
       for mussels, which is 13% in this
       example. To increase the amount
       of  coverage in the study area,
       the cell dimensions could be
       altered or the survey time per cell
       increased.
Figure 8: Hypothetical qualitative bridge survey.
  Photo 13: Unionids collected during a qualitative
  survey.
                                        12

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Quantitative Studies

Quantitative studies are performed when population estimates are desired for a particular
area or target population. Unlike qualitative sampling, a "comprehensive" sampling effort
requiring excavation of each sampling unit (typically a 0.25 m2 quadrat) is needed to
ensure mussel detection. Such sampling efforts are usually time intensive and expensive
due to the number of samples required and the need to excavate sediments. Smith
(2006) found that excavation required 3 to 12x more time than surface counts. However,
guidelines have been developed by Smith et al. (2001 a; 2001 b) to limit the amount of
excavation required based on the traits of the target population.

A number of sampling strategies can be utilized independently or in combination to
assess a study area, including random sampling, systematic sampling, double sampling,
and adaptive cluster sampling. For a detailed explanation of probability-based sampling
strategies, refer to Strayer and Smith (2003). Essentially, the goal of the survey designer
is to take enough samples to achieve the desired amount of precision. Where the target
population is abundant, less effort is generally required. Unfortunately, due to the patchy
nature of unionoid populations (even  within the limits of a mussel bed) and the low
densities at which imperiled species often occur, a large number of samples is usually
needed.
       Example. The objective
       of a survey may be to
       estimate the population
       size of federal
       candidate Sheepnose
       (Plethobasus cyphyus)
       near a bridge site.
       From prior knowledge
       of the site, the
       designer anticipates
       finding Sheepnose at
       densities  of 0.5/m2.
       With these data and
       a few additional site
       attributes (e.g.  survey
       area), the designer
       uses quantitative, systematic sampling techniques (Photos 14 and 15;
       Fig. 9) to collect an unbiased sample of the survey area. The number
       of quadrats required to achieve the desired amount of precision can
       be calculated using the methods presented in Smith et al.  (2001 a) or
       Strayer and Smith (2003).
i L
>J
1
3
1 '
T1 T2

2
1



1


2

3



3











meter


1



1

2



2

3



3





Figure 9: A
systematic sampling
design along 2
transects with 3
random starts (see
Strayer and Smith
2003). Generally,
0.25 m2 quadrats
are used for
quantitative work; 1
m2 sampling units
are used here for
simplicity.
                                        13

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Photo 14 (left) and 15 (right): Excavating sediments within a 0.25 m2 quadrat during a quantitative
survey.
Big River Surveys - ORVET Protocol

Protocols have been developed by the Ohio River Valley Ecosystem Team (ORVET
- Mollusk Subgroup) with the intent of providing a consistent and reliable approach to
mussel survey activities in the Ohio River (ORVET 2004). This methodology has also been
applied to large rivers throughout the Midwest and eastern United States. It is a simple,
adaptable, qualitative method that that does not require quadrat-based sampling or
sediment excavation. The following is a summary of ORVET (2004):

      The protocol calls for 100 meter transects laid perpendicular to
      flow, spaced 100 meters apart. Buffer areas are added to the total
      survey area based on the type of planned disturbance or presence of
      federal species. Transects are divided into (10) 10 meter  segments or
      "samples." A diver searches a 1 meter wide path over each sample (10
      meter segment) for a minimum search time of 5 minutes. Mussels are
      bagged at the end of each 10 meter segment. This protocol assumes
      that the diver detects only 50% of the actual mussels present,
      therefore densities of 0.5/nf may actually equal 1.0/m2.

       Example. Figure 10 provides a plan view example of a typical large
       river survey using the ORVET protocol. In this example,  transects
       are laid according to protocol along the left bank of the river. Divers
       would then proceed to search  each 10 meter segment for a minimum
       of 5 minutes. Mussels are usually identified on a boat by a qualified
       malacologist.
                                       14

-------
          An Introduction to Freshwater Mussels as Biological Indicators
                   Figure 10: Hypothetical survey layout using the
                   ORVET protocol.
FRESHWATER MUSSELS AS  BIOLOGICAL INDICATORS

Freshwater mussels possess several characteristics that make them suitable indicator
organisms (Ortmann 1909; Wurtz 1956; Bedford et al. 1968; Simmons and Reed 1973;
Imlay 1982; Neves 1993; Naimo 1995). These attributes allow individuals or assemblages
to function as "environmental logbooks," effectively recording changes in water and habitat
quality over time. North American unionoids have, in fact, been sounding the alarm for
over the past century. What follows is a short list of qualities that support the use of
mussels as bioindicators:

      Unionoidean Attributes
      1. Long-lived: some species may reach 70+ years.
      2. Sedentary: juvenile and adult mussels move little during their entire
        lifetime.
      3. Burrowers: some species and juveniles burrow deep into the
        streambed.
      4. Filter feeders: mussels obtain food and oxygen from the water column
        and via interstitial flow.
      5. Fairly large: mussels contain ample soft tissue for chemical analysis.
      6. Spent valves: dead mussels leave a historical record.
                                     15

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Photo 16: The Green River, KY, home to 71 mussel species and 151 fish species.
Sensitivity to Environmental
Perturbations
1. Unionoids demonstrate a gradient
  of tolerances to both chemical
  contaminants and physical alterations.
2. Exhibit sensitivity to habitat or
  watershed changes that alter flow
  regimes, reduce substrate  stability, or
  cause siltation.
3. Vulnerable to periods of low dissolved
  oxygen.
4. Sensitive to exotic species  invasions,
  such as the zebra mussel (Dreissena
  polymorpha).

Sampling and Monitoring
1. Unionoids are widespread  throughout
  the United States, and are  particularly
  speciose in the eastern United States.
2. Protocols have been developed to
  survey mussels, although sampling
  techniques have not been standardized.
3. Freshwater mussels are relatively easy
  to tag and monitor.
Biological Indicator
A numerical value(s) derived from actual
measurements, has known statistical
properties, and conveys useful information
for environmental decision making. It can
be a measure, an index of measures, or
a model that characterizes an ecosystem
or one of its critical components (USEPA
2007).

Biological Integrity
The capability of supporting and
maintaining a balanced, integrated,
adapted community of organisms having
a species composition, diversity, and
functional organization comparable to the
natural habitats of the  region (Karr and
Dudley 1981).

Biomonitor
An organism that is sensitive to, or is
capable of detecting, changes in  the
surrounding environment.

Indicator Organism
An organism whose characteristics are
used to point out the presence or absence
of environmental conditions which cannot
be feasibly measured from other taxa
or the environment as  a whole (slightly
modified from  Landres et al. 1988).
                                         16

-------
          An Introduction to Freshwater Mussels as Biological Indicators
 Photo 17: The Shelbyville dam, Duck River, TN.
Tolerance to Habitat Alterations

From the sinking mud of turbid embayments to the sand and gravel of morainal streams,
the Unionidae and Margaritiferidae can be found in a wide range of habitats throughout
North America. Yet, despite the seemingly ubiquitous distribution of some species, the vast
majority of freshwater mussels thrive in clear, oxygenated streams and rivers where the
bed is comprised of sand, gravel, and cobble substrates.

Of the habitat alterations initiated by humans, the systematic damming of creeks and
rivers has likely had the most profound  effect on freshwater  mussels (USFWS 1985a;
Bogan 1993; Neves 1993; Yeager 1993). The alteration of shallow, flowing habitats to long,
linear pools has drastically altered the physical, chemical, and biological characteristics
of numerous North American rivers  (Ellis 1942; Bates 1962; Coon et al. 1977; Yeager
1993; Hughes and Parmalee 1999). Impoundment not only reworks the depth and
hydraulics of a river reach, but also prevents the migration of host fishes and may
severely alter downstream water quality (Walters  1996c; Vaughn and Taylor 1999; Walters
2000). As a result, mussel species adapted to shallow, flowing rivers are now some
of the most imperiled animals in the United States. The destruction of the Epioblasma
(riffleshells), for example, has been  largely attributed to the impoundment of small and
large rivers (USFWS 1983b; USFWS 1985a; USFWS 2004). Nonetheless,  diverse
unionid assemblages have persisted under impounded conditions. For example, Haag
and Warren (2006) recently documented a fairly diverse, recruiting unionid community in
an impounded portion of the Little Tallahatchie River (MS) below Sardis Dam. However,
it should be noted that the assemblage consisted of many species known to tolerate
impoundment or lentic conditions.

Sedimentation is another process that may have harmful impacts on freshwater mussel
communities. With the exception of some anodontines, the majority of North American
unionoid mussels occur in coarse substrates and  flowing water. Soft,  cohesive substrates
                                      17

-------
           An Introduction to Freshwater Mussels as Biological Indicators
and suspended fine sediments are deleterious for most species and may affect respiration,
feeding, and growth (Marking and Bills 1979).

Waterway modifications such as channelization and dredging homogenize habitat,
alter flow regimes, and may increase streambed and bank shear stresses. The physical
straightening and deepening of streams has been associated with the decimation of
mussel communities and changes in faunal composition (Stansbery and Stein 1971;
Walters 1988). In addition, stream "maintenance" is often a reoccurring event, as unstable
streams "silt in" or develop various obstructions. Continuous channel maintenance may
destabilize streams, resulting in shifting, unstable substrates, excessive erosion, and soft
mid-channel bars.

While not frequently named as a primary contributor to the decline of mussels in North
America, landscape alterations such as urbanization have been documented to reduce
stream quality and alter macroinvertebrate communities (Stepenuck et al. 2002; Deacon
et al. 2005). Watershed modifications that increase the volume and change the timing of
stormwater runoff may initiate substrate instability,  increase bank erosion, and promote
the siltation of downstream habitats. Strayer (1999) found mussels to be correlated closely
with areas of hydraulic stability, moreso than other  habitat features such as depth and
substrate size. While American cities and suburbs continue to expand, stable habitat will
likely become increasingly rare to the detriment of freshwater mussel communities.

Indicators of Biological Integrity

Freshwater mussels are commonly labeled as "good" indicators of biological integrity
and water quality by scientists. Despite this, there remains little guidance available for
monitoring groups or agencies as to how to utilize unionoids in this capacity. A review
of published literature, technical reports, and research does provide some information,
however. For example, Kearns and Karr (1994) used mussels from the genus Epioblasma
and three snail genera as an  intolerant metric when developing a B-IBI (Benthic Index of
Biotic Integrity) for the Tennessee Valley. Pip (2006) analyzed water quality and mollusk
communities in southern Lake Winnipeg, Manitoba, Canada. Freshwater mussel species
richness was positively correlated with total dissolved solids and negatively correlated with
lead. She also found a significant reduction in mussel species diversity and suggested the
change was possibly due to oxygen depletion, algal toxins, sewage and agricultural spills
and runoff, application of copper sulphate, and habitat changes. Hoggarth and Goodman
(2007) utilized a multimetric Mussel Index of Biotic  Integrity developed by Goodman (2007)
to evaluate changes in the mussel fauna of the Little Miami River, OH. The Index included
metrics that assessed distribution and abundance,  reproductive potential, and community
structure.
                                        18

-------
           An Introduction to Freshwater Mussels as Biological Indicators
While freshwater mussels do present unique challenges to monitoring (e.g. patchy
distributions, sampling conditions, etc.), the information gained from their study can
provide unique insights regarding biological integrity and water quality. Although
developing complex multimetric mussel indices is beyond the scope of this guide, below
are a few basic recommendations on monitoring techniques that may provide valuable
information when assessing local waterways.

   Community Demographics
   Characterizing community demographics over time may yield important data on
   species viability, conditions conducive to reproductive success, water quality, and
   ecosystem stability.

   When monitoring community demographics, multiple stations with known mussel
   populations should be setup within the desired study area. If possible, monitoring
   should be done quantitatively to limit sample bias.

   To evaluate community age class structure, a malacologist typically uses a metric
   caliper and measures live individuals in one (anterior to posterior) or three dimensions.
   Basic summary statistics can be generated to analyze shell length diversity, age class
   heterogeneity, and recent recruitment. This may be especially interesting when the
   collected data is contrasted with "ideal" study sites that maintain a "healthy" cross
   section of age class diversity. For example, Grabarkiewicz and Crail (2008) used
   simple summary statistics to compare age class diversity in three  different waterways.
   This method might be further developed as a metric in a full multimetric index.
   Mark and Recapture
   Mark and recapture is a method often
   used when translocating mussels
   from one area to another. With this
   technique, mussels are first marked
   or given a unique tag and moved to
   a defined area up or downstream.
   Mark and recapture may also prove
   useful in  water quality assessment. For
   example, with a unique tag the health
   and growth of multiple  individuals may
   be monitored over time by measuring
   shell dimensions, weight, or biological
   markers. This type  of monitoring
   may assist when assessing lethal or
   sublethal impacts of nearby industrial
   or sewage outfalls.
Photo 18: A researcher measures a mussel with a
caliper to collect demographic data.
                                        19

-------
           An Introduction to Freshwater Mussels as Biological Indicators
   Long Term Quantitative Monitoring
   Quantitative sampling generally involves the excavation of quadrats and the sieving
   of sediments. Long-term quantitative monitoring is useful when assessing trends of
   community diversity, abundance, and overall system integrity. For example, Ahlstedt
   and Tuberville (1997) reported trends in species composition, abundance, and
   recruitment between 1979 and 1994 in the Clinch and Powell River (TN, VA).The
   researchers reported that a severe drought had a strong impact on mussel populations
   during the mid-1980s and that mussel distribution and abundance patterns were
   "influenced by proximity of mined land." They also noted that declines in tributary
   streams were generally more severe for freshwater mussels than fish, suggesting that
   mussels are more sensitive to environmental perturbations.


Sensitivity to Toxic Contaminants

Toxic contaminants have long been implicated in the reduction  or extirpation of mussel
populations throughout the country (Lewis 1868; Ortmann 1909; Clark and Wilson 1912;
Baker 1928). Early 20th century accounts of industrial stream pollution tell of dyestuff
discharges from knitting mills "causing widespread destruction" (Clark and Wilson 1912)
and rivers "acting as the sole receptacle of sewage and manufacturing waste" (Howe
1900). More recently, regional and continent-wide assessments of  unionoid populations
have cited toxic contaminants as a contributor to widespread faunal declines (Havlik and
Marking 1987; Bogan 1993; Neves et al. 1997).

Toxic contaminants are defined here as inorganic or organic contaminants that have the
potential to be lethal or elicit sublethal responses from a chosen study population. The
concentration and exposure required to elicit a response from a particular  species may
vary greatly from pollutant to pollutant. Additionally, the toxicity  of a particular pollutant
may be influenced by a number of variables, including concentration and exposure route,
frequency, and duration.

Freshwater mussels exhibit a variety of sensitivities to toxic contaminants based on
species, life stage (glochidium, juvenile, or adult), and environmental conditions. For
example, Wang et al. (2007a) reported that glochidial Oyster Mussel (Epioblasma
capsaeformis) and Scaleshell (Leptodea leptodon) were far more sensitive to copper than
glochidial Dwarf Wedgemussel (Alasmidonta heterodon).  Interestingly, all three species
are listed as federally endangered by the U.S.  Fish and Wildlife Service. Interspecific
disparities like these can be helpful to bioassessment programs in  compiling and
diagnosing sources and causes of impairment.
                                        20

-------
           An Introduction to Freshwater Mussels as Biological Indicators
   Heavy Metals
   The American Society for Testing and Materials (ASTM 2006) issued new guidelines
   for freshwater mussel toxicity testing. The studies included in this document meet
   the requirements of the ASTM guidance. Heavy metals are a concern to freshwater
   mussels due to their ability to cause mortality, disrupt enzyme efficiency, alter filtration
   rate, reduce growth, and change behavior (Naimo 1995). Because freshwater mussels
   exhibit suspension and deposit feeding behaviors (Gatenby et al. 1996; Raikow and
   Hamilton 2001), heavy metals may be available to unionoids through both the water
   column (dissolved or attached to suspended particles) and streambed sediments
   (Naimo 1995). However, the overall bioavailability of metals is complicated and
   influenced by a suite of factors, including metal concentration and speciation, water
   column chemistry, redox potential, particulate matter, and flow regime characteristics
   (Luoma 1989).

   While it is well-known that freshwater mussels readily bioaccumulate metals, the rate
   and location(s) of accrual may vary greatly by unionoid species, unionoid size, and
   heavy metal species (Adams et al. 1981; Naimo et al. 1992b; Pip 1995). For example,
   studies have suggested that metals  such as zinc accumulate most readily in the gills
   (Adams et al. 1981), while others such as cadmium  become concentrated in the heart
   (Pip 1995). In addition to the heart and gills, metal accumulation may occur in the
   kidney, digestive  gland, foot, and mantle.

   Before discussing heavy metals in greater detail, some perspective on the background
   levels at which they occur may be helpful. The following was modified  from the
   excellent review done by Naimo (1995):
Metal
Cd


Cu


Hg


Zn


Locality
Rhone River, France1
Mississippi River, USA2
Lake Vanda, Antartica3
Rhone River, France1
Mississippi River, USA2
Lake Vanda, Antartica3
Silver Lake, CA5
Clear Lake, CA5
Onondaga Lake, NY6
Ohio River, USA7
Lake Erie, USA8
Yangtze River, China7
Condition/Area
Industrial
At mouth
Pristine
Industrial
At mouth
Pristine
Pristine
Polluted
Polluted
Industrial
-
At mouth
Total*
20-117
-
10-70
405-1340
-
400-600
0.6
3.6-104
7-19
-
-
-
Dissolved*
17-80
8-16
-
119-1240
1810-1960
400-600
0.4
1.1-1.5
2-10
288-3203
26-55
39-78
        *in units of ng/L

References: 1Huynh-Ngoe etal. 1988a 2Trefryetal. 1986 3Greenetal. 1986 4Huynh-Ngoe et al. 1988b
5Gill and Bruland 1990 6Bloom and Effler 1990 7Shiller and Boyle 1985 8Coale and Flegal 1989
                                       21

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Cadmium. Cadmium is a common
pollutant found in mine drainage, industrial
discharges, insecticides, fungicides, and
urban runoff. Generally considered  highly
toxic to aquatic life (Eisler 1985), the
effects of cadmium have been evaluated
by mussel toxicologists under both
laboratory and "semi-field" conditions
(Jenner et al. 1991; Lassee  1991;
Hansten et al. 1996). Jenner et al. (1991)
described the accumulation patterns in
adult Painter's Mussel (Unio pictorum) as
follows:

       "....the process of concentration
       (accumulation) to high levels
       is rapid without direct toxic
       (lethal) effects. Detoxification
       by metal-binding proteins will
       require energy and resources
       which are drawn from the
       energy and nitrogen (protein)
       pool of the animal. A delayed
       effect will occur in which the
       population size diminishes due
       to the constant drain of energy
       and protein, causing energy
       exhaustion."
AWQC Ambient Water Quality Criteria
Quantitative concentrations or
qualitative assessments of the levels
of pollutants in water which, if not
exceeded, will generally ensure
adequate water quality for a specified
water use (U.S. EPA 2000).

GMAV  Genus Mean Acute Value
The geometric mean of the SMAVs for
the genus.

SMAV  Species Mean Acute Value
The geometric mean of the results
of all acceptable flow-through acute
toxicity tests with the most sensitive
tested life stage of the species.

LC50 Lethal Concentration (50%)
The concentration of a toxicant within
a medium that causes the death of
50% of a population.

EC50 Effective Concentration (50%)
The dose at which a defined  non-lethal
response occurs in at least 50% of the
study population.
Lasee (1991) and Naimo et al. (1992) also investigated the chronic effects of cadmium
exposure. Lasee (1991) documented the dissolution of the crystalline style, an
anatomical structure that assists in food digestion, when mussels were exposed
to mercury, cadmium, and copper. Naimo et al. (1992a) studied the physiological
responses of adult Plain Pocketbook (Lampsilis cardium) to cadmium concentrations
ranging from 22-305 ug Cd/L. While most physiological responses were widely variable,
respiration rates significantly decreased with increased cadmium exposure.

Copper. Elevated levels of copper in the aquatic environment may come from a variety
of sources, including mine drainage, coal ash effluent, industrial discharges, and urban
runoff. Recent studies and data compilations suggest that freshwater mussels are
among the most sensitive aquatic taxa to copper (Figs. 11  and 12). It should also be
noted that a significant amount of variability has been  observed  among the individual
responses unionids exhibit to copper (Milam et al. 2005).
                                     22

-------
        An Introduction to Freshwater Mussels as Biological Indicators
                       Ranked GMAVs for Copper (1996 AWQC Update)
                           10 most sensitive taxa in the dataset






    Figure 1 1 : A listing of the most sensitive aquatic genera to copper excluding
    freshwater mussels (Augspurger et al. 2006). Used with permission.
                      Ranked GMAVs for Copper (1996 AWQC Update)
                         adding data for mussel genera (shaded)
rdness

8 
3
             *  *
                              *  *
                                              ****
                                                         **
                                                                 *  *  *
    Figure 12: A listing of the most sensitive aquatic genera to copper including freshwater
    mussel taxa (Augspurger et al. 2006). Used with permission.
The toxicity of copper to freshwater mussels has been investigated by several
researchers (e.g. Jacobson et al. 1993; 1997; Cherry et al. 2002; Milam et al. 2005;
Wang et al. 2007a; Wang et al. 2007b).

During 24-hour exposures, Jacobson et al. (1993) calculated EC50s (valve closure) as
low as 33 ug Cu/L and 27 ug Cu/L for juvenile Giant Floater (Pyganodon grandis) and
Rainbow (Villosa iris), respectively. Reported LC50s ranged from 44 ug Cu/L (hardness
= 70 mg/L) to 83 ug Cu/L (hardness = 190 mg/L) for Giant Floater (P. grandis) and
Rainbow (V. iris), respectively.
                                       23

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Jacobson et al. (1997) further investigated the toxicity of copper to the early life
stages of freshwater mussels by assessing exposures to brooded, released, and
encapsulated glochidia. Brooded and encapsulated glochidia exhibited little sensitivity
to copper exposures, while calculated LC50s for released glochidia ranged from 26 to
347 ug Cu/L (hardness = 55-190 mg/l).

Wang et al. (2007a; 2007b) evaluated the acute and chronic toxicity of copper to the
early life stages (glochidia and juveniles) of 11 unionid species. Reported EC50s
for glochidia varied widely between species, ranging from 10 to >100 ug Cu/L
during 24-hour exposures. The most sensitive species to acute exposures of copper
included Wavyrayed  Lampmussel (Lampsilis fasciola), Oyster Mussel (Epioblasma
capsaeformis), Ellipse (Venustaconcha ellipsiformis), Scaleshell (Leptodea leptodon),
and Pink Papershell  (Potamilus ohiensis). As a result of their study, Wang et al. (2007a)
suggested that the U.S. EPA 1996 acute WQC for copper may not be protective of the
early life stages of freshwater mussels.

March et al. (2007) evaluated toxicity data in the derivation of water quality guidance
and standards for copper. Freshwater mussel SMAVs were generally similar to
the more sensitive species in the U.S. EPA database. The Ellipse  (Venustaconcha
ellipsiformis),  Oyster Mussel (E. capsaeformis), and Pink Papershell (Potamilus
ohiensis) were among the most sensitive aquatic species to copper. On the basis
of established ASTM standards, in addition to historical and ongoing research, the
researchers advocated that state and federal agencies consider using freshwater
mussel toxicity data in determining water quality standards.

Zinc. Zinc is commonly discharged into surface waters as a result of mining activities,
industrial processes, and urban runoff. While studies suggest zinc is not as acutely
toxic to freshwater mussels as copper or cadmium (McCann 1993), it may accumulate
to high concentrations in surface waters impacted by mining waste or industrialization
(Adams et al.  1981).  At high concentrations, zinc may elicit sublethal responses or
cause mortality.

Results reported by McCann (1993) for a pair of Cumberlandian species and the
Rainbow (Villosa iris), with  LC50s ranging from 274 to 1230 ug Zn/L during 48-hour
exposures (hardness = 40-160). Likewise, Cherry et al. (1991) documented LC50s
ranging from 212 to 656 ug Zn/L during 48-hour exposures to four species of unionids
(hardness = 170).

Mercury. Mercury contamination in surface waters may result from pesticides,
hazardous waste disposal,  waste incineration, and fossil fuel combustion. Mercury is a
concern in freshwater ecosystems due to its ability to biomagnify  up the food chain and
cause various health  problems in humans and wildlife.
                                    24

-------
         An Introduction to Freshwater Mussels as Biological Indicators
 Valenti et al. (2005) evaluated the acute and chronic toxicity of mercury to the early
 life stages V. iris. A glochidial LC50 of >107 ug Hg/L was reported during 24-hour
 exposures. A juvenile LC50 of 99 ug Hg/L was reported during 96-hour exposures.
 Glochidial Rainbow were determined to be more acutely sensitive to mercury than two
 month old juveniles.

 Valenti et al. (2006b) also assessed the acute toxicity of inorganic and organic mercury
 salts to the glochidia of four freshwater mussel species. Included as test subjects were
 two federally endangered species, the oyster mussel (Epioblasma capsaeformis) and
 Cumberlandian combshell (Epioblasma brevidens). Reported LC50s ranged from 25 to
 54 ug HgCI/L during 24-hour exposures to mercuric chloride (HgCI2). Methylmercuric
 chloride (CH3CIHg) was more acutely toxic to  E. capsaeformis and E. brevidens, with
 reported LC50s of 21 to 26 ug/L during 24-hour exposures. The Rainbow (V. iris) was
 found to be far more tolerant to methylmercuric chloride than both E. capsaeformis and
 E. brevidens, with  less than 50% mortality observed at 120 ug Hg/L after 24 hours.

 Ammonia
 Anthropogenic sources of ammonia include livestock waste, sewage treatment plants,
 faulty septic systems, and industrial wastewater. Like copper,  recent toxicity studies
 have suggested that freshwater mussels are particularly sensitive to ammonia (e.g.
 Goudreau et al. 1993; Bartsch et al. 2003; Augspurger et al. 2003; 2006; Newton et al.
 2003; Wang et al. 2007a; 2007b) (Figs. 13 and 14).
                           Ranked GMAVs for Total Ammonia
                (10 most sensitive taxa in the 1985 water quality criteria dataset)
     30

     25
     20
     15
  (9

                                  **


Figure 13: A listing of the most sensitive aquatic genera to ammonia excluding freshwater mussel
taxa (Augspurger et al. 2006). Used with permission.
                                     25

-------
        An Introduction to Freshwater Mussels as Biological Indicators
                        Ranked GMAVs for Total Ammonia
                [10 most sensitive taxa in the 1985 water quality criteria
                 dataset adding data for freshwater mussels (shaded)]
 s-  30
 S  25
 *  20

 I  15
 I  10
_j**_
                                                         *   *
    ///S'///////////'/
Figure 14: A listing of the most sensitive aquatic genera to ammonia including freshwater mussel taxa
(Augspurger et al. 2006). Used with permission.
 Goudreau et al. (1993) assessed the toxicity of ammonia and monochloroamine
 (MCH) to Rainbow glochidia and investigated the effects of wastewater treatment plant
 (WWTP) effluents on freshwater mussels. In laboratory toxicity studies, V. iris glochidia
 were exposed to ammonia and MCH for 24 hours. Reported EC50s were 0.237 and
 0.042 mg/L for unionized ammonia and MCH, respectively. Reported LC50s were
 0.284 and 0.084 mg/L for unionized ammonia and MCH, respectively. In field studies of
 treatment plant effluents, researchers examined unionid communities above and below
 a pair of WWTPs in the upper Clinch River, VA. River segments directly downstream
 (up to 3.7 km) of both WWTPs were devoid of mussels, while live unionids were found
 above each  plant. Researchers suggested that even if glochidia were not killed outright
 by MCH or ammonia, the sublethal impacts may reduce glochidial viability and prevent
 the colonization of river segments near WWTPs.

 Newton et al. (2003) and Newton and Bartsch (2007) studied the effects of ammonia
 in sediments and water-only exposures to juvenile Plain Pocketbook (L cardium)
 and Higgins' Eye (Lampsilis higginsii). Newton et al. (2003) documented mortality at
 concentrations as low as 93 ug NH3-N/L and growth reduction at 31 ug NH3-N/L. These
 results are at or below acute national water quality criteria. Researchers also noted
 that control survival was much higher when compared with assays where sediments
 were not part of the study. Because juveniles may collect food particles from sediments
 by pedal feeding (Yaeger and Cherry 1994), this observation further accentuated the
 need to examine sediments and pore water as an  important exposure route.
                                  26

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Wang et al. (2007a) examined the acute toxicity of ammonia to the early life stages
of several unionid species. Glochidial mussels exhibited an array of tolerances, with
reported EC50s ranging from 5 to >16 mg N /L during 24-hour exposures. Glochidia
of the Oyster Mussel (E. capsaeformis) and Ellipse (V. ellipsiformis) were among the
most sensitive species tested. During 4-day and  10-day exposures to juvenile mussels,
reported EC50s ranged from 5.7 to 11 mg N/L and 1.7 to 4.5 mg N/L, respectively. The
authors concluded that the 1999 acute WQC for  ammonia many not be protective of
the freshwater mussels species tested.

Chlorine
Anthropogenic sources of chlorine include wastewater treatment plants and industrial
facilities (Valenti 2006a). Chlorine is generally considered highly toxic to most forms of
life and is commonly used as a disinfectant.

Valenti et al. (2006a) evaluated the toxicity of total residual chlorine (TRC) to the early
life stages of five unionid species, including three federally endangered taxa: the
Dwarf Wedgemussel (Alasmidonta heterodon), Cumberland Combshell (E. brevidens),
and Oyster Mussel (E. capsaeformis). Mean LC50s ranged from 70 to 220 ug TRC/L
during 24-hour exposures. Federally endangered mussels were found to be slightly
to far more sensitive than Wavyrayed Lampmussel (L. fasciola) and Rainbow (V. iris),
respectively. The study also reported reduced growth in juvenile  E. capsaeformis at
concentrations as low as 20 ug TRC/L during 21 -day chronic exposures. The authors
suggested that while endpoints were above U.S. EPA WQC for TRC,  potential sublethal
effects to federally endangered juvenile mussels were still a concern.

Wang et al. (2007a) evaluated the acute toxicity of chlorine to the early life stages
of several unionid species. Reported EC50s for mussel glochidia during 24-hour
exposures ranged from 58 to >100 ug TRC/L. Reported EC50s for juvenile mussels
during 4-day and 10-day exposures ranged from 68 to >100 ug TRC/L and 16 to >100
ug TRC/L, respectively. Researchers suggested that the early life stages of mussels
were relatively tolerant of chlorine.

Insecticides, Herbicides, and Fungicides
Insecticides, herbicides, and fungicides are common  contaminants in both rural
and urban settings. In fact, scientists estimate that approximately 1.1  billion  pounds
of pesticides are spread in the United States annually (Aspelin 1994). Freshwater
mussels exhibit an array of tolerances to current-use  pesticides,  largely dependent on
the species of mussel, identity of the contaminant, and length of exposure.

Recent research has provided new insights into the acute effects of various
insecticides, herbicides, and fungicides (e.g. Keller 1993; Moulton et al. 1996; Keller
and Ruessler 1997; Milam et al. 2005; Bringolf et al. 2007a). Keller (1993) evaluated
                                    27

-------
        An Introduction to Freshwater Mussels as Biological Indicators
the toxicity of several organic compounds to Paper Pondshell (U. imbecillis) and
contrasted the results with Daphnia (Daphnia magna) and Bluegill Sunfish (Lepomis
macrochirus}. U. imbecillis was generally less sensitive to most contaminants when
compared with other test organisms, including the pesticides toxaphene, chlordane,
and PCP (pentachlorophenol).

Keller and Ruessler (1997) evaluated the toxicity of malathion, a commonly used
mosquito and fruit fly insecticide, to the early life stages of several unionid species.
Glochidia trials yielded LC50s ranging from 7 to 374 mg/L during exposures of 4 to 48
hours. Glochidial Paper Pondshell were by far the most tolerant species, with reported
LC50s of 324 to 374 mg/L. Reported LC50s for juvenile mussels ranged from 74 to
129 mg/L during exposures of 96 hours in hard water. Researchers concluded that
"expected environmental concentrations should not be lethal to unionids."

Bringolf et al. (2007a) assessed the toxicities of various current-use pesticides to the
glochidia and juveniles of several freshwater mussel species. Fatmucket (Lampsilis
siliquoidea) glochidia and juveniles were found to be highly sensitive to chlorothalonil,
propiconazole, and pyraclostrobin,  with reported glochidial EC50s ranging from 0.09
to 20.75 mg/L during 24-hour exposures. Juvenile 96-hour EC50s ranged from 0.03 to
10.01 mg/L. Technical grade atrazine, permethrin, fipronil, and pendimethalin were not
acutely toxic to the unionids tested. However, chronic studies found juvenile Fatmucket
to be sensitive to atrazine at low concentrations, with reported EC50s of 15.8 mg/L and
4.3 mg/L during 14-day and 21-day exposures, respectively.

Glyphosate is one of the most widely used herbicides today, yet few studies have
analyzed its effects on freshwater mussels. Bringolf et al. (2007b) investigated the
toxicity of several forms of glyphosate, its formulations, and a surfactant (MON 0818) to
juvenile and glochidial Fatmucket (L. siliquoidea). Reported 24-hour EC50s were as low
as 3.0 mg/L and 0.6 mg/L for Roundup and MON 0818, respectively. Reported 96-hour
EC50s for juvenile L. siliquoidea were 5.9 mg/L and 3.8 mg/L for Roundup and MON
0818, respectively.  Researchers concluded that the early life stages of the Fatmucket
are among the most sensitive aquatic organisms to glysphosate-based chemicals  and
MON 0818 tested to date.
                                     28

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Shells as Indicators

The use of freshwater mussel shells as indicators of ecological integrity and environmental
stress has been informally exercised by scientists since the early 1900s (Ortman
1909; Coker et al. 1921). However, only recently have researchers started to collect
quantitative information from shell material (Imlay 1982; Ravera et al. 2005; Brown et al.
2005). Because spent valves persist in aquatic ecosystems for decades or more, shell-
based studies often offer information inaccessible to investigators through traditional
bioassessment strategies.

Mussel shells are comprised of five primary
layers: the periostracum, prismatic layer,
peripheral layer, laminar layer, and inner nacreous
layer (Imlay 1982). The periostracum is mainly
proteinaceous in nature, while the other four
layers are comprised of calcium carbonate, in the
form of calcite or aragonite.  Periods of rest are
delineated by internal and external rings (Fig. 15)
laid down during periods of  latency. These rings
are often used to age mussels, with each well
defined line constituting a rest period during cold
weather.  In addition to growth rings, disturbance
rings may also be present, possibly reflecting
periods of pollution, drought, displacement,
or handling. While aging studies have utilized
both internal and external annuli,  some debate
remains in regards to which is more accurate
(Metcalfe-Smith and Green  1992). Uncertainty
is often due to shell weathering, the presence
of disturbance rings,  and ring crowding resulting
from old age (Ray 1977; Strayer 1981; Anthony
et al. 2001). Although aging  remains a precarious
endeavor with certain specimens, the information
gleaned from growth  and disturbance rings can
provide useful insights into historical growth rates,
disturbance, and water quality (Imlay 1982; Haag
2007}.                                           Figure 15: External rings of the Ohio Pigtoe
                                                (Pleurobema cordatum).
Metals may be present in shell material as a result
of surface adsorption or as metabolic  analogues  of calcium. The metal content of shell
material often varies  greatly from  what is found in soft tissues. For example, Anderson
(1977) found overall metal concentrations to be higher in soft tissues than shell material
during a study of the  Fox River (IL, Wl). Zinc, in particular, was reportedly accumulated
                                        29

-------
           An Introduction to Freshwater Mussels as Biological Indicators
to levels 10-40 times the concentration found in shell material. Ravera et al. (2003) found
shells to contain higher concentrations of Ca, Cr, Mn, Ni, and Mo than soft tissues,
while concentrations of As, Cd, Cu, Ni, and Pb were lower in shells than soft tissues.
Considerable variation was also observed in heavy metal concentrations between different
species.

Chatters et al. (1995) utilized the valves of freshwater mussels to recreate ancient stream
environments in the Columbia River basin (western North America). By analyzing the
archaeological presence of Western Ridged Pearlshell (Gonidea angulata) and Western
Pearlshell (Margaritifera falcata), two species with markedly different habitat requirements,
scientists inferred the crude substrate composition and suspended sediments of historical
stream systems. In addition, researchers analyzed growth increments of Western
Pearlshell to determine historical temperature patterns. The report concluded that the
study area was likely poor for salmon 6,000-7,000 B.P, due mainly to higher stream
temperatures, greater quantities of fine sediments, and lower flows.

Perhaps one of the most interesting application of shell-based strategies is the
examination of heavy metal  trends over long periods of time. For example, Brown et
al. (2005) found freshwater mussel shells of the North Fork Holston River to provide
an otherwise  unavailable record of mercury contamination at five sites near Saltville,
VA. Through analysis of over 350 shells,  researchers verified significant differences in
mercury concentrations between shell assemblages above, within, and  below an area of
contamination.

Similarly, Ravera et al. (2005) analyzed shell material from a pair of Italian lakes to
document changes in metal concentrations over two distinct time periods. Using  recently
collected shells and preserved valves from a museum, researchers were able to analyze
metal concentrations from 1928-1934 and 1995-2000. Several metals significantly differed
in concentration between the two periods, which also varied greatly between the two lakes.
                                        30

-------
           An Introduction to Freshwater Mussels as Biological Indicators
GENUS PROFILE  - ALASMIDONTA
 Photo 19: Swan Creek, OH, headwater habitat of the Slippershell Mussel (Alasmidonta viridis).

Species Diversity and Conservation: A total of 12 species have been assigned to the
genus Alasmidonta (Turgeon et al. 1998). Williams et al. (1993) reviewed the conservation
status of unionoids in North America and reported three Alasmidonta as special concern,
two as threatened, and six species as endangered. Currently, three species are listed as
endangered by the U.S. Fish and Wildlife Service (USFWS 2007), while three species are
considered extinct (Turgeon et al. 1998).
Shell Characteristics: Shell rhomboidal,
elongate, or subquadrate; often quite thin when
young,  becoming moderately stout with age.
Maximum shell length 2.0 to 4.5 inches (50-
115 mm). Periostracum light yellowish-green
to yellowish tan, often with green rays. Some
species with green spots. Beak sculpture of
elevated and heavy double-looped ridges,
concentric loops, or double-looped bars.
Pseduocardinal teeth well developed but not
massive; generally small. Lateral teeth poorly
developed. Nacre white, often with salmon
tinge.
Photo 20: Slippershell Mussel (A. viridis), Swan
Creek, OH.
Habitat: The Alasmidonta are a wideranging group, inhabiting the lower and upper
Mississippi River basin, Great Lakes-St. Lawrence basin, Atlantic Slope, and Gulf
drainages. Several species are endemics and have limited distributions (e.g. Cumberland
River drainage, Altamaha River drainage, etc.). This group may be found in both
headwaters and large rivers in sluggish or swift current. The Alasmidonta may occur in
a variety of substrates, from mud to sand, gravel, and cobble (Gordon and Layzer 1989;
Parmalee and Bogan  1998).
                                      31

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Reproduction: Researchers have identified suitable host fishes for many of the
Alasmidonta. Confirmed hosts belong to one of six families: Cyprinidae (minnows),
Catostomidae (suckers), Ictaluridae (catfishes), Cottidae (sculpins), Centrarchidae
(sunfishes), and Percidae  (perches) (Howard and Anson 1923; Gordon and Layzer 1993;
Moorman and Gordon 1993; Michaelson and Neves 1995; Schulz and Marbain 1998;
Walters et al. 1998c). Many of the Alasmidonta have been documented as bradytictic
(Ortmann 1921; Baker 1928).            	
Tolerance to Habitat Alteration: In
general, the Alasmidonta are sensitive
to alterations that change habitat
dynamics. Walters (1995) noted that the
Elktoe (A. marginata) and Slippershell
Mussel (A. viridis) do not tolerate
impoundment. Several members of the
genus have experienced population
declines rangewide due to dams and
associated hypolimnetic discharges,
coal mine runoff, sedimentation, and
pollutants (Oesch 1984; Master 1986;
USFWS 1993b; Parmalee and Bogan
1998; USFWS 2004; Natureserve).
                                      Taxa List (Turgeon et al. 1998)
Altamaha Arcmussel (Alasmidonta arcula)
Cumberland Elktoe (Alasmidonta atropurpurea)
Dwarf Wedgemussel (Alasmidonta heterodon)
Elktoe (Alasmidonta marginata)
Coosa Elktoe (Alasmidonta mccordi)
Appalachian Elktoe (Alasmidonta raveneliana)
Carolina Elktoe (Alasmidonta robusta)
Southern Elktoe (Alasmidonta triangulata)
Triangle Floater (Alasmidonta undulata)
Brook Floater (Alasmidonta varicosa)
Slippershell Mussel (Alasmidonta viridis)
Ochlockonee Arcmussel (Alasmidonta wrightiana)
Sensitivity to Toxic Contaminants:  Recently, Wang et al. (2007a) evaluated the acute
toxicity of copper, ammonia, and chlorine to the federally endangered Dwarf Wedgemussel
(Alasmidonta heterodon) and 10 other species. The glochidia of A. heterodon were among
the most tolerant species tested to copper and ammonia. Reported 24-hour EC50s were
>100 ug/L and >16 mg N/L for copper and ammonia, respectively.

Keller and Augspurger (2005) evaluated the toxicity of fluoride to the federally endangered
Appalachian Elktoe (Alasmidonta raveneliana) in response to concerns regarding feldspar
mining operations. The reported 24-hour LC50 for glochidial A. raveneliana was 288 mg F/
L. The reported 96-hour LC50 for juvenile Appalachian Elktoe was 303 mg F/L. The study
concluded that acute fluoride toxicity was unlikely although longer tests would be helpful to
determine sublethal effects.
                                        32

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Indicator Use:  Bedford et al. (1968) utilized
A. marginata as a biomonitor of pesticides
in the Red Cedar River (Ml). Reported
concentrations ranged from 0.0153-0.198
ppm total DDT and metabolites. The study
concluded that mussels were excellent
indicators of pesticide contamination; mainly
because of their ability to concentrate
contaminants.

The Alasmidonta are valuable indicators
of habitat and water quality, as they
generally inhabit clear, good quality, flowing
habitats with stable substrates (Walters
1995; Nedeau et al. 2000; Bogan 2002;
N at u reserve).
Turgeon et al. 1 998 Taxa
Presumed Extinct Taxa
Federally Listed Taxa
Williams et al. 1993
Special Concern
Threatened
Endangered
Total
Natu reserve
G5
G4-G5
G4
G3
G2
G1-G2
G1
GH
GX
12
3 (25.0%)
3 (25.0%)

3 (25.0%)
2(16.7%)
6 (50.0%)
11 (91.7%)

0 (0.0%)
1 (8.3%)
2(16.7%)
1 (8.3%)
1 (8.3%)
2(16.7%)
3 (25.0%)
1 (8.3%)
1 (8.3%)
                                       33

-------
           An Introduction to Freshwater Mussels as Biological Indicators
GENUS PROFILE  -  EPIOBLASMA
Species Diversity and Conservation:
A total of 17 species and eight
subspecies comprise the genus
Epioblasma (Turgeon et al. 1998), 14 of
which are considered extinct (Hoggarth
et al. 1995; Turgeon et al. 1998). The
remaining 11 Epioblasma are classified
as vulnerable, highly imperiled, or
critically imperiled (Natureserve). A total
of 14 taxa are listed as endangered
by the U.S.  Fish and Wildlife Service
(USFWS 2007).
Photo 21: The Oyster Mussel (Epioblasma
capsaeformis), Clinch River, TN.
Shell Characteristics:  Shell shape
highly variable; adults usually solid and small (< 70 mm). Most taxa exhibit strong
sexual dimorphism; which varies in pronouncement and morphology. Females generally
possess an expanded and rounded posterior, elongated posterior, or a pronounced
marsupial swelling along the posterior ridge. Males are often shallow to moderately
sulcate; although some taxa lack a sulcus altogether (e.g Epioblasma triquetra).
The periostracum is yellowish-tan to brown with green rays or chevron markings.
Pseudocardinal teeth and lateral teeth are generally well developed; often heavy in
large specimens. Nacre is usually white or purple.
 Photo 22: The Powell River (TN, VA) was historically home to several species of Epioblasma, including the
 extinct Forkshell (Epioblasma lewisii) and Acornshell (Epioblasma haysiana).
                                       34

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Habitat:  The Epioblasma were
formerly widespread throughout the
eastern United States, inhabiting
the Mississippi River basin, Great
Lakes basin, and Mobile basin.
Today, their ranges have been
dramatically reduced, and for the
most part, are small and disjunct
(USFWS1983b;1985a; 1990;
1994; 2004). As a group, this
genus inhabits shallow riffles,
runs, or shoals of moderate-sized
creeks and rivers (Stansberry
1970; Walters 1995; Parmalee and
Bogan  1998). They are often most
abundant in clear water and clean
substrates comprised of sand,
gravel,  and cobble.

Reproduction: Because the
Epioblasma have experienced such
a precipitous decline, very little
information is available regarding
the reproductive habits of most
taxa. However, observations made
by several researchers suggest that
some Epioblasma employ brutal
tactics to entrap host fishes. Much
of the following  is paraphrased from
Barnhart (2007):
Taxa List (Turgeon et al. 1998)
Altamaha Arcmussel (Alasmidonta arcula)
Angled Riffleshell (Epioblasma biemarginata)
Cumberland Combshell (Epioblasma brevidens)
Oyster Mussel (Epioblasma capsaeformis)
Leafshell (Epioblasma flexuosa)
Curtis Pearlymussel (Epioblasma florentina curtisii)
Yellow Blossom (Epioblasma florentina florentina)
Tan Riffleshell (Epioblasma florentina walkeri)
Acornshell (Epioblasma haysiana)
Narrow Catspaw (Epioblasma lenoir)
Forkshell (Epioblasma lewisii)
Upland Combshell (Epioblasma metastriata)
Catspaw (Epioblasma obliquata obliquata)
White Catspaw (Epioblasma obliquata perobliqua)
Southern Acornshell (Epioblasma othcaloogensis)
Southern Combshell (Epioblasma penita)
Round Combshell (Epioblasma personata)
Tennessee Rifflshell (Epioblasma propinqua)
Wabash Riffleshell (Epioblasma sampsonii)
Cumberland Leafshell (Epioblasma stewardsonii)
Green Blossom (Epioblasma torulosa gubernaculum)
Northern Riffleshell (Epioblasma torulosa rangiana)
Tubercled Blossom (Epioblasma torulosa torulosa)
Snuffbox (Epioblasma triquetra)
Turgid Blossom (Epioblasma turgidula)
      Dubbed "fish snappers" by Jess Jones (Virginia Tech University), this
      moniker aptly describes a technique utilized by gravid females to trap
      unwary fishes. To initiate glochidia-host interaction when brooding,
      females migrate to the surface and lie-in-wait. While resting (or slightly
      burrowed) on the substrate some of the Epioblasma gape widely, exposing
      their spongy "mantle pads" (termed cymapallia by Barnhart). When contact
      is initiated with the shell or mantle pads, the female quickly snaps her shell
      shut. This action essentially traps unsuspecting fish, allowing the female to
      directly infect her captive with glochidia. This technique seems especially
      brutal when fishes are observed ensnared by the snout or head.
                                        35

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Identified hosts include fishes from families Percidae (perches), Cottidae (sculpins), and
Salmonidae (trout) (Buchanan 1987; Sherman 1993; Yaeger and Saylor 1995; O'Dee and
Walters 2000; Rogers et al. 2001). More specifically, the most commonly reported hosts
are darters from two genera, Etheostoma and Percina, and sculpin belonging to the genus
Cottus.
Turgeon et al. 1 998 Taxa
Presumed Extinct Taxa
Federally Listed Taxa
Williams et al. 1993
Special Concern
Threatened
Endangered
Total
Natu reserve
G5
G4
G3
G2
G1
G2TX
G2T2
G1
G1TX
G1T1
GHQ
GH
GX
25
14(56.0%)
14(56.0%)

0 (0.0%)
1 (4.0%)
24 (96.0%)
1 1 (91 .7%)

0 (0.0%)
0 (0.0%)
1 (4.0%)
0 (0.0%)
2 (8.0%)
1 (4.0%)
3(12.0%)
1 (4.0%)
1 (4.0%)
4(16.0%)
1 (4.0%)
1 (4.0%)
1 1 (44.0%)
                                     Tolerance to Habitat Alteration: The
                                     Epioblasma are, with few exceptions, habitat
                                     specialists adapted to shallow segments of large
                                     creeks and rivers. The ubiquitous damming and
                                     modification of river habitats has likely impacted
                                     this specialized group more than any other
                                     genera of unionids (USFWS 1983b; 1985a).
                                     Many of the now extinct Epioblasma formerly
                                     occured in riffles of large rivers, a habitat that
                                     has been  virtually eliminated by impoundment
                                     (Stansberry 1970).

                                     Sensitivity to Toxic Contaminants: Recently
                                     Wang et al. (2007a) assessed the acute toxicity
                                     of copper, ammonia, and chlorine to the early life
                                     stages of  11 species, including the oyster mussel
                                     (E. capsaeformis). Newly-transformed Oyster
                                     Mussel juveniles were among  the more sensitive
                                     species tested during 96-hour exposures.
                                     Reported  EC50s were 17 ug/L and 5.7 mg N/L
                                     for copper and ammonia, respectively.
Indicator Use: While generally not used for contaminant biomonitoring studies, the
Epioblasma are certainly among the most sensitive genera to anthropogenic disturbance
and have great value for measuring the biological integrity of surface waters (Ahlstedt
1991; Neves et al. 1997). As such, this group has been utilized as a sensitive indicator. For
example, Kearns and Karr (1994) used Epioblasma as an intolerant mussel genera when
developing a benthic index of biotic integrity (B-IBI) for rivers of the Tennessee Valley.
                                       36

-------
           An Introduction to Freshwater Mussels as Biological Indicators
GENUS PROFILE -  FUSCONAIA
Species Diversity and Conservation: A total of 13 species belong to the genus
Fusconaia (Turgeon et al. 1998). Williams et al. (1993) reviewed the conservation status
of unionoids in North America and reported six Fusconaia as special concern, two
as threatened, and two species as endangered. At present, two species are listed as
endangered by the U.S. Fish and Wildlife Service (USFWS 2007).
                                           Taxa List (Turgeon et al. 1998)
                                           Texas Pigtoe (Fusconaia askewi)
                                           Tennessee Pigtoe (Fusconaia barnesiana)
                                           Southern Pigtoe (Fusoconaia cerina)
                                           Shiny Pigtoe (Fusconaia cor)
                                           Finerayed Pigtoe (Fusconaia cuneolus)
                                           Ebonyshell (Fusconaia ebena)
                                           Narrow Pigtoe (Fusconaia escambia)
                                           Wabash Pigtoe (Fusconaia flava)
                                           Triangle Pigtoe (Fusconaia lanaensis)
                                           Atlantic Pigtoe (Fusconaia masoni)
                                           Ozark Pigtoe (Fusconaia ozarkensis)
                                           Longsolid (Fusconaia subrotunda)
                                           Purple Pigtoe (Fusconaia succissa)
Shell Characteristics:  Shell shape highly
variable; often subtriangular, subovate, or
oval. Valves usually moderately thick and
more often inflated than not (especially big
river forms). Beaks raised above hinge-line.
Shell surface smooth and devoid of sculpture.
Maximum  length ranges from approximately
2.5 to 4.5 inches (65-110 mm). Shell
sexual dimorphism absent or very weakly
pronounced. Periostracum yellowish-tan,
reddish-brown, brown, or dark brown; often
with faint green rays when young. Teeth well
developed. Nacre white, rarely with a salmon
tinge.

Habitat: The Fusconaia are widely
distributed throughout the lower and upper
Mississippi River basin, Great Lakes-St.
Lawrence  basin,  several Gulf drainages, and the southern Atlantic drainage. They occur in
small to large creeks, rivers, lakes, and reservoirs in both fine and coarse substrates.
                                             Reproduction:  Researchers have
                                             identified suitable host fishes for several
                                             Fusconaia. Confirmed hosts belong
                                             to one of five families: Clupeidae
                                             (herrings), Cyprinidae (minnows),
                                             Centrarchidae (sunfishes), Percidae
                                             (darters), and Cottidae (sculpins) (Coker
                                             et al. 1921; Wilson 1916; Bruenderman
                                             and Neves 1993; O'Dee and Walters
                                             2000; Haag and Warren 2003). The
                                             Fusconaia are tachytictic, with the
                                             reproductive period extending from May
                                             to August (Baker 1928).
Photo 23: Roanoke River, VA, home to the Atlantic
Pigtoe (Fusconaia masoni).
                                       37

-------
           An Introduction to Freshwater Mussels as Biological Indicators
   Photo 24: The Wabash Pigtoe (Fusconaia flava),
   Swan Creek, OH.
Photo 25: Streamline chubs (Erimystax
dissimilis) foraging above a Longsolid
(Fusconaia subrotunda), French Creek, PA.
Female Fusconaia package glochidia in semi-cohesive capsules (termed "conglutinates")
that are expelled into the water column (Utterback 1915: 1916). Conglutinates are fed on
by fishes, thereby infecting potential hosts.

Tolerance to Habitat Alteration: The Fusconaia exhibit varying degrees of tolerance
to habitat alteration. The Wabash Pigtoe (Fusconaia flava), for example, is a habitat
generalist capable of tolerating turbid streams, impounded habitats, and a variety of
substrates (Gordon and Layzer 1989; Walters 1995; Strayer and Jirka 1997). Likewise,
the Ebonyshell (Fusconaia ebena) has exhibited the ability to adapt to impoundment
in reaches of the lower Ohio River (Payne and Miller 2001). Other species, such as the
Cumberlandian endemic Finerayed Pigtoe (Fusconaia cuneolus), are adapted to shallow,
swiftly flowing waters of creeks and rivers. Habitat alterations such as impoundment and
siltation have contributed to the decline of this species (USFWS 1984). The Finerayed
Pigtoe  is currently listed as endangered by the U.S. Fish and Wildlife Service.

Sensitivity to Toxic Contaminants:  Relatively little laboratory toxicity testing has been
performed with the Fusconaia.

Waller  et al. (1998b) evaluated the acute toxicity of 3-trifluoromethyl-4-nitrophenol (TFM),
a common lampricide, to the Wabash Pigtoe and Threehorn Wartyback (Obliquaria
reflexa). The Wabash Pigtoe was less sensitive than the Threehorn Wartyback, with
reported LC50s of 3.81  and 1.80 mg/L, respectively. Researchers concluded that sea
lampricide treatments would likely have negligible  effects on the species tested.
                                        38

-------
           An Introduction to Freshwater Mussels as Biological Indicators
 Photo 26: Cumberland River, KY, home to the Ebonyshell (Fusconaia ebena), Longsolid (Fusconaia
 subrotunda), and Wabash Pigtoe (Fusconaia flava).
Indicator Use:  Pip (1995) evaluated heavy
metal contamination in the Assiniboine River
(Manitoba, Canada) using several species of
unionids as biomonitors. The Wabash  Pigtoe
accumulated levels of cadmium, lead,  and
copper comparable to other species. However,
the Mapleleaf (Quadrula quadrula) accumulated
significantly more copper in the gill, while
the Fatmucket (Lampsilis siliquoidea) and
Black Sandshell (Ligumia  recta) accumulated
substantially more cadmium in the heart.
Turgeon et al. 1 998 Taxa
Presumed Extinct Taxa
Federally Listed Taxa
Williams etal. 1993
Special Concern
Threatened
Endangered
Total
Natu reserve
G5
G4-G5
G4
G3-G4
G3
G2-G3
G2
G1Q
G1
13
0 (0.0%)
2(15.4%)

6 (46.2%)
2(15.4%)
2(15.4%)
10(76.9%)

2(15.4%)
1 (7.7%)
0 (0.0%)
2(15.4%)
1 (7.7%)
2(15.4%)
2(15.4%)
1 (7.7%)
2(15.4%
                                       Imlay (1982) advocated the use of several
                                       Fusconaia as biomonitors of heavy metals
                                       based on annual shell growth, including the
                                       Longsolid (Fusconaia subrotunda), Finerayed
                                       Pigtoe, Wabash Pigtoe, Tennesse Pigtoe
                                       (Fusconaia barnesiana), and Shiny Pigtoe
                                       (Fusconaia cor).
                                       39

-------
           An Introduction to Freshwater Mussels as Biological Indicators
GENUS PROFILE - LAMPSILIS
Taxa List (Turgeon et al. 1998)
Pink Mucket (Lampsilis abrupta)
Finelinded Pocketbook (Lampsilis altilis)
Southern Sandshell (Lampsilis australis)
Lined Pocketbook (Lampsilis binominata)
Texas Fatmucket (Lampsilis bracteata)
Plain Pocketbook (Lampsilis cardium)
Yellow Lampmussel (Lampsilis cariosa)
Atlamaha Pocketbook (Lampsilis dolabraeformis)
Wavyrayed Lampmussel (Lampsilis fasciola)
Waccamaw Fatmucket (Lampsilis fullerkati)
Haddleton Lampmussel (Lasmpsilis haddletoni)
Higgins Eye (Lampsilis higginsii)
Louisiana Fatmucket (Lampsilis hydiana)
Southern Pocketbook (Lampsilis ornate)
Pocketbook (Lampsilis ovata)
Orangenacre Mucket (Lampsilis perovalis)
Arkansas Fatmucket (Lampsilis powellli)
Carolina Fatmucket (Lampsilis radiata conspicua)
Eastern Lampmussel (Lampsilis radiata radiata)
Neosho Mucket (Lampsilis rafinesqueana)
Ozark Brokenray (Lampsilis reeveiana brevicula)
Northern Brokenray (Lampsils reeveiana brittsi)
Arkansas Brokenray (Lampsilis reeveiana reeveiana)
Sandbank Pocketbook (Lampsilis satura)
Fatmucket (Lampsilis siliquoidea)
Rayed Pink Fatmucket (Lampsilis splendida)
Southern Fatmucket (Lampsilis straminea claibornensis)
Rough Fatmucket (Lampsilis straminea straminea)
Speckled Pocketbook (Lampsilis streckeri)
Shinyrayed Pocketbook (Lampsilis subangulata)
Yellow Sandshell (Lampsilis teres)
Alabama Lampmussel (Lampsilis virescens)
Species Diversity and
Conservation: A total of 25
species and seven subspecies
have been assigned to the
genus Lampsilis (Turgeon et
al. 1998). A single species, the
Lined Pocketbook (Lampsilis
binominata), is presumed extinct
(Turgeon et al. 1998). Williams
et al. (1993) reviewed the
conservation status of unionoids
in North America and reported
nine Lampsilis as special
concern, 10 as threatened, and
six species as endangered.
Currently, eight Lampsilis are
listed as endangered by the
U.S. Fish and Wildlife Service
(USFWS 2007).

Shell Characteristics:  Shell
elliptical, subovate, elongate,
or subquadrate; moderately
thin to heavy and moderately
compressed to inflated. Most
Lampsilis exhibit strong
sexual dimorphism. Females
are expanded and rounded
posteriorly or obliquely flared
posteriorly.  Males are usually
bluntly pointed. Maximum shell
length variable; usually ranging
from 2.5 to  7.0 inches (65-170
mm). Periostracum often yellow,
yellowish-green, yellowish-tan or
brown; thin  to wide green rays
common but not always present.
Beak nearly even or raised well
above hinge-line; sculpture often
                                       40

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Photo 27: Lake Michigan, home to the Plain Pocketbook (Lampsilis cardium) and Fatmucket (Lampsilis
siliquoidea).
double-looped. Teeth well developed; may
be large and heavy in old individuals. Nacre
usually white, bluish-white, pink, or salmon.

Habitat:  The Lampsilis are a widely
distributed group, ranging geographically
from the Central United States to the
East Coast and north into Canada. They
are known from the upper and lower
Mississippi River basin, Great Lakes-St.
Lawrence basin, Atlantic slope, several Gulf
drainages, and a few Canadian drainages.
Lampsilis are found in small to large creeks,
rivers, and lakes; occurring in both fine and
coarse substrates.

Reproduction: Researchers have
identified suitable host fishes for several
Lampsilis. Confirmed hosts belong to one of
seven families: Acipenseridae (sturgeons),
Lepisosteidae (gars), Cyprinidae (minnows),
Fundulidae (topminnows), Centrarchidae
(sunfishes), Percidae (perches), or
Sciaenidae (drums) (Surber 1913; Coker et
al. 1921;  Fuller 1974;Zaleand Neves  1982;
Waller and Holland-Bartels 1988; O'Dee
and Walters 2000).
Turgeon et al. 1 998 Taxa
Presumed Extinct Taxa
Federally Listed Taxa
Williams et al. 1993
Special Concern
Threatened
Endangered
Total
Natureserve
G5
G5T5
G5T3
G5T2Q
G5T1Q
G4
G4T3
G3G4
G3
G2
G1Q
G1
GXQ
GX
32
1 (3.1%)
8 (25.0%)

9(28.1%)
10(31.2%)
6(18.8%)
25 (84.0%)

7(24.1%)
2 (6.9%)
1 (3.4%)
1 (3.4%)
1 (3.4%)
1(3.4%)
1 (3.4%)
2 (6.9%)
1 (7.7%)
3(10.3%)
2 (6.9%)
3(10.3%)
1 (7.7%)
1 (7.7%)
                                        41

-------
           An Introduction to Freshwater Mussels as Biological Indicators
The Lampsilis have evolved some of the most
extraordinary reproductive adaptations found
in freshwater bivalves. To enhance glochidia-
host interaction, many Lampsilis possess a
conspicuous mantle flap "lure" that appears,
in form and pigmentation, similar to a small
fish (photo 28). Mantle lures may rapidly or
occasionally "pulse" or "swim," distinctive
movements that expose the charged gills. This
motion can be quite variable among species,
season, and time of day, ranging  from 180
movements per minute to virtually no movement
at all (Kraemer 1970). Gravid females use this
amazing tool to lure potential host fishes into
striking the mantle flap, thereby rupturing the
marsupia and liberating hundreds to thousands
of glochidia.

Tolerance to Habitat Aleration: The Lampsilis
vary widely in their tolerance to habitat
alteration. Widespread species such as the
Plain Pocketbook (Lampsilis cardium) and
Fatmucket (Lampsilis siliquoidea) may tolerate
impoundment, turbidity, and sedimentation
(Parmalee and Bogan 1998). Conversely, several
federally listed taxa, many endemic to southern
drainages, have been severely reduced in
number by siltation, dredging,  channelization,
impoundment, and  hypolimnetic releases
(USFWS 1985b; USFWS 1991; USFWS 1992).
Sensitivity to Toxic Contaminants: The Lampsilis have been widely used to evaluate
the toxicity of various contaminants to unionids (e.g. Jacobson et al.1993; Jacobson et
al. 1997; Wang et al. 2007a; Wang et al. 2007b). Refer to the Wavyrayed Lampmussel,
Fatmucket, and Plain Pocketbook species accounts for more information.
                                       42

-------
           An Introduction to Freshwater Mussels as Biological Indicators
Indicator Use:  Several of the Lampsilis have been used to successfully biomonitor heavy
metals, including Plain Pocketbook (Lampsilis cardium), Eastern Lampmussel (Lampsilis
radiata radiata), and Fatmucket (Lampsilis siliquoidea). Refer to the species accounts for
more information.
                    Photo 28:  In-situ mantle flap lure of the
                    Wavyrayed Lampmussel.
                    Photo 29: In-situ apertures of the Plain Pocketbook.
                                        43

-------
           An Introduction to Freshwater Mussels as Biological Indicators
GENUS PROFILE  - LASMIGONA
 Taxa List (Turgeon et al. 1998)
 Alabama Heelsplitter (Lasmigona complanata
 alabamensis)
 White Heelsplitter (Lasmigona complanata
 complanata)
 Creek Heelsplitter (Lasmigona compressa)
 Flutedshell (Lasmigona costata)
 Carolina Heelsplitter (Lasmigona decorata)
 Tennessee Heelsplitter (Lasmigona holstonia)
 Green Floater (Lasmigona subviridis)
Species Diversity and Conservation: A total
of five species and two subspecies have been
assigned to the genus Lasmigona (Turgeon et
al. 1998). Williams et al. (1993) reviewed the
conservation status of unionoids in North America
and reported two Lasmigona as special concern,
one as threatened, and one species as endangered.
Currently, the Carolina Heelsplitter (Lasmigona
decorata) is listed as endangered by the U.S. Fish
and Wildlife Service (USFWS 2007).

Shell Characteristics: Shell variable; generally
rhomboidal, trapezoidal, or subovate; often quite thin
when young. A few members of Lasmigona possess
distinctive undulations or "flutes" posteriorly (e.g.
Lasmigona c. complanata and Lasmigona costata).
Maximum shell length from 2.5 to 7.0 inches (70-
180 mm). Periostracum usually yellowish-brown or
green when young; some species may have fine
rays. Shell becoming dark with age. Beak sculpture
often of well formed double-loops or moderately
heavy bars. Pseduocardinal teeth well developed
although variable in form; may be low and serrated
or elevated. Nacre white, often with a salmon tinge.
                                       44

-------
An Introduction to Freshwater Mussels as Biological Indicators
                    Photo 30: The Flutedshell (Lasmigona costata) in French Creek,
                    PA.
Habitat:  The Lasmigona are a
wideranging group, inhabiting
the lower and upper Mississippi
River basin, Great Lakes-St.
Lawrence basin, Lake Winnipeg
drainage, Atlantic Slope, and
Gulf drainages. This group may
be found in both headwaters
and large rivers, as well as
lakes and reservoirs.

Reproduction:  Researchers
have identified suitable
host fishes  for many of the
Lasmigona. Confirmed hosts
belong to one of nine families:
Lepisosteidae (gars), Clupeidae (herrings and shad), Cyprinidae (minnows), Catostomidae
(suckers), Ictaluridae (catfishes), Fundulidae (topminnnows), Cottidae (sculpins),
Centrarchidae (sunfishes), and Percidae (perches) (Lefevre and Curtis 1910; Young 1911;
Lefevre and Curtis 1912; Hove et al. 1995; Steg and Neves 1997; Walters 1998a; Walters
et al. 1998b; McGill et al. 2002; Walters et al. 2005).

While the reproductive traits of each species belonging to Lasmigona have not been
thoroughly  investigated, most members have been confirmed as bradytictic.
                            Tolerance to Habitat Alteration:  The
                            Lasmigona exhibit a wide array of responses to
                            habitat alteration. The White Heelpslitter (L.c.
                            complanata), for example, has been reported
                            to tolerate impoundment, eutrophication, and
                            disturbed or silty substrates (Walters 1995;
                            Strayer and Jirka 1997; Parmalee and Bogan
                            1998; Metcalfe-Smith et al. 2003; Sietman
                            2003). Furthermore, Walters (1995) noted
                            that L.c. complanata may be abundant below
                            sewage outfalls. Conversely, the federally
                            endangered Carolina Heelsplitter (L. decorata)
                            has unfortunately exhibited sensitivity to a
                            suite of disturbances and stressors, including
                            stream impoundment, unstable stream banks,
                            channelization, siltation, road  construction and
                            maintenance, and mining runoff (Keferl 1991;
                            USFWS  1996).
Turgeon et al. 1998 Taxa
Presumed Extinct Taxa
Federally Listed Taxa
Williams etal. 1993
Special Concern
Threatened
Endangered
Total
Natureserve
G5
G4
G3
G2
G1
7
0 (0.0%)
1 (14.3%)

2 (28.6%)
1 (14.3%)
1 (14.3%)
4 (57.2%)

4 (57.2%)
0 (0.0%)
2 (28.6%)
0 (0.0%)
1 (14.3%)
                            45

-------
           An Introduction to Freshwater Mussels as Biological Indicators
 Photo 31: Green River, KY, home to the Flutedshell (L costata) and White Heelsplitter (L.c.
 complanata).
Sensitivity to Toxic Contaminants: The Lasmigona are rarely used in laboratory toxicity
testing. However, Black (2001) did utilize the Green Floater (L. subviridis) as a surrogate
to derive water quality standards for the protection of North Carolina's endangered
mussels.

Indicator Use:  The Lasmigona are valuable indicators of habitat and water quality.
For example, Metcalfe-Smith et al. (2003) considered the range expansion of the White
Heelsplitter and Flutedshell in the Sydenham River basin a biological indicator of
environmental deterioration.

Bedford et al. (1968) utilized the Flutedshell as a biomonitor of pesticides in the  Red
Cedar River (Ml). Reported concentrations ranged from 0.0153-0.198 ppm total DDT
and metabolites. The study concluded that mussels were excellent indicators of  pesticide
contamination; mainly because of their ability to concentrate contaminants.

Pip (1995) assessed the bioaccumulation and biomonitoring potential of the White
Heelsplitter and several other species in the Assiniboine River, Manitoba (Canada). Unlike
the other test unionids, cadmium, lead, and copper were concentrated to higher levels in
the mantle tissue of L.c. complanata than the heart, gills, gonad, muscle, or foot. It should
be noted, however, that only a single White Heelsplitter was analyzed.
                                        46

-------
           An Introduction to Freshwater Mussels as Biological Indicators
GENUS PROFILE -  PLEUROBEMA
Species Diversity and Conservation:
A total of 32 species belong to the
genus Pleurobema (Turgeon et al.
1998). Williams et al. (1993) reviewed
the conservation status of unionoids
in North America and reported four
Pleurobema as special concern, one
as threatened, and 22 species as
endangered. At present, 12 species
are listed as endangered by the U.S.
Fish and Wildlife Service (USFWS
2007) while a total of  13 species are
presumed extinct (Turgeon et al. 1998).

Shell  Characteristics:  Shell shape
highly variable; often subtriangular or
subelliptical; less often subrhomboidal
or subquadrate. Shells usually
moderately thick to thick and more often
inflated than not (especially big river
forms). With rare exception (e.g. James
spinymussel), shell surface devoid of
sculpture. Maximum lengths range from
approximately 1.5 to 5.0 inches (35-120
mm).  Shell sexual dimorphism absent or
weakly pronounced. Periostracum often
yellowish-tan, brown,  or dark brown;
clubshells and some pigtoes with
rays extending from umbo. Teeth well
developed and heavy. Nacre usually
white  or pink.

Habitat: The Pleurobema are a
wideranging genus, with species
richness maximized in the large creeks
and rivers of the Cumberland Plateau
and Mobile River basin. As a group,
they inhabit the lower and upper
Mississippi River basin, Great Lakes
basin, James  River drainage,  Roanoke
Taxa List (Turgeon et al. 1998)
Highnut (Pleurobema altum)
Hazel Pigtoe (Pleurobema avellanum)
Mississippi Pigtoe (Pleurobema beadleianum)
Scioto Pigtoe (Pleurobema bournianum)
Painted Clubshell (Pleurobema chattanoogaense)
Clubshell (Pleurobema clava)
James Spinymussel (Pleurobema collina)
Ohio Pigtoe (Pleurobema cordatum)
Black Clubshell (Pleurobema curtum)
Southern Clubshell (Pleurobema decisum)
Yellow Pigtoe (Pleurobema flavidulum)
Dark Pigtoe (Pleurobem furvum)
Southern Pigtoe (Pleurobema georgianum)
Cumberland Pigtoe (Pleurobema gibberum)
Brown Pigtoe (Pleurobema hagleri)
Georgia Pigtoe (Pleurobema hanleyianum)
Alabama Pigtoe (Pleurobema johannis)
Flat Pigtoe (Pleurobema marshal!!)
Coosa Pigtoe (Pleurobema murrayense)
Longnut (Pleurobema nucleopsis)
Tennessee Clubshell (Pleurobema oviforme)
Ovate Clubshell (Pleurobema perovatum)
Rough Pigtoe (Pleurobema plenum)
Oval Pigtoe (Pleurobema pyriforme)
Louisiana Pigtoe (Pleurobema riddellii)
Warrior Pigtoe (Pleurobema rubellum)
Pyramid Pigtoe (Pleurobema rubrum)
Round Pigtoe (Pleurobema sintoxia)
Fuzzy Pigtoe (Pleurobema strodeanum)
Heavy Pigtoe (Pleurobema taitianum)
Alabama Clubshell (Pleurobema troschelianum)
True Pigtoe (Pleurobema verum)
                                       47

-------
           An Introduction to Freshwater Mussels as Biological Indicators
 Photo 32: The Green River (KY), home of the federally endangered Rough Pigtoe (Pleurobema plenum).


River drainage, and several Gulf drainages. The Pleurobema are often most abundant in
small and large rivers, where substrates are comprised of sand, gravel, and cobble.

Reproduction:  Researchers have identified suitable host fishes for many of the
Pleurobema. Confirmed hosts belong to one of four families - Cyprinidae (minnows),
Fundulidae (topminnows), Percidae (perches), or Centrarchidae (sunfishes) (Surber 1913;
Yokley 1972; Weaver et al. 1991; Hove 1995a; O'Dee and Walters 2000; Haag and Warren
2003). Although the reproductive traits of numerous species remain undocumented,
studies have reported several Pleurobema as tachytictic, with the reproductive period
extending from May to August (Ortmann 1909; Baker 1928; Haag and Warren 2003).

Tolerance to Habitat Alteration:  The Pleurbema
have been severely impacted by habitat alterations
that have changed free-flowing, riffle-pool river
segments to impounded,  lentic habitats. For example,
widespread modification of the  Upper Tombigbee River
(Mobile River basin) occurred when construction of
the Tombigbee-Tennessee Waterway was completed
in 1984. The Waterway shortened the river by 48
miles, destroyed and fragmented suitable streambed
habitat, profoundly altered the flow regime, and initiated
geomorphic instability (ARA et  al. 1999). Once home
to 50 species of freshwater mussels, including several
pleurobemids, approximately 30% of the fauna is now
imperiled, extirpated, or extinct as a direct result of river
impoundment and related impacts (ARA et al. 1999).
Four federally endangered species, the Black Clubshell
(Pleurobema curtum), Southern Clubshell (Pleurobema decisum), Ovate Clubshell
(Pleurobema perovatum), and Heavy Pigtoe (Pleurobema taitianum) once occurred in the
Tombigbee River (USFWS 2000). They are  now considered extirpated or limited to small
segments where suitable habitat still exists  (Hartfield and Jones 1989; USFWS 2000).
Photo 33: The federally
endangered Clubshell (Pleurobema
clava), French Creek, PA.
                                       48

-------
           An Introduction to Freshwater Mussels as Biological Indicators
 Photo 34: East Fork West Branch St. Joseph River, Ml, habitat of the Clubshell (P. clava).
Sensitivity to Toxic Contaminants: The
Pleurobema have not been used in laboratory
toxicity testing.

Indicator Use: The Pleurobema are among
the most imperiled mollusks in North America,
with 78% of the genus either listed as federally
endangered or extinct (Turgeon et  al. 1998;
USFWS 2007). Many are endemic to Mobile
Basin, including over a dozen extinct species
(Neves et al. 1997; Turgeon et al. 1998). They
are sensitive to habitat alterations such as river
impoundment and channelization,  in addition to
stressors such as water quality degradation and
sedimentation (USFWS  2000).

The use of  Pleurobema  in bioaccumulation
studies has not been reported on. However, Imlay
(1982)  recommended the use of the Ohio Pigtoe
(Pleurobema cordatum), Tennessee Clubshell
(Pleurobema oviforme),  and Round Pigtoe
(Pleurobema sintoxia) as biomonitors of heavy
metals  on the basis of annual shell growth. This
recommendation was based on "widespread
distribution, age, pollution tolerance, and/or
conchological reflection  of stream location."
Turgeon et al. 1 998 Taxa
Presumed Extinct Taxa
Federally Listed Taxa
Williams et al. 1993
Special Concern
Threatened
Endangered
Total
Natureserve
G4G5
G4
G3
G2G3
G2
G1G2Q
G1G2
G1Q
G1
GHQ
GH
GX
32
13(41.0%)
12(38.0%)

4(13.0%)
1 (3.0%)
22 (69.0%)
27 (84.0%)

1 (3.0%)
1 (3.0%)
1 (3.0%)
3(9.1%)
3(9.1%)
1 (3.0%)
1 (3.0%)
3(9.1%)
10(30.3%)
1 (3.0%)
1 (3.0%)
7(21.2%)
                                       49

-------
           An Introduction to Freshwater Mussels as Biological Indicators
GENUS  PROFILE -  QUADRULA
Species Diversity and Conservation: A total
of 16 species and four subspecies have been
assigned to the genus Quadrula (Turgeon et
al. 1998). A single species, the rough rockshell
(Quadrula  tuberosa), is presumed extinct
(Turgeon et al. 1998). Williams et al. (1993)
reviewed the conservation status of unionoids
in North America and reported five Quadrula
as special  concern, three as threatened, six
species as endangered, and one as possibly
extinct. Currently, five taxa are listed as
endangered by the U.S. Fish and
Wildlife Service (USFWS 2007).
Shell Characteristics: Shell
quadrate or round; often heavy
and moderately inflated to inflated.|
Maximum shell length variable;
usually ranging from 2.5 to 6.0
inches (64-153 mm). Shell sexual
dimorphism weakly pronounced
or absent. Periostracum often
yellowish-tan or brown; with green
smudges, chevrons, or faint rays
commonly found in several taxa.  If present, shell sculpture consists of few to numerous
bumps, pustules, or knobs. Teeth well developed and heavy. Nacre usually white.

Habitat: The Quadrula are a wideranging group, inhabiting the lower and upper
Mississippi River basin, Great Lakes basin, and several Gulf drainages. In general, this
group is most abundant in small and large rivers, where substrates are comprised of
packed sand, gravel, and cobble. Several Quadrula may also occur in lakes and reservoirs.

Reproduction: Researchers have identified suitable host fishes for several Quadrula.
Confirmed hosts belong to one of three families - Cyprinidae (minnows), Ictaluridae
(catfishes), or Centrarchidae (sunfishes) (Surber 1913; Coker 1921; Yeager and Neves
1986; Barnhart 2000; Hove et al. 2001; Haag and Warren 2003). However, host studies
have not been performed on a fair number of taxa (many endemic to southern drainages).
The genus is apparently tachytictic, with the reproductive period extending from May to
August (Utterback 1915; Baker 1928).
                                      50

-------
          An Introduction to Freshwater Mussels as Biological Indicators
Taxa List (Turgeon et al. 1998)
Southern Mapleleaf (Quadrula apiculata)
Alabama Orb (Quadrula asperata)
Golden Orb (Quadrula aurea)
Rio Grande Monkeyface (Quadrula couchiana)
Rabbitsfoot (Quadrula cylindrica cylindrica)
Rough Rabbitsfoot (Quadrula cylindrica strigillata)
Winged Mapleleaf (Quadrula fragosa)
Smooth Pimpleback (Quadrula houstonensis)
Cumberland Monkeyface (Quadrula Intermedia}
Monkeyface (Quadrula metanevra)
Wartyback (Quadrula nodulata)
Texas Pimpleback (Quadrula petrina)
Western Pimpleback (Quadrula pustulosa
mortoni)
Pimpleback (Quadrula pustulosa pustulosa)
Mapleleaf (Quadrula quadrula)
Purple Pimpleback (Quadrula refulgens)
Ridged Mapleleaf (Quadrula rumphiana)
Appalachian Monkeyface (Quadrula sparsa)
Stirrupshell (Quadrula stapes)
Rough Rockshell (Quadrula tuberosa)
   Photo 35: Rabbitsfoot (Quadrula cylindrica
   cylindrica), French Creek, PA.
Tolerance to Habitat Alteration:
Members of genus Quadrula have
demonstrated a wide array of
sensitivities to habitat alteration.
For example, species such as the
Wartyback (Quadrula nodulata),
Pimpleback (Quadrula pustulosa
pustulosa), and Mapleleaf (Quadrula
quadrula) appear capable of tolerating
river impoundment (Oesch 1984;
Parmalee and Bogan 1998; ESI
2001; WDNR 2003). Conversely,
unionids such as the Rabbitsfoot
(Q.c. cylindrica) have experienced
widespread population reductions due
to river impoundment and associated
hypolimnetic releases (Bates 1962;
Butler 2005b). The Rabbitsfoot is
currently under assessment for
federal status, while the Wartyback,
Pimpleback, and Mapleleaf remain
secure throughout their respective
ranges (Williams et al. 1993; Butler
2005b).
                                       51

-------
           An Introduction to Freshwater Mussels as Biological Indicators
 Photo 36: French Creek, PA, habitat of the Rabbitsfoot (Q.c. cylindrica).
Sensitivity to Toxic Contaminants: The
Quadrula are not commonly used in laboratory
toxicity testing.

Indicator Use:  Foster and Bates (1978) reported
the use of Q. quadrula as a biomonitor of copper
electroplating wastes in the Muskingum River, OH.
Caged mussels were placed at various intervals
downstream of the study outfall for 14, 30, and 45
days. Mortality of caged mussels was observed
after 11 days and associated with body burdens
of 20 ug Cu/g wet tissue weight. Researchers
concluded that elevated levels of copper were
likely responsible for mass mortalities of freshwater
mussels.

In addition to the study above, Q. quadrula has
been used as a biomonitor of iron-dominated
mine discharges (Milam and Farris 1998) and
ambient cadmium, lead, and copper levels in
the Assiniboine  River, Canada (Pip 1995). The
Monkeyface (Quadrula metanevra) and Pimpleback
were utilized by Allen et al. (2001) to assess
potential heavy metal contamination within the
habitat range of the federally threatened Neosho Madtom (Noturus placidus).

Imlay (1982) advocated the use of several species as biomonitors of heavy metals based
on annual shell growth, including the Rabbitsfoot, Pimpleback, and Monkeyface. This
recommendation was based on "widespread distribution, age, pollution tolerance, and/or
conchological reflection of stream location."
Turgeon et al. 1 998 Taxa
Presumed Extinct Taxa
Federally Listed Taxa
Williams etal. 1993
Special Concern
Threatened
Endangered
Total
G5
G5T5
G5T3Q
G4
G3G4
G3G4T3
G3G4T2
G2
G1
GH
GXQ
20
1 (5.0%)
5 (25.0%)

4 (20.0%)
3(15.0%)
7 (35.0%)
14(70.0%)
3(13.6%)
1 (4.5%)
1 (4.5%)
4(18.1%)
2(9.1%)
1 (4.5%)
1 (4.5%)
2(9.1%)
4(18.1%)
2(9.1%)
1 (4.5%)
                                       52

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Mucket
Actinonaias ligamentina
(Lamarck, 1819)
Identification tips: Shell oval to elliptical,
thick, and somewhat compressed when young,
becoming inflated with age. Periostracum light
tannish-green to brown; young individuals often
with wide green rays (A) Beak slightly raised above
hinge-line; sculpture of a few concentric ridges
that are often eroded (B) Teeth well developed;
especially heavy in older individuals. Nacre white.
Shell up to 7 inches in length.

Indicator use: A widespread and often abundant
species, the Mucket is currently stable throughout
its range (Williams et al. 1993; Natureserve).
   Spooner et al.  (2005) studied the physiological
effects of high water temperatures on eight species
of unionids, including A. ligamentina.The mucket
was reported as the most thermally sensitive
species studied, with reduced respiration rates
at 32C. The authors suggested the use of A.
ligamentina as an indicator species for mussel
bed health in the  Kiamachi River, OK. It was
also advised that  managing to protect Mucket
populations should translate into thermal  protection
for federally listed species.
   GMAVs compiled and ranked by Augspurger et
al. (2003), Augspurger et  al. (2006), and March et
al. (2007) placed  Actinonaias as "intermediately
tolerant" of ammonia and copper when compared
to other unionid genera.

Habitat: Widespread in the Mississippi River basin
and Great Lakes-St. Lawrence basin. The Mucket
is found in creeks and rivers where substrates are
comprised of stable sand, gravel, and cobble.
Reproduction:  Identified host species include
the American Eel, Central Stoneroller, Silverjaw Minnow, Common Carp, Tadpole Madtom,
Banded Killifish, White Bass, Rock Bass, Green Sunfish, Orangespotted Sunfish, Bluegill
Sunfish, Black and White Crappie, Smallmouth Bass, Largemouth Bass, Tippecanoe
Darter, and Yellow Perch (Young 1911; Lefevre and Curtis 1912; Coker et al. 1921; Walters
et al. 1998b). The Mucket is bradytictic, with the  reproductive period extending from May to
August (Surber 1912).
                                       53

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Pheasantshell
Actinonaias pectorosa
(Conrad, 1834)
Identification tips: Shell elliptical, moderately
thick, and moderately inflated. Posterior ridge
usually well defined. Periostracum greenish-yellow,
yellowish-tan, or brown; often with distinctive,
broken green rays. Beak sculpture of indistinct lines
(B); usually eroded. Teeth well developed. Nacre
white. Shell up to 7  inches in length.

Indicator use: A Cumberlandian endemic that has
experienced declines  in portions of its range, the
Pheasantshell is considered a species of "special
concern" (Williams et  al. 1993; Parmalee and
Bogan 1998).
    GMAVs compiled and ranked by Augspurger
et al. (2003), Augspurger et al. (2006), and March
et al. (2007) placed Actinonaias among the
"intermediately tolerant" unionid genera to  ammonia
and copper.
    Keller and Augspurger (2005) evaluated the
toxicity of fluoride from feldspar mining operations
as a limiting factor in the recovery of the federally
endangered Appalachian Elktoe (Alasmidonta
raveneliana). Four unionid species were tested, with
96-hour LC50s of 178 ug/L and 303 ug/L observed
for juvenile A. pectorosa and A. raveneliana,
respectively. The  researchers concluded that acute
toxicity from fluoride was unlikely, although further
sublethal tests at lower concentrations and longer
durations would be  worthwhile.

Habitat: Endemic to the Cumberland River system
and Tennessee River  system. The Pheasantshell
is a species of large creeks and rivers where the
water is shallow and flow is swift (Gordon and
Layzer 1989; Parmalee and Bogan 1998). Occurs in
sand, gravel, and cobble substrates.

Reproduction:  Layzer and Khym (2005) identified several suitable hosts species, including
the Rock Bass, Smallmouth Bass, Largemouth Bass, Spotted Bass, Banded Sculpin, and
Sauger. Successful transformation was most often observed on Microptems spp. with
reported percentages of 35-43%. Several species (e.g. Etheostoma and cyprinids) sloughed
glochidia and were found to be unsuitable hosts (Layzer and Khym 2005).
                                        54

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Dwarf Wedgemussel
Alasmidonta heterodon  (I. Lea, 1830)

Identification tips: Shell subovate to
subtrapezoidal, somewhat elongate, moderately
thin, and moderately inflated. Periostracum
yellowish-tan to brown; green rays may be
present in young individuals (A). Beak elevated
slightly above hinge-line; sculpture of a few
conspicuous ridges (B), may be eroded. Teeth
well developed, although small  (C); two lateral
teeth in right valve. Nacre bluish-white or white.
Shell up to 2 inches in length.

Indicator use: Widely distributed but rare
throughout its range, the Dwarf Wedgemussel is
currently listed as endangered by the U.S. Fish
and Wildlife Service. Like many other freshwater
mussel species, the Dwarf Wedgemussel is
considered relatively intolerant of impoundment
and chemical pollutants (Master 1986; USFWS
1993c).
    GMAVs compiled and ranked March et al.
(2007) placed Alasmidonta heterodon among the
15 most sensitive taxa to copper.

Habitat: Distributed throughout the Atlantic
Slope, from North Carolina to New Brunswick,
Canada. Populations are often very patchily
distributed (Nedeau 2008). Occurs in headwaters
to rivers where the current is slow to moderate.
Generally found in stable muddy sand, sand,
or sand and gravel substrates (USFWS 1993c;
Nedeau 2008).
Reproduction: Confirmed host fishes include
the Atlantic Salmon, Mottled Sculpin, Tessellated Darter, and
Johnny Darter (Michaelson and Neves 1995; Wicklow 1999).
Michaelson and Neves (1995) reported glochidial metamorphosis
on 3 of 15 fish species.
    The Dwarf Wedgemussel is bradytictic, with glochidia released
during April and May (Michaelson and Neves 1995; McLain and
Ross 2005).
                                      55

-------
         An Introduction to Freshwater Mussels as Biological Indicators
                                                  "
Elktoe
Alasmidonta marginata  (Say, 1818)

Identification tips: Shell elongate to elliptical,
somewhat thin and inflated, with an abruptly angled
posterior (A). Periostracum yellowish-tan to brownish;
with wide green  rays and flecks (A). Beak sculpture
of distinctive, heavy ridges (B); usually conspicuous
in both young and old individuals. Pseudocardinal
teeth weakly developed, lateral teeth present as a
thickened hinge  (C). Nacre white. Shell up to 4 inches
in length. Notes:  Orange foot. Live Elktoe are often
covered with periphyton (see upper right photo).

Indicator use: While widely distributed, the Elktoe
occurs sporadically throughout its range and is
considered a species of "special concern" (Williams
et al. 1993; USFWS 2007c). It is characteristic of
flowing streams  of good quality and does not appear
to tolerate impoundment (Walters 1995; Parmalee
and Bogan 1998). Oesch (1984) reported that wastes
from mining activities reduced its abundance in the
Big River, MO.
    Bedford et al. (1968) harvested Elktoe and
several other unionid species from the Red
Cedar River (Ml) for pesticide analysis. Reported
concentrations ranged from 0.0153-0.198  ppm
total  DDT and metabolites. Concentrations did
not significantly vary between species. The study
concluded that mussels were excellent indicators
of pesticide contamination; mainly because of their
ability to concentrate contaminants.
Habitat:  Distributed throughout the Mississippi
River basin, Great Lakes-St. Lawrence basin, and
Susquehanna drainage. Occurs in moderate-sized
streams to small rivers where the current is swift and streambed comprised
of sand, gravel, and small cobble substrates.

Reproduction:  Identified host species include the White Sucker, Northern
Hog Sucker, Shorthead Redhorse, Rock Bass, and Warmouth Sunfish
(Howard and Anson  1922; Howard and Anson 1923).
    The Elktoe is bradytictic, with the reproductive period extending from
June to July (Baker 1928).
                                        56

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Threeridge
Amblema plicata
(Say, 1817)
Identification tips: Shell subquadrate or
subrhomboidal, thick, and somewhat compressed to
inflated. Periostracum light tannish-green (A), brown,
or dark brown; rayless. Beak nearly even to raised
above hinge-line; sculpture of a few coarse ridges
(B). Teeth well-developed (C); especially heavy in
older individuals. Nacre white. Shell up to 7 inches in
length.

Indicator use: A widely distributed species,
the Threeridge has demonstrated tolerance to
impoundment, pollutants, and regular harvest
(Starrett 1971; Oesch 1984; WDNR 2003). ESI
(2000) reported A. plicata as common to dominant
in several of the navigational pools of the upper
Ohio River. The Threeridge is currently considered
secure throughout its range (Williams et al. 1993;
Natu reserve).
    Spooner et al. (2005) studied the physiological
effects of high water temperatures to eight species
of unionids, including A. plicata. The Threeridge
was the among the more tolerant unionid species
to high temperatures, exhibiting stress at 34-35C
and maximal stress at 42C. The authors suggested
the use of A. ligamentina as an indicator species in
lieu of more thermally tolerant species such as the
Threeridge.
    The Threeridge has been used extensively
to biomonitor pollutants, for more information see
Adams et al. (1980; 1981), Naimo et al. (1992), and
Pip  (1995).
Habitat: Widespread in the Mississippi basin, Great
Lakes-St. Lawrence basin, north into Canada, and
several Gulf drainages. The Threeridge occurs in small creeks to rivers, embayments,
and lakes. It may be found at depths ranging from 0.5-30 feet, in both fine and coarse
substrates.

Reproduction:  Over 20 species of fish belonging to eight taxonomical families have
been identified as suitable hosts for A. plicata (Howard 1914; Wilson 1916; Coker et al.
1921; Stein 1968; Weiss and Layzer 1995).
                                       57

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Purple Wartyback
Cyclonaias tuberculata
(Rafinesque, 1820)
Identification tips: Shell round or subquadrate,
thick, and moderately compressed. Shell surface
with numerous pustules, usually most abundant
medially and posteriorly (A). Periostracum brown to
dark brown, with well defined rest lines (A). Beak
even or slightly raised above hinge-line; sculpture of
numerous ridges (B). Teeth well developed (C); may
be particularly heavy in old individuals. Nacre purple
(C) or white. Shell up to 6 inches  in length.

Indicator use: Widely distributed but sporadically
occurring, the Purple Wartyback is an inhabitant of
good quality creeks and rivers where the water is
clear (Walters 1995; Badra and Goforth 2002). C.
tuberculata has also been recorded from lentic or
impounded habitats, although the long-term viability
of these populations remains unclear (Bates 1962;
Parmalee and Bogan  1998). Williams et al. (1993)
considered  it a species of special concern.
    Imlay (1982) suggested of the use of C.
tuberculata as a biomonitor of heavy metals on the
basis of annual shell growth. This recommendation
was based on "widespread distribution, age, pollution
tolerance, and/or conchological reflection of stream
location."

Habitat:  Fairly widespread throughout the Mississippi
River basin and Great Lakes basin. Occurs in both
creeks and  rivers where the current is slow to swift.
May also be found in lentic  habitats. Often most
abundant in a mixture of mud, sand,  and gravel.

Reproduction:  Confirmed host fishes include the
Black Bullhead, Yellow Bullhead, Channel Catfish,
and Flathead Catfish (Hove 1994b; Hove et al. 1997).
    The Purple Wartyback is tachytictic, with the
reproductive period extending from June to August
(Ortmann 1919).
                                        58

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Dromedary Pearlymussel
Dromus dramas  (Lea, 1834)

Identification tips: A round, deep, thick, and slightly
inflated shell. Periostracum yellowish-tan with very
fine, broken green  rays or lines; often more prominent
anteriorly (A). Beak sculpture of indistinct ridges; often
eroded (B). Teeth well developed and large (C). Nacre
white or pink. Shell up to 4 inches in length.

Indicator use: This once widespread and abundant
Cumberlandian species has declined dramatically during
the 20th century. A study by Hughes and Parmalee
(1999) reported the notable abundance of D. dromas at
prehistoric aboriginal sites along the Tennessee River.
Of the 159,450 freshwater mussel shells recovered
from 15 sites, the Dromedary Pearlymussel constituted
32% of the identified specimens. The widespread
impoundment of the Tennessee and Cumberland
drainages has probably contributed more to the decline
of D. dromas than any other factor, although dredging,
sand and gravel  mining, coal mining, and sewage
wastes have also been  implicated (USFWS 1983a;
Hughes and Parmalee  1999; Jones et al. 2004). This
species is now listed as endangered by the U.S. Fish
and Wildlife Service.

Habitat: Endemic to the Cumberland River and
Tennessee River drainages. Viable populations  of D.
dromas occur in the Clinch and Powell rivers (Jones
et al. 2004). Historically, this species occurred in
moderate sized streams to rivers in shallow water (<3
ft.). Most often found in  packed sand, gravel, and cobble
substrates.

Reproduction:  Identified host fishes include numerous
darter and sculpin  species, including the Black Sculpin,
Greenside Darter,  Fantail Darter, Snubnose Darter, Tangerine
Darter, Blotchside  Logperch, Logperch, Channel Darter, Gilt
Darter, and Roanoke Darter (Jones et al. 2004). Glochidia are
packed into 20-40  mm conglutinates that resemble leeches
or flatworms (Jones et al. 2004). D. dromas is bradytictic,
although the species shares some traits of tachytictic taxa
(Ortmann 1912; Jones  et al. 2004).
                                       59

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Eastern Elliptic
Elliptic complanata
(Lightfoot, 1786)
Identification tips: Shell variable; subtrapezoidal,
elongate, moderately thin to thick, and compressed
to slightly inflated. Periostracum yellowish-tan to
dark brown; green rays may be present in young
individuals. Beak roughly even to slightly elevated
above hinge-line; sculpture of several ridges, usually
eroded (C). Teeth well developed (D). Nacre white,
salmon, or purple. Shell up to 5 inches in length.

Indicator use: Widely distributed in eastern North
America, the Eastern Elliptic has been reported as a
habitat generalist that tolerates disturbance (Ortmann
1919; Johnson 1970; Nedeau 2008; Natureserve).
    Of the freshwater mussels found in North
America, no other species has been so extensively
used as a biomonitor of pollutants (e.g. Campbell and
Evans 1991; Renaud et al. 1995; Beckvar et al. 2000;
Gagne et al. 2001; Mierzykowski and Carr 2001;
Gewurtz et al. 2002; Gewurtz et al. 2003; Martel et al.
2003). In addition, E. complanata has been frequently
employed to better understand the bioavailability,
bioaccumulation, and biotransformation of pollutants
(e.g. Day et al. 1990; Metcalfe-Smith 1994; Tessier et
al. 1994; Muncaster et al. 2002; Gewurtz et al. 2002;
O'Rourke et al. 2004; Thorsen et. al 2004).

Habitat: Distributed throughout the northern and
southern Atlantic Slope, Hudson Bay basin, and
parts of the Great Lakes-St. Lawrence basin. Occurs
in a wide variety of habitats, including creeks, rivers,
embayments, and lakes. May be found in both coarse
and fine substrates.
Reproduction:  Confirmed host fishes include the Banded
Killifish, Green Sunfish, RedearSunfish, Orangespotted Sunfish,
Largemouth Bass, White Crappie, and Yellow Perch (Young 1911;
Walters 1994; Walters et al. 2005).
    The Easlern Elliplio is lachyliclic, wilh Ihe reproduclive
period extending from May lo July. Orlmann (1919) reported lhal
Ihe glochidia of E. complanata are packaged in conglulinales.
                                        60

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Spike
Elliptic dilatata
(Rafinesque, 1820)
Identification tips: Shell elongate, moderately thick,
and somewhat compressed. Periostracum yellowish-
tan to brown; young often with faint green rays (A).
Older individuals brown to dark brown and rayless.
Beak with distinctive, coarse ridges (C). Teeth well
developed. Nacre white, salmon, or purple (B). Shell
up to 6 inches in length.

Indicator use: A wideranging unionid that may be
locally abundant, the Spike  is secure throughout its
range (Williams et al. 1993; Natureserve). Stansberry
(1965) considered the spike intolerant of water
pollution and Oesch (1984)  reported a reduction in its
range where severe channelization and siltation had
occurred.
    Wren and  MacCrimmon (1983) analyzed the
bioaccumulation and biomagnification of metals in an
undisturbed lake in Ontario, Canada. Tissue samples
were collected  from a number of fish, birds, mammals,
and the freshwater mussel - E. dilatata. The following
wet weight metal concentrations (ug/g) were reported:
Cd 5.8; Cu 2.0; Pb 4.5; Hg 0.17; Zn 78.5. In general,
E. dilatata bioaccumulated higher concentrations of
cadmium, copper,  lead, and zinc than fish species.
However, mercury was found to  biomagnify up the food
chain, with concentrations of 1.0 and 1.7 ug/g found
in the Northern Pike (Esox lucius) and Herring Gull
(Larus argentatus), respectively.

Habitat:  Widespread in the Mississippi River basin
and Great Lakes-St. Lawrence basin. The Spike
occurs in small to large creeks, rivers, lakes, and
impoundments. Often most  abundant in flowing
habitats where the streambed is comprised of stable
sand and gravel substrates.
Reproduction:  Identified host fishes include the Flathead Catfish, Gizzard Shad,
Rock Bass, White and Black Crappie, Banded Sculpin, Rainbow Darter, Yellow Perch,
and Sauger (Howard 1914; Wilson 1916; Clark 1981; Luo 1993).
    The Spike is tachytictic, with the reproductive period extending from mid-May to
August (Baker 1928).
                                       61

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Oyster Mussel
Epioblasma capsaeformis  (Lea, 1834)

Identification tips: General: Shell elliptical,
somewhat thin, and moderately inflated. Sexually
dimorphic: Females (A) expanded and rounded
posteriorly, males (B) elliptical and without expansion.
General: Periostracum yellowish-tan to light brown
with numerous green rays of varying widths. Beak
sculpture of indistinctive loops; often eroded. Teeth well
developed. Nacre white. Shell up to 3 inches in length.

Indicator use: The Oyster Mussel is listed as
federally endangered, occupying just a minute fraction
of its former range (USFWS 2004). Historically, it
was one of the most widely distributed and common
Cumberlandian species (Ortmann 1918; 1924;
1925). The decline of E. capsaeformis is most often
associated with impoundment, channelization, and
mineral extraction (Bates 1962; USFWS 2004).
    Recent toxicological studies have evaluated
the sensitivity of the Oyster Mussel to a variety of
pollutants. For example, Valenti et al. (2006a) evaluated
the toxicity of chlorine to five unionid species,  including
three federally listed taxa. Federally listed species
were reportedly more sensitive to TRC (total residual
chlorine) than two non-listed species. Mean 24-hr
LC50s for non-listed species ranged from 145 to 220
TRC ug/L, while federally listed LC50s ranged from 70
to 107 TRC ug/L. The reported 24-hr mean LC50 for E.
capsaeformis was 107 ug/L.

Habitat:  Endemic to the Cumberland River system
and Tennessee River system. Occurs in moderate-
sized streams to rivers where the current is swift.
Generally most abundant at shallow depths (< 3 ft.)
where substrates are comprised of stable sand, gravel,
and cobble.
Reproduction:  Identified host fishes include the Banded Sculpin,
Wounded Darter, Redline Darter, Spotted Darter and Dusky Darter
(Hill 1986; Yaeger and Saylor 1995).
    The Oyster Mussel has been documented with mature glochidia
during May, June, and July (Gordon and Layzer  1989; Yaeger and
Saylor 1995).
                                       62

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Northern Riffleshell
Epioblasma torulosa rangiana  (Lea, 1838)

Identification tips: General:  Shell moderately thick
and moderately inflated. Sexually dimorphic:  Females
(A) expanded, rounded, and compressed posteriorly,
males (B) somewhat triangular and sulcate. General:
Periostracum yellowish-tan to light brown with fine green
rays. Beak sculpture of double-loops; often eroded or
indistinct (C). Teeth well developed (D). Nacre white.
Shell up to 3 inches in length.

Indicator use: This once widespread subspecies
has declined sharply and is now listed as federally
endangered, occupying less than 5% of its former
range (USFWS 2007). E.t. torulosa is thought to be
sensitive to siltation, impoundment, and water pollution
(USFWS 1994; USFWS 1997).Toxicity testing of a
congener (Epioblasma capsaeformis) suggests that the
Epioblasma may be among the most sensitive aquatic
genera to copper and ammonia.

Habitat: Occurs in the Mississippi River basin and
Great Lakes basin. Found in flowing reaches  of large
creeks and rivers where substrates are comprised of
stable sand, gravel, and cobble. The largest remaining
populations occur in the Allegheny River and  French
Creek, PA  (USFWS 1994).

Reproduction: Identified host fishes include the Brown
Trout, Banded Darter, Bluebreast Darter, and Banded
Sculpin (Walters 1996a). Anecdotal evidence and recent
investigations suggest that E.t. rangiana may  capture
host fishes to facilitate glochidia transfer (Barnhart 2006).
The Northern Riffleshell is likely bradytictic, with gravid
females having been observed in September (Ortmann
1919).
                                      63

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Tubercled Blossom
Epioblasma torulosa torulosa
(Rafinesque, 1820)
Identification tips: General: Shell moderately thick
and moderately inflated; with a row of irregular medial
knobs often extending from the beak to ventral margin.
Sexually dimporphic: Females (A) greatly expanded
and rounded posteriorly, males (B) sulcate and with
a distinctive posterior-ventral indentation. General:
Periostracum yellowish-tan with fine green rays. Beak
sculpture of indistinct ridges, often absent in adults (C).
Teeth well developed (D).  Nacre white. Shell up to 3
inches in  length.

Indicator use: The Tubercled Blossom is a federally
endangered species and may now be extinct (Parmalee
and Bogan 1998; USFWS 2007a; USFWS 2007b). E.t.
torulosa formerly occurred throughout the Tennessee
River drainage, Cumberland River, and upper Ohio
River drainage (USFWS 1985a). Investigations of
archaeological shell middens along the Tennessee
River suggest that this species was once fairly common
in the Tennessee mainstem (Hughes and Parmalee
1999). It was last found fresh dead below Kanawha
Falls (WV) in 1969 (USFWS 2007a).
    The decline of E.t torulosa (and many of its
congeners) has been attributed to ubiquitous river
impoundment, increased turbidity and siltation
associated with agriculture and deforestation, and
pollution (USFWS 1985a; USFWS 2007a).

Habitat:  Formerly occurred in the Tennessee River
drainage, Cumberland drainage, and  upper Ohio
drainage. E.t. torulosa has been found in shallow
reaches of rivers with swift current and substrates
comprised of stable sand and gravel.

Reproduction:  Unknown.
                                       64

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Wabash Pigtoe
Fusconaia flava  (Rafinesque, 1820)

Identification tips: Shell highly variable; usually sub-
triangular, moderately thick, and moderately inflated.
Ventral margin of shell may have a velvet-like texture.
Big river forms usually with greater inflation and umbo
often more anterior. Periostracum yellowish-tan to brown,
rest lines distinctive; young often with fine green rays.
Beak sculpture of indistinct ridges as adult (B). Teeth well
developed (C). Nacre white, may have a salmon tinge.
Shell up to 4 inches in length.

Indicator use: A unionid that occurs in a broad range of
habitats, the Wabash Pigtoe is one of the most ubiquitous
mussels in North America. It reportedly adapts to a
variety of substrate types and habitat conditions (Walters
1995; Parmalee and Bogan 1998). Strayer (1983)
commented that the Wabash Pigtoe  "seems to do well in
muddy, hydrologically unstable,  low-gradient streams."
    Spooner et al. (2005) studied the physiological
effects of high water temperatures on eight species of
unionids, including F. flava. The Wabash Pigtoe was
reported as among the more thermally tolerant species,
exhibiting stress at 34-35C and maximal stress at 38C.
The authors suggested the use  of A. ligamentina as
an indicator species in lieu of more thermally tolerant
species, such as the Wabash Pigtoe.
    Waller and Fisher (1998a) exposed F. flava and a
number of other unionids to various chloride salts. The
Wabash Pigtoe was among the  most tolerant unionids
to the various salt treatments, while the Threehorn
Wartyback (Obliquaria reflexa) and Fragile Papershell
(Leptodea fragilis) were among  the more sensitive.

Habitat:  Occurs throughout the Mississippi River basin,
Great Lakes-St. Lawrence basin, and Mobile basin. Found
in creeks, rivers, embayments, and lakes. Often most
abundant where substrates are  comprised of stable sand,
gravel and cobble, although F. flava may also occur in fine
substrates.

Reproduction:  Identified host fishes include the Creek
Chub, Silver Shiner, Bluegill Sunfish, Black Crappie, and
White Crappie (Howard  1914; Wilson 1916; Walters and
O'Dee 1997). The Wabash Pigtoe is  lachyliclic, wilh Ihe
reproduclive period extending from May lo August
                                       65

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Pink Mucket
Lasmpsilis abrupta (=orbiculata)  (Say, 1831)

Identification tips: General: Shell elliptical or
subquadrate, thick, and slightly inflated to inflated.
Sexually dimorphic: Females expanded and inflated
posteriorly (A), males bluntly pointed (B). General:
Periostracum yellowish-tan or brown; often rayless,
although faint rays may be seen near the beak (A) and
in young individuals. Beak sculpture of indistinct double-
loops; often eroded (C). Teeth well developed (D);
pseudocardinal teeth large and heavy in older individuals.
Nacre white or pink. Shell up to 5 inches in length.

Indicator use: Although widely distributed, the  Pink
Mucket remains imperiled or critically imperiled throughout
its range (Natureserve). Collections made by early
naturalists suggest that L. abrupta may have also been
uncommon in the recent past (USFWS 1985c).The Pink
Mucket is currently listed as endangered by the  U.S. Fish
and Wildlife Service (USFWS 1985c; USFWS 2007).
    Wang et al. (2007a) evaluated the toxicity of copper,
and ammonia to the early life stages of L. abrupta and
several other unionid species. Short-term exposures of
copper to L. abrupta glochidia yielded a 24-hr EC50 of
34 ug Cu/L, a test result comparable to other species.
Juvenile (2-month old) L abrupta were slightly more
sensitive than other test species during 96-hour exposures
to ammonia, with a reported  EC50s of 2.3 mg N/L.

Habitat: Widespread throughout the Mississippi Basin,
Tennessee River, Cumberland River, and Ohio River
drainage (USFWS 1985c).The Pink Mucket is found in
small to large rivers where substrates are comprised
of stable sand, gravel, and cobble. L. abrupta typically
inhabits shallow, swiftly flowing areas, which may include
the tailwaters and upper reaches of navigational pools
where adequate habitat is present (USFWS 1985).

Reproduction:  Identified host fishes include the
Smallmouth Bass, Largemouth Bass, Spotted Bass, and
Walleye (Barnhart et al.1997). The confirmed hosts  of a
relative, Lampsilis higginsi, include the Sauger, Freshwater
Drum, and Yellow Perch, in addition to some of the fishes
named above (Surber 1913; Waller and Holland-Bartels
1988).
                                        66

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Plain Pocketbook
Lampsilis cardium  (Rafinesque, 1820)

Identification tips: General: Shell moderately thick
to thick and inflated. Sexually dimorphic: Females (A)
inflated and rounded posteriorly, males (B) pointed
posteriorly. General: Periostracum yellowish-tan to
brown; with few to numerous green rays (A-B). Beak
elevated above hingeline; sculpture double-looped (C),
often more distinctive in younger individuals. Teeth well
developed. Nacre white. Shell up to 7 inches in length.

Indicator use: The Plain Pocketbook is a widespread
species that occurs in a variety of habitats. In
Tennessee, it has been reported to tolerate
impoundment, poor water quality, and substrates
comprised of mud and silt (Parmalee and Bogan 1998).
    In an effort to assess lead and cadmium
contamination from tailing ponds and chat piles in the
Big River watershed (MO), Czarnezki (1987) used
L. cardium to biomonitor contaminant levels at five
sites. The mussels were found to accumulate metals
quickly and assisted in identifying the main sources of
contamination.
    Under laboratory conditions, juvenile L. cardium
exhibited sensitivity to ammonia during acute pore
water exposures  (Newton et al. 2003). Fifty percent
mortality was observed at concentrations as low as 93
ug NH3-N/L and sublethal effects (50% reduced growth)
occurred at 31  ug NH3-N/L. An in-situ companion
study performed  by Bartsch et al. (2003) deployed
caged juveniles below the substrate surface  in the St.
Croix  River, Wl. Survival and growth were  reported as
highly variable and generally unrelated to ammonia
concentrations found at the study sites.

Habitat: Widely  distributed throughout the Mississippi
River  basin, Great Lakes-St. Lawrence Basin, and
north  into Canada. Occurs in moderate-sized streams
to rivers, lakes, reservoirs, and coastal marshes. Found
in a variety of substrates, from sand, gravel, and cobble
to mud and silt.
Reproduction:  Identified host fishes include the Pumpkinseed Sunfish, Bluegill
Sunfish, Green Sunfish, Largemouth Bass, Smallmouth Bass, White Crappie, Black
crappie, Yellow Perch, Sauger and Walleye (Coker 1921; Waller et al. 1985; Walters
1996b; Draxler et al. 2006). The Plain Pocketbook utilizes a minnow-like lure to attract
host fishes (partially visible in upper right photo).
                                       67

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Wavyrayed Lampmussel
Lasmpsilis fasciola  (Rafinesque, 1820)

Identification tips: General: Shell oval, moderately
thick, and moderately inflated to inflated. Sexually
dimorphic: Females (A) expanded and rounded
posteriorly, males (B)  bluntly pointed. General: Shell
periostracum with distinctive, wavy green rays (A-
B). Beak slightly raised above hinge-line; sculpture
of somewhat irregular double-loops (C). Teeth well
developed. Nacre white. Shell up to 5 inches in length.

Indicator use: The Wavyrayed Lampmussel is a
species of hydrologically stable and good quality
streams (Strayer 1983; Walters 1995). It may be
locally abundant when found and is considered stable
throughout its range (Williams et al. 1993; Natureserve).
    Several researchers have used L fasciola as a test
organism when evaluating the sensitivity of unionids
to contaminants (e.g. Jacobson et al. 1997; Cherry
et al. 2002; Keller and Augspurger 2005; Valenti et al.
2006; Bringolf et al. 2007; Wang et al. 2007a; 2007b).
Wang et al. (2007) conducted a series of ammonia
toxicity trials using L. fasciola glochidia and juveniles,
in addition to the early life stages of several other
unionid species. Reported EC50s for Wavyrayed
glochidia ranged from 6.2 to 8.7 mg N/L during 24-hour
exposures. These results were generally comparable to
the values reported for other species, with the exception
of two particularly sensitive species - the Ellipse
(Venustaconcha ellipsiformis) and Oyster Mussel (E.
capsaeformis). GMAVs compiled and by Augpsurger
et al. (2003), Augspurger et al. (2003), and March et al.
(2007) rank L. fasciola among the most sensitive  aquatic
species to ammonia and copper.

Habitat: Occurs disjunctly throughout the Mississippi
River basin and Great Lakes basin. Generally found in
creeks to small rivers  at shallow depths in stable  sand
and gravel. This species has also been documented
to occur at depths of 15 feet or more in the Tennessee
River and Allegheny River.
Reproduction:  Identified host fishes include the
Smallmouth Bass (Zale and Neves 1982). The
Wavyrayed Lampmussel utilizes a mantle flap lure (upper right photo) to entice
host fishes. The striking action of predators triggers the expulsion of hundreds to
thousands of glochidia, thereby facilitating the parasitization of the host fish.
                                        68

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Fatmucket
Lampsilis siliquoidea
(Barnes, 1823)

Identification tips: General: Shell moderately thick
and somewhat compressed to moderately inflated.
Sexually dimorphic: Females (A) inflated and rounded
posteriorly, males (B) bluntly pointed posteriorly.
General:  Periostracum yellowish-tan to brown; with
few to numerous green rays (A-B). Beak elevated
slightly above hinge-line; sculpture double-looped (C),
often more prominent in younger individuals. Teeth well
developed. Nacre white. Shell up to 5 inches in length.

Indicator use: Widely distributed and often abundant,
the Fatmucket has been described as tolerant of silt
and disturbance (Dawley 1947; Walters 1995; McRae
etal.2004).
    Manny and Kenaga (1991) reported the use of
L. siliquoidea (= L. radiata siliquoidea, see Turgeon
et al. 1998) as a biomonitor of heavy metals, PCBs,
and octachlorostyrene in the Detroit River, a heavily
urbanized watershed. Researchers found toxic
contaminants concentrated by L. siliquoidea to levels
59 times nearby sediments (GLI 1984; Pugsley et al.
1985).
    Bringolf  et al. (2007b) investigated the toxicity
of several forms of glyphosate, its formulations, and
a surfactant (MON 0818) to juvenile and glochidial
Fatmucket (L. siliquoidea). Reported 24-hour EC50s
were as low as 3.0 mg/L and 0.6 mg/L for Roundup
and MON 0818, respectively. Reported 96-hour
EC50s for juvenile L. siliquoidea were 5.9 mg/L and
3.8 mg/L for  Roundup and MON 0818, respectively.
Researchers concluded that the early life stages of
the Fatmucket are among the most sensitive aquatic
organisms to glysphosate-based chemicals and MON
0818 tested to date.
Habitat: Widely distributed throughout the Mississippi
River basin, Great Lakes-St. Lawrence drainage, and
north into Canada. Occurs in a wide variety of habitats,
including creeks,  rivers, lakes, and backwaters. Generally most abundant in sluggish to
moderate currents, in both fine and coarse substrates.

Reproduction: A total of 20 fishes have been identified as suitable host species for
L. siliquoidea (Evermann and Clark 1918; Coker et al. 1921; Fuller 1978; Trdan 1981;
Walters and O'Dee 1997; O'Dee and Wallers 2000; Wallers el al. 2005).
    The Falmuckel is bradyliclic, wilh Ihe reproduclive period extending from Augusl lo
July (Baker 1928).
                                       69

-------
         An Introduction to Freshwater Mussels as Biological Indicators
White Heelsplitter
Lasmigona complanata complanata  (Barnes 1823)

Identification tips: Shell large, compressed, and
moderately thin to moderately thick; with  a distinctive,
often ribbed dorsal wing (A-B). Periostracum light to dark
brown; usually with fine green rays in young individuals.
Beak sculpture of conspicuous double-loops (C).
Pseudocardinal teeth well developed although low and
irregularly serrated; lateral teeth present  as an under
developed raised and striated ridge. Nacre white. Shell
up to 8 inches in  length.

Indicator use: This wideranging unionid has been
reported to be tolerant  of silt, habitat disturbance, and
impoundment by numerous authors (Stansberry 1965;
Walters 1995; Dean et  al. 2002; Metcalfe-Smith et al.
2003; Sietman 2003). Stayer and Jirka (1997) noted
that L.c. complanata was "one of the few unionoids that
seemed to do well in disturbed substrates."
    The White Heelsplitter may potentially exploit areas
that other unionids find unfavorable for colonization.
For example, in the early 1900s, Goodrich and van der
Schalie (1932)  observed the colonization of Michigan's
Saginaw  Bay by L.c. complanata during a period of
eutrophication resulting from increased sewage wastes.
Metcalfe-Smith et al. (2003) recently noted the range
expansion of L.c. complanata in the Sydenham River,
Ontario. The researchers speculated that the rapid
expansion of such an opportunistic unionid indicated
deteriorating conditions within the study area.
Habitat:  Distributed throughout the Mississippi River
basin, Great Lakes-St. Lawrence basin, and north
into Canada. Occurs in creeks, rivers, reservoirs, lakes, and
embayments. Adapts well to turbid waters. Tolerates a wide range
of substrates, including unstable sand and gravel, silt, and mud.

Reproduction:  Identified host fishes include the Common
Carp, Banded Killifish, Green  Sunfish, Orangespotted Sunfish,
Largemouth Bass, and White  Crappie (Lefevre and Curtis 1910;
Young 1911).
    The White Heelsplitter is  bradytictic, with the reproductive
period extending from September to May (Baker 1928).
                                        70

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Flutedshell
Lasmigona costata
(Rafinesque, 1820)
Identification tips: Shell elongate, moderately
thick, and somewhat compressed; with several
undulations or "flutes" present on the posterior slope
(A-B). Periostracum brownish with striking green
rays in young individuals; adults often dark brown
and rayless. Beak even with hinge-line; sculpture of
a few concentric ridges that are often eroded (C).
Pseudocardinal teeth distinctive, low, and heavy (D).
Lateral teeth weakly developed (D). Nacre white.
Shell up to 7 inches in length.

Indicator use: While not often locally abundant,
this widespread species is secure throughout its
range (Williams 1993; Natureserve). Kidd (1973)
documented an increase in L costata in the the
polluted waters of the Grand River, indicating that
this species may  be capable of colonizing disturbed
or polluted habitats.
    Tetzloff (2001) investigated the survival rates
of unionid species following a low dissolved oxygen
(DO) event  in Big Darby Creek, OH. The event
was initiated by an agribusiness spill of molasses,
fermented grain, and other organic substances.
The Flutedshell, a common species within the
study area,  experienced lower rates of mortality
than several other species at the site (-10%).
The Kidneyshell (P. fasciolaris) and Wavyrayed
Lampmussel (L. fasciola) were among the most
sensitive species to the event.

Habitat: Widespread throughout the Mississippi
River basin  and Great Lakes-St. Lawrence basin.
The Flutedshell is found in small creeks to rivers
where substrates are comprised of stable sand,
gravel, and  cobble. While usually most abundant in
shallow water, L. costata has been documented from
depths of 15-20 feet.
Reproduction:  Identified host species include the Creek
Chub, Central Stoneroller, Longnose Dace, Common Carp,
Northern Hog Sucker, Bluegill Sunfish, Pumpkinseed
Sunfish, Largemouth Bass, and Banded Darter (Lefevre
and Curtis 1910; Walters et al. 1998c; Walters et al. 2005).
    The Fluledshell is lachyliclic, wilh Ihe reproduclive
period extending from September unlil May (Baker 1928).
                                       71

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Black Sandshell
Ligumia recta  (Lamarck, 1819)

Identification tips: General: Shell elongate,
thick, and moderately inflated. Sexually dimorphic:
Females obliquely flared posteriorly (A), males
bluntly pointed (B). General: Periostracum dark
brown to black, smooth, and lustrous; young
individuals often with brillant green rays. Beak
raised slightly above hinge-line; sculpture of a few
indistinct ridges that are often eroded. Teeth well
developed; lateral teeth distinctive, long, narrow,
and straight (C). Nacre white; often with purplish
tinge near beak cavity and pseudocardinal teeth.
Shell up to 9 inches in length.

Indicator Use: Although widespread, L. recta
is relatively uncommon throughout its range and
has significantly declined in some states (e.g.
Kansas, Illinois). Khym and Layzer (2000)  observed
that the "decline and low abundance of L. recta
is concordant with a decline in sauger (Sander
canadensis)  runs," a suitable host species. Williams
et al. (1993) considered the Black Sandshell a
species of "special concern".
    Pip (1995) evaluated the use of L. recta and
eight other unionids as biomonitors of heavy metals
in the Assiniboine  River, Manitoba, Canada. Of the
nine unionids studied, the Black Sandshell and
Mapleleaf (Quadrula quadrula) were determined
to have sequestered the highest concentrations of
copper.

Habitat: Known from the Mississippi River basin,
Great Lakes-St. Lawrence River basin, a few Gulf
Coast drainages, and north into Canada. The Black
Sandshell is  found in large creeks, rivers, and lakes
where substrates consist of mud, sand, gravel, or
cobble. In riverine habitats,  it occurs in both current and slackwater areas.

Reproduction: Identified host species include the Banded Killifish, Green Sunfish,
Bluegill Sunfish, Orangespotted Sunfish, White Crappie, Largemouth Bass, and Sauger
(Young 1911; Surber 1913;  Pearse 1924; Walters 1994; Hove 1994; Barnhart 2000; Khym
et al. 2000). Khym and Layzer (2000) reported poor glochidia metamorphosis in Black
and White Crappie, Bluegill Sunfish, and Largemouth Bass (<5%). Conversely,  Sauger
proved an excellent host, with 53% of glochidia transforming into juveniles.
    The Black Sandshell is bradytictic, with the reproductive period extending from
August to July (Ortmann 1919).
                                        72

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Cumberland Moccasinshell
Medionidus conradicus  (Lea, 1834)

Identification tips: Shell small, elongate,
moderately thin, and compressed. Periostracum
glossy and yellowish-tan with numerous green rays
(A). Beak sculpture of fine, broken double-looped
ridges (B); usually eroded in adults. Teeth well
developed although delicate (C). Nacre bluish-
white, often iridescent. Shell up to 3 inches in
length.

Indicator use: A Cumberlandian  endemic
that has experienced declines in portions of
its range (Williams  et al. 1993; Natureserve),
the Cumberland Moccasinshell occurs in
unimpounded, high quality stream and river
reaches. Williams et al. (1993) considered M.
conradicus a species of "special concern".
    Jacobson et al. 1997 evaluated the toxicity of
copper to the glochidial stages of M. conradicus
and four additional  unionid species. Reported
LC50s for released glochidia ranged from 37 to
81 ug Cu/L during 24-hour exposures. Similar
results were documented by Cherry et al. (2002),
who reported an acute mean LC50 of 41  ug Cu/L.
GMAVs compiled and ranked by Augspurger (2006)
and March et al. (2007) placed Medionidus among
the most sensitive aquatic genera to copper.
    Cherry et al. (1991) and  McCann (1993)
assessed the acute toxicity of zinc to the  early life
stages of M. conradicus and several other unionid
species. Reported  LC50s ranged from 492 to 570
ug Zn/L during 48-hour exposures (hardness = 60
to 170).

Habitat:  Endemic  to the Cumberland  River
system and Tennessee River system. Occurs in small streams to small rivers where
the current is swift. Generally most abundant at shallow depths (< 3 ft.), where
substrates are comprised of stable sand, gravel, cobble, and slab rock (Gordon and
Layzer  1989; Parmalee and Bogan 1998).

Reproduction: Identified host fishes include the Warmouth Sunfish, Redline
Darter,  Fantail Darter, Striped Darter, and Rainbow Darter (Stern and Felder 1978;
Zale and Neves 1982;  Luo and Layzer 1993).
    Cumberland Moccasinshell glochidia have been documented in Big Moccasin
Creek (VA) drift from January to June,  September to October, and infrequently
during November (Zale and Neves 1982).
                                      73

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Threehorn Wartyback
Obliquaria reflexa  (Rafinesque, 1820)

Identification tips: Shell round, moderately thick,
and moderately inflated; anterior of shell noticeably
thicker than posterior. A single row of large medial
knobs extends from the umbo to dorsal margin (A).
Knobs alternate in position on left and right valve (B).
Posterior edge with fine ribs or small undulations (C).
Shell periostracum variable, usually tan or green with
fine green rays. Beak sculpture of fine, indistinctive
lines often with small knob near hinge-line. Teeth
well developed (D). Nacre white. Shell up to 3 inches
in length.

Indicator use: This wideranging unionid has
exhibited tolerance to river impoundment and a wide
variety of substrates. It often sustains or increases
in relative abundance where impoundment has
occurred (Fuller 1985; Parmalee and Bogan 1998;
WDNR 2003). ESI (2000) consistently reported O.
reflexa as a dominant species in the impounded
pools of the upper Ohio River.
    Levengood et al. (2004) evaluated contaminant
concentrations in freshwater mussels at the
confluence of the Mississippi River and Illinois
River. Five regionally abundant mussels, including
O. reflexa, were used to evaluate contaminant
burdens of local unionids. Cadmium and arsenic
were below detection limits in O. reflexa, while most
EPA priority metals were  accumulated to comparable
concentrations by Amblema plicata, Obovaria
olivaria,  and O. reflexa upstream of the Mississippi-
Illinois confluence. Threehorn wartyback were not
collected below the confluence.

Habitat:  Widespread in the lower and upper
Mississippi basin, Great Lakes basin, and Gulf
drainages. Found in small to large rivers, lakes,
reservoirs, and embayments. Often most abundant
in substrates comprised of mud, sand, and gravel
where the current is slow to moderate.
Reproduction:  Identified host fishes include the Common Shiner, Longnose Dace, and
Silverjaw Minnow (Walters et al. 1998). However, only a few juveniles were recovered from
the above species, giving credence to the possibility that the true host(s) has yet to be
found.
    The Threehorn Wartyback is tachytictic, with the reproductive period extending from
June to August (Utterback 1915).
                                        74

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Sheepnose
Plethobasus cyphyus  (Rafinesque,  1820)

Identification tips: Shell subovate, thick, and
moderately inflated; often with a row of medial
tubercles extending from below the umbo to the
ventral margin. The tubercles may vary in number,
size, and shape. Periostracum yellowish-tan and
rayless (A) usually brown to dark brown in old
individuals. Beak slightly raised above hinge-line;
sculpture of indistinct ridges, often eroded in adults
(B). Teeth well developed (C). Nacre white. Shell up to
5 inches in length.

Indicator use: Once widespread in the small
and large rivers of the Mississippi drainage, the
Sheepnose now occupies just 34% of its former
range (Butler 2002). It is currently a candidate
for federal listing and is considered threatened,
imperiled, or critically imperiled throughout its range
(Cummings and Mayer 1992; Williams et al. 1993;
Natureserve). Interestingly, archaeological evidence
suggests that this species was rare in some systems
historically (Parmalee et al. 1980; Parmalee and
Hughes 1994; Hughes  and Parmalee 1999; Butler
2002).
    Perhaps the largest contributing factor to the
decline of P. cyphyus has been habitat fragmentation
and associated hypolimnetic releases resulting
from the construction of dams (Butler 2002). Other
suspected contributors include large channel
maintenance, mine drainage, in-stream gravel mining,
sedimentation, turbidity, and  chemical contaminants
(Hartfield and Hartfield 1996; Butler 2002).

Habitat:  Widespread in the upper and lower
Mississippi River, Ohio River, Tennessee River, and
Cumberland River drainages. Occurs in small to large
rivers where the current is moderate to swift. Often
found at shallow depths (<3 ft.) where the streambed
is comprised of sand and gravel substrates
(Parmalee and Bogan 1998).

Reproduction: Identified host fishes include the
Central Stoneroller Minnow and Sauger (Wilson
1916; Walters et al. 2005). Glochidia are packaged in "narrow, lanceolate shapes which
are solid, red and discharge in  unbroken form" (Oesch  1984).
    The Sheepnose is tachytictic, with the reproductive period occurring in early
summer (Parmalee and Bogan 1998).
                                       75

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Clubshell
Pleurobema clava
(Lamarck, 1819)
Identification tips: Shell triangular, elongate, and
moderately inflated; noticeably thicker anteriorly
than posteriorly. The shell is perhaps best described
as "wedge-shaped" (Walters 1995). Periostracum
yellowish-tan; umbo with prominent, broken green
rays (upper right photo) (A). Rays generally less
conspicuous in older individuals. Beak slightly
raised above hinge-line and set anteriorly; sculpture
of indistinct ridges, usually eroded (B). Teeth well
developed (C).  Nacre white. Shell up to 3 inches in
length.

Indicator use:  The Clubshell was formerly
widespread and abundant throughout the upper
Ohio River drainage and western Lake Erie
tributaries. It now occupies less than 5% of its
former range (USFWS  1993; Natureserve). The
dramatic decline of P. clava has been attributed to
siltation, impoundment, in-stream sand and gravel
mining, pollutants, and  exotic species (USFWS
1993a; USFWS 1994).  While there is little doubt the
Clubshell is a sensitive species, the causal factors
of decline have not been evaluated, quantitatively
or otherwise, for their individual impacts. It is now
listed as an endangered species by the U.S. Fish and
Wildlife Service.

Habitat: Formerly widespread in the upper Ohio
River basin and the western tributaries of Lake Erie.
Occurs in creeks  and rivers where the streambed
is comprised of clean sand, gravel, and small
cobble substrates. Many authors have reported on
its propensity to burrow deep into the streambed
(Ortmann 1919; Walter 1995; USFWS 1997),
although il may also be found in ihe more lypical life
posilion  assumed by mosl unionids.
Reproduction:  Idenlified hosl fishes include Ihe
Cenlral Sloneroller Minnnow, Slriped Shiner, Blackside
Darler, and Logperch (Wallers and O'Dee 1997; O'Dee and
Wallers 2000).
    The Clubshell is apparenlly lachyliclic, wilh Ihe
reproduclive season extending from May lo mid-June
(Orlmann 1919).
                                        76

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Ohio Pigtoe
Pleurobema cordatum
(Rafinesque, 1820)
Identification tips: Shell subtriangular, deep, heavy, and
inflated; usually with a shallow sulcus. Periostracum light
brown to reddish-brown; young individuals may have faint
green rays. Rest lines prominent (A). Beak raised and
turned forward (A-B); sculpture generally indistinct or of
elevated ridges (Cummings and Mayer 1992). Teeth well
developed (C). Nacre white. Shell up to 4 inches in  length.

Indicator use: The Ohio Pigtoe is a large river species
that is of conservation concern throughout its range
(Williams 1993; Roe 2002; Natureserve). Parmalee
and Bogan (1998) reported P. cordatum to be intolerant
of impounded reservoirs  in Tennessee. Conversely,
Gordon  and Layzer (1989) commented that it may be
somewhat tolerant of lentic habitats. Investigations into
the impounded pools of the upper Ohio River found P.
cordatum to be "fairly abundant" at Greenup and Meldahl
(ESI 2000). Thus, the tolerance of this unionid (and
hosts) to impoundment may depend on local habitat
conditions or undetermined factors. It is also suspected
to be sensitive to poor water quality, siltation, and zebra
mussels (Roe 2002).
    Chen (1998) analyzed the ability of P. cordatum
and several other unionid species to regulate oxygen
consumption (OC) with declining dissolved oxygen  levels.
The study results suggested that P. cordatum was likely
vulnerable to hypoxia due to its poor ability to regulate OC.

Habitat: Distributed throughout the upper Mississippi
River, Ohio River, Cumberland River, and Tennessee
River basins. Generally occurs in flowing sections of
medium to large rivers in shallow or deep water (up to
25 ft.). Often found in stable sand, gravel, and cobble
substrates.

Reproduction: Identified host fishes include the Guppy,
Brook Stickleback, Creek Chub, Rosefin Shiner, and
Bluegill Sunfish (Fuller 1974; Walters and Kuehnl 2004).
    The Ohio Pigtoe is apparently tachytictic, with the
reproductive period occurring in late spring to summer.
                                       77

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Round Pigtoe
Pleurobema sintoxia
(Rafinesque, 1820)
Identification tips: Shell highly variable; generally
round to subquadrate and moderately thick. Shell
inflation variable; often compressed in smaller
systems and inflated in large rivers. Periostracum
yellowish-tan, reddish-brown, or dark brown; young
individuals may have faint rays. Rays often absent in
older individuals. Beak sculpture somewhat indistinct,
usually of irregular ridges. Beaks often low in creek
and small river forms; higher in large river forms.
Teeth  well developed (B). Nacre white or pink (B).
Shell up to 5 inches in length.

Indicator use: The Round Pigtoe is widely
distributed although rarely abundant throughout its
range (Cummings and Mayer 1992; Sietman 2003;
WDNR 2003; Natureserve). It most commonly
occurs in areas of current and good water quality
(Walters 1995; Parmalee and Bogan 1998; Zanatta
and Metcalfe-Smith 2004). P. sintoxia has apparently
tolerated impoundment in some rivers, although
this may be dependent on localized conditions. For
example, while historically reported from the Upper
Ohio River,  recent sampling has found it to be rare
with no evidence of recent recruitment (Taylor 1989;
ESI 2000). Populations of P. sintoxia may also be
vulnerable to zebra mussel infestations,  as recent
reports suggest from the Detroit River (tributary
between Lake St. Clair and Lake Erie) (Schloesser et
al.2006).

Habitat: Widespread in the Mississippi  River basin
and lower Great Lakes. Often most abundant in
large creeks or rivers with moderate current (Walters
1995;  Parmalee and Bogan 1998). However, it is also
known from Lake Erie and Lake St. Clair. Occurs in
packed mud, sand, and gravel subslrales (Oesch
1984;  Parmalee and Bogan 1998).
Reproduction:  Idenlified hosl fishes include Ihe
Cenlral Sloneroller Minnow, Spolfin Shiner, Norlhern
Redbelly Dace, Soulhern Redbelly Dace, Blunlnose Minnow, and Bluegill Sunfish
(Surber 1913; Coker el al. 1921; Hove 1995a; Hove el al. 1997; Wallers el al. 2005).
    The Round Pigloe is apparenlly lachyliclic, wilh Ihe reproductive season
extending from May lo late July (Baker 1928).
                                        78

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Kidneyshell
Ptychobranchus fasciolaris
(Rafinesque, 1820)
Identification tips:  Shell somewhat elongate
and sub-elliptical, moderately thick to thick, and
compressed to slightly inflated. Periostracum yellow,
yellowish-tan, or light brown; often with numerous
broken green rays (A). Beak sculpture of indistinct
ridges; usually eroded  (B). Beak roughly even
to slightly elevated above hinge-line. Teeth well
developed (C). Nacre white. Shell up to 6 inches in
length.

Indicator use:  Widely distributed but sporadically
occurring, the Kidneyshell may be locally abundant
in good habitat. It has reportedly tolerated
impoundment in Tennessee (Parmalee and Bogan
1998), but is more typical of shallow, flowing creeks
and rivers (van der Schalie 1938; Gordon and
Layzer 1989; Walters 1995). Williams et al. (1993)
considered it secure throughout its range.
    Positive associations have been documented
between Kidneyshell populations and other species
of unionids, including the Spike (Elliptic dilatata),
Wavyrayed Lampmussel (Lampsilis fasciola),
Clubshell (Pleurobema clava), and Rainbow (Villosa
iris) (van der Schalie 1938; Metcalfe-Smith et al.
1999; Badra and Goforth 2001). These reports
suggest the use of the Kidneyshell as an indicator of
suitable conditions for the presence  or reintroduction
of the species listed  above.
    Tetzloff (2001) investigated the survival rates
of unionid species following a low dissolved oxygen
(DO) event in Big Darby Creek, OH.  The Kidneyshell,
an abundant species within the study area, was
reported with the Wayrayed Lampmussel (L. fasciola)
as experiencing the  highest mortality rates (-95%).

Habitat: Fairly widespread throughout the Mississippi River basin and Great
Lakes basin. Occurs in creeks and rivers where the current is moderate to
swift. Often most abundant in  sand and gravel substrates.

Reproduction:  Confirmed host fishes include the Brook Stickleback (Walters
et al. 2005). Hosls observed infecled in Ihe field include Ihe Johnny Darler,
Fanlail Darler, Greenside Darler, and Banded Darler (While el al. 1996).
    The Kidneyshell is bradyliclic, wilh glochidia overwinlering in Ihe marsupia
(Orlmann 1919).
                                       79

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Fluted Kidneyshell
Ptychobranchus subtentum  (Say, 1825)

Identification tips: Shell elongate, moderately thick,
with a fluted or undulating posterior dorsal slope (A-
B). Periostracum usually yellowish-tan with few to
several wide green rays (A). Rays generally fade with
age. Beak sculpture of indistinct loops; often eroded
(C). Teeth well developed (D). Nacre white. Shell up
to 5 inches in length.

Indicator use: The Fluted Kidneyshell has
undergone a drastic range reduction in the past 100
years, a result of stream and river impoundment,
toxic contaminants, and siltation (Butler 2005a). This
sensitive species is currently a candidate for federal
listing.

Habitat:  Endemic to the Cumberland River system
and Tennessee River system. Occurs in moderate-
sized streams to small rivers where the current is
swift. Generally most abundant at shallow depths
(< 2 ft.) where substrates are comprised of packed
sand and gravel. This species requires flowing, well-
oxygenated waters to thrive (Butler 2005a).

Reproduction:  Identified host fishes include
many riffle-dwelling species, including the Banded
Sculpin, Redline Darter, Rainbow Darter, Barcheek
Darter, and Fantail Darter (Luo and Layzer 1993).
The Fluted Kidneyshell utilizes a fascinating tool for
reproduction: a gelatinous capsule shaped like insect.
These "conglutinates" are packed with glochidia and
liberated into the stream current where they adhere
to stones. Unsuspecting host fishes then strike the
conglutinates, infecting their gill tissue with glochidia.
                                        80

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Giant Floater
Pyganodon grandis
(Say,  1829)
Identification tips: Shell elongate, thin, and inflated
(A) Periostracum yellow, yellowish-tan, or green when
young; often with faint green rays. Older individuals light
brown to dark brown; usually rayless. Beak elevated
above hinge-line; sculpture of pronounced double-loops
(B). Teeth poorly developed; hinge thickened. Nacre
white; beak cavity may be tinged with salmon (C). Shell
up to 9 inches in length.

Indicator use:  This wideranging unionid adapts well
to impoundments and tolerates moderate levels of silt
(Walters 1995; WDNR 2003). Pip (2006) described the
Giant Floater as one of the most tolerant unionids in
Manitoba, Canada. It may also persist in soft substrates
where heavier shelled species sink or suffocate (Coker
1921).
    GMAVs compiled and ranked by Augspurger et
al. (2003) and Augspurger (2006) placed Pyganodon
among the more sensitive aquatic genera to copper and
ammonia.
    Black et al.  (1995) exposed the Giant Floater
to lead in the laboratory and field and found that
DMA strand breakage occurred only at the lowest
exposure level (50 ug/L). They attributed this to higher
lead concentrations inducing DMA repair processes,
whereas lower concentrations may have not initiated or
maximized repair processes. A secondary hypothesis
was localized cellular necrosis (cell death and
breakage) of the foot.
    The Giant Floater has been  used extensively as
a surrogate in contaminant uptake and loss studies by
several researchers (e.g.  Bedford and Zabik 1973; Heit et al. 1980; Perry et al. 1980; Malley
et al. 1995; Stewart 1999; Wang et al. 1999; Perceval et al. 2002). Additionally, P. grandis has
been used to evaluate potential biomarkers to assess heavy metal exposure (Chamberland
et al. 1995; Couillard et al. 1995;  Perceval 2002).

Habitat: Distributed throughout the Mississippi River basin, Great Lakes-St. Lawrence
basin, several Gulf drainages, and north  into Canada. Typically found in low-gradient stream
reaches, backwaters, lakes, and  impoundments. Often most abundant in fine substrates.

Reproduction:  Over 35 species of fish (including some  exotic species) have been identified
as hosts for the  Giant Floater. Jacobson et al. (1997) reported that glochidia of P. grandis
survived longer  in natural river water than did the glochidia of three lampsiline species.

Converted to mg/L total ammonia as N, normalized to pH 8.
                                       81

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Rabbitsfoot
Quadrula cylindrica cylindrical (Say, 1817)

Identification tips:  Shell elongate, rectangular,
moderately thick, and somewhat compressed
to inflated; sculpturing often present in the form
of knobs, bumps, or ribs. Shell periostracum
and sculpturing often variable intraspecifically.
Periostracum usually yellowish-tan or green,  with
numerous dark green chevrons; streaking may also
be present (A). Beak slightly raised above hinge-
line; sculpture often eroded or indistinct (B). Teeth
well developed; lateral teeth very long and narrow
(C). Nacre white. Shell up to 5 inches in length.

Indicator use: A rare taxon throughout its range
(Williams et al. 1993; Natureserve), the Rabbitsfoot
is a unionid of clear, high quality streams (Oesch
1984). It is listed as endangered by several
midwestern states (IL, IN, KS, OH). A close relative
and Tennessee River endemic, Quadrula cylindrica
strigillata, is currently listed as federally endangered
(USFWS 2004).
    Butler (2005b) noted the elimination of Q.c.
cylindrica from 66% of the waterways where
it formerly occurred, although realistically  he
remarked that total range reductions and population
losses were closer to 90%. This dramatic decline
was primarily attributed to the inability of the
Rabbitsfoot to persist in impounded habitats and
tolerate cold hypolimnetic tailwater releases.
Other causal factors included channelization,
mining activities,  chemical contaminants, and
sedimentation (Butler 2005b).

Habitat:  Distributed throughout the upper and
lower Mississippi River basin and western Lake  Erie basin. Occurs in both moderate-sized
streams and rivers in swift flow at depths up to 12 feet (Parmalee and Bogan 1998). Most
abundant in sand, gravel, and cobble substrates. This interesting mussel does not exhibit the
burrowing tendencies of its congeners, preferring instead to rest on the substrate surface
(photo - upper right).

Reproduction: Identified hosts for Q.c. cylindrica  include the Blacktail Shiner, Spotfin
Shiner, and Rosyface Shiner (Barnhart and Baird 2000; Butler 2005b). Yeager and Neves
(1986) identified the Bigeye Chub, Spotfin Shiner, and Whitetail  Shiner as suitable hosts for
Q.c. strigillata, a Tennessee River basin endemic.
    The Rabbitsfoot packages its glochidia into lanceolate conglutinates, generally orange
or yellowish-brown in color (Ortmann 1919).
                                        82

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Pimpleback
Quadrula pustulosa pustulosa  (Lea, 1831)

Identification tips: Shell round or quadrate, thick, and
usually inflated. Periostracum yellowish-tan to brown
with few to numerous pustules (A). A conspicuous green
smudge or broken, wide green ray(s) present in young
individuals (B) less apparent or absent in adults (A) Beak
sculpture of indistinct lines; often eroded (C). Teeth well
developed and heavy (D). Nacre white. Shell up to 4
inches in length.

Indicator use: The Pimpleback tolerates a wide range
of substrates and adapts well to impounded conditions
(Oesch 1984; Parmalee and Bogan  1998; WDNR 2003).
ESI (2000) consistently reported Q.  pustulosa from the
navigational pools of the Upper Ohio River, where it
comprised 1.4% -18.4% of the mussel community.
    In Kansas, researchers utilized  tissue samples
from Q. pustulosa to  evaluate the bioavailability of
heavy metals in the Neosho River, home of the federally
threatened Neosho Madtom (Noturus placidus) (Allen et
al. 2001). Most of the metals of concern were found in low
concentrations.

Habitat:  A wideranging species, the Pimpleback occurs
in large streams, rivers, lakes, and reservoirs. It may be
found in both shallow and deep water (-20 ft.). Generally
most abundant in packed sand and  gravel.

Reproduction:  Identified host fishes include the
Shovelnose Sturgeon, Black Bullhead, Brown Bullhead,
Channel Catfish, Flathead Catfish, and White Crappie
(Surber 1916; Coker  1921). The reproductive period is
from June through August (Howard  1914).
                                       83

-------
         An Introduction to Freshwater Mussels as Biological Indicators
Mapleleaf
Quadrula quadrula
(Rafinesque, 1820)
Identification tips: Shell subquadrate, thick, and
slightly inflated. Two rows of pustules present on shell;
separated by a shallow to well-defined sulcus (A).
Small flute-like projections or bumps often present
on posterior slope and posterior-dorsal margin (B).
Periostracum yellowish-tan, brown, or dark brown;
green rays often present in younger individuals. Beak
sculpture of double-looped ridges; often eroded or
indistinct (C). Teeth well-developed (D); pseudocardinal
teeth may be large and heavy in older individuals.
Nacre white. Shell up to 6 inches in length.

Indicator use: The Mapleleaf is an adaptable species,
tolerant of (and perhaps exploiting) impoundment,
moderate levels  of turbidity, and a variety of
substrates (Oesch 1984; Parmalee and Bogan 1998;
Metcalfe-Smith et al. 2003; WDNR 2003). ESI (2000)
documented Q. quadrula as one of the most abundant
species in the navigational pools of the upper Ohio
River.
    The  Mapleleaf has been utilized extensively
as a biomonitor and surrogate to evaluate the
potential  impacts of industrial effluents and coal mine
discharges. In the early 1970s, Foster and Bates
(1978) employed juvenile Q. quadrula as in-stream
biomonitors of copper electroplating wastes in the
Muskingum River, OH. Body burdens as high as
20.64 ug Cu/g (10x background levels) were reported
for caged Q. quadrula 0.1 km below electroplating
discharges. Ultimately, the study concluded that
electroplating wastes were responsible for the
decimation of 60% and 39% of all mussels up to 5 km
and 21 km downstream, respectively.

Habitat:  Distributed throughout the Mississippi
River basin, Great Lakes-St. Lawrence drainage,  and
north in to Canada. Occurs in small to large rivers,
embayments, and lakes. Found in firm  of substrates of mud, sand, gravel, and
cobble at depths ranging from several inches to 30 ft.

Reproduction:  Identified host fishes include the Flathead Catfish and
Channel Catfish (Howard and Anson 1923; Schwebach et al. 2002). The
Mapleaf is tachytictic, with the reproductive period extending from May and
August (Baker 1928).
                                        84

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Creeper
Strophitus undulatus
(Say,  1817)
Identification tips: Shell highly variable; generally
subelliptical to subtrapezoidal, thin to moderately thick,
and compressed to inflated. Periostracum usually
light brown to dark brown (A); young individuals often
with bold green rays. Beak raised slightly above
hinge-line; sculpture of concentric, oblique ridges (B).
Pseudocardinal teeth  present as a thickened, indented
hinge (C). Lateral teeth also present as a thickened
hinge. Shell up to 4 inches in length.

Indicator use: Widely distributed and relatively
common, the Creeper is frequently described as a
tolerant species (Gordon and Layzer 1989; Walters
1995; Parmalee and Bogan 1998). Williams et al.
(1993) reported the conservation status of S. undulatus
as "currently stable".
    Harman (1997) utilized molluscan and
macroinvertebrate communities as indicators of water
quality and habitat degradation in Otsego Lake, NY.
Over a period of 25 years, he reported a decline in
molluscan and intolerant Ephemeroptera, Plecoptera
and Trichoptera (EPT) richness of 52.9% and 56.1%,
respectively. The Creeper was among the declining
bivalve species,  having been eliminated from two sites
where it formerly occurred.
    Pip (2002) utilized bivalves and  gastropods in
a water quality study of southern Lake Winnipeg,
Canada. Occurrences of S. undulatus were correlated
with lower lead values, while the Giant Floater
(Pyganodon grandis)  was linked to higher dissolved
solids and the Fatmucket (Lampsilis  siliquoidea) to
higher dissolved organic matter

Habitat:  Widespread in the Mississippi River basin,
Great Lakes-St.  Lawrence basin, and northern Atlantic
drainages. Occurs in creeks, rivers, and lakes in both
still waters and moderate current. Found in both coarse
and fine substrates.
Reproduction: Well over 30 fishes from 9 taxonomical families have been
confirmed hosts for the Creeper (Baker 1928; Hove 1995b; Hillegrass and Hove
1997; Hove 1997; Walters et al. 1998c; Wicklow and Beisheim 1998; Van Snik
Gray el al. 1999; 2002; Cliff 2001).
    The Creeper is bradyliclic, wilh Ihe reproduclive period extending from July
lo May (Baker 1928).
                                       85

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Pistolgrip
Tritogonia verrucosa
     (Rafinesque, 1820)
Identification tips:  Shell subquadrate,
somewhat compressed to moderately inflated,
and thick. Shell covered with numerous tubercles
anterior of the posterior ridge (A). Posterior with
wavy undulations or irregular flutes (B). Shell
periostracum dark green or yellowish-brown,
sometimes with V-shaped markings. Beak with
indistinct ridges and tubercles (C). Teeth well
developed and heavy (D). Nacre white (D). Shell
up to 8 inches in length.

Indicator use: While intolerant of pollution, the
Pistolgrip has demonstrated the ability to adapt
to a variety of habitat conditions (Walters 1995;
Parmalee and Bogan 1998). In the state of Ohio,
T. verrucosa strongly repopulated a decimated
stretch of the Scioto River following major sewage
treatment plant upgrades (Tetzloff and Akison
1999).

Habitat: Well distributed throughout the
Mississippi River basin and Alabama River
system. Generally found  in large streams where
substrates are comprised of stable sandy mud,
gravel, or cobble. May become abundant in
oxygen-rich riffles  and runs (Stansberry 1965).
Often found resting on the substrate surface.
Reproduction:
Brown Bullhead,
Catfish (Howells
andKurth 1998)
period, Pepi and
mantle dorsal to
with a blue-gray
Identified host fishes include the
Yellow Bullhead, and Flathead
1997; Pepi and Hove 1997; Hove
, During the glochidia release
Hove (1997) observed an inflated
the excurrent siphon, crenulated
edge (top right).
                                     86

-------
        An Introduction to Freshwater Mussels as Biological Indicators
Rainbow
Villosairis  (I. Lea, 1829)

Identification tips: General:  Shell elliptical and
elongate, somewhat thin to moderately thick, and
compressed to moderately inflated. Sexually dimorphic:
Females (A) inflated and obliquely flared or rounded
posteriorly, males (B) pointed posteriorly. Sexual
dimorphism may be cryptic in some specimens. General:
Periostracum yellowish-tan to light brown with broken or
solid bright green rays. Beak relatively even to slightly
raised above hinge-line; sculpture of erratic double-loops
(C). Teeth well developed, although somewhat small and
delicate. Nacre white. Shell up to 4 inches in length.

Indicator use: Although fairly widespread and abundant
(Williams et al. 1993), the Rainbow is reportedly
declining in some portions of its range (Metcalfe-Smith
et al. 2003; COSEWIC 2006). It generally inhabits
clean, well oxygenated stream reaches (Walters 1995;
Parmalee and Bogan 1998).
    The Rainbow has been used extensively as
a surrogate to evaluate the effects of various toxic
contaminants to freshwater mussels (e.g. Goudreau et
al. 1993; Jacobson et al. 1993; Jacobson et al. 1997;
Cherry et al. 2002; Mummert et al. 2003; Valenti et al.
2005; Valenti et al. 2006b; Wang et al. 2007a; 2007b).
GMAVs compiled and ranked by Augspurger et al.
(2003), Augspurger (2006), and March et al. (2007)
placed V. iris among the 15 most sensitive aquatic taxa
to copper and ammonia.

Habitat: Widespread in the upper Mississippi River
basin and Great Lakes basin. Occurs in creeks to small
rivers where the water is shallow and current sluggish to
moderately strong. May also be found  in lakes (Gordon
and Layzer 1989; Walters 1995). Most abundanl in
mixlures of sand, gravel, and cobble.
Reproduction:  Confirmed hosl fishes include Ihe Weslern
Mosquilofish, Rock Bass, Largemoulh Bass, Smallmoulh
Bass, Suwanee  Bass, and Spoiled Bass (Zale and Neves
1982; Neves el al. 1985).
    The Rainbow is bradyliclic, wilh Ihe reproduclive period
extending from July lo May (Orlmann 1919).
                                       87

-------
             An Introduction to Freshwater Mussels as Biological Indicators
CONSERVATION STATUS
Common Name
Mucket
Pheasantshell
Dwarf Wedaemussel
Elktoe
Threeridae
Purple Wartvback
Dromedary Pearlvmussel
Eastern Elliptic
Spike
Oyster Mussel
Northern Riffleshell
Tubercled Blossom
Wabash Piatoe
Pink Mucket
Plain Pocketbook
Wavvraved lampmussel
Fatmucket
White Heelsplitter
Flutedshell
Black Sandshell
Cumberland Moccasinshell
Threehorn Wartvback
Sheepnose
Clubshell
Ohio Piatoe
Round Piatoe
Kidnevshell
Fluted Kidnevshell
Giant Floater
Rabbitsfoot
Pimpleback
Mapleleaf
Creeper
Pistolarip
Rainbow
Scientific Name
Actinonaias liaamentina
Actinonaias pectorosa
Alasmidonta heterodon
Alasmidonta marainata
Amblema plicata
Cvclonaias tuberculata
Dromus dromas
Elliptic complanata
Elliptic dilatata
Epioblasma capsaeformis
Epioblasma torulosa ranaiana
Epioblasma torulosa torulosa
Fusconaia flava
Lampsilis abrupta
Lampsilis cardium
Lampsilis fasciola
Lampsilis siliauoidea
Lasmiaona complanata complanata
Lasmiaona costata
Liaumia recta
Medionidus conradicus
Obliauaria reflexa
Plethobasus cvphvus
Pleurobema clava
Pleurobema cordatum
Pleurobema sintoxia
Ptvchobranchus fasciolaris
Ptvchobranchus subtentum
Pvaanodon arandis
Quadrula cvlindrica cvlindrica
Quadrula pustulosa pustulosa
Quadrula Quadrula
Strophitus undulatus
Tritoaonia verrucosa
Villosa iris
Federal (1)
-
-
E
SC
-
-
E
-
-
E
E
E
-
E
-
-
-
-
-
-
-
-
C
E
SC
-
-
C
-
SC
-
-
-
-
-
Indiana (2)
-
-
-
-
-
-
-
-
-
-
E
-
-
E
-
SC
-
-
-
-
-
-
E
E
SC
-
SC
-
-
E
-
-
-
-
-
o"
.0
IS
O
-
-
-
SC
-



-
-
E
-
-
E
-
SC
-
-
-
T
-
T
E
E
E
SC
SC
-
-
E
-
-
-
-
-
Michigan (4)
-
-
-
SC
-



-
-
E
-
-
-
-
T
-
-
-
-
-
-
-
E
-
SC
-
-
-
-
-
-
-
-
SC
N. Carolina (5)
-
-
-
-
-
E
-
-
SC
-
-
-
-
-
-
SC
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
T
-
SC
S
re
'E
'5>
>
-
-
E
-
-
-
E
-
-
E
-
-
-
E
-
-
-
-
-
T
-
-
T
-
E
-
-
-
-
-
T
-
-
-
-
Natureserve (7)
G5
G4
G1G2
G4
G5
G5
G1
G5
G5
G1
G2T2
G2TX
G5
G2
G5
G5
G5
G5T5
G5
G5
G3G4
G5
G3
G2
G4
G4G5
G4G5
G2
G5
G3G4T3
G5
G5
G5
G4G5
G5Q
Williams et al. 1993
CS
SC
E
SC
CS
SC
E
CS
CS
E
E
E*
CS
E
SC
CS
CS
CS
CS
SC
SC
CS
T
E
SC
CS
CS
SC
CS
T
CS
CS
CS
CS
CS
        CS = Currently stable  SC = Special concern  C = Candidate species  T = Threatened  E = Endangered
             G5 = Secure  G4 = Apparently secure  G3 = Vulnerable   G2 = Imperiled   G1 = Critically imperiled
                             T = Infraspecific taxon X = Presumed extinct   Q = Questionable taxonomy
                     (1) U.S. Fish and Wildlife Service, report generated 12/04/2007
                     (2) Indiana Department of Natural Resources, last updated 9/2004
                     (3) Ohio Department of Natural Resources, last updated 9/2007
                     (4) Michigan Natural Features Inventory, last updated 7/2002
                     (5) North Carolina Wildlife Resources Commission
                     (6) Virginia Department of Inland Game and Fishes, last updated 7/24/06
                     (7) Natureserve, Accessed 12/04/2007
                                               88

-------
           An Introduction to Freshwater Mussels as Biological Indicators
GLOSSARY
Adductor muscles:  Muscles anterior and posterior that close the mussel shell.

Anterior:  Forward portion of the shell.

Beak: Raised area on the dorsal margin near hinge.

Beak sculpture: Small, textured patterns on the beak.

Chevron: A V-shaped marking on the periostracum.

Cumberlandian: An ecoregion that encompasses the Cumberland River and Tennessee
River basins. This guide follows the interpretation of Parmalee and Bogan  (1998) that
extends the region down to the mouth of both the Cumberland and Tennessee rivers.

Dorsal wing: An extension of a shell from the dorsal margin, posterior of the beak.

Extirpation: The elimination of a population from a certain geographic area.

Lateral teeth: The narrow, thin teeth located near the hinge-line.

Muscle scar: Impressions in the nacre where a muscle was previously attached.

Nacre:  The inside of the shell, often  pearly white, salmon, or purple.

Pallial line: A line present on the inner nacre where muscles previously attached the
mantle to the shell.

Periostracum: The outside layer of the shell or epidermis.

Posterior:  Rear portion of the shell.

Posterior ridge: A ridge extending from the beak to the posterior margin.

Pseudocardinal teeth: Located anterior of the lateral teeth near the hinge, often raised
and triangular.

Unionid: A freshwater mussel belonging to the family Unionidae.

Unionoid:  A freshwater mussel belonging to the order Unionoida.
                                       89

-------
            An Introduction to Freshwater Mussels as Biological Indicators
LITERATURE CITED
Abell, R.A., Olson, D.M., Dinerstein, E., and RT. Hurley. (2000). Freshwater Ecoregions of North
   America: A Conservation Assessment. Island  Press, Washington, DC. 368 pp.
Adams, T.G., Atchison, G.J., and R.J. Vetter. (1980). The impact of an industrially contaminated
   lake on heavy metal levels in its effluent stream. Hydrobiologia 69(1-2):187-193.
Adams, T.G., Atchison, G.J., and R.J. Vetter. (1981). The use of the three-ridge clam (Amblema
   perplicata) to monitor trace metal contamination. Hydrobiologia 83:67-72.
Ahlstedt, S.A. and J.D. Tuberville. (1997). Quantitative reassessment of the freshwater mussel
   fauna in the Clinch and Powell  Rivers, Tennessee and Virginia, in Cummings, K.S., Buchanan,
   A.C., Mayer, C.A., and Naimo, T.J., eds., Conservation and  management of freshwater mussels
   II, Proceedings of a Upper Mississippi River Conservation Committee symposium, October
   16-18, 1995, St.Louis, MO. p. 71-77.
Alabama Rivers Alliance (ARA), Hartfield, P., Freeman, M., Lydeard, C., and R. Haddock. (1999).
   The State of Alabama's Rivers: A Blueprint for the Conservation of Alabama's Freshwater River
   Ecosystems Through the 21st Century.
Alderman, J.A. (1990). Fusconaia masoni (Conrad, 1834). pp 63-65. In: A report on the
   conservation status of North Carolina's freshwater and terrestrial molluscan fauna. Scientific
   Council on Freshwater and Terrestrial Mollusks. Raleigh, NC.
Allen, G.T., Blackford, S.H., Tabor,  V.M., and M.S. Cringan. (2001). Metals, boron, selenium
   in Neosho Madtom in the Neosho River in Kansas, U.S.A. Environmental Monitoring and
   Assessment 66(1 ):1-21.
ASTM (American Society for Testing and Materials). (2006). Standard guide for conducting
   laboratory toxicity tests with freshwater mussels. In: Annual book of ASTM standards, Vol.
   11.06.  Philadelphia, PA. pp. 1393-1444.
Anderson, R.V. (1977). Concentration of cadmium, copper, lead, and zinc in six species of
   freshwater clams. Bulletin of Environmental Contamination and Toxicology 18(4):492-496.
Anthony, J.J. and J.A. Downing. (2001). Exploitation trajectory of a declining fauna: a century of
   freshwater mussel fisheries in North America. Canadian Journal of Fisheries and Aquatic
   Sciences 58(10): 2071 -2090.
Anthony, J.L., Kesler, D.H., Downing, W.L., and J.A. Downing. (2001). Length-specific growth
   rates in freshwater mussels (Bivalvia: Unionidae): extreme longevity or generalized growth
   cessation? Freshwater Biology 46:1349-1359.
Aspelin, A.L. (1994). Pesticide Industry Sales and Usage, 1992 and 1993 Market Estimates. U.S.
   Environmental Protection Agency. Washington, D.C. 33 pp.
Augspurger, T, Keller, A.E., Black, M.C., Cope, W.G., and F.J. Dwyer. (2003). Water quality
   guidance for protection of freshwater mussels (Unionidae) from  ammonia exposure.
   Environmental Toxicology and Chemistry 22(11 ):2569-2575.
Augspurger, T, Dwyer, J., and C. Ingersoll. (2006). Implications of including freshwater mussel
   toxicity data  in water quality criteria derivation datasets. Presentation # 724 at the 27th annual
   meeting of the Society of Environmental Toxicology and Chemistry, Montreal, Quebec,
   November 2006.
Badra, RJ. and R.R. Goforth. (2001). Surveys for the clubshell (Pleurobema clava) and other rare
   clams in Michigan: Final Report 2000. Report to U.S. Fish and Wildlife Region 3 Endangered
   Species Office. 52pp. + appendices.
                                          90

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Badra, RJ. and R.R. Goforth. (2002). Surveys of Native Freshwater Mussels in the Lower Reaches
   of Great Lakes Tributary Rivers in Michigan. Report number MNFI 2002-03. Report to Michigan
   Dept. of Environmental Quality, Coastal Zone Management Unit, Lansing, Ml. 39pp.
Baker, F.C. (1928). The fresh water Mollusca of Wisconsin. Part II. Pelecypoda. Bulletin of the
   Wisconsin Geological and Natural History Survey. University of Wisconsin. 70(2):vi 495 + 76
   plates.
Barfield, M.L. and G.T. Walters. (1998). Non-parasitic life cycle in the green floater, Lasmigona
   subviridis (Conrad, 1835).Triannual Unionid Report 16:22.
Barnhart, M.C., Riusech, F.A., and A.D. Roberts. (1997). Fish hosts of the federally endangered
   pink mucket, Lampsilis abrupta. Triannual Unionid Report 13:35.
Barnhart, M.C. and M.S. Baird. (2000). Fish hosts and culture of mussel species of special
   concern. Annual Report to U.S. Fish and Wildlife Service and Missouri Department of
   Conservation. 39 pp.
Barnhart, M.C. (2006). Unio Gallery:  http://unionid.missouristate.edu. Accessed 06/06/2007.
Bartsch, M.R., Newton, T.J., All ran, J.W., O'Donnell, J.A., and W.B. Richardson. (2003).
   Environmental Toxicology and Chemistry 22(1 1):2561 -2568.
Bates, J.M. (1962). The impact of impoundment on  the mussel fauna of Kentucky Reservoir,
   Tennessee River. American Midland Naturalist 68:232-236.
Bauer, G. (1987). Reproductive strategy of the freshwater pearl mussel Margaritifera margaritifera.
   Journal of Animal  Ecology 56:691-704.
Beckvar, N., Salazar, S., Salazar, M., and K. Finkelstein. (2000). An in-situ assessment of mercury
   contamination in the Sudbury River,  Massachusetts, using transplanted freshwater mussels
   (Elliptio complanata) . Canadian Journal of Fisheries and Aquatic Sciences 57:1 103-1 112.
Bedford, J.W., Roelofs, E.W., and  M.J. Zabik. (1968). The freshwater mussel as a biological
   monitor of pesticide concentrations in a lotic environment. Limnology and Oceanography
Bedford, J.W. and M.J. Zabik. (1973). Bioactive compounds in the aquatic environment: uptake and
   loss of DDT and dieldrin by freshwater mussels. Bulletin of Environmental Contamination and
   Toxicology 1:97-111.
Black, M.C.,  Ferrell, J.R., Horning, R.C., and LK. Martin. (1996). DNA strand breakage
   in freshwater mussels (Anodonta grandis) exposed to lead in the laboratory and field.
   Environmental Toxicology and Chemistry 15(5):802-808.
Black, M.C. (2001 ). Water Quality Standards for North Carolina's Endangered Mussels.
   Cooperative Agreement No. 1434-HQ-97-RU-01551.
Bloom, N.S. and Effler, S.W. (1990). Seasonal variability in the mercury speciation of Onondaga
   Lake (New York). Water, Air, and Soil Pollution 53:251-265.
Bogan, A.E. (1993). Freshwater bivalve extinctions (Mollusca: Unionoida): A search for causes.
   American Zoologist 33:599-609.
Bogan, A.E. (2002). Workbook and key to the freshwater bivalves of North Carolina. North Carolina
   Freshwater Mussel Conservation Partnership, Raleigh,  NC, 101 pp, 10 color plates.
Bogan, A.E. and J.M. Alderman. (2004). Workbook and  Key to the freshwater bivalves  of South
   Carolina. Available at: www.fs.fed.us/r8/fms/forest/publications/bivalves.pdf. 64 pp + plates.
Bringolf, R.B., Cope, W.G.,  Eads, C.B., Lazaro, PR., Barnhart, M.C., and D.  Shea. (2007a). Acute
   and chronic toxicity of technical-grade pesticides to  glochidia and juveniles of freshwater
   mussels (Unionidae). Environmental Toxicology and Chemistry 26(10):2086-2093.
Bringolf, R.B., Cope, W.G.,  Mosher, S., Barnhart, C., and D. Shea. (2007b). Acute and  chronic
   toxicity of glyphosate compounds to glochidia and juveniles of Lampsilis siliquoidea
   (Unionidae). Environmental Toxicology and Chemistry 26(1 0):2094-21 00.
                                          91

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Brown, M.E., Kowalewski, M., Neves, R.J., Cherry, D.S., and M.E. Schreiber. (2005). Freshwater
   mussel shells as environmental chronicles: Geochemical and taphonomic signatures of
   mercury-related extirpations in the North Fork Holston River, Virginia. Environmental Science
   and Technology 39:1455-1462.
Bruenderman, S.A. and R.J. Neves. (1993). Life history of the endangered fine-rayed pigtoe
   Fusconaia cuneolus (Bivalvia: Unionidae) in the Clinch River, Virginia. American Malacological
   Bulletin 10(1):83-91.
Buchanan, A.C. 1987. Aspects of the life history of the Curtis' pearly mussel, Epioblasma
   florentina curtisi (Utterback 1915). Final Report, Endangered Species Project SE-3-2, Missouri
   Department of Conservation, 21  pp.
Butler, R.S. (2002). Status assessment report for the Sheepsnose, Plethobasus cyphyus, occurring
   in the Mississippi River system (U.S. Fish and Wildlife Service Regions 3,4,5). U.S. Fish and
   Wildlife Service, Ohio River Ecosystem Team Mollusk Subgroup. 78 pp.
Butler, R.S. (2005a). Status assessment of the fluted kidneyshell (Ptychobranchus subtentum),
   candidate listing and priority assignment form. U.S. Fish and Wildlife Service. 15 pp.
Butler, R.S. (2005b). Status assessment report for the rabbitsfoot, Quadmla cylindrica cylindrica,
   a freshwater mussel occurring in the Mississippi River and Great Lakes Basins. U.S. Fish and
   Wildlife Service, prepared for the Ohio River Valley Ecosystem Team Mollusk Subgroup, 206
   pp.
Campbell, J. and R.D. Evans. (1991). Cadmium concentrations in the freshwater mussel
   (Elliptic complanata) and their relationship to water chemistry. Archives of Environmental
   Contamination and Toxicology 20(1 ):125-131.
Chamberland, G., Belanger, D., Lariviere, N., Vermette, L, Klaverkamp, J.F., and J.S. Biais.
   (1995). Abnormal poryphin profile in mussels exposed to low concentrations of cadmium in  an
   experimental Precambrian Shield lake. Canadian Journal of Fisheries and Aquatic Sciences
   52:186-1293.
Chatters, J.C., Butler, V.L, Scott, M.J., Anderson, D.M., and D.A. Neitzel.  (1995). A Pleistocene
   approach to estimating the effects of climatic warming on salmonid fisheries of the Columbia
   River basin. Canadian Special Publication of Journal Fisheries and Aquatic Sciences 121:489-
   496.
Chen, L.Y. (1998). The respiratory physiology and energy metabolism of freshwater mussels
   and their responses to back of oxygen. Dissertation submitted to the Faculty of the Virginia
   Polytechnic Institute and State University. 87 pp.
Cherry, D.S., Farris, J.L., and R.J. Neves. (1991). Laboratory and field ecotoxicological studies
   at the Clinch River Plant, Virginia Final Report to the American Electric Power Service
   Corporation, Virginia Polytechnic Institute State University, Columbus, OH. Blacksburg, VA. 228
   pp.
Cherry, D. S., Van Hassel, J.H., Farris, J.L., Soucek, D.J., and R. J. Neves. (2002). Site-Specific
   Derivation of the Acute Copper Criteria for the Clinch River, Virginia. Human and Ecological
   Risk Assessment 8(3):591 -601.
Cicerello, R.R. and G.A. Schuster. (2003). A guide to the freshwater mussels of Kentucky. Kentucky
   State Nature Preserves Commission Scientific and Technical Series 7:1-62.
Clark, H.W. and C.B.Wilson. (1912). The mussel fauna of the Maumee River.  U.S. Bureau of
   Fisheries Doc. 757. 72 pp.
Clarke, A.H. (1981). The freshwater molluscs of Canada. National Museum of Natural Sciences,
   National Museums of Canada, Ottawa, Canada. 446 pp.
Cliff, M., Hove, M., and M. Haas. (2001). Creeper glochidia appear to be host  generalists. Ellipsaria
   3(1):19-20.
                                           92

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Coale. K.H. and A.R. Flegal. (1989). Copper, zinc, cadmium, and lead in surface waters of Lakes
   Erie and Ontario. Science of the Total Environment 87/88:297-304.
Coker, R.E., A.R Shira, H.W. Clark, and A.D. Howard. (1921). Natural history and propagation of
   fresh-water mussels. Bulletin of the Bureau of Fisheries. [Issued separately as U.S. Bureau of
   Fisheries Document 893]. 37(1919-20):77-181 + 17 plates.
Coon, T.G., Eckblad, J.W., and P.W. Trygstad. (1977). Relative abundance and growth of mussels
   (Mollusca: Eulamellibranchia) in pools 8, 9, and 10 of the Mississippi River. Freshwater Biology
   7:279-85.
COSEWIC. (2006). COSEWIC assessment and status report on the rainbow mussel Villosa iris
   in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa, vii + 38 pp.
   (www.sararegistry.gc.ca/status/status_e.cfm).
Couillard, Y, Campbell, P.G., Tessier, A., Pellerin-Massicotte, J., and J.C. Auclair. (1995). Field
   transplantation of a freshwater bivalve, Pyganodon grandis, across  a metal contamination
   gradient. I. Temporal changes in metallothionein and metal (Cd, Cu, and Zn) concentrations in
   soft tissues. Canadian Journal of Fisheries and Aquatic Sciences 52:690-702.
Cummings, K.S. and C.A. Mayer. (1992). Field Guide to Freshwater Mussels of the Midwest. Illinois
   Natural History Survey Manual 5.194  pp.
Czarnezki, J.M. (1987). Use of the plain pocketbook mussel, Lampsilis  ventricosa, for monitoring
   heavy  metal pollution in an Ozark stream. Bulletin of Environmental Contamination and
   Toxicology 38(4):641 -646.
Dawley, C. (1947). Distribution of aquatic mollusks in Minnesota. American Midland  Naturalist
   38(3):671-6973.
Day,  K.E.,  Metcalfe, J.L., and S.P. Batchelor. (1990). Changes in intracellularfree amino acids in
   tissues of the caged mussel, Elliptic complanata, exposed to contaminated environments.
   Archives of Environmental Contamination and Toxicology 19:816-827.
Deacon, J.R., Soule, S.A., and T.E. Smith. (2005). Effects of urbanization on stream quality at
   selected sites in the Seacoast region in New Hampshire. 2001-03: U.S. Geological Survey
   Scientific Investigations Report 2005-5103.18 pp.
Dean, J., Edds,  D., Gillette, D., Howard, J., Sherraden, S., and J.Tiemann. (2002). Effects of
   lowhead dams on freshwater mussels  in the Neosho River, Kansas. Transactions of the
   Kansas Academy of Science 105(3-4):232-240.
Doran, W.J., Cope, W.G., Rada, R.G., and M.B. Sandheinrich. (2001). Acetlycholinesterase
   inhibition in the threeridge mussel (Amblema plicata) by chlorpyrifos: implications for
   biomonitoring. Ecotoxicology and Environmental Safety 49(1 ):91-98.
Draxler, B., Hove, M., Schieffer, S., Berg, M., Widiker, G., Sietman, B., Allen, D., and Hornback, D.
   (2006). Suitable Host Fishes for Fatmucket (Lampsilis siliquoidea) and Pocketbook (Lampsilis
   cardium). Evaluated by High School and University Researchers. Ellipsaria 8(1):12.
Ecological Specialists, Inc (ESI). (2000). Final Report: Freshwater Mussels (Bivalvia: Unionidae) of
   the Upper Ohio River. Prepared for: Mussel Mitigation Trust Fund Committee, Cincinnati, OH
   and U.S. Fish and Wildlife Service,  Cookeville, TN. 99 pp.
Eisler, R. (1985). Cadmium hazards to  fish, wildlife and invertebrates: A synoptic review,
   Washington D.C., U.S. Department of the Interior, Fish and Wildlife Service. Biological Report
   No. 85.
Ellis, M.M. (1942). Fresh-water impoundments. Transactions of the American Fisheries Soceity,
   71st Annual Meeting, 80-93. Evermann,  B.W., and H.W. Clark. 1918. The Unionidae of Lake
   Maxinkukee. Proceedings of the Indiana Academy of Science 1917:251-285.
                                           93

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Evermann, B.W. and H.W. Clark. (1918). The Unionidae of Lake Maxinkukee. Proceedings of the
   Indiana Academy of Science, 1917: 251-285. Evermann, B.W. and H.W. Clark. 1918. The
   Unionidae of Lake Maxinkukee. Proceedings of the Indiana Academy of Science, 1917:251 -
   285.
Foster, R.B. and J.M. Bates. (1978). Use of Freshwater Mussels to Monitor Point Source Industrial
   Discharges. Environmental Science and Technology 12(8):958-962.
Fuller, S.L.H. (1974). Clams and mussels (Mollusca: Bivalvia). pp. 215-273 in C.W. Hart, Jr. and
   S.L.H. Fuller (eds.) Pollution Ecology of Freshwater Invertebrates. Academic Press, New York.
   389 pp.
Fuller, S. (1985). Freshwater Mussels of the upper Mississippi River. Wisconsin Department of
   Natural Resources, Madison. (Revision by I. Brynildson).
Gagne, F, Blaise, C., Aoyama, I., Luo,  R.,  Gagnon, C., Couillard, Y, Campbell, P., and M. Salazar.
   (2002). Biomarker study of municipal effluent dispersion plume in two species of freshwater
   mussels. Environmental Toxicology 17(3):149-159.
Gatenby, C., Neves, R.J., and B.C. Parker. (1996). Influence of sediment and  algal food on cultured
   juvenile freshwater mussels. Journal of the North American Benthological Society 15(4):597-
   609.
Gewurtz, S.B., Drouillard,  K.G., Lazar,  R.,  and G.D. Haffner. (2002). Quantitative biomonitoring
   of PAHs using the Barnes mussel. Archives of Environmental Contamination and Toxicology
   43:497-504.
Gewurtz, S.B, Lazar, R., and G.D. Haffner. (2003). Biomonitoring of bioavailable PAH and PCB
   water concentrations in the Detroit  River using the freshwater mussel, Elliptic complanata.
   Journal of Great Lakes Research 29(2):242-255.
Gill, G.A. and K.W. Bruland. (1990). Mercury speciation in surface freshwater systems in California
   and other areas. Environmental Science and Technology 24:1392-1400.
(GLI) Great Lakes Institute. (1984). A case study of selected race contaminants in the Essex
   region. Univ. Windsor, Ann. Rep. Up-175, Vol. 1: Physical Sciences.
Goodman, M.H. (2007). A Mussel Index of Biotic Integrity. Thesis submitted to The Department of
   Life and Earth Sciences, Otterbein  College, Westerville, OH. 79 pp.
Goodrich, C., and H. van der Schalie. (1932). I. On an increase in the naiad fauna of Saginaw
   Bay Michigan. II. The naiad species of  the Great Lakes. Occasional papers of the Museum of
   Zoology, Number 238. University of Michigan, Ann Arbor, Michigan. 14 pp.
Gordon, M.E. and J.B. Layzer. (1989). Mussels (Bivalvia: Unionoidea) of the Cumberland River:
   review of life histories and ecological relationships. U.S. Fish and Wildlife Service Biological
   Report 89(15). 99 pp.
Gordon, M.E. and J.B. Layzer. (1993). Glochidial host of Alasmidonta atropurpurea (Bivalvia:
   Unionoidea, Unionidae). Transactions of the American Microscopical Society 112(2):145-150.
Goudreau, S.E., Neves, R.J., and S.J. Sheehan. (1993). Effects of wastewater treatment plant
   effluents on freshwater mollusks in the upper Clinch River, Virginia, USA. Hydrobiologia
   252:211-230.
Grabarkiewicz, J.D. and T.C. Crail. (2008). An examination of freshwater mussel recruitment in the
   West Branch St. Joseph River. Final Report to Ohio  Biological Survey. 20 pp.
Graf, D.L. and K.S. Cummings. (2007).  Review of the systematics and global diversity of freshwater
   mussel species (Bivalvia: Unionoida). Journal of Molluscan Studies 73:291-314.
Green, W.J., Canfield, D.E., Lee, G.F., and A.R. Jones. (1986). Mn, Fe, Cu, and Cd distributions
   and residence times in closed basin Lake Vanda (Wright Valley, Antarctica). Hydrobiologica
   134:237-248.
                                           94

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Haag, W.R. (2007). Biochronology of shell rings in freshwater mussels. Poster at All Scientist's
   Meeting 2007.
Haag, W.R. and J.L. Staton. (2003). Variation in fecundity and other reproductive traits in freshwater
   mussels. Freshwater Biology 48(12):2118-2130.
Haag, W.R. and M.L. Warren. (1997). Host fishes and reproductive biology of 6 freshwater mussel
   species from the Mobile basin, USA. Journal of the North American Benthological Society
   16(3):576-585.
Haag, W.R. and M.L. Warren. (1999). Mantle displays of freshwater mussels elicit attacks from fish.
   Freshwater Biology 42:35-40.
Haag, W.R. and M.L. Warren. (2003). Host fishes and infection strategies of freshwater mussels in
   large Mobile Basin streams, USA. Journal of the North American Benthological Society 22:78-
   91.
Haag, W.R. and M.L. Warren. (2006). Freshwater mussel assemblage structure in a regulated
   river in the Lower Mississippi River Alluvial Basin, USA. Aquatic Conservation: Marine and
   Freshwater Ecosystems 17(1):25-36.
Hansten, C., Heino, M., and K. Pynnonen. (1996). Viability of glochidia of Anodonta anatina
   (Unionidae) exposed to selected metals and chelating agents. Aquatic Toxicology 34:1-12.
Harman, W.N. (1997). Otsego Lake macrobenthos communities between 1968 and 1993:
   indicators of decreasing water quality. Journal of Freshwater Ecology 12(3):465-476.
Hartfield P. and E. Hartfield. (1996). Observations on the conglutinates of Ptychobranchus greeni
   (Conrad, 1834) (Mollusca: Bivalvia: Unionoidea). American Midland Naturalist 135:370-375.
Hartfield, P. and R. Jones. (1989). The status of Epioblasma penita, Pleurobema curtum, and P.
   taitianum in the East ForkTombigbee River -1988. Mississippi Museum  of Natural Sciences
   Technology Report 8.44 pp.
Havlik, M.E. and L.L. Marking. (1987). Effects of Contaminants on Naiad Mollusks (Unionidae): A
   Review. U.S. Department of the Interior, Fish and Wildlife Service, Resource Publication  164.
   Washington, D.C. 20pp.
Heit, M., Klusek, C.S., and K.M. Miller. (1980). Trace element, radionuclide, and polynuclear
   aromatic hydrocarbon concentrations in Unionidae mussels from northern Lake George.
   Environmental Science and Technology 14(4):465-468.
Hill, D.M. (1986). Cumberlandian Mollusks Conservation Program, activity 3: Identification of fish
   hosts. Office of Natural Resources and Economic Development, Tennessee Valley Authority,
   Knoxville. 57 pp.
Hillegrass, K.R. and M.C. Hove. (1997). Suitable fish hosts for glochidia of three freshwater
   mussels: squawfoot, ellipse, and snuffbox. Triannual Unionid Report 13:16.
Hoggarth, M.A., D.L. Rice, and D.L. Lee. (1995). Discovery of the Federally Endangered
   Freshwater Mussel, Epioblasma obliquata obliquata (Rafinesque, 1820)(Unionidae), in Ohio.
   Ohio Journal of Science 95(4):298-299.
Hoggarth, M.A., D.L. Rice, and T.L. Grove. (2000). The correlation of mussels with fish in the upper
   Blanchard River in Hardin and Hancock counties, Ohio, with special regard to the rayed bean
   (Villosa fabalis). Pp. 19-26 in: R.A.Tankersley, D.I. Warmolts, G.T. Walters, and B.J. Armitage,
   eds. Part I. Proceedings of the conservation, captive care, and propagation of freshwater
   mussels symposium, March 1998, Columbus, Ohio. Ohio Biological Survey, Columbus.
Hoggarth, M.A. and M.H. Goodman. (2007). Report on a reexamination of the mussels of the Little
   Miami River and it major tributaries: Final Report, end of year two. 77 pp.
Hove, M.C. (1995a). Host research on the round  pigtoe  glochidia. Triannual Unionid Report 8:8.
Hove, M.C. (1995b). Early life history research on the squawfoot, Strophitus undulatus. Triannual
   Unionid Report 7:28-29.
                                          95

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Hove, M.C., Engelking, R., Evers, E., Peteler, M., and E. Peterson. (1994a). Ligumia recta host fish
   suitability tests. Triannual Unionid Report 5:8.
Hove, M.C., Engelking, R.A., Evers,  E., Peteler, M.E., and E.M. Peterson. (1994b). Cyclonaias
   tuberculata host suitability tests. Triannual Unionid Report 5.1 pp.
Hove, M.C., Engelking, R.A., Long, E.M., Peteler, M.E.,  and E.M. Peterson. (1995). Life history
   research on the creek heelsplitter, Lasmigona compressa. Triannual Unionid Report No. 6 1 pp.
Hove, M.C., Engelking, R.A., Peteler, M.E., Peterson, E.M., Kapuscinski, A.R., Sovell, L.A., and
   E.R. Evers. (1997). Suitable fish hosts for glochidia of four freshwater mussels. Pages 21 -
   25 in: K.S. Cummings, A.C. Buchanan, C.A. Mayer, and T.J. Naimo (eds.). Conservation and
   Management of Freshwater Mussels  II. Proceedings of a UMRCC Symposium, 16-18 October
   1995, St. Louis, Missouri. 293 pp.
Hove, M.C., Kurth, J.E.,  and A.R. Kapuscinski. (1998). Brown bullhead suitable host for Tritogonia
   vermcosa; Cumberlandia monodonta host(s) remain elusive. Triannual  Unionid Report 15:13.
Hove, M.C., Medland, J., Cliff, P., Haas, M., Whaley, B.,  Woods, J. and A. Kapuscinski. (2001).
   Winged mapleleaf glochidial metamorphosis on channel catfish verified. Ellipsaria 3(1): 16-17.
Howard, A.D. (1914). Experiments in propagation of fresh-water mussels of the Quadrula group.
   Report of the U.S. Commissioner of Fisheries for 1913. Appendix 4:1-52 + 6 plates. [Issued
   separately as U.S. Bureau of Fisheries Document No. 801].
Howard, A.D. and B.J. Anson. (1922). Phases in the parasitism of the Unionidae. Journal of
   Parasitology 9(2):68-82 + 2 plates.
Howard, A.D. and B.J. Anson. (1923). Phases in the parasitism of the Unionidae. Journal of
   Parasitology 9(2):68-82 + 2 plates.
Howard, J.K. and K.M. Cuffey. (2006). The functional role of native freshwater mussels in the fluvial
   benthic environment. Freshwater Biology 51:460-474.
Howe, H. (1900). Historical collections of Ohio. C.J. Krehbiel and Co., Cincinnati:!-992 and 2:1-
   911.
Howells, R.G. (1997). New fish hosts for nine freshwater mussels (Bivalvia: Unionidae) in Texas.
   Texas Journal of Science 49(3):255-258.
Hughes, M.H. and P.W. Parmalee. (1999). Prehistoric and modern freshwater mussel (mollusca:
   bivalvia) faunas of the Tennessee River: Alabama, Kentucky, and Tennessee. Regulated
   Rivers: Research and Management 15:24-42.
Huynh-Ngoc, L., Whitehead, N.E., and B. Oregioni. (1998a). Cadmium in the Rhone River. Water
   Resources 22:571-576.
Huynh-Ngoc, L., Whitehead, N.E., and B. Oregioni. (1998b). Low levels of copper and lead in a
   highly industrialized  river. Toxicology and Environmental Chemistry 17:223-236.
Imlay, M.J. (1982). The use of shells  of freshwater mussels in monitoring heavy metals and
   environmental stresses: a review. Malacological Review 15:1-14.
Jacobson, P.J., Farris, J.L., Cherry, D.S.,  and R.J. Neves. (1993). Juvenile freshwater mussel
   (Bivalvia:Unionidae) responses to acute toxicity testing with copper. Environmental Toxicology
   and Chemistry 12:879-883.
Jacobson, P.J., Farris, J.L, Neves, R.J., and D.S. Cherry. (1997). Sensitivity of Glochidia Stages of
   Freshwater Mussels to Copper. Journal of Aquatic Toxicology 16:2384-2392.
Jenner, H.A., Hemelraad, J., Marquenie,  J.M., and  F. Noppert. (1991). Cadmium kinetics in
   freshwater clams (Unionidae) under field and laboratory conditions. Science of the Total
   Environment  108:205-241.
Johnson, R.I. (1970). The systematics and zoogeography of the Unionidae (Mollusca: Bivalvia)
   of the southern Atlantic Slope region. Bulletin of the Museum of Comparative Zoology
   140(6):263-449.
                                           96

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Jones, J.W., Neves, F.J., Ahlstedt, S.A., and R.A. Mair. (2004). Life history and propagation of the
   endangered dromedary pearlymussel (Dromus dramas) (Bivalvia:Unionidae). Journal of the
   North American Benthiological Society 23(3):515-525.
Karr, J.R., and D.R. Dudley. (1981). Ecological perspective on water quality goals. Environmental
   Management 5:55-68.
Kearns, B.L. and J.R. Karr. (1994). A benthic index of biotic integrity (B-IBI) for rivers of the
   Tennessee Valley. Ecological Applications 4:768-785.
Keferl, E.P. (1991). A Status Survey for the Carolina heelsplitter (Lasmigona decorata), a
   Freshwater Mussel Endemic to the Carolinas. Unpublished report to the U.S. Department of
   the Interior, Fish and Wildlife Service. 51 pp
Keller, A.E. (1993). Acute toxicity of several pesticides, organic compounds, and a wastewater
   effluent to the freshwater mussel, Anondonta imbecillis, Ceriodaphnia dubia, and Pimephales
   promelas. Environmental Contamination and Toxicology 51:696-702.
Keller, A.E. and T. Augspurger. (2005). Toxicity of fluoride to the endangered unionid mussel,
   Alasmidonta raveneliana, and surrogate species. Bulletin of Environmental Contamination and
   Toxicology 74:242-249.
Keller, A.E., and D.S.  Ruessler. (1997). The toxicity of  malathion to unionid mussels: relationship to
   expected environmental concentrations. Environmental Toxicology and Chemistry 16(5): 1028-
   1033.
Khym, J.R. and J.B. Layzer. (2000). Host fish suitability for glochidia of Ligumia recta. The
   American Midland Naturalist 143:178-184.
Kidd,  B.T. (1973). Unionidae of the Grand River drainage, Ontario, Canada. M.Sc. thesis, Carleton
   University, Ottawa, ON.
Kraemer, L.R. (1970). The mantle flap in three species of Lampsilis (Pelecypoda: Unionidae).
   Malacologia10(1):225-282.
Landres, P.B., Verner, J., and  J.W.Thomas. (1988). Ecological uses of vertebrate indicator species:
   a critique. Conservation Biology 2(4):316-328.
LaRoe, E.T., Farris, G.S., Puckett, C.E., Doran, P.O., and M.J. Mac, eds. (1995). Our living
   resources: a report to the nation on the distribution, abundance, and health of U.S. plants,
   animals, and ecosystems. U.S. Department of the Interior, National Biological Service,
   Washington, DC. 530 pp.
Lasee, B.A. (1991). Histological and ultrastructural studies of larval and juvenile Lampsilis
   (Bivalvia) from the Upper  Mississippi River. PhD Dissertation, Iowa State University, Ames,  IA.
Layzer, J.B., Adair, B., Saha, S.,  and L.M. Woods. (2003). Glochidial hosts and other aspects of the
   life history of the Cumberland pigtoe (Pleurobema gibberum). Southeastern Naturalist 2:73-84.
Layzer, J.B. and J.R. Khym. (2005). Fish hosts for glochidia of the pheasantshell, Actinonaias
   pectorosa. Walkerana  14(31 ):79-85.
Lefevre, G. and W.C. Curtis. (1910). Reproduction and parasitism in the Unionidae. Journal of
   Experimental Zoology 9(1 ):79-115 + 5  plates.
Lefevre, G., and W.C. Curtis. (1912). Studies on the reproduction and artificial propagation of
   fresh-water mussels. Bulletin of the Bureau of Fisheries. 30(1910):105-201 + 12 plates. [Issued
   separately as U.S. Bureau of Fisheries Document 756. Reprinted  in Sterkiana 47, 48 (1972);
   49,51 (1973); 57 (1975); and 61, 63, 64 (1976)].
Lellis, W.A. and T.L. King. (1998). Release of metamorphosed juveniles by the green floater,
   Lasmigona subviridis. Triannual Unionid Report 16:23.
Levengood, J.M., Soucek, D.J., Esarey, J., Hudson, R.J., Wimer, W., and R.S. Halbrook. (2004).
   Contaminants in Mussels from the Mississippi and Illinois Rivers Confluence Area. Final
   Report to the National Great Rivers Research and Education Center. 35pp.
                                           97

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Lewis, J. (1868). Remarks on the mollusks of the Valley of the Mohawk. American Journal of
   Conchology 4:241-145.
Luo, M. (1993). Host fishes of four species of freshwater mussels and development of an immune
   response. Unpublished M.S. thesis in Biology, Tennessee Technological University, Cookeville.
   v + 32 pp.
Luo, M. and J.B. Layzer. (1993). Host fish of three freshwater mussels. (Abstract), pp. 182 in
   K.S. Cummings, A.C. Buchanan, and L.M. Koch. (eds.). Conservation and Management of
   Freshwater Mussels. Proceedings of a UMRCC Symposium, 12-14 October 1992, St. Louis,
   Missouri. Upper Mississippi River Conservation Committee, Rock Island, Illinois. 189 pp.
Luoma, S.N. (1989). Can we determine the biological availability of sediment-bound trace
   elements? Hydrobiologia 176-177(1 ):379-396.
Malley, D.F., Stewart, A.R., and B.D. Hall. (1996). Uptake of methyl mercury by the floater mussel,
   Pyganodon grandis (Bivalvia:Unionidae), caged in a flooded wetland. Environmental Toxicology
   and Chemistry 15(6):928-936.
March, F.A., Dwyer, F.J., Augspurger, A., Ingersoll, C.G., Wang, N., and C.A. Mebane. (2007). An
   evaluation of freshwater mussel toxicity data in the derivation of water quality guidance and
   standards for copper. Environmental Toxicology and Chemistry 26(10):2066-2074.
Marking, L.L. and T.D. Bills. (1979). Acute effects of silt and sand sedimentation on freshwater
   mussels. Pp. 204-211 in: J.R. Rasmussen, ed. Proceedings of the UMRCC symposium on
   Upper Mississippi River bivalve mollusks. Upper Mississippi River Conservation Committee,
   Rock Island, Illinois
Martel, P., Kovacs, T, Voss, R., and S. Megraw. (2003). Evaluation of caged freshwater mussels
   as an alternative method for environmental effects monitoring (EEM) studies. Environmental
   Pollution 124:471-483.
Master, L.L. (1986). Alasmidonta heterodon:  results of a global status survey and proposal  to list
   as an endangered species. A report submitted to  region 5 of the U.S. Fish and Wildlife Service,
   Hadley, MA. 10 pp.
Master, L.L., Stein, B.A., Kutner, S., and G.A. Hammerson. (2000). Vanishing assets: Conservation
   status of U.S. species. Pages 93-118 in B.A. Stein, L.S. Kutner, and J.S. Adams (eds.).
   Precious Heritage: The status of biodiversity in the United States. Oxford University Press,
   New York.
McCann, M.T. (1993). Toxicity of zinc, copper, and sediments to early life stages of freshwater
   mussels in the Powell River, Virginia. M.S. Thesis, Virginia Polytechnic Institute and State
   University, Blacksburg, Virginia. 143 pp.
McGill, M., Hove. M., Diedrich, T, Nelson, C., Taylor, W. and A. Kapuscinski. (2002). Several fishes
   are suitable hosts for creek heelspiltter glochidia.  Ellipsaria 4(2): 18-19.
McLaine, D.C. and M.R. Ross. (2005). Reproduction based on local patch  size of Alasmidonta
   heterodon and dispersal  by its darter host in the Mill River, Massachusetts, USA. Journal of the
   North American Benthological Society 24:138-147.
McRae, S.E., Allan, J.D., and J.B. Burch. (2004). Reach and catchment-scale determinants of
   the distribution of freshwater mussels (Bivalvia: Unionidae) in south-eastern Michigan,  U.S.A.
   Freshwater Biology 49:127-142.
Metcalfe-Smith, J.L. (1994). Influence of species and  sex on metal residues in freshwater mussels
   (family Unionidae) from the St. Lawrence River, with implications for biomonitoring programs.
   Environmental Toxicology and Chemistry 13(9): 1433-1443.
Metcalfe-Smith, J.L. and B. Cudmore-Vokey. (2004). National general status assessment of
   freshwater mussels (Unionacea). National Water Research Institute/NWRI  Contribution No. 04-
   027. Environment Canada,  March 2004.
                                           98

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Metcalfe-Smith, J.L. and R.H. Green. (1992). Ageing studies on three species of freshwater
   mussels from a metal-polluted watershed in Nova Scotia, Canada. Canadian Journal of
   Zoology 70:1284-1291.
Metcalfe-Smith, J.L., Maio, J.D., Staton, S.K., and S.R. Desolla. (2003). Status of the Freshwater
   Mussel Communities of the Sydenham River, Ontario, Canada. The American Midland
   Naturalist 150(1 ):37-50.
Metcalfe-Smith, J.L., Staton, S.K., Mackie, G.L, and I.M. Scott. (1999). Range, population stability
   and environmental requirements of rare species of freshwater mussels in southern Ontario.
   NWRI Contribution No. 99-058. Environment Canada, National Water Research Institute,
   Burlington,  Ontario.
Michaelson, D.L. and R.J. Neves. (1995). Life history and habitat of the endangered dwarf
   wedgemussel Alasmodonta heterodon (Bivalvia: Unionidae). Journal of the North American
   Benthological Society 14(2):324-340.
Mierzykowski S.E. and K.C. Carr. (2001). Total mercury and methyl mercury in freshwater mussels
   (Elliptic complanata) from the Sudbury River watershed, Massachusetts. USFWS. Special
   Project Report FY98-MEFO-2-EC. Old Town, ME.
Milam, C.D. and J.L.  Farris. (1998). Risk identification associated with iron-dominated mine
   discharges  and their effect upon freshwater bivalves. Environmental Toxicology and Chemistry
   17:1611-1619.
Milam, C.D., Farris, J.L., Dwyer, F.J., and O.K. Hardesty. (2005). Acute toxicity of six freshwater
   mussel species (glochidia) to six chemicals: implications for daphnids and Utterbackia
   imbecillis as surrogates for protection of freshwater mussels (Unionidae). Archives of
   Environmental Contamination and Toxicology 48(2):166-173.
Moorman, J.R.  and M.E. Gordon. (1993). Identification of a glochidial host for Alasmidonta
   raveneliana (Bivalvia: Unionoidea). (Abstract). Bulletin of the North American Benthological
   Society 10(1 ):198.
Moulton, C.A.,  Fleming, W.J., and C.E. Purnell. (1996). Effects of two cholinesterase-inhibiting
   pesticides on freshwater mussels. Environmental Toxicology and Chemistry 15(2):131-137.
Mummert, A.K., Neves, R.J., Newcomb, T.J., and D.S. Cherry. (2003). Sensitivity to juvenile
   freshwater  mussels (Lampsilis fasciola, Villosa iris) to total and un-ionized ammonia.
   Environmental Toxicology and Chemistry 22(11 ):2545-2553.
Naimo, T.J. (1995). A review of the effects of heavy metals on freshwater mussels. Ecotoxicology
   4:341-362.
Naimo, T.J., Atchison, G.J., and L.E. Holland-Bartels. (1992a). Sublethal effects of cadmium
   on physiological responses in the pocketbook mussel, Lampsilis ventricosa. Environmental
   Toxicology and Chemistry 11:1013-1021.
Naimo, T.J., Waller, D. and L.E. Holland- Bartels. (1992b). Heavy metals in the threeridge mussel
   Amblema plicata plicata (Say, 1817) in the Upper Mississippi River. Journal of Freshwater
   Ecology 7:209-218.
NatureServe. (2008). Invertebrate Records in NatureServe Explorer (Native and Exotic). Version
   7.0, February 2008. http://www.natureserve.org/explorer/suminvert.htm
Nedeau, E.J. (2008). Freshwater Mussels and the Connecticut River Watershed. Connecticut River
   Watershed  Council, Greenfield, Massachusetts, xviii +132 pp.
Nedeau, E.J., McCollough, M.A., and B.I. Swartz. (2000). The freshwater mussels of Maine. Maine
   Department of Inland Fisheries and Wildlife, Augusta, Maine. 118 pp.
Nedeau, E.J. and J.Victoria. (2003). A Field Guide to the Freshwater Mussels of Connecticut.
   Connecticut Department of Environmental Protection, Hartford, CT. 31 pp.
                                          99

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Nelapa, T.F., Gardner, W.S., and J.M. Malczyk. (1991). Phosphorus cycling by mussels (Unionidae:
   Bivalvia) in Lake St. Clair. Hydrobologia 219:239-250.
Neves, R.J. (1993). A state-of-the-unionids address. Pp. 1 -10 In: S. K. Cummings, A.C. Buchanan,
   and L.M. Koch, editors. Conservation and management of freshwater mussels.
Neves, R.J., Bogan, A.E., Williams, J.D., Ahlstedt, S.A., and RW. Hartfield. (1997). Status of
   aquatic mollusks in the southeastern United States: A downward spiral of diversity. Pp.
   43-86 in: Aquatic Fauna in Peril: The Southeastern Perspective (Benz GW, Collins DE,
   editors). Special Publication 1,  Southeast Aquatic Research Institute, Lenz Design and
   Communications, Decatur, GA. Proceedings of a UMRCC symposium, 12-14 October 1992,
   St. Louis, Missouri. Upper Mississippi River Conservation Committee, Rock Island, Illinois.
Neves, R.J. and M.C. Odom. (1989). Muskrat Predation on Endangered Freshwater Mussels in
   Virginia. The Journal of Wildlife Management 53(4):934-941.
Neves, R.J., Weaver, L.R., and A.V. Zale. (1985). An evaluation of host suitability for glochidia
   of Villosa vanuxemiand V. nebulosa (Pelecypoda: Unionidae). American Midland Naturalist
   113:13-19.
Newton, T.J., Allran, J.W., O'Donnell, J.A., Bartsch, M.R., and W.B. Richardson. (2003). Effects of
   Ammonia  on juvenile unionid mussels (Lampsilis cardium) in laboratory sediment toxicity tests.
   Environmental Toxicology and Chemistry 22(11 ):2554-2560.
Newton, T.J., and M.R. Bartsch. (2007). Lethal and sublethal effects of ammonia to juvenile
   Lampsilis mussels (Unionidae) in sediment and water-only exposures. Environmental
   Toxicology and Chemistry 26(10):2057-2065.
O'Brien, D.J.,  Kaneene, J.B., and R.H. Poppenga. (1993). The Use of Mammals as Sentinels
   for Human Exposure to Toxic Contaminants in the Environment. Environmental Health
   Perspectives 99: 351-368.
O'Rourke, S.,  Drouillard, K.G., and G.D. Haffner. (2004). Determination of laboratory and field
   elimination rates of polychlorinated biphenyls (PCBs) in the freshwater mussel, Elliptic
   complanata. Archives of Environmental Contamination and Toxicology 47:74-83.
Obermeyer, B.K. (1998). A comparison of quadrats versus timed snorkel searches for assessing
   freshwater mussels. American  Midland Naturalist 139(2):331-339.
O'Dee, S.H. and G.T. Walters. (2000). New or confirmed host identifications for ten freshwater
   mussels. Pp. 77-82, [in:] Tankersley, R.A., Warmoltz, D.I., Walters, G.T, Armitage, B.J.,
   Johnson, P.O. and  R.S. Buller. Freshwater Mollusk Symposium Proceedings, Ohio Biological
   Survey, Columbus.
Oesch, R.D. (1984). Missouri Naiades: A guide lo Ihe mussels of Missouri. Missouri Deparlmenl of
   Conservalion, Jefferson Cily. 270 pp.
Orlmann, A.E. (1909). The deslruclion of Ihe fresh-waler fauna in western Pennsylvania.
   Proceedings of Ihe American Philosophical Society 48(191 ):90-110.
Orlmann, A.E. (1912). Notes upon  Ihe families and genera of najades. Annals of Ihe Carnegie
   Museum 8:222-366.
Orlmann, A.E. (1918). The naiades (freshwater mussels) of Ihe upper Tennessee drainage wilh
   notes on synonymy and dislribulion. Proceedings of Ihe American Philosophical. Society,
   Philadelphia 57:521-626.
Orlmann, A.E. (1919). Monograph  of Ihe naiades of Pennsylvania. Parl III. Syslemalic accounl of
   Ihe genera and species. Memoirs of Ihe Carnegie Museum, 8(1): 1-385.
Orlmann, A.E. (1921). The analomy of certain mussels from Ihe Upper Tennessee. The Naulilus
   34(3):81-91.
Orlmann, A.E. (1924). The naiad fauna of Duck River in Tennessee. American Midland Naluralisl
   9:18-62.
                                          100

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Ortmann, A.E. (1925). The naiad fauna of the Tennessee River system below Walden Gorge. The
   American Midland Naturalist 9(8):321-372.
ORVET (Ohio River Valley Ecosystem Team). Draft Protocol For Mussel Surveys in the Ohio River
   Where Dredging/Disposal/ Development Activity Is Proposed. Ohio River Valley Ecosystem
   Mollusk Subgroup (clarified April 2004). 4 pp.
Parmalee, RW. and A.E. Bogan. (1998). The Freshwater Mussels of Tennessee. The University of
   Tennessee Press, Knoxville, Tennessee. 328 pp.
Parmalee, RW. and M.H. Hughes. (1994). Freshwater mussels (Bivalvia: Unionidae) of the
   Hiwassee River in east Tennessee. American Malacological Bulletin 11(1):21-27.
Parmalee, P.W., Klippel, W.E., and A.E. Bogan. (1980). Notes  on the prehistoric and present status
   of the naiad  fauna on the middle Cumberland River, Smith County, Tennessee. The Nautilus
   94(3):93-105.
Payne, B.S. and A.C. Miller. (2001). Status of freshwater mussels in the lower Ohio River in relation
   totheOlmsted Locks and Dam  Project: 1999 studies, ERDC/ELTR-01-12, U.S. Army Engineer
   Research and Development Center, Vicksburg, MS.
Peacock, E., Haag, W.R., and W.L. Warren. (2005). Prehistoric decline in freshwater mussels
   coincident with the advent of maize agriculture. Conservation Biology 19(2):547-551.
Pearse, A.S. (1924). The parasites of lake fishes. Transactions of the Wisconsin Academy of
   Sciences, Arts and Letters 21:161-194.
Pepi, V.E. and M.C. Hove. (1997). Suitable fish hosts and mantle display behavior of Tritogonia
   verrucosa. Triannual Unionid Report (11):5.
Perceval, O., Pinel-Alloul, B., Methot, G., Couillard, Y, Giguere, A., Campbell, P.G., and L
   Hare. (2002). Cadmium accumulation and metallothionein sythesis in freshwater bivalves
   (Pyganodon grandis): relative influence of the metal exposure gradient versus limnological
   variability. Environmental Pollution 118:5-17.
Perry, C.M., Gauvin, J.M., and H.D. Booth. (1980). C-labeled PCB uptake in the freshwater clam,
   Anodonta grandis. Michigan Academician:213-219.
Pip, E. (1995). Cadmium, lead and copper in freshwater mussels from the Assiniboine River,
   Manitoba, Canada. Journal of Molluscan Studies 61:295-302.
Pip, E. (2006). Littoral mollusc communities and water quality  in southern Lake Winnipeg,
   Manitoba, Canada. Biodiversity and Conservation 15(11):3637-3652.
Price, J. (2006). South Carolina Department of Natural Resources website. Accessed 10/12/2007
   [http://www.dnr.sc.gov/cwcs/pdf/AtlanticPigtoe.pdf\.
Pritchard, J. (2001). An historical analysis of mussel propagation and culture: research performed
   at the Fairport Biological Station. Contract No. DACW-25-01-M-0312, U.S. Army Corps of
   Engineers, Rock Island, IL. 76 pp + attachments.
Pugsley, C.W., Herbert, P.D.N., Wood, G.W., Brotea, G., and T.W. Obal. (1985). Distribution
   of contaminants in clams and sediments from the Huron-Erie corridor. I - PCBs and
   Octachlorostyrene. J. Great Lakes Research. 11:275-289.
Raikow, D.F. and S.K. Hamilton. (2001). Bivalve diets in a midwestern U.S. stream: A stable isotope
   enrichment study. Limnology and Oceanography 46:514-522.
Ravera, O., Cenci, R., Beone, G.M., Dantas, M., and P. Lodigiani. (2003). Trace element
   concentrations in freshwater mussels and macrophytes as related to those in their environment.
   Journal of Limnology 62(1 ):61-70.
Ravera, O., Trincherini, P.R., Beone, G.M., and B. Maiolini. (2005). The trend from 1934 to 2001  of
   metal concentrations in bivalve shells (Unio pictorum) from two small lakes: Lake Levico and
   Lake Caldonazzo (Trento Province, Northern Italy). Journal of Limnology 64(2): 113-118.
                                          101

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Ray, R.H. (1977). Application of an acetate peal technique to analysis of growth processes in
    bivalve unionid shells. Bulletin of the American Malacological Union 44:79-82.
Renaud, C.B., Kaiser, K.L.E., Comba, M.E., and J.L. Metcalfe-Smith. (1995). Comparison between
    lamprey ammocoetes and bivalve molluscs as biomonitors of organochlorine contaminants.
    Canadian Journal of Fisheries and Aquatic Sciences 52:276-282.
Roe, K.J. (2002). Conservation Assessment for the Ohio Pigtoe (Pleurobema cordatum),
    Rafinesque, 1820. USDA Forest Service Eastern Region. 10 pp.
Rogers, S.O., Watsons, B.T., and R.J. Neves. (2001). Life history and population biology of the
    endangered tan riffleshell (Epioblasma florentina walker!) (Bivalvia:Unionidae). Journal of the
    North American Benthological Society 20(4):582-594.
Roy, A.M., Rosemond, A.D., Paul, M.J., Leigh, D.S., and J.B.Wallace. (2003). Stream
    macroinvertebrate response to catchment urbanisation (Georgia, U.S.A.). Freshwater Biology
    48(2):329-346.
Scheller, J.L. (1997). The Effect of Dieoffs of Asian Clams (Corbicula fluminea) on Native
    Freshwater Mussels (Unionidae). Master's Thesis, Virginia Tech University, Blacksburg, VA. 92
    pp.
Schloesser, D.W., Metcalfe-Smith, J.L., Kovalak, W.R, Longton, G.D., and R.D. Smithee. (2006).
    Extirpation of freshwater mussels (Bivalvia: Unionidae) following the invasion of dreissenid
    mussels in an interconnecting river of the Laurentian Great Lakes. American Midland  Naturalist
    155:307-320.
Schulz, C. and K. Marbain. (1998). Hosts species for rare freshwater  mussels in Virginia. Triannual
    Unionid report (15):32-38.
Schwebach, M., Schriever, D.,  Kanodia, V, Dillon, N., Hove, M., McGill, M., Nelson, C., Thomas,
    J., and A. Kapuscinski. (2002). Channel catfish is a suitable host for Mapleleaf glochidia.
    Ellipsaria4:12-13.
Sherman, R.A. (1993). Glochidial release and reproduction of the snuffbox mussel, Epioblasma
    triquetra; timing in southern Michigan. Abstract. Bulletin of the North American Benthological
    Society 10(1 ):197.
Shiller, A.M. and E. Boyle. (1985). Dissolved zinc in rivers. Nature 317:49-52.
Sietman,  B.E. (2003). Field Guide to the Freshwater Mussels of Minnesota. State of Minnesota,
    Department of Natural Resources. 144pp.
Simmons, G.M.  and J.R.  Reed. (1973). Mussels as indicators of biological zone recovery.  Water
    Pollution Control Federation 45(12):2480-2492.
Simpson, C.T. (1900). Synopsis of the naiads, or pearly fresh-water mussels. Proceedings of the
    United States National Museum  22(1205):501-1044.
Smith, D.R. (2006). Survey design for detecting  rare freshwater mussels. Journal of the North
    American Benthological Society  25(3):701 -711.
Smith, D.R., Villella, R.F., and D.R Lemarie. (2001 a). Survey protocol for assessment of
    endangered freshwater mussels in the Allegheny River, Pennsylvania. Journal of the North
    American Benthological Society  20:118-132.
Smith, David R., Villella, Rita F, Lemarie, D.R, and S. von Oettingen. (2001 b). How much
    excavation is needed to monitor  freshwater mussels? In RD. Johnson and R.S. Butler (editors).
    Proceedings of the first symposium of the Freshwater Mollusk Conservation Society. Ohio
    Biological Survey, Columbus, Ohio.
Spooner, D.E., Vaughn, C.V., and H.S. Galbraith. (2005). Physiological determination of mussel
    sensitivity to water management practices in the Kiamichi River and review and summarization
    of literature pertaining to mussels of the Kiamichi and Little River watersheds, Oklahoma.
    Submitted to the Oklahoma Department of Wildlife Conservation, Oklahoma City, OK. 53 pp.
                                           102

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Stansbery, D.H. (1965). Changes in naiad fauna of the Cumberland River at Cumberland Falls in
   eastern Kentucky. American Malacological Union Annual Report 1965:16-17.
Stansberry, D.H. (1970). Eastern freshwater mollusks (I) The Mississippi and St. Lawerence River
   systems. Malacologia 10(1):9-22.
Stansberry, D.H and C.B. Stein. Stream channelization and the preservation of biological variability:
   why naiads (pearly freshwater mussels) should be preserved. Reprinted from Stream
   Channelization (Part 4). Hearings before a subcommittee of the Committee on Government
   Operations,  House of Representatives, Ninety-Second Congress, first session, June 14,
   1971:2177-2179.
Starrett, W.C. (1971). A Survey of the Mussels (Unionacea) of the Illinois River: A Polluted Stream,
   Illinois Natural History Survey Bulletin 20(5):267-403.
Steg, M.B. and R.J. Neves. (1997). Fish host identification for Virginia listed unionids in the upper
   Tennessee River drainage. Triannual Unionid Report (13):34.
Stein, C.B. (1968). Studies in the life history of naiad, Amblema plicata (Say, 1817). Annual Report,
   American Malacological Union for 1968:46-47.
Stepenuck, K.F., Crunkilton, R.L., and L.Wang. (2002). Impacts of urban land use on
   macroinvertebrate communities in southeastern Wisconsin streams. Journal of the American
   Water Resources Association 38(4):1041-1051.
Stern, E.M. and D.L. Felder. (1978). Identification of host fishes for four species of freshwater
   mussels (Bivalvia: Unionidae). American Midland Naturalist 100(1):233-236.
Stewart, A.R. (1999). Accumulation of Cd by a freshwater mussel (Pyganodon grandis) is reduced
   in the presence of Cu, Zn, Pb, and Ni. 1999. Canadian Journal of Fisheries and Aquatic
   Sciences 56:467-478.
Strayer, D.L. (1983). The effects of surface geology and stream size on freshwater mussel (Bivalvia,
   Unionidae) distribution in southeastern Michigan, U.S.A. Freshwater Biology 13:253-264.
Strayer, D.L. (1999). Use of flow refuges by unionid mussels in rivers. Journal of the North
   American Benthological Society 18(4):468-476.
Strayer, D.L., Cole, J.J., Likens, G.E., and D.C. Buso. (1981). Biomass and annual production of
   the freshwater mussel Elliptic complanata in an  oligotrophic softwater lake. Freshwater Biology
   11:435-440.
Strayer, D.L., Downing, J.A., Haag, W.R., King, T.L., Layer, J.B., Newton, T.J., and S.J. Nichols.
   (2004). Changing perspectives on pearly mussels, North America's most imperiled animals.
   Bioscience 54(5):429-439.
Strayer, D.L. and K.J. Jirka. (1997). The Pearly Mussels of New York State. New York State Museum
   Memoir 26. The University of the State of New York, The State Education Department. 113pp +
   plates.
Strayer, D.L. and D.R. Smith. (2003). A guide to sampling freshwater mussel populations. American
   Fisheries Society Monograph 8:1-103.
Surber, T. (1912). Identification of the Glochidia of Fresh-Water Mussels. Bull. Bur. of Fisheries.
   Doc. No. 771.
Surber, T. (1913). Notes on the natural hosts of freshwater mussels. Bulletin of the Bureau of
   Fisheries. [Issued separately as U.S. Bureau of Fisheries Document 778]. 32(1912):103-116 +
   3 plates.
Tessier, L., Vaillancourt, G., and L. Pazdernik. (1994). Temperature effects on cadmium and
   mercury kinetics in freshwater molluscs under laboratory conditions. Archives of Environmental
   Contamination and Toxicology 26:179-184.
                                          103

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Teztloff, J. (2001). Survival Rates of Unionid Species Following a Low Oxygen Event in Big Darby
   Creek, Ohio. Ellipsaria3(3):18-19.
Tetzloff, J. and D. Akison. (1999). 1999 Survey of the Freshwater Mussels of the Middle Scioto
   River. Final Report to the Division of Wildlife, the Ohio Department of Natural Resources. 12 pp
   + app.
Thorsen, W.A., Cope, W.G.,  and D. Shea. (2004). Bioavailability of PAHs: effects of soot carbon
   and PAH source. Environmental Science and Technology 38(7):2029-2037.
Trdan,  R.J. (1981). Reproductive biology of Lampsilis radiata siliquoidea (Pelecypoda: Unionidae).
   American Midland Naturalist 106(2):243-248.
Trdan,  R.J. and W.R. Hoeh. (1982). Eurytopic host use by two congeneric species of freshwater
   mussel (Pelecypoda: Unionidae: Anondonta). American Midland Naturalist 108:381-388.
Trefry, J.H., Nelsen, T.A., Trocine, R.R, Metz, S., and T.W. Vetter. (1986). Trace metal fluxes
   through the Mississippi River Delta system. Rapport et Proces-Verbaux des Reunions Conseil
   International pour ('Exploration  de la Mer186:277-288.
Turgeon D.D., Quinn,  J.F., Bogan, A.E., Coan, E.V.,  Hochberg,  F.G., Lyons, W.G., Mikkelsen,
   P.M., Neves, R.J., Roper, C.F.E., Rosenberg, G., Roth,  B., Scheltema, A., Thompson,
   F.G., Vecchione, M., and J.D.Williams. (1998). Common and scientific names of aquatic
   invertebrates from the United States and Canada: Mollusks, 2nd edition. American Fisheries
   Society, Special Publication 26, Bethesda, Maryland.
U.S. Bureau of Mines. (1995). 1994 Minerals Yearbook - Gemstones. U.S. Department of
   the Interior. Washington  DC. 18 pp. http://minerals.usgs.gov/minerals/pubs/commodity/
   gemstones/290494.pdf
U.S. Environmental Protection Agency. (2000). Methodology for Deriving Ambient Water Quality
   Criteria for the Protection of Human Health. Office of Science and Technology, Office of Water,
   Washington, D.C.  152 pp.
U.S. Environmental Protection Agency. (2007). U.S.  EPA Biological Indicators of Watershed Health
   webpage. Accessed 09/12/2007 [http://www.epa.gov/bioindicators].
U.S. Fish and Wildlife Service. (1983a). Dromedary  Pearly  Mussel Recovery Plan. U.S. Fish and
   Wildlife Service. Atlanta, Georgia. 58 pp.
U.S. Fish and Wildlife Service. (1983b). Green Blossom Pearly  Mussel Recovery Plan. U.S. Fish
   and Wildlife Service. Atlanta, Georgia. 50 pp.
U.S. Fish and Wildlife service. (1984). Fine-rayed Pigtoe Pearly Mussel Recovery Plan. U.S. Fish
   and Wildlife Service. Atlanta, Georgia. 67 pp.
U.S. Fish and Wildlife Service. (1985a). Recovery Plan fortheTubercled-Blossom Pearly Mussel,
   Turgid Blossom Pearly Mussel, and Yellow Blossom Pearly  Mussel. Atlanta, Georgia. 42 pp.
U.S. Fish and Wildlife Service. (1985b). A Recovery Plan for the Alabama Lamp Pearly Mussel,
   Lampsilis virescens (Lea, 1858). Atlanta, Georgia. 41 pp.
U.S. Fish and Wildlife Service. (1985c). Recovery Plan for the Pink Mucket Pearly Mussel. U.S.
   Fish and Wildlife Service, Atlanta, Georgia. 47 pp.
U.S. Fish and Wildlife Service. (1990). White Cat's Paw  Pearly Mussel Recovery Plan. U.S. Fish
   and Wildlife Service. Twin Cities, Minnesota. 42 pp.
U.S. Fish and Wildlife Service. (1991). Speckled Pocketbook Mussel (Lampsilis streckeri) Recovery
   Plan. U.S. Fish and Wildlife Service. Jackson, Mississippi. 14 pp.
U.S. Fish and Wildlife Service. (1992). Arkansas Fatmucket Mussel (Lampsilis powellii) Recovery
   Plan. U.S. Fish and Wildlife Service. Jackson, Mississippi. 19 pp.
                                           104

-------
            An Introduction to Freshwater Mussels as Biological Indicators
U.S. Fish and Wildlife Service. (1993a). Endangered and Threatened Wildlife and Plants:
    Determination of Endangered Species Status for the Northern Riffleshell Mussel (Epioblasma
    tumlosa rangiana) and the Clubshell Mussel (Pleurobema clava). Federal Register 58(13):
    5638-5642.
U.S. Fish and Wildlife Service. (1993b). Endangered and Threatened Wildlife and Plants;
    Endangered Status for Eight Freshwater Mussels and Threatened Status for Three Freshwater
    Mussels in the Mobile River Drainage. Adapted from the Federal Register for Wednesday,
    March 17, 1993. Accessed 8/24/2007 [http://www.fws.gov/endangered/r/fr93495.html\.
U.S. Fish and Wildlife Service. (1993c). Dwarf Wedge Mussel (Alasmidonta heterodon) Recovery
    Plan. Hadley, Massachusetts. 52 pp.
U.S. Fish and wildlife Service. (1994). Clubshell (Pleurobema clava) and Northern Riffleshell
    (Epioblasma torulosa rangiana) Recovery Plan. Hadley, Massachusetts. 68 pp.
U.S. Fish and Wildlife Service. (1996). Carolina Heelsplitter Recovery Plan. U.S. Fish and Wildlife
    Service, Atlanta, GA. 30 pp.
U.S. Fish and Wildlife Serivce. (1997). U.S. Fish and Wildlife Service, Region 3, Endangered
    Species Fact Sheets "Clubshell". Accessed 08/10/2007 [http://www.fws.gov/Midwest/
    Endangered/clams/clubs_fc.html\.
U.S. Fish and Wildlife Service. (2000). Mobile River Basin Aquatic Ecosystem Recovery Plan.
    Atlanta, GA. 128pp.
U.S. Fish and Wildlife Service. (2004). Recovery Plan for Cumberland Elktoe,  Oyster Mussel,
    Cumberlandian Combshell, Purple Bean, and Rough Rabbitsfoot. Atlanta, Georgia. 168 pp.
U.S. Fish and Wildlife Service. (2007a). U.S. Fish and Wildlife Service, Region 3, Endangered
    Species Fact Sheets "Tubercled-Blossom Pearly Mussel". Accessed 07/05/2007 [http://www.
    fws.gov/Midwest/Endangered/clams/tuber_fc.html\.
U.S. Fish and Wildlife Service. (2007b). U.S. Fish and Wildlife Service Endangered Species
    Webpage. Accessed 07/12/2007 [http://ecos.fws.gov/tess_public/SpeciesReport. do?groups=F
    &HstingType=L&mapstatus= 1].
U.S. Fish and Wildlife Service. (2007c). U.S. Fish and Wildlife Service, Reynoldsburg Ohio
    Ecological Services  Office. Accessed 12/17/2007 [http://www.fws.gov/midwest/reynoldsburg/
    endangered\.
U.S. Geological  Survey.  (1996). Preliminary Compilation of Descriptive Geo-environmental Mineral
    Deposit Models. U.S. Department of the  Interior, U.S. Geological Survey, Open File 95-831.
    272-299.
U.S. Geological  Survey.  (1999). Ecological status and trends of the Upper Mississippi River System
    1998: A report of the Long Term Resource Monitoring Program. U.S. Geological Survey, Upper
    Midwest Environmental Sciences Center, La Crosse, Wisconsin. LTRMP 99-T001.236 pp.
U.S. Geological  Survey.  (2002). Effects of ammonia on freshwater mussels in the St. Croix River
    (Fact Sheet  FS 2004-3046). Upper Midwest Environmental Sciences Center, La Crosse,
    Wisconsin.
U.S. Geological  Survey.  (2006). 2005 Minerals Yearbook - Gemstones. U.S. Department of the
    Interior. Washington  DC. 22 pp.
Utterback, W.I. (1915). The naiades of Missouri. American Midland Naturalist 4:41-53, 69-152, 189-
    204, 244-273.
Utterback, W.I. (1916). The naiades of Missouri. American Midland Naturalist 4:311 -327, 339-354,
    387-400, 432-464.
van der Schalie, H. (1938). The naiad fauna  of the Huron River, in southeastern Michigan.
    Miscellaneous Publication No. 40, Museum of Zoology,  University of Michigan. University of
    Michigan Press, Ann Arbor, Michigan. 83 pp + Plates I-XII.
                                          105

-------
            An Introduction to Freshwater Mussels as Biological Indicators
van der Schalie, H. (1970). Hermaphrodism among North American freshwater mussels.
   Malacologia10(1):93-112.
van der schalie, H. and A. van der Schalie. (1950). The mussels of the Mississippi River. The
   American Midland Naturalist 44(2):448-466.
Valenti, T.W., Cherry,  D.S., Currie, R.J., Neves,  R.J., Jones, J.W.,  Mair, R., and C.M. Kane. (2006a).
   Chlorine toxicity to early life stages of freshwater mussels (bivalvia:unionidae). Environmental
   Toxicology and Chemistry 25(9):2512-2518.
Valenti, T.W., Cherry,  D.S., Neves, R.J., Locke, B.A., and J.J. Schmerfeld. (2006b). Case study:
   Sensitivity of mussel glochidia and regulatory test organisms  to mercury and a reference
   toxicant. Chapter  14 in Freshwater Bivalve Ecotoxicology, J. L. Farris and J. H. Van Hassel
   (eds.), pp.351-367.
Valenti, T.W., Cherry,  D.S., Neves, R.J., and J. Schmerfeld. (2005). Acute and chronic toxicity
   of mercury to early life stages of the rainbow mussel, Villosa iris (Bivalvia: Unionidae).
   Environmental Toxicology and Chemistry 24 (5):1242-1246.
van Snik Gray, E., Lellis, W.A., Cole, J.C., and C.S. Johnson. (1999). Host of Pyganodon cataracta
   (eastern floater) and Strophitus undulatus (squawfoot) from the upper Susquehanna River
   basin,  Pennsylvania. Triannual Unionid  Report 18.
van Snik Gray, E., Lellis, W.A., Cole, J.C., and C.S. Johnson. (2002). Host identification for
   Strophitus undulatus (Bivalvia: Unionidae), the creeper, in the Upper Susquehanna River
   Basin, Pennsylvania. American Midland Naturalist 147(1):153-161.
Vaughn, C.C. and C.C. Hakenkamp. (2001). The functional role of burrowing bivalves in freshwater
   ecosystems. Freshwater Biology 46:1431-1446.
Vaughn, C.C. and C.M. Taylor. (1999). Impoundments and the decline of freshwater mussels: a
   case study of an extinction gradient. Conservation Biology 13(4):912-920.
Waller, D.L. and S.W. Fisher. (1998a). Evaluation of several chemical disinfectants for removing
   zebra mussels from unionid mussels. The Progressive Fish Culturist 60:307-310.
Waller, D.L., S. Gutreuter and J.J. Rach. (1999). Behavioral Responses to Disturbance in
   Freshwater Mussels with  Implications for Conservation and Management. Journal of the North
   American Benthological Society 18(3):381-390.
Waller, D.L. and L.E. Holland-Bartels. (1988). Fish hosts for glochidia of the endangered freshwater
   mussel, Lampsilis higginsi Lea (Bivalvia, Unionidae). Malacological Review 21:119-122.
Waller, D.L., Holland-Bartels, L.E., Mitchell, L.G.,  andT.W. Kammer. (1985). Artificial infestation of
   largemouth bass and walleye with glochidia of Lampsilis ventricosa (Pelecypoda: Unionidae).
   Freshwater Invertebrate Biology 4(3):152-153.
Waller, D.L., Rach, J.J., and J.A. Luoma. (1998b). Acute toxicity and accumulation of the
   piscicide 3-trifluoromethyl- 4-nitrophenol (TFM) in freshwater  mussels (Bivalvia: Unionidae).
   Ecotoxicology 7(2): 113-121.
Wang, D.,  Couillard, Y, Campbell, P.G., and P. Jolicoeur. (1999). Changes in subcelluar
   metal partitioning in the gills of freshwater bivalves (Pyganodon grandis) living along an
   environmental cadmium gradient. Canadian Journal of Fisheries and Aquatic Sciences
   56:1999.
Wang, N., Ingersoll, C.G., Greer, I.E., Hardesty, O.K., Ivey, C.D., Kunz, J.L, Brumbaugh, W.G.,
   Dwyer, F.J., Robers, A.D., Augspurger,  T, Kane, C.M.,  Neves, R.J., and M.C. Barnhart.
   (2007a) (in press). Assessing contaminant sensitivity of early life stages of freshwater mussels
   (Unionidae): Acute toxicity testing of copper, ammonia, and chlorine to glochidia and juvenile
   mussels. Environmental Toxicology and Chemistry. 38pp.
                                           106

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Wang, N., Ingersoll, C.G., Greer, I.E., Hardesty, O.K., Ivey, C.D., Kunz, J.L, Brumbaugh, W.G.,
   Dwyer, F.J., Robers, A.D., Augspurger, T., Kane, C.M., Neves,  R.J., and M.C. Barnhart.
   (2007b) (in press). Assessing contaminant sensitivity of early life stages of freshwater
   mussels (Unionidae): Chronic toxicity testing of juvenile mussels with copper and ammonia.
   Environmental Toxicology and Chemistry. 35pp.
Walters, G.T. (1988). The naiad fauna of selected streams in Ohio. I. Stillwater River of Miami
   River. II. Stream systems of south central Ohio from the Little Miami River to the Hocking
   River, excluding the Scioto River proper. Unpublished report to the Division of Wildlife, Ohio
   Department of Natural Resources, Columbus. 44 pp.
Walters, G.T. (1994). An Annotated Bibliography of Ihe Reproduclion and Propagalion of Ihe
   Unionoidea (Primarily of Norlh America). Ohio Biological Survey Miscellaneous Conlribulion 1.
   Columbus, Ohio.
Wallers, G.T. (1995). A Guide lo Ihe Freshwater Mussels of Ohio. 3rd Edilion. Ohio Division of
   Wildlife, Columbus, OH. 122pp.
Wallers, G.T. (1996a). Hosls for Ihe northern riffle shell (Epioblasma tomlosa rangiana). Triannual
   Unionid Report 10:14.
Wallers, G.T. (1996b). New hosls for Lampsilis cardium. Triannual Unionid Report 9:8.
Wallers, G.T. (1996c). Small dams as barriers lo freshwater mussels (bivalvia: unionoida) and Iheir
   hosls. Biological Conservalion 75(1):79-85.
Wallers, G.T. (1999). Morphology of Ihe conglulinale of Ihe kidneyshell freshwater mussel,
   Ptychobranchus fasciolaris. Invertebrate Biology 118:289-295.
Wallers, G.T. (2000). Freshwater mussels and water quality: a review of Ihe effecls of hydrologic
   and inslream habilal alleralions. Proceedings of Ihe Conservalion, Caplive Care, and
   Propagalion of Freshwater Mussels Symposium, 1999. pp. 1-14.
Wallers, G.T. and K. Kuehnl. (2004). Ohio pigloe hosl suilabilily trials. Ellipsaria 6(2):10.
Wallers, G.T. and S.H. O'Dee. (1997). Idenlificalion of polenlial hosls. Triannual Unionid  Report
   13:38-39.
Wallers, G.T, Chordas, S.W., O'Dee, S.H., and J. Reiger. (1998a). Hosl idenlificalion sludies for
   six species of Unionidae. Firsl Symposium of Ihe Freshwater Mollusk Conservalion Society,
   Challanooga, TN. Program Guide and Abslracls.
Wallers, G.T, O'Dee, S.H. and S. Chordas. (1998b). New polenlial hosls. Triannual Unionid Report
   15:27-29.
Wallers, G.T, O'Dee, S.H. and S. Chordas. (1998c). New polenlial hosls for:  Strophitus undulates
   - Ohio River drainage; Strophitus undulatus- Susquehanna River drainage; Alasmidonta
   undulata- Susquehanna River drainage; Actinonaias ligamentina - Ohio River drainage; and
   Lasmigona costata- Ohio  River drainage. Triannual Unionid Report 15:27-29.
Wallers, G.T, Menker, T, Thomas, S. and K. Kuehnl. (2005). Hosl idenlificalions or confirmalions.
   Ellipsaria 7(2):11-12.
Weaver, L.R., Pardue, G.B., and R.J. Neves. (1991). Reproduclive Biology and Fish Hosls of
   Ihe Tennessee Clubshell Pleurobema oviforme (Mollusca: Unionidae) in Virginia. American
   Midland Naluralisl (126)1:82-89.
Weiss, J.L. and J.B. Layzer. (1995). Infeslalions of glochidia on fishes in Ihe Barren River,
   Kenlucky. American Malacological  Bullelin 11(2):153-159.
While, L.R., McPheron, B.A.,  and J.R.  Slauffer,  Jr. (1996). Molecular genelic idenlificalion lools for
   Ihe unionids of French Creek, Pennsylvania. Malacologia 38(1-2):181-202.
                                          107

-------
            An Introduction to Freshwater Mussels as Biological Indicators
Wicklow, B.J. and P.M. Beisheim. (1998). Life history studies of the squawfoot mussel Strophitus
   undulatus in the Piscataquog River watershed, New Hampshire. P. 41 in Conservation, Captive
   Care, and Propagation Freshwater Mussel Symposium Program and Abstracts, 6-8 March
   1998, Columbus, Ohio.
Wicklow, B.J. (1999). Life history of the endangered Dwarf Wedgemussel, Alasmidonta heterodon:
   glochidial release, phenology, mantle display behavior, and anadromous fish host relationship.
   Page 28 in Program Abstract of the 1st Symposium of the Freshwater Conservation Society,
   17-19 March 1999, Chattanooga, TN. 92 pp.
Williams, J.D., Fuller, S.L.H., and R. Grace. (1992). Effects of impoundments on freshwater
   mussels (Mollusca: Bivalvia: Unionidae) in the main channel of the Black Warrior and
   Tombigbee Rivers in western Alabama. Bull. Alabama Museum of Natural History 13:1-10.
Williams, J.D., Warren, M.L., Cummings, K.S., Harris, J.L., and R.J. Neves. (1993). Conservation
   status of freshwater mussels of the United States and Canada. Fisheries 18(9):6-22.
Wilson, C.B. (1 91 6). Copepod parasites of fresh-water fishes and their economic relations to
   mussel glochidia. Bulletin of the Bureau of Fisheries. [Issued separately as U.S. Bureau of
   Fisheries Document 824]. 34:333-374 + 15 plates.
Wisconsin Department of Natural Resources (WDNR). (2003). Freshwater mussels of the upper
   Mississippi River. Wisconsin Department of Natural Resources, Madision, Wl. 60 pp.
Wren, C.D. and  H.R. Maccrimmon. (1983). Examination of bioaccumulation and biomagnification  of
   metals in a precambrian shield lake. Water, Air, and Soil Pollution  19:277-291.
Wurtz, C.B. (1956). Fresh-water mollusks and stream pollution. Nautilus 69:96-100.
Yeager, B.L. (1993). Dams. Pp. 57-1 13 in: C. F. Bryan and D. A. Rutherford, eds. Impacts on
   warmwater streams: guidelines for evaluation. Warmwater Stream Committee, Southern
   Division, American Fisheries Society, Little Rock, Arkansas.
Yaeger, M.M., and D.S. Cherry. (1994). Feeding and burrowing behaviors of juvenile rainbow
   mussels, Villosa iris (Bivalvia:Unionidae). Journal  of the North American  Benthological Society
   13(2):21 7-222.
Yeager, B.L. and R.J. Neves. (1986). Reproductive cycle and fish hosts of the rabbit's foot mussel,
   Quadrula cylindrica strigillata (Mollusca: Unionidae) in the Upper Tennessee River drainage.
   American Midland Naturalist 116(2):329-340.
Yeager, B.L. and C.F. Saylor. (1 995). Fish hosts for four species of freshwater mussels
   (Pelecypoda: Unionidae) in the Upper Tennessee  River drainage. American Midland Naturalist
Yokley, P. (1972). Life history of Pleurobema cordatum (Rafinesque, 1820) (Bivalvia: Unionacea).
   Malacologia11(2):351-364.
Young, D. (1 91 1 ). The implantation of the glochidium on the fish. University of Missouri Bulletin
   Science Series 2:1-20.
Zale, A.V. and R.J. Neves. (1982). Fish hosts of four species of lampsiline mussels (Mollusca:
   Unionidae) in Big Moccasin Creek, Virginia. Canadian Journal of Zoology 60(1 1):2535-2542.
Zanatta, D.T. and J.L. Metcalfe-Smith. (2004). COSEWIC Status Report on Round Pigtoe
   Pleurobema sintoxia in Canada. COSEWIC. 40 pages.
Zimmerman, G.F. and FA. de Szalay. (2007). Influence of unionid mussels (Mollusca:  Unionidae)
   on sediment stability: an artificial stream study. Fundamental and Applied Limnology
   168(4):299-306.
                                          108

-------

-------

-------

-------
&EPA
     United States
     Environmental Protection
     Agency
Please make all necessary changes on the below label,
detach or copy, and return to the address in the upper
left-hand corner.

If you do not wish to receive these reports CHECK
HERE   detach, or copy the cover, and return to the
address in the upper left-hand corner.
PRESORTED STANDARD
 POSTAGE & FEES PAID
        EPA
   PERMIT No. G-35
     Office of Environmental Information
     Office of Information Analysis and
       Access
     Environmental Analysis Division
     Washington, DC 20460
     Official Business
     Penalty for Private Use
     $300
     EPA-260-R-08-015
     November 2008

-------