Oregon Growth of Shiner Perch
and Buffalo Sculpin
under Laboratory Conditions
by Anne Myers
.4'
Resources Development Internship Program
Western Interstate Commission for Higher Education
Urban Studies Center,
Portland State University
Environmental Protection Agency
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GROWTH OF SHINER PERCH (CYMATOGASTER AGGREGATA) AND
BUFFALO SCULPIN (ENOPHRYS BISON) UNDER LABORATORY CONDITIONS
By
Anne Hutchison Ityers
Western Interstate Council for Higher Education Intern
National Coastal Pollution Research Program
U. S. Environmental Protection Agency
Marine Science Center
Newport, Oregon 97305
SEPTEMBER 1973
Comnittee Members:
R. C. Swartz
D. T. Martin
W. A. DeBen
D. J. Baumgartner
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ABSTRACT
Growth rate experiments were carried.out for two fish, Enophrys
bison and Cymatogaster aggregata, under separate feeding conditions to
determine tne feasibility of using either for pollutant stress experiments-
Enophrys bison would not feed on the three prey species presented.
Two month old Cymatogaster apgregata fed Oregon pellets showed an increase
in growth rate of 10 mg per gram of body weight per day (dry weight) for
each increase in consumption rate of 20 mg per gram of body weight per
day (dry weight). A feeding schedule of 0.12 gm (wet weight) of Oregon
pellets per day caused a significant weight gain in one week. Feeding
0.06 gm per day caused no significant weight change. Lengths were
not significantly different.
The equations for the relationship of dry weight (y) to wet weight (x)
for fish was y = 0.22x; for Oregon pellets this relationship was y = 0.708x.
The equation computed for the relationship of dry weight (y, in mg) to
fork length (x, in mg) was log y = 3.50 log x - 3.22 with correlation
coefficient R = 0.92.
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INTRODUCTION
Water pollution standards are often based on acute toxicity bioassays. "Safe"
concentrations are estimated by reducing median survival concentration by
one or two orders of magnitude. Such limits may not reflect the water
quality required for growth, development, reproduction, behavior or
even long-*term survival, in order to provide a more reliable basis
for predicting the fate and effects of pollutants in the oceans, EPA's
National Coastal Pollution Research Program has initiated a study of
the behavior of experimental marine ecosystems exposed to stress.
I have examined techiques for documenting energy flow through biological
systems under normal environmental conditions. This report discusses two
experimental approaches: 0) a predator--prey system involving buffalo sculpin
(Enophyrs bison) as the predator and two decapod crustaceans and shiner perch
as prey; and (.2) growth in a single species population of shiner perch
(Cyroatogaster aggregata) fed an artificial diet. The ultimate application
of the results lies in future experiments comparing the flow of energy
under normal and stressed conditions.
METHODS
TANK SYSTEM
A flow-through seawater system was established at the Marine Science Center
of Oregon State University in Newport, Oregon. Two 575 gallon circular
tanks were connected via separate filters to the main seawater supply. The
seawater at the Center is pumped from Yaquina Bay through a sand filter.
During the period of this experiment salinity was 34 ± 1 percent and the
temperature was 12 ± 2°C.
The tanks were zinc-coated iron painted with two coats of Valspar 2802
L.S.C. Primer. Tank A received two coats of Valspar 3825 Nile Green and
one coat of Valspar 3836 Dolphin Blue. Tank B had two coats of 3836 Dolphin
Blue. All fittings and pipes were PVC. The flow system is diagrammed in
Figure 1. A drain cover was placed on the outflow pipe to prevent loss of
animals from the system. The flow rate was 2-3 gallons/minute. Both filters
were back-washed daily except weekends.
The filters consisted of one foot thick layers of activated carbon, small
grain sand (F
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EXPERIMENT 1: PREDATOR-PREY RELATIONS
Buffalo sculpin were collected with an otter trawl during the end of
June and the beginning of July, 1973. All the fish were weighed and
a few individuals were tagged with Peterson disks and lengths taken.
Eleven fish were placed in each of the two large tanks and three food
choices were offered for periods of at least one week. Hemiqrapsus nudus,
a small black shore crab, was collected at Yaquina Head. Crago nigricauda,
a small bay shrimp, and Cymatoqaster aggregata, a small bay fish, were
collected with a push net in shallow water eelgrass in Yaquina Bay. The prey
were weighed and counted before they were added to the system. The prey were
counted daily and the predators were weighed at the end of the experiment.
EXPERIMENT II: GROWTH OF CYMATOGASTER AGGREGATA
Approximately 400 shiner perch were collected in the first week of August in
shallow eelgrass near the Marine Science Center. Each day's collection of
fish was placed in the large tanks. At the end of the week all the fish
were weighed in groups of ten in beakers of water on a Mettler top pan balance.
Equal numbers of fish were placed in each-tank.
The fish were fed Oregon pellets three or four times each day. Oregon pellets
are a commercial fish food developed by the Oregon Fish Commission and O.S.U.
for feeding salmon in hatcheries. The pellets are produced by Bioproducts, Inc.
of Warrenton, Oregon. (Formula specifications available from the company and
Crawford and Law, 1972). The fish were started on 1/16 inch pellets and then
changed to 3/32 inch pellets. Specimens in Tank A received as many pellets
as they could eat. Feeding was stopped when pellets hit the bottom of the
tank without being consumed. Tank B received 1/2 the weight of food per
fish placed in Tank A.
Ten fish were removed every six days. Live wet weights were recorded to the
nearest 0.1 gm. Some fish were sacrificed and dried in a vacuum desicator
overnight at 100°C. Fork lengths were recorded in millimeters. Dried weights
and precise wet weights were obtained,in milligrams on a Mettlet balance. Dried
fish were then ashed in a muffle oven overnight at 500°C and then ashed
weights determined.
Some of the fish removed after live weight measurements were placed in the
small tank (A-l) and feces were collected daily to establish a relationship
between food consumption and feces production. These fish were on the
same feeding schedule as Tank A (as much food as they could eat three or
four times a day). Some of the live weight fish were returned to their
original tank.
Stomach contents were recorded for some of the freshly caught fish.
2
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RESULTS
EXPERIMENT I: PREDATOR-PREY RELATIONS
Sculpins were maintained for two weeks in the presence of prey
specimens in the seawater tanks. Typically they congregated on the
bottom of the tanks in the vicinity of the out flow pipes, movements
were rare, and they were never observed feeding on the prey. Counts of the
food organisms (Hemisqrapsus nudus, Crago niqricauda, and C.ymatogaster
agqreqata) remainded constant. Individual sculpins which had been weighed
and tagged lost approximately 10 percent of their body weight after two weeks,
at which time the experiment was terminated.
The stomach contents of Enophrys bison about 10 cm long indicated that
they fed mostly on green algae. The small amount of animal material
found included small crabs, ghost shrimp and a polychaete worm.
EXPERIMENT II: GROWTH OF CYMATOGASTER AGGREGATA
The shiner perch was selected for this experiment because 1t acclimated
well to laboratory conditions, readily accepted Oregon pellets,and had
low mortality after the first week following capture. Their small size
meant that a large population could be maintained in the laboratory. The
use of Oregon pellets as a food source gave the further advantage that
regulated amounts of pollutants could be added to the food source. Monitoring
of intake, mode and percent of uptake could be much more definitive.
Initial mortality after collecting and weighing fish was very high. The
number of fish in Tank A fell from 200 to 107 and in Tank B from 191 to 63 in
the first week. Subsequent mortality in the next three weeks was six and
eight, respectively. This initial stress situation selected for those fish
which could withstand the stress of capture and weighing as there was no more
10 percent mortality among the samples of ten fish removed each week from the
tank for weighing and then returned.
The stomach analysis revealed that the fish are probably primary carnivores.
Stomachs were full of harpacticoid copepods, mostly nauplii. Observation of
feeding behavior and the place of capture indicates that they find their
prey on the eelgrass. At the time of capture, shiner perch made up 50
percent by numbers of the small fish captured with a push net.
Figure 2 gives the mean wet weight of fish throughout the experiment. Feeding
levels of 0.725 g (wet weight) of Oregon pellets per fish during the six day
interval produced significant weight gain. Feeding rates of 0.36 g seemed to
be a maintenance level as there was no significant gain or loss. The lack
of growth for the feeding level of 1.25 g suggests a leveling off after an
initial period of rapid growth, however, this may not have been a
representative sample.
3
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The very rapid increase in growth rate with increase in consumption rate is
shown in Figure 3. Graphs of this relationship normally show an increase
in growth with consumption followed by a horizontal asymptote where increase
in consumption does not cause an increase in growth (Davis and Warren, 1968).
The relationship indicated in Figure 3 may be a short-term phenomenon
characteristic of very young fish.
The relationship of dry weight (y) to wet weight (x), y=0.22x, is illustrated
in Figure 4. Figure 5 shows the relationship of dry weight (mg) to fork
length (mm); log y = 3.50 log x - 3.22. For 3/16 inch Oregon pellets dry
weight is 70 percent of wet weight.
The relationships of wet to dry weight given above were used to calculate the
data in Figure.6. Direct caloric measurements were not made, but they may
be determined indirectly for food and fish by using the average value of
5.65 kcal./gm. (dry weight) (Davis and Warren, 1968). A change of 15 mg. per
day is significant at the 90 percent confidence level.
The mean fork length of speciments in Tank A increased 5.8 mm (13.2 percent
of initial length) during the experiment (Fig. 7). There is no significant
difference in length between fish on either feeding rate.
Eleven fish were kept at the same_feeding level as Tank A in the small
tank. A daily collection of feces showed that dry weight of feces is
10 percent of the dry weight of Oregon pellet food consumed.
Maximum levels of six heavy metals were determined and are listed in Figure
8. These can be used as a baseline for further study on the uptake and
effects of heavy metals. All the figures preceded by a less than sign
indicate that the sample tested was not large enough to test helow that
upper limit. Levels may actually be far below these maxima.
Observations of the fish indicated that it took about one week for most
of the fish to be conditioned to feeding; that is, come to the surface to
await food when a hand was placed over the tank. For the first two weeks of the
experiment fish were fed 1/16 inch Oregon pellets. Because there is much
more dust with this size pellet which is not eaten by the fish a change was
made to 3/32 inch pellets as soon as most of the fish seemed large enough to
ingest them. When a pellet was taken, it was chewed and then swallowed.
The particles remaining in the mouth were spit out. It was impossible to
quantify what percentage of the food this represented and for now it will
have to be lumped with respiration as the amount of food placed in the tank
less feces recovered and growth recorded (dry weights).
DISCUSSION
It was found that buffalo sculpins did not adapt to the experimental
conditions. They are not recommended for laboratory growth experiments.
4
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The shiner perch are viviparous, our experimental fish were probably born
in June or July. Measurements by Wilson and Milleman (1969) in Yaquina
Bay indicate that mean weight at birth is 0.494 ± 0.154 gm and mean total
length is 36.2 ± 5.5 mm. At the beginning of the experiment on August 4,
the mean weight was 2.000 ± 0.277 gm and the mean total length was 52.8
± 9.5 mm.
Shiner perch are distributed along the Pacific coast from Southern California to
Alaska (Wilson and Milleman, 1969). They inhabit bays and estuaries in
large numbers during the summer months. This makes them an ideal fish for
studying the effects of pollutants in the coastal marine environment.
The work to date indicates that Cymatogaster aggregata can be successfully
maintained in the laboratory and that growth rates can be fairly well
predicted for this stage in the life cycle. The two populations gave
consistent and similar results.
The fish did not show any tendency to school separately by age and sex
(Wiebe, 1968) but this may have been a factor of tank size and young age.
A cinder block was placed in the small rectangular tank (1-A) and the
fish quickly adopted it as a hiding place, retreating when frightened. The
fish in the large tanks did not have hiding placed although they would
congregate near inflow and outflow pipes. Their behavior was not as timid
as the fish in the small tank.
Experiments should be carried out with small groups of fish (10 to 2Q fish)
in small tanks so that the growth rates of individual groups may be
monitored. Several experiments may than be carried on simultaneously.
In the future, a large stock population should be maintained in the large
tanks. The less adaptable fish could be weeded out before being placed in
an experimental situation.
At the end of the experiment all fish could be sacrified for weight and
length measurements and any applicable bio-assays.
Smaller tanks might also break down pecking orders especially notable in
the low feeding rate tanks where a few fish got larger while the majority
did not gain weight. Smaller groups of experimental fish would also
allow more opportunity to match sizes of fish and keep out the extreme
outliers.
It may be possible to establish a breeding population in the large tanks.
It will probably be necessary to-establish hiding places.
To date there have been no problems with disease or water quality. As the
water is drawn from the bay it is not expected that the salinity or
temperature extremes will harm these fish.
This work has found Cymatogaster suitable for experimental work because
growth rates are consistent with consumption rates for different groups of
fish.
5
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CONCLUSIONS
1. Enophrys bison can not be successfully cultured in a predator-prey
system.
2. There was a 50 percent mortality when one month old C.ymatogaster
aggregata were introduced to the laboratory. After this initial stress,
mortality dropped to about 1 percent per week.
3. A feeding schedule of 0.12 gm (wet weight) of Oregon pellets per
fish per day will cause a significant weight gain in one week among fish
one to two months old.
4. A feeding schedule of half this amount to a comparable group of fish
caused no weight gain. There was no significant difference in fork length
for either group.
5. Dry weight of feces was 10 percent of dry weight of food under feeding
conditions of 0.12 gm (wet weight) of Oregon pellets per fish per day.
6. The relationship of wet weight (x) to dry weight (y) for fish was
y = 0.22x. For Oregon pellets the comparable relationship was y = 0.708x.
7. Growth rate increased rapidly with consumption rate. . For the age
group tested, there was a fairly steady increase of 10 mg per gram of
body weight each day for each 20 mg increase in consumption rate. This
relationship apparently peaked at a consumption rate of 240 mg of Oregon
pellets per gram of ftsh body weight per day. This sharp increase in
growth rate with consumption rate was probably a factor of the very young
age of the fish.
8. The relationship of dry weight (y, in mg) to fork length (x, in mm)
was log y = -3.22 + 3.50 log x.
ACKNOWLEDGMENTS
This study would not have been possible without the continued support
of WICHE, the members of the National Coastal Research Program in Newport,
the many scientists and students attached to the Marine Science Center,
the zooplankton group of the School of Oceanography of Oregon State University
and my husband, Roger.
6
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LITERATURE CITED
Crawford, D. L., and D. K. Law. 1972. Mineral Composition of Oregon
Pellet Production Formulations. The Progressive Fish-Culturist,
Vol. 34, No. 3. pp. 126-130.
Davis, G. E., and C. E. Warren. 1968. Estimation of Food Consumption
Rates in Fish Production in Fresh Waters. W. E. Ricker, Ed. London
313 pp.
Wiebe, J. P. 1968. The Reproductive Cycle of the Viviparous Sea Perch,
Cymatogaster aggregata. Gibbons. Canadian J. Zool. 46: 1221-1234.
Wilson, D. C., and R. E. Millemann. 1969. Relationships of Female Age and
Size to Embryo Number and Size in the Shiner Perch, Cymatogaster
aggregates J. Fish. Res." Bd. Canada 26:2339-2344.
7
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Figure 1. A diagram of a filter and large cirular tank. Tank, capacity
= 575 gallons. Flow rate = 2-3 gal/min.
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Figure 2. A graph of live weight of 10 fish at six day intervals. Tank A
is designated by a solid line, Tank B by a broken line. The
vertical lines at Aug. 4 indicate the 90 percent confidence
limits for the 200 and 191 fish, respectively, placed in each
tank. The numbers above the lines indicate the wet weight in
grams of Oregon pellets fed per fish during the six day interval.
1.254
28
26
24
CT>
0.35?
•*-
o
28 Aug
2 2 Aug
4 Aug
stress
9
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Figure 3-
A graph of consumption rate versus growth rate. Rates are
determined by milligrams of food consumed or weight gained per gram
of fish per day. All measurements are dry weights.
80-
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Figure 4. A graph of wet weight versus dry weight for Cvmatoqaster
aggregata two to three months old.
0.22 x
0.8
0.6
05
0.4
0.3
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
wet weight ( 9 )
11
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Figur
1000
900
800
700
600
500
400
300
20C
100
5* fn!°rJr+Ph f°rk len9th 1n m M versus dr^ wei9ht in m9 (y)
for Cymatogaster aj£j^gata. two to three months old.
og y 3.50 log x - 3.221. Correlation coefficient, R = 0.92.
60
50
30
40
20
fork length ( m m)
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Dry weight Values of Food and Fish
Avg. wt. of
fish at
Population Sample mg, of food mg. of wt.
Tank
Dates
Size
Size
fed/fish/day
gained/fish/dav
mg
A
Aug.
4
200
200
436 ± 104
B
Aug.
4
191
191
444 ± 90
A
Aug.
4-10
107
10
77
-11
371
B
Aug.
4-10
63
10
62
A
Aug.
10-16
92
10
90
29
543
B
Aug.
10-16
58
10
44
- 2
422
A
Aug.
16-22
82
10
88
11
609
B
Aug.
16-22
58
10
42
- 1
416
A
Aug.
22-28
71
10
148
1
614
B
Aug.
22-28
56
10
86
25
563
Conments
90% CI
stress
Figure 6. Dry weight of food consumed and weight gained for C.ymatogaster
aqgreqata experiments.. Dry weight (y) relationship to wet
weight (x) for Oregon pellets : y = 0.708x; and for fish
y = 0.22x.
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Mean Fork Length
Population
Sample
Mean Fork
Tank
Dates
Size
Size
Lenqth (mm)
A
Aug. 4
200
6
43 8
B
Aug. 4
191
• U
A
Aug. 10
107
-
-
B
Aug. 10
63
-
-
A
Aug. 16
92
3
46.3
B
Aug. 16
58
-
-
A
Aug. 22
82
9
48.0
B.
Aug. 22
58
-
A'
Aug. 28
71
5
49.6
&
Aug. 28
56
5
"4;8.2
Figure %. Mean length of Cymatogaster aggregata during experiments.
14
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Sample
Whole Fish Oregon Pellets Feces
Metal ppm pph PPm
Cr <1 <1
Cu <0.5 <0.5
Hg 0.8* 0.2 0.5
Ni <1.5 <1.5
pb <4 <4
Zn 17.3 51
~Muscle Tissue only
Figure 8. Parts per million of heavy metals found in one to two month
old Cymatogaster aggregata removed from Yaquina Bay, Oregon
pellets, and feces of Cymatogaster aggregata fed on Oregon
pellets. Values preceded by a "less than" sign are the
minimum detection limits and no detectable amount was present.
15
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This report was completed by the following Intern:
Name:
Address:
Anne H. Myers
4230 N.W. Delta, #4
Corvallis, Oregon 97330
Immediately prior to this internship, the intern was a student at:
College:
Major Field:
Oregon State University
Bio. Ocean.
Year in School: M.S. June 1974
This Intern report was read and accepted by a staff member at:
Agency: Environmental Protection Agency
Pacific Northwest Environmental Research Lab
Address: 200 S.W. 35th Street
Corvallis, Oregon 97365
If you have further comments about this intern report * please write or phone:
Bob Hullinghorst, Director
Resources Development Internship Program
Western Interstate Commission for Higher Education
P.O. Drawer "P"
Boulder, Colorado 80302
Phone: (303) 449-3333
16
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The ideas and opinions expressed
in this report
are those of the author.
They do not necessarily reflect
the views of the
WICHE Commissioners or WICHE staff.
The Resources Development Internship Program
has been financed during 1973 by grants
from the
Economic Development Administration,
Jessie Smith Noyes Foundation,
National Endowment for the Humanities,
National Science Foundation
and by more than one hundred community
agencies throughout the West.
WICHE is an Equal Opportunity Employer
In the interest of resource conservation
and environmental improvement, this report
has been printed on recycled paper.
17
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THE RESOURCES DEVELOPMENT INTERNSHIP PROGRAM
The preceding report was completed by a WICHE intern during the sumner of 1973
This intern's project was part of the Resources Development Internship Program
administered by the Western Interstate Commission for Higher Education (WICHE).
The purpose of the internship program is to bring organizations involved in com-
munity and economic development, environmental problems and the humanities togeth-
er with institutions of higher education and their students in the West for the
benefit of all.
For these organizations, the intern program provides the problem-solving talents
of student manpower while making the resources of universities and colleges more
available. For institutions of higher education, the program provides relevant
field education for their students while building their capacity for problem-solving.
WICHE is an organization in the West uniquely suited for sponsoring such a program.
It is an interstate agency formed by the thirteen western states for the specific
purpose of relating the resources of higher education to the needs of western citi-
zens. WICHE has been concerned with a broad range of community needs in the West
for some time, insofar as they bear directly on the well-being of western peoples
and the future of higher education in the West. WICHE feels that the internship
program is one method for meeting its obligations within the thirteen western
• •
states. In its efforts to achieve these objectives, WICHE appreciates having re-
m eg
lO • •
g iJ ceived the generous support and assistance of the Economic Development Administra-
O CO
on
tion, the Jessie Smith Noyes Foundation, the National Endowment for the Humanities,
m ••
£ the National Science Foundation, and of innumerable local leaders and community
00 CO
^2 organizations, including the agency that sponsored this intern project.
P** ••
CM O
CO 1—I
For further information, write Bob Hullinghorst, Director, Resources Development
Internship Program, WICHE, Drawer "P", Boulder, Colorado, 80302, (303)443-6144.
18
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