EPA-660/3-75-017
MAY 1975
                                       Ecological  Research  Series
Temperature  Effects on Eggs and  Fry
of  Percoid  Fishes
                                       National Environmental Research Center
                                        Office of Research and Development
                                        U.S. Environmental Protection Agency
                                               Corvallis, Oregon 97330

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                      RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development,
U.S. Environmental Protection Agency, have been grouped into
five series.  These five broad categories were established to
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related fields.  The five series are:

          1.   Environmental Health Effects Research
          2.   Environmental Protection Technology
          3.   Ecological Research
          4.   Environmental Monitoring
          5.   Socioeconomic Environmental Studies

This report has been assigned to the ECOLOGICAL RESEARCH STUDIES
series.  This series describes research on the effects of pollution
on humans, plant and animal species, and materials.  Problems
are assessed for their long- and short-term influences.  Investigations
include formation, transport, and pathway studies to determine
the fate of pollutants and their effects.  This work provides
the technical basis for setting standards to minimize undesirable
changes in living organisms in the aquatic, terrestrial and atmospheric
envi ronments.

This report has been reviewed by the Office of Research and
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not signify that the contents necessarily reflect the views and
policies of the Environmental Protection Agency, nor does mention
of trade names or commercial products constitute endorsement or
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                                            EPA-660/3-75-017
                                            MAY 1975
TEMPERATURE EFFECTS ON EGGS AND FRY OF PERCOID FISHES
                           By
                  Lloyd L. Smith, Jr.
                    Walter M. Koenst
 Department of  Entomology, Fisheries,  and Wildlife
              University of Minnesota
            St.  Paul,  Minnesota  55101
                   Grant No. R800704
                   Project 18050 PAB
                 Program Element 1BA021

                    Project Officer

                 Kenneth E. H. Hokanson
         National  Water Quality Laboratory
      National Environmental  Research Center
               Monticello Field Station
                        Box 500
             Monticello,  Minnesota  55362
       NATIONAL ENVIRONMENTAL RESEARCH CENTER
         OFFICE OF RESEARCH AND DEVELOPMENT
       U. S. ENVIRONMENTAL PROTECTION AGENCY
              CORVALLIS, OREGON 97330
      For sale by the Superintendent of Documents, U.S. Government Printing Office
             Washington D.C. 20402 - Stock No. 055-001-01018

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                               ABSTRACT

Temperature effects on the early life history stages of the walleye
(Stizostedion vitreum vitreum (Mitchill)) and sauger (Stizostedion
canadense  (Smith)) were examined.  Walleye eggs and fry were exposed
to six temperatures (6-21 C) for effects on fertilization, incubation,
and fry survival.  Mature sauger were held and eggs were fertilized
at four temperatures (9-18 C).   Both species were incubated at 6-21 C.
Sauger fry survival was also tested at 6-21 C.  Optimum fertilization
temperatures were 6-12 C for walleye and 9-15 C for sauger.  Optimum
incubation temperatures were 12-15 C for both walleye and sauger.  A
sharp drop or rise in temperature had no great effect on walleye fry
and juvenile survival except when the upper lethal or lower lethal
temperature was approached.  Optimum temperature for juvenile walleye
and sauger growth was 22 C.  Upper lethal temperatures for walleye
juveniles were determined for acclimation temperatures at 2 C intervals
between 8-26 C.  The upper lethal temperature of walleye juveniles
was 27.0-31.6 C, depending on acclimation.  The upper lethal tempera-
ture of sauger acclimated to 10-26 C was 26.6-30.4 C.  There was little
temperature difference (1-2 C)  between 100% survival and no survival.

This report was submitted in fulfillment of Project Number 18050 PAB,
Contract Number R800704, by the Department of Entomology, Fisheries,
and Wildlife, University of Minnesota, under the sponsorship of the
Environmental Protection Agency.  Work was completed as of November
1973.
                                  ii

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                               CONTENTS
                                                            Page
Abstract                                                     ±±
List of Figures                                              iv
List of Tables                                               v
Acknowledgments                                              vii
Sections
I      Conclusions                                            1
II     Recommendations                                        3
III    Introduction                                           4
IV     Materials and Methods                                  6
V      Walleye Egg and Fry Survival                          17
VI     Growth of Juvenile Walleyes                           29
VII    Effect of a Sudden Temperature Change on Walleye      34
VIII   Walleye Upper Lethal Temperature                      40
IX     Sauger Egg and Fry Survival                           44
X      Growth of Juvenile Saugers                            50
XI     Upper Lethal Temperatures for Sauger Juveniles        52
XII    Discussion                                            57
XIII   References                                            61
XIV    Appendix A - Statistical Tables                       65
XV     Appendix B - Annotated Bibliography                   69
                                  iii.

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                               FIGURES
No.                                                         Page
 1    Diagram of the Experimental Apparatus                   8
 2    Diagram of the Continuous Flow-Through Incubation
        Chamber                                               9
 3    Diagram of the Incubation Cylinder                     10
 4    Schematic Diagram of the Experimental Design
        for the Egg and Fry Experiments                      18
 5    The Combined Effect of Fertilization Temperature
        and Incubation Temperature on the Hatchability
        of Walleye Eggs                                      20
 6    Growth of Walleye Juveniles Exposed to Temperatures
        Ranging from 18 C to 28 C                            32
 7    TL10 and TL90 Levels of Walleye Juveniles Exposed
        to Upper Lethal Temperatures                         43
 8    The Combined Effect of Fertilization Temperature
        and Incubation Temperature on the Hatchability
        of Sauger Eggs                                       45
 9    TL10 and TL90 Levels of Sauger Juveniles Exposed
        to Upper Lethal Temperatures                         53
                                  iv

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                           TABLES
No.
 1    Temperature, pH, Dissolved Oxygen (CO, and
        Total Alkalinity of Temperature Experiments         12
 2    Chemical Analysis of Laboratory Well Water            14
 3    Percentage Hatch of Walleye Eggs Fertilized at
        6 Different Temperatures and Incubated at 6 Dif-
        ferent Temperatures                                 19
 4    Time to Median Hatch in Days for Walleye Eggs
        Incubated and Fertilized at 6 Different Temper-
        atures                                              23
 5    Size of Walleye Fry at Hatch Calculated From the
        Regression Equations                                25
 6    The Effect of 6 Different Temperatures on Walleye
        Eggs and Fry Held at a Constant Temperature
        During Fertilization, Incubation, and After
        Hatching                                            27
 7    Growth of Walleye Juveniles for 28 Days at
        Different Temperatures                              30
 8    Effects of Temperature Change on Walleye Fry
        Incubated and Reared at 6 C, 11 C, and 21 C -
        72 Hours                                            36
 9    Effects of Sudden Temperature Change on Walleye
        Juveniles Exposed Below Their Acclimation
        Temperature - 96 Hours                              38
                           !
10    Effects of Sudden Temperature Change on Walleye
        Juveniles Exposed to a Temperature Above Their
        Acclimation Temperature                             39
11    Percentage Survival of Walleye Juveniles Exposed
        to Upper Lethal Temperature Levels for Each
        Acclimation Temperature for 96 Hours                41

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No.                                     ,                    Page
12    Percentage Hatch of Sauger Eggs Fertilized at
        Four Temperatures and Incubated at Six Temper-
        atures                                              46
13    The Effect of Six Constant Temperatures on Sauger
        Eggs and Fry                                        48
14    Growth of Sauger Juveniles for 36 Days at Differ-
        ent Temperatures                                    51
15    Percentage Survival of Sauger Juveniles Acclimated
        to 10 - 26 C and Exposed to Higher Temperatures
        for 96 Hours                                        54
16    Median Survival Time of Juvenile Saugers Acclima-
        ted to 10 - 26 C and Exposed to Upper Lethal
        Temperatures                                        55

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                           ACKNOWLEDGMENTS

The authors wish to thank Donavon M. Oseid for assistance in logis-
tical problems; the Minnesota Department of Natural Resources for
assistance in acquiring walleyes and saugers; the Wisconsin Depart-
ment of Natural Resources for their assistance in obtaining adult
saugers; and Robert G. Ruesink and Michael Bronowski for their
assistance in laboratory operations.
                                  vii

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                              SECTION I

                             CONCLUSIONS

The response of walleyes and sauger to temperature are not greatly
different except that the optimum range for fertilization is higher
in the sauger.  The upper lethal temperature is slightly higher for
walleyes.

The optimum temperature range for egg survival in walleyes occurs
with fertilization at 6-12 C and incubation at  9-15 C.  In sauger
the optimum range is 9-15 C for fertilization and 12-15 C for incu-
bation.  The incubation temperature TL50 on normalized hatch data
for walleyes when maximum hatch is greater than 50% for the fertili-
zation temperatures of 6, 9, and 12 C was 19.0, 20.1, and 19.0 C,
respectively.  Sauger eggs fertilized at 9, 15, and 18 C had a 50%
hatch OTC greater at the incubation temperatures of 6.5-21.0, 10.2-
17.5, and 11.0-17.6 C, respectively.  Survival of hatched fry through
abosrption of the yolk sac is best at the same temperature range
(9-21 C) for both species.  Survival to the juvenile stage requires
a relatively higher temperature (21 C) than through incubation to yolk
sac absorption.

Growth rate of juveniles is optimum for both species at 22 C.  A sudden
temperature change does not appear to be a significant lethal factor
for either species until upper lethal temperature is closely approached
or very low temperature (6 C) is reached.  The amount of temperature
change is not important.  Upper lethal temperature for walleye is from
27.0-31.6 C and for sauger 26.6-30.4 C, depending on acclimation tem-
perature.

With acclimation to normal summer ambient temperature (22 C) upper

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lethal temperature is 31 C and 30 C for nonfceding fish.

Based on tests when walleye juveniles were exposed to a sudden tem-
perature change, the lower lethal temperaure for walleyes accclimated
to 25 C is slightly lower than 8 C.

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                                SECTION II
                             RECOMMENDATIONS
Recommendations for thermal criteria for saugers and walleyes based
on the laboratory studies reported here indicate different levels
for spawning and incubation and for later stages.  For the period
of fertilization and incubation temperature should not exceed 15 C.
During the period of early fry development temperature should not
exceed 18-21 C.  Summer temperature should not exceed a weekly
average of 24 C or a maximum of 27 C to insure sustained growth and
survival of juveniles.

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                             SECTION III
                             INTRODUCTION

Increased steam power requirements will add to problems of thermal
pollution during the immediate future.  It is therefore important to
define temperature requirements for all life history stages of fish.
The effect of temperature is most critical during the early life his-
tory stages but is probably most noticeable for its effect on sustained
growth and survival.

The determination of temperature effects on the early life history
stages of the walleye, Stizostedion vitreum vitreum (Mitchill), and
sauger, Stizostedion canadense canadense (Smith), is necessary to
establish thermal criteria for these species.  To determine tempera-
ture influence on early life history stages of walleyes and saugers
both optimum and critical temperatures must be defined.  Definitive
information is scarce on detrimental effects of high temperatures on
the Stizostedion species as well as optimum temperatures for different
life stages.  Many authors have reported that walleye spawning generally
                                                               1      2
takes place in a temperature range of 6-12 C (Bradshaw and Muir , Cobb ,
Eddy and Surber , Ellis and Giles , Eschmeyer , Grinstead , Johnson ,
              89         10        11          12             13
Niemuth et al. , Payne , Priegel  , Rawson  , Schumann  , and Spinner  ).
Others have reported that sauger spawn generally at the same tempera-
ture range as the walleye (Carufel  , Nelson  , and Priegel  ).  Priegel
reported that walleye eggs will hatch in 21 days at temperatures of 10-
12 C while saugers will hatch in 13-15 days at that temperature.
                                                                       18
Various authors have reported thermal effects on egg survival.  Steucke
concluded that the apparent optimum temperature range for hatching
walleye eggs is 16.7-19.4 C.  Furthermore it was pointed out by Allbaugh
        19
and Manz   that temperature fluctuations during incubation of walleye
eggs had no great effect on the percentage hatch.  Johnson  showed that

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best egg survival in natural conditions occurred in years of warm water
temperatures and shorter incubation periods.  Therefore, the effect of
higher temperature caused by electric generating power plants could
have both beneficial and detrimental effects on walleye survival.

The objective of the present investigation was to determine thermal
requirements for early life history stages of the walleye and sauger
and to provide a basis for the establishment of accurate water quality
criteria.  These studies include the determination of lethal and sub-
lethal temperature effects on eggs, fry, and juveniles tested in the
laboratory at the University of Minnesota.  The specific objectives of
the study were to determine: 1) optimum temperatures for egg and fry
survival; .2) optimum temperatures for juvenile growth; 3) effects of a
sudden temperature change on fry and juveniles; and 4) the upper lethal
temperatures for juveniles.  Optimum temperatures for fertilization,
incubation, and fry survival were determined.  Juvenile fish were
exposed to a series of constant temperatures to determine optimum
growth levels.  Walleye fry and juveniles were also subjected to a
series of test temperatures to determine the effect of a temperature
change on survival.  To conclude the study, walleye and sauger juveniles
were exposed to high temperatures to determine the upper lethal tempera-
tures after acclimation to a series of temperatures.

This study was funded by the Environmental Protection Agency (Project
No. 18050 PAB) and the Agricultural Experiment Station of the Univer-
sity of Minnesota.

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                              SECTION IV
                         MATERIALS AND METHODS

EXPERIMENTAL FISH STOCK
Adult walleyes were secured from Little Cutfoot Sioux Lake and Upper
Red Lake in the spring of 1971 and 1972.  The fish were captured with
trapnets by the Minnesota Department of Natural Resources during the
spawning run.  Adult saugers were taken from Lake Winnebago, Wisconsin
in 1972 and from the Mississippi River, below Lock and Dam #3 in Red
Wing during the spring of 1972 and 1973.  The saugers from Lake Win-
nebago were captured with trapnets by the Wisconsin Department of
Natural Resources during the spawning period.  Fish from the Missis-
sippi River were collected with a boom shocker by the Minnesota
Department of Natural Resources during the spawning run.  Adult fish
were taken 1 to 2 days prior to full ripeness and transported to the
laboratory at the University of Minnesota in 100 gallon stock tanks
aerated with compressed air.

Juvenile walleyes were secured from natural rearing ponds stocked by
the Minnesota Department of Natural Resources.  These fish were cap-
tured in July and August of 1971 and 1972 with seine nets and small-
mesh trapnets.   Juvenile saugers were collected from Lake Pepin,
Minnesota with a seining net during the months of July and August 1973.

EXPERIMENTAL APPARATUS
Apparatus used for thermal tests consisted of six polyethylene head
tanks, each with 114 liters capacity.  The temperature of the water
entering the head tanks was 10 C for experiments conducted above 10
C.  Chilled water at 4 C was supplied in head tanks in experiments
run at less than 10 C.  The water was aerated in each head tank to

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produce an oxygen concentration of 5 mg/liter or greater.

The temperature in each head tank was controlled with a bimetal thermo-
regulator wired through a relay to two 1000-watt immersion heaters.
They maintained temperatures in the experimental chambers within a
range of + 0.2-0.3 C  (SD = 0.26) of the desired temperature of each
experiment.

After temperature adjustment water was fed to a set of experimental
incubation, fry, and juvenile test chambers.  Water from the head tank
flowed by gravity through 3/4 inch polyvinyl chloride pipe to each
set of chambers and then through tygon tubing to individual chambers
(Figure 1).

Eggs were tested in incubation chambers consisting of acrylic tubes
10 cm long, with an inside diameter of 3.8 cm.  Inside the cylinder,
5 cm from the top, the eggs lay on #656 Nitex screen where water
flowed past at an average rate of 325 ml/min (range, 200-425).  The
incubation cylinders were submerged in small, 13.5 x 10.5 x 20 cm,
cases with three glass sides and one of #656 Nitex screen.  These
cases were placed in larger aquaria so that the cylinders were sub-
merged but not the top of the cases.  This arrangement allowed the
fry to swim out of the incubation cylinders and be removed to larger
fry chambers.  Incubation chambers are shown in Figures 2 and 3.
                                i
Fry chambers were set up in a flow-through system consisting of glass
aquaria 25 x 25 x 50 cm, constructed of double strength window glass
and silicone adhesive (General Electric Silicone Seal).  An outlet
tube (1/2 inch OD) set 20 cm from the bottom maintained a volume of
25 liters in the chamber.  The flow rate through the aquaria was about
1 liter/min (+ 100 ml).

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                                          HEAD  TANK
                                       INCUBATION
                                        CHAMBERS
                                           FRY AND
                                           JUVENILE
                                           CHAMBERS
Figure 1. Diagram of the experimental apparatus showing the head tank,
        incubation chambers, and fry chambers.
                           8

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                                                                        NO. 9
                                                                         NEOPRENE
                                                                          STOPPER
Figure 2.  Diagram of the continuous flow-through incubation chamber.

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              Figure 3.  Diagram of  the incubation cylinder showing the top,  bottom, and side views.

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The chambers used for tests on juveniles were identical to the fry
chambers except that a higher flow rate was used.  Flow rates were
controlled with a utility clamp and were adjusted according to the
temperature level with flows at higher temperatures of about 2 liters/
min.  Each chamber was lighted with a 40 watt incandescent light
placed approximately 2 feet from the water surface and the photoperiod
was adjusted bi-monthly to follow the natural environmental day length
cycles.
TEST WATER CONDITIONS
The incubation, fry survival, and growth experiments were conducted at
six constant temperatures.  The temperature, pH, oxygen concentration,
and total alkalinity for the tests are shown in Table 1.  The tempera-
ture was measured daily with a total immersion thermometer graduated
to 0.1 C.  A 24 channel temperature recorder was used to monitor tem-
perature variation through  the tests. Dissolved oxygen was
measured bi-weekly with the azide modification of the Winkler method
     20
(APHA  ).  Total alkalinity was determined weekly as mg/liter CaCO-
                                          21
by the brom-cresol method (Dobie and Moyle  ).  Temperatures fluctuated
only slightly, the pH averaged 8.00, the 02 concentration was 5.8
mg/liter or greater depending on the temperature, and the total alka-
linity averaged 225 mg/liter.

Test water was taken from the laboratory well which had a pH at 10 C
of 7.5.  A complete analysis of water was made by the Minnesota Depart-
ment of Health, Division of Environmental Sanitation (Table 2).
ACCLIMATION PROCEDURE
The adult fish taken in the field at 5-10 C were acclimated to six
test temperatures in the laboratory (6, 9, 12, 15, 18, and 21 C)
before they were stripped for eggs.  When brought into the laboratory
the adults were placed in 335 gallon holding tanks at the temperature
of capture.  Twelve hours later temperatures were changed in 24 hours
                                  11

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Table 1.  TEMPERATURE, pH, DISSOLVED OXYGEN (02),
 AND TOTAL ALKALINITY OF TEMPERATURE EXPERIMENTS

Observed
Nominal
temperature , Mean ,
Test C C
Walleye
adult ac-
climation
and ferti-
lization

S auger
adult ac-
climation
and ferti-
lization
Walleye and sauger
egg incubation
and fry
survival


Walleye
juvenile
growth I
6
9
12
15
18
21

9
12
15
18
6
9
12
15
18
21
16
21
25
6.2
9.1
12.0
15.2
17.9
20.9

9.2
11.9
15.0
18.2
6.0
8.9
12.0
15.0
18.1
20.9
16.3
21.1
25.2
temperature
Standard
deviation ,
C pH
+0.32
+0.11
+0.14
+0.27
+0.09
+0. 12

+0.16
+0.10
+0.11
+0.21
+0.22 8.0
+0.26 7.9
+0.07 8.0
+0.19 8.0
+0.21 8.0
+0.22 8.1
+0.16 8.1
+0.24 8.2
+0.26 8.2
Mean
°2
mj?/l
8.1
7.9
8.0
7.4
7.2
7.9

7.8
7.9
7.5
8.0
8.0
7.1
7.6
7.3
7.5
8.4
9.4
8.3
8.6
Mean
TA
mg/1
236
232
225
234
237
215

225
230
215
230
232
232
227
215
230
230
238
236
238
                        12

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Table 1 (continued).  TEMPERATURE, pH, DISSOLVED OXYGEN (02),



          TOTAL ALKALINITY OF TEMPERATURE  EXPERIMENTS

Test
Walleye
juvenile
growth II



S auger
j uvenile
growth


Nominal
temperature ,
C
18
20
22
24
26
28
16
18
20
22
26
Observed
Mean,
C
18.1
20.2
22.1
23.9
26.0
28.0
16.1
18.1
20.0
22.0
26.0
temperature
Standard
deviation ,
C
+0.13
+0-15
+0.08
+0.08
+0.12
+0.14
+0.09
+0.08
+0.12
+0.11
+0.10
pH
8.1
8.1
8.2
8.2
8.3
8.2
8.2
8.2
8.3
8.3
8.3
Mean
°2
ma/1
7.6
7.0
7.0
6.8
6.1
6.1
7.9
6.8
7.0
6.1
5.8
Mean
TA
me/1
232
232
225
234
237
215
230
234
237
237
232
                       13

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        Table 2.  CHEMICAL ANALYSIS OF LABORATORY WELL WATER
     Item
Concentration,
   mg/liter
Total hardness as
Alkalinity as CaCO-
Iron
Manganese
Chloride
Sulfate
Fluoride
Total phosphorus
Methylene blue active sub. as ABS
Calcium as CaCOg
Sodium
Potassium
Ammonia nitrogen
Organic nitrogen
Phenols
Copper
Cadmium
Zinc
Nickel
Lead
   220
   230
     0.02
     0.04
     0.22
     0.03
     0.1
   140
     6
     2
     0.20
     0.20
   <0.005
   <0.01
   <0.01
   <0.01
   <0.01
                                  14

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to the test temperatures which ranged from 6 to 21 C.  The water tem-
perature was controlled in each tank with a polyethylene heat ex-
changer.  After acclimation temperature was reached the fish were
held from 1 to 2 days before being stripped.  The fish were stripped
when eggs were released by the females when minimum pressure was
applied to the lower abdomen.

Juveniles were captured in the field when the water temperature
ranged from 18 to 24 C.  At the laboratory, they were given a pro-
phylactic treatment of 20 mg/liter neomycin sulfate for 3 days before
the acclimation process was started.  The holding tanks were then
flushed and the temperature was raised with a polyethylene heat ex-
changer.  The fish were acclimated at a rate of 2 C/day and were held
at the desired test temperature for at least 2 weeks before testing
was initiated.  During acclimation fish were fed with fathead minnows.
The fish were held in a flow-through system thus requirements for
cleaning tanks were minimal.  Tanks were siphoned clean every other
day.  At the time of testing fish were transferred in plastic pails
to the test chambers without going through a temperature change.

EGG STRIPPING

Adult fish were stripped and eggs were fertilized at the same water
temperature to which the adults were acclimated.  Eggs from two females
were stripped into a Nalgene beaker, then seconds later milt was
stripped from two males and mixed thoroughly with the eggs.  At the
same time the milt was added, water at the required fertilization tem-
perature was gradually introduced and mixed.  Finally bentonite clay
was added to the fertilized eggs to prevent clumping.  The eggs were
then rinsed clean and the beaker was then placed in a water bath to
acclimate the eggs to their respective incubation temperatures and
allow them to water harden.  Within 1 hour after fertilization the
eggs were examined under a microscope and 100 to 300 pooled eggs were
                                  15

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randomly removed with an eye dropper and placed in the incubation
chambers.  Eggs that were small and opaque were discarded.  The number
of opaque eggs varied from 0 to 80% with no relation to temperature
of fertilization.

EGG TEST PROCEDURE

Eggs were counted, dead eggs were removed, and mortality counts were
recorded daily.  Only eggs that had turned white were counted as dead.
Live eggs were not handled and remained in the incubation chambers
until hatched.

FRY TEST PROCEDURE

Upon hatching fry were removed with a glass tube and gradually trans-
ferred to the fry chambers.  Fry were sampled for size determinations
each day after hatching started.  Ten percent of the fry from each
day's hatch were randomly removed and preserved in 5% formalin, and
100 fry were placed in each fry chamber for survival tests.  All fry
were fed twice a day with natural plankton which consisted mostly of
copepods and once a day with brine shrimp.  Black plastic sheets were
taped to the outside walls of all aquaria since it was found that fry
in chambers without the black walls did not swim freely but clung to
the sides of the chamber without feeding and eventually died.  Fry in
chambers with black walls swam freely and fed well.
                                   16

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                              SECTION V
                     WALLEYE EGG AND FRY SURVIVAL

EXPERIMENTAL DESIGN
Walleye adults were acclimated to six different temperatures, 6, 9, 12,
15, 18, and 21 C.  After the adults became ripe, the fish were stripped
and the eggs were fertilized at the same six temperatures.  To separate
the effects of fertilization (parental) temperature and incubation
temperature on the hatchability of eggs, the eggs fertilized at each
temperature were incubated at six different temperatures, 6, 9, 12, 15,
18, and 21 C.  The fry hatched at these temperatures were carried
through at the same six temperatures to determine fry survival to yolk
sac absorbtion and to the juvenile stage.  This design is schematically
shown in Figure 4.

HATCHABILITY OF WALLEYE EGGS
Effect of Fertilization Temperature on Hatch
The tests described above on walleye eggs determined the optimum in-
cubation and fertilization temperature range for hatch and permitted
separation of effects of incubation temperature, fertilization tem-
perature, or interaction between the two on egg mortality (Table 3,
Figure 5).

The lowest fertilization temperature, 6 C, resulted in the highest per-
centage hatch for each of the incubation temperatures except for the
highest, 21 C, where 0.0% of eggs survived.  A maximum hatch of 84.0%
was obtained at a fertilization temperature of 6 C and an incubation
temperature of 6 C.  As the fertilization temperature increased the
percentage hatch progressively decreased with the highest fertilization
temperature resulting in the lowest percentage hatch.  At a fertiliza-
tion temperature of 21 C the percentage hatch ranged from 10.0% at an
                                  17

-------
                                          ADULT   ACCLIMATION
                                                                                                                       ADULT   ACCLIMATION
00
                           ADULT
                            6*c
                    EOO EDO EOO EOO E30 EOO
                    6'c 9'ci2*ci8'cie'c 2i*c
                     FRY FRY FRY FRY FRY FRY
                     8'C 9'C I2'C IB'C ICC 2I'C
       ADULT
        9'C
                                              FERTILIZATION
                                                     EOO
                                                     9'C
       ADULT
       12'C
       ADULT
       IB'C
                                             EGG  ACCLIMATION
EOO EOO EOO EOO EOO E«0
6'C 9'C I2'C • •011*021*0
                                                 INCUBATION
 FRY FRY FRY FRY FRY FRY
 6'c 9'c iz'c ia>c ia*c 2i*c
EOO COO COO EOO EOO EOO
6'C 9'C I2'C 15'C I8'C 2I'C
FRY FRY FRY FRY FRY FRY
8'C 9'C 12'C IB'C H'C 2I'C
EOO EOO EOO COO EOO COO
8'C 9'C I2'C I»'C I6'C 2I'C
FRY FRY FRY FRY FRY FRY
«'c g*c 12'c is'c ire 2i'c
                                                                             FERTILIZATION
                                                                                    EOO
                                                                                    IB'C
                                                                            EGG  ACCLIMATION
EOO EOO E09 EIO COO COO
6'c 9'c I2'c e«c ia'c arc
                                                                                INCUBATION
 FRY FRY FRY FRY FRY FRY
 6'C 9'C 12'C U'C It'C tl'C
                                ADULT
                                2I«C
                     FRY FRY FRY FRY FRY FRY
                     6'C »'C I2'C U'C U'C 21'C
FRY FRY FRY FRY FRY FRY
6'C 9'C 12'C IB'C I»'C 2I'C
FRY FRY FRY FRY FRY FRY
6'C 9'C I2'C B'C I9'C 2I'C
FRY FRY FRY FRY FRY FRY
6'C 9'C 12'C IS'C 16'C 2I'C
FRY FRY FRY FRY FRY FRY
6'C 9'C 12'C IB'C H'C 2I'C
EOO EOO COO EOO COO EOO
6«0 »«C I2*C B'C U'C 2I'C
 FR» FRY FRY FRY FRY FRY
 6'C 9'C I2'C IB'C »'C 2I'C






FR
Y
SU
»VI
VAI













FR
Y
SI
JRV
IVA
L





FRY FRY FRY FRY FRY FRY
6'C 9'C I2'C Ifl'C I6'C 2I'C
                        Figure 4.    Schematic  diagram of  the  experimental  design  for  the  egg and  fry  experiments.

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Table 3.  PERCENTAGE HATCH OF WALLEYE EGGS FERTILIZED AT 6 DIFFERENT
        TEMPERATURES AND INCUBATED AT 6 DIFFERENT TEMPERATURES

Fertilization
temperature ,
C
6.2
9.1
12.0
15.2
17.9
20.9






Incubation temperature, C
6.0
84.0
51.0
37.7
5.0
11.0
1.0
8.9
77.0
66.5
59.0
11.0
39.0
5.0
12.0
77.0
67.0
61.5
15.0
27.0
10.0
15.0
80.0
73.0
53.0
15.0
41.0
7.0
18.1
63.0
61.0
38.0
0.0
32.0
0.0
20.9
0.0
23.0
10.0
0.0
1.0
0.0
                                   19

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          100
           80
           60
     UJ
     o
     IT
     liJ
     Q.
40
           20
                     FERTILIZATION   TEMPERATURE
                         6
                     9
12
15
18
21
                INCUBATION    TEMPERATURE    (°C)
Figure 5.  The combined effect of fertilization temperature and incubation

          temperature on the hatchability of walleye eggs.  Each line
          represents the percentage hatch of eggs fertilized at one of

          six temperatures and incubated at six temperatures, 6, 9, 12,
          15, 18,  and 21 C.
                              20

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incubation temperature of 12 C to 0.0% at incubation temperatures of
18 and 21 C.  At a fertilization temperature of 18 C the percentage
hatch ranged from 41.0% at an incubation temperature of 15 C to 1.0%
at an incubation temperature of 21 C.  The percentage hatch of eggs
fertilized at 15 C ranged from 15.0% at the incubation temperatures of
12 and 15 C to 0.0% at the incubation temperatures of 18 and 21 C.  At
a fertilization temperature of 12 C the percentage hatch ranged from
61.5% at an incubation temperature of 12 C to 10.0% at an incubation
temperature of 21 C.  Eggs fertilized at 9 C resulted in a percentage
hatch that ranged from 73.0% at an   incubation temperature of 15 C to
23.0% at an incubation temperature of 21 C.  With fertilization at 6
C the percentage hatch ranged from 84.0% at an incubation temperature
of 6 C to 0.0% at an incubation temperature of 21 C.

The effect of incubation temperatures on the hatchability was modified
substantially by temperature at fertilization.  Independent of the
effect of fertilization temperature the greatest percentage hatch was
at incubation temperatures of 9-15 C.  The lowest percentage hatch was
at incubation temperatures of 6 and 21 C.  The only exception was at
a fertilization temperature of 6 C and an incubation temperature of
6 C, where 84.0% hatch was obtained.  The 21 C incubation temperature
appears to be lethal for eggs fertilized at all temperatures.  At the
incubation temperatures of 6 to 18 C there was a mean difference be-
tween the highest and lowest percentage hatch of 19.5% (range 10.0-
30.0) for all fertilization temperatures.  The incubation temperature
of 21 C was not included in this analysis for the reasons stated above.
The TL50, when maximum hatch is greater than 50%, of the incubation
temperature for each fertilization temperature was 19.0 C for the fer-
tilization temperatures of 6 and 12 C and 20.1 C for the fertilization
temperature of 9 C.

To determine whether any interaction occurred between the fertilizatior

                                  21

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temperature and the incubation temperature, a statistical analysis was
                                                      22
done using a 3-dimensional contingency table (Feinberg  ).  Setting
up the data in a 6 x 6 x 2 contingency table and by comparing the
Freeman-Tukey Deviations, it was determined that the only place where
statistically real interaction occurred was at the 6 C incubation and
6 C fertilization temperatures.  At this point there was an unexpected
high percentage egg survival.  The observed survival was 84.0% while
the expected egg survival was 64.29%.  Appendix A, Table 1 lists all
expected values of egg survival for all incubation and fertilization
temperatures.

Effect of Fertilization Temperature on Fry Size

Walleye fry hatched from eggs fertilized at six different temperatures,
6-21 C, were measured from each of the six incubation temperatures.

Time to hatch did not vary between fertilization temperatures within
each incubation temperature (Table 4), but the size of the fry showed
a significant difference at the .05 level between the fertilization
temperatures for each incubation temperature, except at the incubation
temperature of 18 C.  It was determined from regression analysis that
the size of the fry at each fertilization temperature played a signi-
ficant part in the regression equations calculated for each incubation
temperature.  The regression equations were determined with the use of
dummy variables representing each fertilization temperature.  This
procedure was done to avoid testing only for a straight line.  The
dummy variables are presented in Appendix A, Tables 2 and 3.  The
regression equations determined for each incubation temperature are as
follows:
   6 C  Y = 1.6054 + .OUSX-  + .0124X2 - .0035X3 - .0137X4
                                       - .0088XC + .0036X,         (1)
                                               j         b
                                  22

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Table 4.  TIME TO MEDIAN HATCH IN DAYS FOR WALLEYE EGGS INCUBATED AND
                FERTILIZED AT 6 DIFFERENT TEMPERATURES

Nominal
incubation
temperature ,
C
6
9
12
15
18
21
Nominal fertilization temperature,
C
6
34
26
16
10
7
__
9
34
27
17
11
8
6
12
33
25
15
10
7
5
15
33
25
14
10
—
—
18
35
26
14
10
7
—
21
33
25
16
10
—
—
                                  23

-------
  9  C  Y =  1.5432 + .0157X.. + .0130X-  -  .0190X.  -  .0328X.
                          1234
                                          +  .0288X, +  .0103X,      (2)
                                                   J          D
12 C  Y = 1.6645 +  .0076X-L +  .0102X2 +  .0137X3  -  .0141X4
                                          -  .0117X,. +  .0121X,      (3)
                                                   5          o
15 C  Y = 1.6802 +  .0025X1 +  .0100X2 +  .0238X3 -  .0130X4
                                          -  .0019XC +  .0161X,      (4)
                                                  3          D
18 C  Y = 1.6363 -  .0027X1 -  .0069X2 +  .0097X3 +  .0267X6           (5)
 ,           „    n  (size in mm)
where       Y =     ^       -
        X1~XC. = dummy variables (see Appendix A, Tables 2 and 3)
           X, = Mean number of days to hatch.

The F-ratios calculated for each incubation temperature were as
follows (*significant at .05 level) :
                         6 C  F = 2.51*
                         9 C  F = 27.40*
                        12 C  F = 8.25*
                        15 C  F = 8.47*
                        18 C  F = .8151
                       ^
Table 5 shows the size of the fry at the different temperatures cal-
culated from the regression equations.

With incubation temperatures of 6 C, 9 C, 12 C, and 15 C, the size of
the fry at hatch was consistently greater at the lower fertilization
temperatures, 6 and 9 C.  At the incubation temperature of 18 C there
was no significant difference at the  .05 level in the size of the fry
                                  24

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          Table 5.  SIZE OF WALLEYE FRY  (MILLIMETERS) AT HATCH CALCULATED FROM THE REGRESSION EQUATIONS

                                      Number of Measurements  in Parentheses
to
Ol

Incubation
Fertilization
temperature ,
C
6
9
12
15
18
6
6.06(16)
7.09(13)
7.66(12)
7.53(9)
7.18(8)
9
6.03(11)
7.05(13)
7.72(8)
7.65(11)
7.11(8)
temperature ,
C
12
5.81(12)
6.55(11)
7.77(12)
7.90(9)
7.39(5)
15
5.68(2)
6.35(7)
7.13(3)
7.26(5)
-
18
5.75(6)
7.29(11)
7.33(6)
7.45(7)
7.22(6)
21
5.86(1)
6.75(4)
7.44(5)
7.12(1)
-
Mean number
of days
to hatch
37.8
25.8
15.4
10.4
7.3

-------
between  the  fertilization  temperatures.  Due to the low hatch at the
incubation temperature of  21 C, the sample size was too small for any
type of  statistical analysis.

Effect of Constant Temperature on Eggs and Fry

Eggs and fry were held at  six constant temperatures through fertili-
zation, incubation, and after hatching.  Fry were held to the juvenile
stage.  Survival of eggs,  sac fry, and juveniles as well as time to
hatch and size of the fry  at hatch were determined (Table 6).  Repli-
cates were combined in the final analysis since there was no signifi-
cant difference found at the .05 level between the replicates.

The lowest temperature, 6  C, resulted in the highest percentage hatch
(84.0%) and progressively  decreased as the temperature increased, with
the highest temperature, 21 C, resulting in 0.0% hatch.  As noted
above, the high egg survival at 6 C was caused by the interaction of
the fertilization temperature and the incubation temperature.  If
interaction had not occurred, the hatch at 6 C (expected hatch of
64.29%) would have been about the same as the egg survival at 9 C
(66.5%) and 12 C (61.5%).  Temperatures higher than 12 C had a much
lower percentage hatch with 15 C resulting in a 15.0% hatch and 18 C
in a 32.0% hatch.

Incidence of abnormalities in fry increased as the temperature in-
creased.  The percentage of fry abnormalities was 1.0-3.8% at a tem-
perature range of 6-15 C and increased up to 15-18% at 18 and 21 C,
respectively.  Percentage  of abnormal fry was included in total hatch.

Time to first hatch, to median hatch, and to the completion of hatch
was 30, 34, and 49 days at 6 C; 23, 27, and 31 days at 9 C; 12, 15^
and 18 days at 12 C; 8, 10, and 11 days at 15 C; 6, 7, and 8 days at
                                  26

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          Table 6.   THE EFFECT OF 6 DIFFERENT TEMPERATURES ON WALLEYE EGGS AND FRY 2/  HELD AT A CONSTANT

                        TEMPERATURE DURING FERTILIZATION,  INCUBATION, AND AFTER HATCHING
N)







Mean
Tempera- Egg Abnormal Days to Days to Days to size at
ture, survival- fry, first median completion hatch,
C % % hatch hatch hatch mm
6.0
8.9
12.0
15.0
18.1
20.9
84.0
66.5
61.5
15.0
32.0
0.0
1.0
3.8
3.3
1.0
15.0
18.0
30
23
12
8
6
52'
34
27
15
10
7
55'
49
31
18
11
8
6!'
6.0
7.3
7.8
7.2
7.2
6.62'
Survival Survival
of sac
fry.*
%
0
78
88
95
97
982'
to juvenile
stage,-
%
0
0
0
0
1
*f
      a/
      -  Fry data was determined from 100 hatched fry that were taken at random from the  total  hatch at
      -  / each temperature.   Abnormal fry were not included.
      -, 200 eggs tested at each temperature.
      -j. The sac fry stage  was determined to be from hatch to the disappearance of  the yolk sac.
      -i Fish were denoted  as juveniles when they reached a length of 40 mm.
      -  Data obtained from fry hatched from eggs incubated at 21 C but fertilized  at 9 and 12  C.

-------
18 C; and 5, 5, and 6 days at 21 C.  Time to first hatch  (30 days),
median hatch (34 days), and to the completion of hatch  (49 days)  was
longest at the lowest temperature, 6 C, and decreased exponentially to
a minimum of 5 days to first hatch, 5 days to median hatch, and 6 days
to the completion of hatch at the highest temperature,  21 C.

The mean size of the fry at hatch varied from 6.0 mm at 6 C to 7.8 mm
at 12 C.  The mean size of the fry at hatch was greatest  (7.2-7.8 mm)
at the intermediate temperatures, 9-18 C, and least at  the temperature
extremes, 6 and 21 C, where the mean size of the fry were 6.0 and 6.6
mm, respectively.

The survival of walleye fry from hatch to resorbtion of the yolk sac
was high (78-98%) at all temperatures except 6 C.  At this temperature
the fry never resorbed their yolk sac completely and eventually died
about 30 days after hatching.

Total survival of walleye fry from hatch to the juvenile stage was very
low.  All fry died at the four lowest temperatures and  there was only
1% survival at 18 C.  At 21 C, 8% of the fry survived to the juvenile
stage.  The fry at 6, 9, and 12 C never accepted food, but the fry at
the higher temperatures, 15, 18, and 21 C, did accept food.  A few
walleye fry at 15 C accepted food, at 18 C about 50% fed, and at 21 C
about 75% of the fry fed on plankton.
                                   28

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                              SECTION VI

                     GROWTH OF JUVENILE WALLEYES

EXPERIMENTAL DESIGN
Two experiments were conducted to determine  the optimum temperature
for growth of walleye juveniles in 1971 and  1972.  The growth tests
were made in constant-flow chambers of 25-liter capacity.  Temperatures
from 16-28 C were used and all tests consisted of two replicates with
10 fish in each.  The replicates were combined in the final analysis
since there was no significant difference at the .05 level found be-
tween them.  The fish were distributed randomly to the respective
chambers and acclimated therein.  They were  allowed to feed on an
excess of small fathead minnows (Pimephales promelas).  The walleyes
were weighed and measured to 0.01 g at the beginning and at the com-
pletion of the 28-day test.  To facilitate measurement they were
anesthetized with tricaine methanesulfonate  (MS 222) at a concentra-
tion of 100 mg/liter.  Total length was measured to the nearest milli-
meter .
GROWTH AT 16 C, 21 C, AND 25 C (1971)
In 1971 walleye juveniles were grown at three temperatures: 16, 21, and
25 C (Table 7).  Mean weights of the fish at the beginning of the test
were 2.00, 1.91, and 1.81 g at 16, 21, and 25 C, respectively.  The
greatest increment in length and weight was at 25 C with an increase
in length of 69.7% and in weight of 429.3%.  The specific growth rate
was 5.950.  Growth decreased progressively with a decrease in tempera-
ture, with the lowest gain in weight occurring at 16 C where the fish
increased 35.5% in length and 156.5% in weight.  The corresponding
specific growth rate at this temperature was 3.371.
                                  29

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                  Table  7.  GROWTH OF WALLEYE JUVENILES  FOR 28 DAYS AT  DIFFERENT TEMPERATURES
co
o

Mean length
Temper-
ature,
C
16.3
21.1
25.2
18.1
20.2
22.1
23.9
26.0
28.0
at start of Increase
test,
mm
65.1
65.0
63.7
84.2
84.6
85.5
85.7
85.2
86.5
in length,
mm
23.1
39.0
44.4
25.8
31.6
36.1
32.6
29.3
23.7
Increase
in length,
%
35.5
60.0
69.7
30.6
37.4
42.2
38.0
34.4
27.4
Mean weight
at start of Increase
test,
e
2.00
1.91
1.81
4.30
4.59
4.62
4.71
4.42
4.94
in weight,
K
3.13
6.53
7.77
6.48
8.13
9.58
7.79
6.66
5.15
Increase
in weight,
%
156.5
341.9
429.3
150.7
177.1
207.4
165.4
150.7
104.3
Specific
growth
rate,
%/dav
3.371
5.325
5.950
3.286
3.639
4.007
3.482
3.286
2.546


Survival ,
%
100
100
100
100
100
100
80
80
60

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GROWTH AT 18-28 C  (1972)
In 1972 walleye juvenile  growth was  tested at six temperatures, 18,
20, 22, 24,  26, and  28 C  (Table 7).  The mean weight of these fish at
the beginning of the test was 4.30 g at 18 C, 4.59 g at 20 C, 4.62 g
at 22 C, 4.71 g at 24 C,  4.42 g at 26 C, and 4.94 g at 28 C.  Maximum
growth was at 22 C where  the juveniles increased 42.2% in length and
207.4% in weight and had  a  corresponding specific growth rate of 4.007.
Minimum growth was obtained at 28 C.  At this temperature the juveniles
tained 27.4% in length, 104.3% in weight and had a specific growth
rate of 2.546.  At 18 and 26 C the growth rate was identical.  Although
the percentage gain  in length at 18  C (30.6%) differed from 26 C
(34.4%), the specific growth rate was 3.286 and the percentage gain in
weight was 150.7% for both  temperatures.  The rate of increase in the
specific growth rate between 18 and  22 C was the same as the rate of
decrease between 22  and 26  C.

A multiple regression analysis was done to determine the temperature
where the asymptote  of the  growth curve occurs.  The regression equa-
tion describing the  growth  of walleye juveniles of 1972 at different
temperatures was determined to be
                   Y = -50.917 + 5.3740X - .1211X2                (6)
where  Y = weight increase in grams
       X = temperature in C.
                      2
This equation has an R  of 79.3%, which indicates that the resulting
binomial curve reduced the variability in the data by  70.3%. Curves
for both the actual data and the predicted data are shown in Figure 6.
                                  31

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    10.0
     9.0
     8.0
o
I-

UJ
     7.0
     6.0
     5.0
                                                                  B
                 18        20       22       24
                     TEMPERATURE   (°C)
                                                     26
28
Figure 6.  Growth of walleye juveniles exposed to temperatures ranging
          from 18-28 C.  Line A represents the actual  data points.
          Line B represents the predicted points calculated from the
          equation, Y = -50.917 + 5.3740X - .1211X .
                               32

-------
In both curves 22 C was the optimum temperature for growth of walleye
juveniles but the optimum temperature range can be extended to include
19-25 C.

In the 1972 study mortality occurred at the higher temperature levels.
At 28 C, 40% of the fish died during the study and at 24 and 26 C,
20% of the fish died.
                                  33

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                             SECTION VII

           EFFECT OF A SUDDEN TEMPERATURE CHANGE ON WALLEYE

EXPERIMENTAL DESIGN
Tests were performed on walleye fry and juveniles to determine the
effect of a sudden temperature change on survival.  Fry were slowly
removed with a glass tube from their respective chambers to a beaker
with the same temperature water to which they were acclimated.  Then
they were transferred to another fry chamber with a higher or lower
temperature by lowering the beaker to water level and pouring the fry
slowly out into the other chamber.  A control was run with each test
when the fish went through the same transfer process from one chamber
to another but were not exposed to a temperature change.  The sur-
vival of the control fry was corrected to 100% and the survival in the
treatments was corrected Accordingly.  Walleye juveniles were subjected
to a similar transfer process but a net was used for capture and a
larger container was used to transfer the fish from the acclimation
chamber to the test chamber.

Temperatures did not fluctuate more than + 0.1 C and the pouring process
at the start of the test did not lower or raise the initial test tem-
perature more than 0.1 C.

Tests were done over a 72-hour period for fry and 96-hour period for
juveniles.  The 72-hour period for fry tests was used to eliminate
starvation as a factor of mortality.

FRY TESTS
Sudden temperature changes were performed on walleye fry hatched and
acclimated at 6, 11, and 21 C.  The fry were subjected to both an up-
                                  34

-------
ward and downward temperature change over a 72-hour period.  A corrected
survival rate was determined by comparison to the controls where there
was no temperature  change.

Five-day old walleye fry reared at 6 C were exposed to test tempera-
tures at 11, 16, and 21 C.  Fry mortality was observed only at 21 C,
a change of +15 C, where 56% of the fry survived.  No mortality was
observed at the other  temperatures.

Two-day old fry reared at 11 C were tested at 6, 16, and 21 C.  The
lowest survival, 58%,  was at 6 C, a change of -5 C.  No mortality
occurred at 16 C, a change of +5 C.  At a change of +10 C  (21 C)
78% of the fry survived.

Seven-day old fry reared at 21 C were exposed to test temperatures at
6, 11, and 16 C.  A 100% mortality occurred at 6 C with a  change of
-15 C.  No large mortality was observed at the other temperatures.
There was 91% survival at 11 C, a change of -10 C, and no mortality
at 16 C, a change of -5 C.                               Table 8
lists the actual and corrected percentage survival of fry  for all
tests.
JUVENILE TESTS
Juvenile walleyes (80-100 mm in length) acclimated to various tempera-
tures were exposed to  higher and lower temperatures for thermal treat-
ment over a 96-hour period.  Both lethal effects and sublethal responses
were observed.  Sublethal response was recorded in terms of abnormal
behavior and food acceptance.

Walleye juveniles acclimated to 16, 21, and 25 C were exposed to tem-
peratures as much as 17 degrees below the acclimation temperature.  The
only mortality that occurred, 30%, was at a temperature change of -17
                                 35

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                  Table 8.  EFFECTS OF TEMPERATURE CHANGE ON WALLEYE FRY INCUBATED AND REARED
                                       AT 6 C, 11 C, AND 21 C - 72 HOURS
u>

Number
of fish
10
10
10
10
50
50
50
50
50
50
50
50
Age of fry
after hatch,
days
5
5
5
5
2 '
2
2
2
7
7
7
7
Rearing
temperature,
C
6.0
6.0
6.0
6.0
11.1
11.1
11.1
11.1
21.1
21.1
21.1
21.1
Test
temperature ,
C
6.0
11.1
15.9
21.1
11.1
6.0
15.9
21.1
21.1
6.0
11.1
15.9
Temperature
change ,
C
0
+5.1
+9.9
+15.1
0
-5.1
+4.8
+10.0
0
-15.1
-10.0
-5.2
Survival
%
90
90
100
50
98
56
100
76
66
0
60
72
Corrected
a/
survival—
%
100
100
111
56
100
58
102
78
100
0
91
109
        Control corrected to 100% and other temperature levels adjusted accordingly.

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C when juveniles acclimated to 25 C were exposed to 8 C (Table 9).
Sublethal response was observed with a change of -17 C.  Initially  all
fish lost their equilibrium and then swam belly up for the first 30
min of the test.  Thereafter the survivors (70%) adjusted to the cooler
temperature but remained inactive and did not feed.  Sublethal effects
but no mortality were observed with a temperature change of -13 C when
fish acclimated to 21 C were exposed to a temperature of 8 C.  Some
of the fish lost their equilibrium with this temperature drop.  Initially
30% of the juveniles swam belly up but adjusted after 10 min.  All  the
fish were slightly inactive and only a few accepted food.  No mortality
or abnormal behavior was observed with fish exposed to a -9 to -4 C
temperature change.  Percentage survival and test temperatures are
indicated on Table 9.

Juveniles acclimated to 16 and 21 C were subjected to temperatures  as
high as 12 C above the acclimation temperature  (Table 10).  Fish
acclimated to 21 C were exposed to temperature  changes of +4 and +7 C
but no mortality or abnormal behavior was observed.
                                   37

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  Table 9.  EFFECTS OF SUDDEN TEMPERATURE CHANGE ON WALLEYE JUVENILES
         EXPOSED BELOW THEIR ACCLIMATION TEMPERATURE - 96 HOURS
Number
of fish
Acclimation
temperature,
     C
Test
temperature,
     C
Temperature
change,
     C
Survival
    %
  20
  20
  20
  20
  20
  20
  20
    16.0
    21.0
    16.0
    21.0
    25.0
    21.0
    25.0
    12.1
    16.0
     8.1
    12.1
    16.0
     8.1
     8.1
   - 3.9
   - 5.0
   - 7.9
   - 8.9
   - 9.0
   -12.9
   -16.9
   100
   100
   100
   100
   100
   100
    70
                                   38

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 Table 10.  EFFECTS OF SUDDEN TEMPERATURE CHANGE ON WALLEYE JUVENILES
      EXPOSED TO A TEMPERATURE ABOVE THEIR ACCLIMATION TEMPERATURE
               Acclimation    Test           Temperature
Number         temperature,   temperature,   change,        Survival,
of fish             C              C             C              %

  20               21.0           24.9          +3.9          100
  20               16.0           21.0          + 5.0          100
  20               21.0           27.8          + 6.8          100
  20               16.0           24.9          + 8.9          100
  20               16.0           27.7          +11.8          100
                                    39

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                              SECTION VIII

                    WALLEYE UPPER LETHAL TEMPERATURE

EXPERIMENTAL DESIGN
Upper lethal temperature tests were conducted on juvenile walleyes
which had been subjected to a wide range of acclimation temperatures.
These fish had a mean length of 115 mm.  All fish were acclimated to-
gether in a large holding tank for 2 weeks.  They were then placed in
three 25-liter flow-through chambers at- their acclimation temperature
in groups of ten for 2 days before each test began.  Temperatures were
held constant throughout each acclimation period (S.D. = 0.07).  Ac-
                23
cording to Brett   the rate of temperature change over a period of a
few hours will not greatly affect the thermal tolerance limit since
the acclimation to changing temperatures requires several days.  There-
fore for these tests the temperatures were raised to the experimental
temperatures at a rate of 3-4 C/hour.  The test began at the end of the
temperature rise.  Test temperatures did not fluctuate greatly (S.D. =
0.11).  Fish were not fed for 96 hours prior to testing since feeding
                                                                   24
could influence the upper lethal temperatures.  Javaid and Anderson
found that starvation influences the selected temperatures of salmonids.
LETHAL TESTS
Upper lethal temperatures of TL50s were graphically determined for wall-
eye juveniles acclimated to temperatures ranging from 8 to 26 C by 2 C
intervals (Table 11).  Fish were tested for 96 hours only since mortal-
ity occurred mostly within the first 12 hours of the test.  The upper
lethal temperature is the incipient lethal temperature which is defined
      25
by Fry   as the temperature at which 50% or more of the fish died.

The upper lethal temperature increased as the acclimation temperature
increased.  From an acclimation temperature of 8 to 14 C the TL50 in-

                                   40

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Table 11.  PERCENTAGE SURVIVAL OF WALLEYE JUVENILES EXPOSED TO UPPER
            LETHAL TEMPERATURE LEVELS FOR EACH ACCLIMATION
                       TEMPERATURE FOR 96 HOURS

Acclimation
temperature
C
8.0
10.1
12.1
13.9
16.0
18.2
20.2
22.1
24.0
25.8
Test temperature,
C
26.0 27.0 28.0 29.0
100 50 10
100 100 10
100 50
- - 90
- 100
- - 100
_ _ _ _
_
_ _ -
_ _ _ —
30.0
-
-
0
10
100
100
100
100
-
—
31.0
-
-
-
0
10
0
0
0
90
100
32.0 33.0
-
-
-
-
-
-
0
0
10
10 0
TL50,
C
27.0
28.6
29.0
29.5
30.6
30.5
30.5
30.5
31.5
31.6
                                  41

-------
creased from 27.0 to 29.5, then at the acclimation temperatures of
16.0 to 22.0 C the upper lethal temperature remained stable at 30.5-
30.6 C.  The TL50 increased slightly to 31.5 and 31.6 C for the
acclimation temperature of 24 and 26 C, respectively.  In most cases
there was a temperature difference of 1 C between 90-100% survival
and 0-10% survival.  This effect is shown in Figure 7 where both
TL90 and TL10 are plotted.
                                  42

-------
o
e
32

31

30
   26
     6    10  12   14   16    18   20  22   24   26
     ACCLIMATION   TEMPERATURE (°C)
       Figure 7.  TL10 and TL90 levels of walleye juveniles
       exposed to upper lethal temperatures.  TL10 and TL90
       were at 10 and 90% survival plotted on arithmetic
       paper.
                        43

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                              SECTION IX

                     SAUCER EGG AND FRY SURVIVAL

EXPERIMENTAL DESIGN
Sauger adults were acclimated to four temperatures, 9, 12, 15, and
18 C.  After the adults became ripe they were stripped and the eggs
were fertilized at the same four temperatures.  After fertilization
the eggs were incubated in the same manner and at the same six tem-
peratures (6-21 C) as the walleye eggs (Figure 4).  The fry hatched
at these temperatures were carried through to juveniles at the same
temperatures to determine fry survival to yolk sac absorbtion and to
the juvenile stage.  Replicates were combined in the final analysis
since there was no significant difference between replicates at the
.05 level.

HATCHABILITY OF SAUGER EGGS
Effect of Fertilization Temperature on Hatch
Sauger eggs were tested to determine the effect of various temperatures
on fertilization, incubation, and egg survival (Figure 8, Table 12).
Eggs were fertilized at 9, 12, 15, and 18 C and the group of eggs
fertilized at each temperature was incubated at six temperatures; 6,
9, 12, 15, 18 and 21 C.

The lowest fertilization temperature (9C)  resulted in the highest per-
centage hatch for each of the incubation temperatures except at 12 C
where eggs fertilized at 15 C had a slightly higher percentage hatch
(77.0%) than at 9 C (75.7%).  The percentage hatch decreased as the
fertilization temperature increased.  Lowest egg survival resulted from
a fertilization temperature of 12 C but these eggs may have had low sur-
vival from similar reasons noted for walleye eggs fertilized at 15 C.
                                  44

-------
          100
           80
           60
     bl
     O
     K
     Ul
     Q.
40
           20
                     FERTILIZATION   TEMPERATURE
                               9    12    15    18    21
                INCUBATION    TEMPERATURE    (*O
Figure 8.  The combined effect of fertilization temperature and incuba-
          tion temperature on the hatchability of sauger eggs.  Each
          line represents the percentage hatch of eggs fertilized at
          one of four temperatures and incubated at six temperatures.
                              45

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Table 12.  PERCENTAGE HATCH OF SAUCER EGGS FERTILIZED AT
   FOUR TEMPERATURES AND INCUBATED AT SIX TEMPERATURES

Fertilization
Incubation
temperature.
C
9.2
11.9
15.0
18.2
6.0
46.2
1.7
2.0
0.0
8.9
72.2
14.8
34.0
25.5
12.0
75.7
32.0
77.0
58.6
temperature,
C
15.0
77.8
27.2
73.5
54.0

18.1
80.4
2.2
12.0
44.5

20.9
65.7
0.0
1.0
42.0
                           46

-------
Eggs fertilized at 9 C had a percentage hatch which varied from 80.4%
at an incubation temperature of 18 C to 46.2% at an incubation temper-
ature of 6 C.  With fertilization at 12 C the percentage hatch ranged
from 32.0%  at an incubation temperature of 12 C to 0.0% at 21 C.  The
percentage hatch of eggs fertilized at 15 C ranged from 77.0% at an
incubation temperature of 12 C to 1.0% at 21 C.  With fertilization at
18 C the percentage hatch ranged from 58.6% at an incubation temperature
of 12 C to 0.0% at 6 C.  By separation of the effects of fertilization
temperature and incubation temperature on egg survival it was deter-
mined that egg survival  was greatest at incubation temperatures from
12-15 C regardless of the fertilization temperature.  Egg survival was
lowest at an incubation temperature of 6 C.  Egg survival rates  (Table
12) at incubation temperatures of 12-15 C were 75.7-77.8%, 32.0-27.2%,
77.0-73.5% and 58.6-54.0% at fertilization temperatures of 9, 12, 15,
and 18 C, respectively.  Survival of eggs fertilized at these four
temperatures but incubated at 6 C was 46.2%, 1.7%, 2.0%, and 0.0%, re-
spectively.
Effect of Constant Temperature on Eggs and Fry
Sauger eggs and fry were held in six constant temperatures through
fertilization, incubation, and after hatching to the juvenile stage.
Survival of eggs, sac fry, and juveniles, time to hatch, and size of
the fry at hatch were determined (Table 13).  Highest egg survival was
at 9 and 15 C with 72.2% and 73.5% hatching.  At 12 C and 18 C,  32.0%
and 44.5% hatched.
                                 }
Incidence of abnormalities in hatched fry increased as the temperature
increased.  The percentage of abnormal fry was low at 6, 9, and  12 C
where 2.0%, 2.0%, and 3.5% of the total hatch was abnormal.  At  a tem-
perature of 15 C the percentage of abnormal fry was high (18.0%) but
then dropped to 3.3% at 18 C.  At 21 C the incidence of abnormalities
was highest (23.0%).  The percentage abnormal fry were included  in the
percentage of total hatch.
                                   47

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                    Table 13.  THE EFFECT OF SIX CONSTANT TEMPERATURES ON SAUCER EGGS AND FRY-
                                                                                             a/
00


Tempera-
ture,
C
6.0
8.9
12.0
15.0
18.1
20.9

Egg
4 -, V
survival, -
%
_
72.2
32.0
73.5
44.5

Abnormal
fry,
%
2.0^
2.0
3.5
18,0
3.3
23. O-/
Time to
first
hatch,
days
37S/
22
12
8
7
£'
Time to
median
hatch ,
days
«s/
28
16
10
8
6!>
Time to
completion
hatch,
days
58S'
35
21
13
10
sV
Mean
size at
hatch ,
mm
4.77S'
5.76
5.84
5,58
5.64
5,59^
Survival
of sac
fry,
%
OS/
92
86
75
90
85S/
Survival
to juvenile
stage,-'
%
flS/
0
0
0
1
8S/
        -  Fry data were determined from 100 hatched fry taken at random from the total hatch at each
          . temperature.  Abnormal fry were not included.
        "y Two hundred eggs were tested at each temperature.
        y. Sac fry stage was determined to be from hatch to the disappearance of the yolk sac.
        -, Fish were determined to be juveniles when they reached a length of 40 mm.
        -  .Data from fry fertilized at 9-18 C but incubated at 6 and 21 C.

-------
Times to first hatch, median hatch, and total hatch were 37, 45, and
58 days at 6 C; 22, 28, and 35 days at 9 C; 12, 16, and 21 days at
12 C; 8, 10, and 13 days at 15 C; 7, 8, and 10 days at 18 C; and 5,
6, and 8 days at 21 C.  Time to first hatch, median hatch, and total
hatch was longest at the lowest temperature (6 C) and decreased to a
minimum of 5 days to first hatch, 6 days to median hatch, and 8 days
to total hatch at the highest temperature  (21 C).

The mean size of the fry at hatch was 4.77, 5.76, 5.84, 5.58, 5.64,
and 5.59 mm at 6, 9, 12, 15, 18, and 21 C, respectively.  The size of
the fry was least at 6 C (4.77 mm) but did not vary greatly at the
other temperatures.

The survival of sauger fry from hatch to the disappearance of the yolk
sac was high for all temperatures except 6 C.  At 6 C the fry did not
lose the yolk sac before dying although they survived about 30 days.
The fry survival at the temperature of 9 to 21 C ranged from 75 - 92%.

Total survival of sauger fry from hatch to the juvenile stage was low
at all temperatures.  At 21 C 8% of the fry survived, at 18 C 1% sur-
vived, and at 6-15 C all died before the juvenile stage.  All fry were
fed large quantities of .plankton.  Most of the fry at the higher tem-
peratures fed well while fry at the lower temperatures did not accept
food.  Fry mortality was observed to be caused by starvation, since
temperature was the trigger mechanism to feeding for fry held in
                             i
captivity under laboratory conditions.
                                  49

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                              SECTION X

                      GROWTH OF JUVENILE SAUCERS

Optimum temperature for growth of sauger juveniles was determined in
a test running 36 days and conducted in the same manner as that des-
cribed above for walleye growth experiments.  Saugers were tested at
2 C intervals ranging from 16 to 26 C (Table 14). A malfunction in the
apparatus caused total loss of fish at 24 C.  The mean weight of the
fish at the beginning of the test was 5.85 g at 16 C, 5.33 g at 18 C,
5.80 g at 20 C, 5.62 g at 22 C, and 6.42 g at 26 C.  Maximum growth
was at 22 C where the fish increased 22.9% in length and 96.8% in
weight, corresponding to a specific growth rate of 1.883.  Minimum
growth was at 16 C, the lowest temperature, where the juveniles
gained 14.0% in length and 52.2% in weight and corresponding to a.
specific growth rate of 1.164.  At 26 C the percentage gains in
length and weight and the specific growth rate were 13.6%, 53.9%,
and 1.200, respectively.  At 18 C the fish gained 20.3% in length,
79.4% in weight, and had a specific growth rate of 1.617.  At 20 C
the fish increased their length 16.5%, weight 62.9%, and had a specific
growth rate of 1.358.

Juvenile mortality occurred at the high temperature (26 C) where the
percentage survival was 60%.
                                  50

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                  Table  14.   GROWTH OF SAUCER JUVENILES FOR 36  DAYS AT DIFFERENT TEMPERATURES
In
H


Temper-
ature ,
C
16.1
18.1
20.0
22.0
26.0
Mean length
at start of
test,
nun
96.0 _
93.5
95.5
96.0
99.0

Increase
in length,
nun
13.5
19.0
16.5
22.0
13.5

Increase
in length,
%
14.0
20.3
17.3
22.9
13.6
Mean weight
at start of
test,
e
5.85
5.33
5.80
5.62
6.42

Increase
in weight,
£
3.06
4.23
3.65
5.44
3.46

Increase
in weight,
%
52.2
79.4
62.9
96.8
53.9
Specific
growth
rate,
%/dav
1.164
1.617
1.358
1.883
1.200


Survival ,
%
100
100
90
100
60

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                              SECTION XI

            UPPER LETHAL TEMPERATURES FOR SAUCER JUVENILES

EXPERIMENTAL DESIGN
Upper lethal temperature (TL50) tests were conducted on juvenile
saugers acclimated to temperatures from 10 to 26 C at 2 degree inter-
vals.  The fish which had a mean total length of 119 mm were acclimated
in 25-liter flow-through chambers in groups of 24 for a period of 2
weeks prior to the test.  After acclimation the fish were randomly
divided into three groups of eight fish.  Each group was then subjected
to a sudden temperature change by transferring the fish directly from
the acclimation chamber to a higher test temperature.  Fish were not
fed for 96 hours prior to testing.

LETHAL TEMPERATURE TESTS
After acclimation upper lethal temperature was tested and time of death
for each individual fish was recorded.  The upper lethal temperature
is defined as in the walleye experiments above.  Upper lethal tempera-
tures are shown in Table 15 and Figure 9 and median survival times
are on Table 16.

Fish acclimated to 10 C and 12 C had an upper lethal temperature of
26.6 C and 26.7 C, respectively.  Of the fish acclimated to 10 C and 12
C, 12.5% and 25.0%, respectively, survived at 27 C, while 100% survived
at 26 C.  The median survival times of the fish exposed to 27 C were
114 minutes for those acclimated at 10 C and 260 minutes for those
acclimated at 12 C.  The median survival time of fish acclimated to
12 C and exposed to 28 C was 68 minutes.  Fish acclimated to 14, 16,
and 18 C had an upper lethal temperature of 28.4, 28.6, and 28.7 C,
respectively.  The percentage survival of the fish acclimated to 14,
                                  52

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    31

0  30
UJ  29
o:
I-  28
    27
    26
      8   10   12   14   16   18   20  22  24   26

      ACCLIMATION    TEMPERATURE (°C)
       Figure 9. TL10 and TL90 levels of sauger juveniles
       exposed to upper lethal temperatures.  TL10 and TL90
       were at 10 and 90% survival plotted on arithmetic
       paper.
                       53

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  Table 15.  PERCENTAGE SURVIVAL OF SAUGER JUVENILES ACCLIMATED TO
      10 - 26 C AND EXPOSED TO HIGHER TEMPERATURES FOR 96 HOURS
Acclimation                    Temperature,
temperature, 	C	   TL50,
C
10.1
12.0
13.9
16.0
18.3
19.9
22.0
23.9
25.8
25.0 26.0 27.0 28.0
100 100 12.5
100 25.0 0
- 87.5
- 100
- - 100
- - - -
- - - -
- - - -
_ _ _ _
29.0
-
-
0
12.5
25.0
100
100
-
—
30.0
-
-
12.5
0
0
0
25.0
87.5
87.5
31.0
-
-
-
-
-
12.5
12.5
0
0
32.0
-
-
-
-
-
-
-
0
0
C
26.6
26.7
28.4
28.6
28.7
29.5
29.9
30.4
30.4
                                  54

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    Table 16.  MEDIAN SURVIVAL TIME  (MINUTES) OF JUVENILE SAUCERS
   ACCLIMATED TO 10 - 26 C AND EXPOSED TO UPPER LETHAL TEMPERATURES
Acclimation                      Test temperature,
temperature,  	C	
    C  	    27^0      28.0	29.0	30.0      31.0      32.0
10.1 114
12.0 260
13.9
16.0
18.3
19.9
22.0
23.9
25.8
_
68
32 16
29 18
31 19
1328
1512
- - -
— _ —
-
-
-
-
-
122
545
1242
690
-
-
-
-
-
-
-
348
246
                                  55

-------
16, and 18 C and exposed to 29 C was 0.0, 12.5, and  25.0%,  respectively.
The percentage survival at 28 C for the same acclimation  temperatures
was 87.5, 100, and 100%, respectively.  The median survival times  for
the exposure to 29 C were 32, 29, and 31 minutes  for the  fish accli-
mated to 14, 16, and 18 C.  The median survival times for the same
acclimation temperature and exposure to 30 C was  16,  18,  and 19 minutes,
respectively.  Juvenile fish acclimated to 20 and 22  C had  an upper
lethal temperature of 29.5 and 29.9 C.  Survival  was  0% and 25.0%  at
30 C and 100% at 29 C for both acclimation temperatures (20 and 22 C).
The median survival times for the fish acclimated to  20 and 22 C was
1328 and 1512 minutes for exposure to 30 C and 122 and 545  minutes
for exposure to 31 C.  Fish acclimated to 24 and  26  C had an upper
lethal temperature of 30.4 C.  At a temperature of 31 C no  fish sur-
vived from both acclimation temperatures and 87.5% of the fish sur-
vived at a temperature of 30 C for both acclimation  temperatures.
The median survival times for fish acclimated to  24 and 26  C and ex-
posed to 31 C was 1242 and 690 minutes, respectively.  The  median
survival times for exposure to 32 C was 348 minutes  for fish accli-
mated to 24 C and 246 minutes for fish acclimated to 26 C.
                                  56

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                             SECTION XII

                              DISCUSSION

The results of this investigation show that temperature has an impor-
tant impact on walleye and sauger eggs, fry, and juveniles.  The
optimum temperatures and lethal temperatures vary significantly for
different life history stages with the optima for fertilization, in-
cubation, and fry survival gradually increasing in the successive
stages.  The optimum temperature ranges for fertilization, incubation,
and fry survival of walleyes are 6-9 C, 9-15 C, and 15-21 C, respec-
tively.  The optimum temperatures for the same stages in sauger are
9-15 C, 12-15 C, and 15-21 C, respectively.  These ranges correspond
closely to the temperatures found in nature when the various stages
are present.  Under normal conditions adult sauger and walleye spawn
at temperatures of 6-12 C with the temperature gradually rising to
15 C by the time eggs hatch.  Fry development takes place at 15-21 C.
On the basis of studies reported here temperature regimes must be
considered as an important factor in the establishment of year classes
and maintenance of populations in natural water.

If unusually cold weather occurs after fry emergence, fry survival
may be inhibited.  Conversely strong year class may be dependent on
gradual warming of water during egg deposition and incubation, and
after fry emergence.  Johnson  stated that egg mortality, associated
with unuaully cold weather during the incubation period, may be an
important factor in the limiting of the size of year classes.  Feeding
of fry may also be reduced when temperatures are low.  Fry fed well
at the higher temperatures (18-21 C).

One discrepancy in the hatch data (Table 3, Figure 5) suggests that

                                  57

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15 C is more detrimental to egg survival than 18 C.  It is believed
that eggs fertilized at 15 C were of poor quality and less viable for
an undetermined reason, but the egg mortality from this cause was con-
sistent and independent of the incubation temperature or occurred
before the incubation temperature had any effect.  The shape of the
15 C fertilization curve shown in Figure 5 is the same as that for
other temperatures but probably should lie between the 12 and 18 C
curves.  This descrepancy was also noted with saugers fertilized at
12 C (Table 12, Figure 8).  It is believed that these eggs were also
less viable for some reason other than temperature.

Incidence of abnormalities was affected by temperature.  Both walleyes
and saugers showed a substantial increase in abvormalities as the
temperature increased.

The size of the walleye fry at hatch was affected by fertilization
temperature as well as incubation temperature.  The results indicate
that lower fertilization temperatures resulted in larger fry.  The
sauger fry did not show any significant variation in size attributable
to the fertilization temperatures.

Optimum temperature for walleye growth was influenced by the size of
the juvenile.  Smaller fish (mean weight 1.91 g) had a higher optimum
temperature (25 C) than the larger fish (mean weight 4.59 g) (22 C).
This shift in the optimum temperature could have been caused by dif-
ferences in dissolved oxygen.  Juvenile saugers also had an optimum
temperature for growth of 22 C.  These fish were uniform in size so no
variation due to size difference was noted.  The preferred temperature
                          2fi
of fish according to Brett   is also the optimum temperature for ac-
tivity and growth, thus the preferred temperature for walleye juveniles
                                27           28          29
is estimated to be 22-25 C.  Fry  , Doudoroff   , Proffitt   , and
Merriman   have noted the tendency for young fish to remain in warm
                                   58

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                                                    31
water more than older and larger individuals.  Kelso   reported 20 C
as the optimum temperature for growth of walleyes, age II-VI.   Hile and
     32
Juday   reported the preferred temperature of adult walleyes to be
                                         33
20.6 C during summer months, and Ferguson   reported the preferred
temperature of adult walleyes to be 22.7-23.2 C.
Walleye fry and juveniles acclimated to different temperatures were
exposed to a sudden temperature change without severe mortality.  It
is apparent that the extent of temperature change is less important
than the absolute test temperature.  If the temperature change is
within the upper or lower tolerance limits, little or no mortality
will occur.  Mortality of fry from temperature change occurred only
when fry hatched at 11 C were transferred to 6 C, a net change of -5 C,
and fry hatched at 21 C were transferred to 6 C, a change of -15 C.
It appears that 6 C is a lethal temperature for fry hatched at 11 and
21 C, since fry hatched at 21 C and transferred to a. temperature of
11 C, a change of -10 C, did not incur high mortality.

Juvenile walleyes exposed to a sudden temperature change showed a
mortality only in fish acclimated to 25 C and dropped to 8 C, a change
of -17 C, where loss was 30%.  This suggests that 8 C is probably
close to the lower lethal temperature of juveniles acclimated to 25 C.
Tests done with saugers were upward shifts toward lethal temperatures
so the effect of drops in temperature were not assessed.  However, the
extent of a sudden change in temperature did not harm fish until upper
lethal temperature was approached.

The upper lethal temperatures determined for walleye and sauger ju-
veniles can be applied to juveniles only.  The upper lethal tempera-
ture for larger fish may be slightly lower.

It is apparent from the results of the tests described herein that

                                   59

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temperature standards in natural waters must be adjusted for seasonal
changes in requirements of the fish and that maximum temperatures not
causing death are above the optimum levels for adequate population
maintenance.  Temperature maxima insuring natural population safety
will probably be 3 to 4 degrees below the upper lethal temperature
found for unfed fish.  Short periods of excess heat could be fatal
to the population if permitted levels are too close to the lethal
level.
                                  60

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                             SECTION XIII

                              REFERENCES

1.  Bradshaw, J., and B. S. Muir.  The 1960 Spawning Run of Yellow
    Pickerel at Bobcaygeon in Relation to Water Temperature.  Ontario
    Dept. Lands & Forests, Southeastern Region, Spec. Fish. Wildl.
    Bull. 3.  1960.  p. 4-6.
2.  Cobb, E. W.  Pike-Perch Propagation in Northern Minnesota.  Trans.
    Amer. Fish. Soc. .53:95-105, September 1923.
3.  Eddy, S., and T. Surber.  Northern Fishes with Special Reference
    to the Upper Mississippi Valley.  Minneapolis, Univ. of Minnesota
    Press. 1943.  276 p.
4.  Ellis, D. V., and M. A. Giles.  The Spawning Behavior of the Walleye,
    Stizostedion vitreum (Mitchill).  Trans. Amer. Fish. Soc. 94(4);
    358-362, October 1965.
5.  Eschmeyer, P. H.  The Life Histroy of the Walleye, Stizostedion
    vitreum vitreum (Mitchill), in Michigan.  Ann Arbor, Mich. Dept.
    Conserv., Inst. Fish. Res. Bull. 3.  1950.  99 p.
6.  Grinstead, B. G.  Reproduction and Some Aspects of the Early Life
    History of Walleye, Stizostedion vitreum (Mitchill), in Canton
    Reservoir, Oklahoma.  In:  Reservoir Fisheries and Limnology,
    Hall, G. E. (ed.).  Washington, Amer. Fish. Soc. Spec. Pub. No.  8.
    1971.  p. 41-51.
7.  Johnson, F. H.  Walleye Egg Survival During Incubation on Several
    Types of Bottom in Lake Winnibigoshish, Minnesota, and Connecting
    Waters.  Trans. Amer. Fish. Soc.  9£(3):312-322, July 1961.
8.  Niemuth, W., W. Churchill, and T. Wirth.  The Walleye—Its Life
    History, Ecology, and Management.  Madison, Wise. Conserv. Dept.
    Pub. 227.  1959.  14 p.
                                  61

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 9.  Payne, N. R.  The Life History of the Walleye, Stizostedion
     vitreum vitreum (Mitchill), in the Bay of Quinte.  M.A. Thesis,
     Univ. of Toronto, Toronto.  1964.  40 p.
10.  Priegel, G. R.  Reproduction and Early Life History of the Walleye
     in the Lake Winnebago Region.  Madison, Wise. Dept. Nat. Res.
     Tech. Bull. 45.  1970.  105 p.
11.  Rawson, D. S.  The Life History and Ecology of the Yellow Walleye,
     Stizostedion vitreum. in Lac la Ronge, Saskatchewan.  Trans. Amer.
     Fish. Soc.  J36(1956): 15-37, 1957.
12.  Schumann, G. 0.  The Effect of Abnormal Temperatures on the Spawning
     and Developmental Success of Eggs from the North American Walleye.
     Transl. by D. N.  Busch, TJ. S. Bur. Comm. Fish., Sandusky, Ohio.
     Osterreichs Fischerei.  5.:85-87, May 1964.
13.  Spinner, J.  Environmental Effect on the Spawning Run of Northern
     Pike and Walleye in the Upper Mississippi River.  Proc. North
     Central Warm Water Fish Culture Workshop, Ames, Iowa Coop. Fish.
     Unit, February 15-16, 1968.   p. 9-12.
14.  Carufel, L. H.  Life History of Saugers in Garrison Reservoir.   J.
     Wildl. Manag.  27/3):450-456, July 1963.
15.  Nelson, W. R.  Reproduction and Early Life History of Sauger,
     Stizostedion canadense, in Lewis and Clark Lake.  Trans. Amer.
     Fish. Soc. £7(2):159-166, April 1968.
16.  Priegel, G. R.  The Lake Winnebago Sauger—Age, Growth, Reproduction,
     Food Habits and Early Life History.   Madison, Wise. Dept. Nat.  Res.
     Tech. Bull. 43.  1969.  63 p.
17.  Priegel, G. R.  Lake Winnebago Cousins.  Wise. Conserv. Bull.
     .33(2): 24-25, 1968.
18.  Steucke, E. W.  Optimum Temperatures for Hatching Northern Pike
     and Walleye Eggs.   Proc. North Central Warm-Water Fish Culture
     Workshop, Ames, Iowa Coop. Fish. Unit, February 15-16, 1968.
     p. 32-34.
                                   62

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19.  Allbaugh, C. A., and J. V. Manz.  Preliminary Study of the Effects
     of Temperature Fluctuations on Developing Walleye Eggs and Fry.
     Prog. Fish-Cult.  26(4):175-180, October 1964.
20.  American Public Health Association, American Water Works Associ-
     ation, Water Pollution Control Federation.  Standard Methods for
     the Examination of Water and Wastewater.  13th ed.  1971.  874 p.
21.  Dobie, J., and J. B. Moyle.  Methods Used for Investigating Pro-
     ductivity of Fish-Rearing Ponds in Minnesota.  St. Paul, Minn.
     Dept. Conserv., Fish. Res. Unit.  Spec. Publ. No. 2.  1962.  62 p.
22.  Fienberg, S. E.  The Analysis of Multidimensional Contingency
     Tables.  Ecology.  51(3):419-433, 1970.
23.  Brett, J. R.  Tempering versus Acclimation in the Planting of
     Speckled Trout.  Trans. Amer. Fish. Soc.  .70:397-403, September
     1940.
24.  Javaid, M. Y., and J, M. Anderson.  Influence of Starvation on
     Selected Temperature of Some Salmonids.  J. Fish. Res. Bd. Canada
     24:1515-1519, July 1967.
25.  Fry, F. E. J.  Effects of the Environment on Animal Activity.
     Univ. of Toronto Studies, Biol. Ser. No. 55.  Publ. Ont. Fish.
     Res. Lab. No. 68.  1947.  62 p.
26.  Brett, J. R.  Some Principles in the Thermal Requirements of
     Fishes.  Quart. Rev. Biol.  .31(2):75-87, 1956.
27.  Fry, F. E. J.  The Summer Migration of Cisco, Leucichthvs artedi
     (Le Sueur), in Lake Nipissing, Ontario.  Univ. of Toronto Studies,
     Biol. Ser. No. 44.   1937.  91 p.
28.  Doudoro'ff, P.  Reactions of Marine Fishes to Temperature Gradients.
     Biol. Bull.  25:494-509, 1938.
29.  Proffitt, M. A.  Effects of Heated Discharge upon Aquatic Resources
     of White River at Petersburg, Indiana.  Water Resources Res. Center.
     Rept. of Invest. No. 3.  1969.  101 p.
30.  Merriman, D.  The Calefaction of a River.  Sci.  Amer. 222(5):42-52,
     1970.

                                  63

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31.  Kelso, J. R. M.  Conversion, Maintenance, and Assimilation for
     Walleye, Stizostedion vitreum vitreum. as Affected by Size, Diet,
     and Temperature.  J. Fish. Res. Bd. Canada.  29;1181-1192,
     August 1972.
32.  Hile, R., and C. Juday.  Bathymetric Distribution of Fish in Lakes
     of the Northeastern Highlands, Wisconsin.  Trans. Wise. Acad. Sci.,
     Arts & Letters.  33:147-187, 1941.
33.  Ferguson, R. G.  The Preferred Temperature of Fish and Their Mid-
     summer Distribution in Temperate Lakes and Streams.  J. Fish. Res.
     Bd. Canada.   15(4):607-624, July 1958.
                                   64

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   SECTION XIV
    APPENDIX A
STATISTICAL TABLES
        65

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                   Appendix A, Table 1
 THE EXPECTED VALUES OF PERCENTAGE HATCH OF WALLEYE EGGS
FERTILIZED AT SIX DIFFERENT TEMPERATURES AND INCUBATED AT
                SIX DIFFERENT TEMPERATURES
The Observed Values Are Shown on Table 3 in The Main Text

Nominal
fertilizatioi
temperature,
C
6
9
12
15
18
21
i
6
64.29
55.25
24.71
5.77
22.15
2.82
Incubation temperature,
C
9
77.27
69.98
56.25
10.37
34.95
5.20
12
78.48
71.43
57.97
11.04
36.56
5.56
15
79.80
73.04
59.90
11.84
38.43
5.99
18
66.83
58.02
43.26
6.42
48.32
3.15
21
14.34
10.30
5.95
0.57
2.58
0.27
                            66

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                  Appendix A, Table 2
 DUMMY VARIABLES REPRESENTING FERTILIZATION TEMPERATURE
      IN THE REGRESSION EQUATIONS FOR DETERMINING
            THE SIZE OF WALLEYE FRY AT HATCH
Variables Used in Equations for Incubation Temperatures
                 of 6, 9, 12, and 15 C

Nominal
fertilization
temperature ,
C
6
9
12
15
18
21



Xl
1
0
0
0
0
-1


Dummy
X2
0
1
0
0
0
-1


variables
X3
0
0
1
0
0
-1



X4
0
0
0
1
0
-1



X5
0
0
0
0
1
-1
                           67

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                   Appendix A, Table 3
  DUMMY VARIABLES REPRESENTING FERTILIZATION TEMPERATURE
       IN THE REGRESSION EQUATIONS FOR DETERMINING
             THE SIZE OF WALLEYE FRY AT HATCH
Variables Used in Equation for Incubation Temperature of 18 C

Nominal
fertilization
temperature,
C
6
9
12
18

Dummy
Xl
1
0
0
-1

variables
X2
0
1
0
-1


X3
0
0
1
-1
                            68

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                 SECTION XV

                 APPENDIX B

AN ANNOTATED BIBLIOGRAPHY OF THERMAL EFFECTS
 ON THE NORTH AMERICAN STIZOSTEDION SPECIES
                      69

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                               INTRODUCTION

     The literature on thermal effects on the North American Stizo-
stedion species was compiled and presented in annotated form.  Only
temperature-related literature was reviewed.  Temperature data reported
in the original literature as Fahrenheit has been changed to Centigrade.
The annotated bibliography lists the effects of temperature on the wall-
eye, sauger, and blue pike.  The listing of unpublished data is incom-
plete in university reports as well as unpublished reports of state,
provincial, and federal agencies.
     Each reference is cross-indexed by species, geographical location,
and additional subject headings.  Listed numbers in the index refer
to the numbers on publications in the main body of the citation list.
                                   70

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                        ANNOTATED BIBLIOGRAPHY

1.  Allbaugh, Clyde A., and Jerry V. Manz              Descriptors
    1964.  Preliminary study of the effects of         WALLEYE
           temperature fluctuations on developing      LAKE ERIE
           walleye eggs and fry.  Prog. Fish-Cult.      INCUBATION
           26(4): 175-180.
    A study of the effect of fluctuating  temperatures on different
    stages of embryo development of walleye eggs was done at Put-In-
    Bay in western Lake Erie.  The study was started at 6.7 C and was
    raised 0.56 C every 48 hours.  The rising temperature of the system
    was called the base temperature or the normal rise in water tempera-
    ture during incubation of walleye eggs.  The temperature fluctuation
    test was administered by slowly raising the water temperature 4.4 C
    in 4 hours, and then gradually reducing to the base temperature.
    The temperature fluctuation was applied at 4 stages of embryo develop-
    ment: cleavage, differentiation, organogenesis, and hatching.  28%
    of the eggs hatched in the control, 30% of the eggs hatched when the
    temperature was fluctuated at cleavage, 28% of the eggs hatched when
    the temperature was fluctuated at differentiation, and 39% of the
    eggs hatched when the temperature was fluctuated at organogenesis.
    Due to an accident the water temperature rose to 1.1 C during hatching
    and no excessive mortalities occurred in 7 out of 8 hatching jars.
    The author concluded that 399 temperature units are required for
    normal development and hatching, when 1 temperature unit = 1 degree-
    day above 32 F.

2.  Anonymous                                          Descriptors
    1967.  Temperatures for hatching walleye           WALLEYE
           eggs.  Prog. Fish-Cult. 29(1): 20.          WISCONSIN
                                                       INCUBATION
    At a Wisconsin hatchery, jars containing 1.5 quarts of walleye  eggs
    were set up to test temperatures ranging from 12.8-19.4 C in incre-
    ments of 1.7 C.  Additional tests were set up at 21.7 C and 23.9 C
                                 71

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    because of the high percentage of hatching success at the higher
    temperatures.  The results of the tests were as follows:
          Temperature   Days to     Days to   Percentage
             (C)	eye-up	hatch	hatch
12.8
14.4
16.1
17.8
19.4
21.7
23.9
7
6
5
4
3.5
3
3
10
10
8
8.5
6
5
4
50
50
51
65
60
10
10
    The author concluded that the apparent optimum temperature for
    hatching walleye eggs is 17.8-19.4 C.

3.  Arnold, Dean E.                                     Descriptors
    1969.  The ecological decline of Lake Erie.         BLUE PIKE
           N. Y. Fish Game J. 16(1): 27-45.            LAKE ERIE
                                                       DISTRIBUTION
    There are five main hypotheses to explain the decline and the
    extinction of the blue pike (Stizostedion vitreum glaucum) in
    Lake Erie that have been proposed by various schools of thought.
    They are: 1) high temperature, 2)  0~ depletion in the central
    basin, 3) overfishing, 4) pollution, and 5)  new predators or com-
    petitors .  All of these are probably interrelated and mutually
    responsible.  The blue pike have been restricted to the colder
    waters of the lake, thus being placed at a disadvantage as the
    waters become warmer.

4.  Bradshaw, J., and B.S. Muir                        Descriptors
    1960.  The 1960 spawning run of yellow pickerel    WALLEYE
           at Bobcaygeon in relation to water          ONTARIO
           temperature.  Ont. Dept. Lands &            SPAWN
           Forests, Southeastern Region, Spec.
           Fish. Wildl. Bull. 3: 4-6.
                                  72

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    In the Bobcaygeon region of the Kawantha Lakes the heavy run of
    spawning walleyes occurred when river temperatures were at 4.4-
    7.2 C.  The greatest spawning activity occurred at temperatures
    between 6.1 and 8.3 C.  Spawning appeared to be completed when the
    water temperature reached 10.0 C.  In all cases, the heavy spawning
    run commenced at a temperature 1.7-2.2 C lower than the actual
    spawning temperature.

5.  Butler, G.E.                                       Descriptors
    1937.  Artificial propagation of walleyed          WALLEYE
           pike.  Trans. Amer. Fish. Soc.              MANITOBA
           66(1936): 277-278.                          INCUBATION
    It was reported that strong winds stirred up the mud from the
    creek that fed water to the walleye hatchery and subsequently
    raised the temperature to 18.3-21.1 C.  The combination of mud
    and high temperatures caused the mortality of a large number of
    eggs.

6.  Carufel, Louis H.                                  Descriptors
    1963.  Life history of saugers in Garrison         SAUCER
           Reservoir.  J. Wildl. Manag. 27(3):         N. DAKOTA
           450-456.                                    SPAWN
    The 1960 spawning season for saugers in Garrison Reservoir ran
    from May 2 - June 25, where the height of the season was from May
    8-28.  Water temperatures ranged from 3.9-11.7 C.

7.  Cobb, Eben W.                                      Descriptors
    1923.  Pike-perch propagation in northern          WALLEYE
           Minnesota.  Trans. Amer. Fish. Soc.         MINNESOTA
           53: 95-105.                                 SPAWN
                                                       INCUBATION
    It was decided that the best temperatures for taking walleye eggs
    range from 7.2-10.0 C, preferably between 7.8-8.9 C.  Although
                                  73

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    eggs were taken at a temperature as high as 17.2 C, they were poor
    as a rule.  Also good hatches have occurred with walleye eggs
    subjected to as low a temperature as where slush ice had formed in
    the water.

8.  Dendy, Jack S.                                     Descriptors
    1948.  Predicting depth distribution of fish       WALLEYE
           in three TVA storage type reservoirs.       SAUCER
           Trans. Amer. Fish. Soc. 75(1945):           TENNESSEE
           65-71.                                      DISTRIBUTION
    In TVA reservoirs the depth distribution of walleyes and saugers
    were predictable on a weekly basis based on the relation of tempera-
    ture and dissolved 0» to the distribution of fish in gill nets
    during the years 1943, 1944, and 1945.   Thus it can be predicted
    that in the latter part of July, saugers were most abundant at a
    depth where the temperature was about 18.3 C and walleyes were most
    abundant at a depth where the temperature was about 25.0 C.

9.  Derback, B.                                         Descriptors
    1947.  The adverse effect of cold weather          WALLEYE
           upon the successful reproduction of         MANITOBA
           pickerel, Stizostedion vitreum,  at          SPAWN
           Hemming Lake, Manitoba, in 1942.
           Can.  Fish-Cult. 2(1): 22-23.
    The author believed that there seemed to be a strong correlation
    between spawning activity and water temperature.  In Hemming Lake,
    Manitoba, when walleyes ran up the creek to spawn the temperature
    was 5.6 C.  The first walleye eggs were observed 4 days later at
    6".l C.  Then a period of cold weather set in to lower the tempera-
    ture the following week to 5.0 C, and as a result the walleye
    moved back downstream into the lake.   Resulting catches of walleye
    in late June showed that the females were resorbing their eggs.
                                  74

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10.  Doan, Kenneth H.                                  Descriptors
     1942.  Some metereological and limnological       WALLEYE
            conditions as factors in the abundance     BLUE PIKE
            of certain fishes in Lake Erie.             SAUCER
            Ecol. Monogr. 12(3): 294-314.              LAKE ERIE
                                                       SIZE OF  CATCH
     Because water temperature has considerable influence over  the
     success of fishing, an attempt was made to correlate the size  of
     the catch of walleyes, blue pike, and saugers in Lake Erie with
     mean spring air temperatures.
     Walleyes:  Spring temperatures have shown no relation to sizes of
     catch.  Mean April-May air temperatures at Cleveland, Sandusky,
     and Toledo had non-significant "r" values with Ohio  catches  in
     the same year, and with catches 3 or 4 years later.
     Blue Pike:  Temperature variations affect the stock  of blue  pike
     by affecting the vulnerability of adults to capture  and by in-
     fluencing spawning and fry survival.  Over half of the total blue
     pike catch is taken in May and June, these months also include
     spawning and early fry stages.  However there was no correlation
     between the mean May-June air temperatures at Cleveland and  Erie
     and the size of the Ohio catches of blue pike the same year.  But
     there was a definite relation between May-June air temperatures
     and the catch of blue pike 2 years later.
     Sauger:  There was no significant correlation with catches of
     sauger and mean spring air temperatures.
     It was thought that in Lake Erie the factor to which these fish
     react most strongly would be temperature since they  seek colder
     waters in the summer by going deeper.  To support this view,
     movements of tagged blue pike and walleyes in Lake Erie were ob-
     served.  The blue pike inhabited the colder waters,  and the  wall-
     eyes were more tolerant of warmer water but still moved eastward
     out of the excessively higher temperature waters during the
     summer in the western section of the lake.
                                 75

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11.  Eddy, Samuel                                      Descriptors
     1938.  A classification of Minnesota lakes        WALLEYE
            for fish propagation.  Prog. Fish-         MINNESOTA
            Cult. 41: 9-13.                            DISTRIBUTION
     Minnesota lakes were classified on the physical, chemical, and
     biological features.  Pike Lake No. 1 has summer temperatures of
     surface water range between 15.6-23.9 C and bottom waters between
     6.7-12.8 C.  The difference between the summer surface and bottom
     temperatures is usually 5.6-11.2 C.  Pike Lake No. 2 has summer
     surface temperature range between 20.0-23.9 C or higher and bottom
     temperatures range between 18.3-21.1 C.  The difference between
     surface and bottom temperatures is 0.56-2.8 C.

12.  Eddy, Samuel, and Thaddeus Surber                 Descriptors
     1943.  Northern fishes with special reference     WALLEYE
            to the upper Mississippi valley.           MINNESOTA
            Univ. Minnesota Press, 276 p.               SPAWN
     In Minnesota the spawning run of walleyes starts when water tem-
     peratures range from 3.3-6.7 C.

13.  Eley, Rex L., Neil E. Carter, and Troy C. Dorris  Descriptors
     1967.  Physiochemical limnology and related       WALLEYE
            fish distribution of Keystone Reservoir.   OKLAHOMA
            In Reservoir Fishery Resources Symposium,  DISTRIBUTION
            p. 333-357.   Reservoir Comm. Southern
            Div., Amer.  Fish.  Soc.
     Temperature and other limnological parameters were measured at
     each meter of depth at different stations in Keystone Reservoir,
     Oklahoma.  Depth distribution of fish was determined by suspending
     a vertical latin-square gill net from the water surface to the
     bottom for two consecutive 24-hour periods per month at each
     station.   Walleyes were captured within 4 meters of the surface
     during the summer when temperatures ranged from 26-27 C.
                                 76

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14.  Ellis, D. V., and M. A. Giles                     Descriptors
     1965.  The spawning behavior of the walleye,      WALLEYE
            Stizostedion vitreum (Mitchill).           MANITOBA
            Trans. Amer. Fish. Soc. 94(4): 358-362.    SPAWN
     Spawning activity and courtship was studied in Manitoba.   Walleyes
     have a diel behavioral cycle, low activity in day-time and court-
     ship activity in the evening.  The water temperature during the
     spawning period ranged from 6.7-13.0 C.

15.  Eschmeyer, Paul H.                                Descriptors
     1950.  The life history of the walleye            WALLEYE
            Stizostedion vitreum vitreum (Mitchill),   MICHIGAN
            in Michigan.  Mich. Dept. Conserv.,        SPAWN
            liist. Fish. Res., Bull. 3, 99 p.
     Walleye spawning was observed in Lake Gogebic, Michigan in the years
     1941, 1942, 1947, and in the Muskegon River in 1936, 1944, 1947,
     and 1948.  The results were:
                                   Start of            Peak of
          Location	spawning run	spawning run
Lake Gogebic (1941)
Lake Gogebic (1942)
Lake Gogebic (1947)
Muskegon R. (1936)
Muskegon R. (1944)
Muskegon R. (1947)
Muskegon R. (1948)
3.9 C
4.4 C
1.1 C
—
—
—
—
8.3 C
7.8-8.9 C
—
4.4-5.6 C
3.3 C
4.4 C
6.7 C
     The peak of the spawning run in Lake Gogebic occurs when shoal
     temperatures range from 7.2-10.0 C.   In the Muskegon  River  the
     peak of the spawning run occurs when the temperatures range from
     4.4-6.7 C.
                                 77

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16.  Ferguson, R. G.                                   Descriptors
     1958.  The preferred temperature of fish          WALLEYE
            and their midsummer distribution in        SAUCER
            temperate lakes and streams.  J. Fish.     DISTRIBUTION
            Res. Bd. Canada 15(4): 607-624.
     The preferred temperature for walleyes is 22.7-23.2 C, and the
     preferred temperature for saugers is 18.6-19.2 C.

17.  Forney, John L.                                   Descriptors
     1966.  Factors affecting first-year growth        WALLEYE
            of walleyes in Oneida Lake, New York.      NEW YORK
            N.Y. Fish & Game J. 13(2): 146-167.        GROWTH
     Annual May-June air temperatures suggest that lake temperatures
     determine the rate of walleye growth in early summer and to some
     extent may influence the time of hatching of walleye fry. •'

18.  Grinstead, Bobby G.                               Descriptors
     1971.  Reproduction and some aspects of the       WALLEYE
            early life history of walleye, Stizo-      OKLAHOMA
            stedion vitreum (Mi^chill), in Canton      SPAWN
            Reservoir, Oklahoma.   In Reservoir
            Fisheries and Limnology, Amer. Fish.
            Soc., Spec. Pub. No.  8, p. 41-51.
     Walleyes in Canton Reservoir, Oklahoma spawn in March.  Water
     temperatures during peak spawning activities ranged from 5.0-
     12.8 C in 1966, 7.2-14.4 C in 1967, and 3.9-8.9 C in 1968.  It
     was suggested that these data support the theory that water tem-
     perature is the primary controlling influence in determining the
     time walleyes spawn.  In Canton Reservoir they spawn considerably
     earlier in the year, but within temperature ranges similar to
     walleyes in other regions.
                                 78

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19.  Hassler, William W.                               Descriptors
     1955.  The influence of certain environmental     SAUCER
            factors on the growth of Norris Reser-     TENNESSEE
            voir sauger, Stizostedion canadense        GROWTH
            canadense (Smith).  Proc. Southeastern
            Ass. Game Fish Comm. Mtg., p.  111-119.
     First year growth rates of .sauger during a 13-year span were
     correlated with:
        1.  Water temperature data for 13 years.  Water temperatures
            of 15.6 C at a depth of 0.5 feet were used to demarcate
            the length of the sauger growing season.
        2.  Time in days between 10.0 C and 15.6 C at a depth of 0.5
            feet.
        3.  Air temperature, both mean monthly and mean annual.
     Growth rates were significantly correlated with  water temperature
     with a correlation coefficient of .69.  There was an inverse
     relationship between degree days and growth rates with a corre-
     lation coefficient of -.51.  There was no correlation between  air
     temperature and growth rates.
     It was suggested that there are three possible ways in which
     sauger growth may be affected inversely during the spring:
        1.  There is a lower metabolic rate during a  prolonged period
            of time if the water temperature increases slowly.
        2.  A greater survival of sauger fry and fingerlings may occur
            during the years when temperature increases slowly.   This
            would result in a greater population density which in turn
            could be a limiting factor on growth.
        3.  Because forage fish spawn later than sauger (10.0 C  for
            sauger and 15.6 C for forage fish), there would be a lower
            rate of growth if the lake warms up slowly.  The period of
            planktonic feeding would be prolonged since forage fish
            would be available at a later time than usual.
                                  79

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20.  Herman, Elmer F.                                  Descriptors
     1947.  Notes on tagging walleyes on the           WALLEYE
            Wolf River.  Wise. Conserv. Bull.          WISCONSIN
            12(4): 7-9.                                SPAWN
     The 1946 spawning run in the Wolf River, Wisconsin, started after
     the ice left the river when the temperature ranged from 3.3-6.7
     C.  The actual spawning occurred when the temperature reached
     14.4 C.

21.  Hile, R., and C. Juday                            Descriptors
     1941.  Bathymetric distribution of fish in        WALLEYE
            lakes of the northeastern highlands,       WISCONSIN
            Wisconsin.   Trans. Wise. Acad.  Sci.,       DISTRIBUTION
            Arts, & Lett. 33: 147-187.
     The average thermal distribution of walleyes during August in
     Trout Lake, Wisconsin was reported to be 20.6 C.

22.  Hurley, Donald A.                                  Descriptors
     1972.  Observations on incubating walleye         WALLEYE
            eggs.  Prog. Fish-Cult.  34(1):  49-54.      INCUBATION
     In the years 1969  and 1970, walleye eggs were at  the eyed stage
     at 274 and 234 thermal units (TU), median hatch occurred at 440
     TU, completion of  hatching required 467 TU's, and yolk absorption
     was completed at 690 TU's.  1 TU = 1 degree-day above 32 F.

23.  Johnson, Fritz H.                                  Descriptors
     1961.  Walleye egg survival during incubation     WALLEYE
            on several  types of bottom in Lake         MINNESOTA
            Winnibigoshish, Minnesota, and             INCUBATION
            connecting waters.  Trans. Amer.
            Fish. Soc.  90(3): 312-322.
     Survival of naturally spawned walleye eggs was determined for five
     types of bottom areas of Lake Winnibigoshish and  connecting waters
                                  80

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over  a  4-year  period.  The results were:
Year  Bottom  Incubation    Water        Daily mean   Estimated
        type    period  (days) temperature    water      percentage
                            during in-   temperature  egg
                            bation (C)       (C)
1956



1957



1958

Area
H
ti
ii
Area
it
n
M
Area
ii
1
2
3
4
1
2
3
4
1
2
20-24
20-24
14-16
-
12-14
12-14
12-16
12-16
16-21
16-21
5.
5.
6.

7.
8.
7.
7.
6.
6.
0-16.
0-15.
1-13.
-
8-8.9
9-14.
8-14.
8-14.
1-12.
1-12.
1
0
3


4
4
4
8
8
8
8
11

11
11
11
11
10
9
.3
.3
.1
-
.7
.7
.7
.7
.0
.4
0.
2.
17.
34.
4.
9.
17.
17.
3.
35.
6
7
5
3
7
9
9
4
6
7
(improved)



1959

n
n
n
Area
n
3
4
5
1
2
-
18-21
16-21
16-18
12-18

6.
6.
7.
12.
-
1-17.
1-12.
2-17.
8-15.

8
8
2
6


9
10
10
-
-
.4
.6
.6
-
5.
13.
1.
25.

2
2
2
9
   Area 1 = soft, mucky bottom
   Area 2 = firm, fine sand
   Area 2 (improved) = former area 2 covered with. 6 inches of
                       gravel
   Area 3 = gravel and rubble bottom with occasional boulders
   Area 4 (1956) = gravel and rubble bottom
   Area 4 (1957) = gradually sloping bottom with 60% gravel and
                   40% sand
   Area 4 (1958) = gravel-rubble bar with occasional boulders
   Area 5 = bar of firm clean sand
Temperature determinations were made with maximum-minimum thermo-
meters.  The author felt that observations on max-min water tem-
peratures do not lend themselves to critical analysis of the effect
                             81

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     of water temperature on the rate.of embryo development.  But he
     observed that most rapid embryo development and short incubation
     periods were associated with high daytime water temperatures and
     high minimum water temperatures.  Egg survival was best in years
     of warmer water temperatures and shorter incubation periods.  Also
     it was stated that egg mortality, especially as associated with
     unusually cold water during the incubation period, may be an im-
     portant factor in the establishment of year classes.

24.  Johnson, Fritz H.                                 Descriptors
     1966.  Environmental and species associations     WALLEYE
            of the walleye in Lake Winnibigoshish      MINNESOTA
            and connected waters, including ob-        DISTRIBUTION
            servations on food habits and predator-
            prey relationships.  Minn. Dept. Conserv.
            Invest. Rep.  301, 34 p.
     Walleye distribution in Lake Winnibigoshish, Minnesota was not
     influenced by bottom temperatures that ranged between 13.3 C and
     20.6 C, but the fish extended their range into deeper, cooler
     waters when the surface temperatures rose above 21.1 C.  Tol-
     erance for water temperatures above 21.1 C appeared to decrease as
     age and size of the  fish increased.  When late fall water tem-
     peratures on the shoals ranged from 6.7-8.9 C, the fish were no
     longer in shore.  This indicates that there could be a minimum
     fall temperature threshold below which the fish seek deeper,
     warmer water.

25.  Kelso, John R. M.                                 Descriptors
     1972.  Conversion, maintenance, and assimilation  WALLEYE
            for walleye,  Stizostedion vitreum vitreum. MANITOBA
            as affected by size, diet, and tempera-    GROWTH
            ture.  J. Fish. Res. Bd. Canada 29:
            1181-1192.
     Walleyes of age II to VI were tested for growth and food conversion
                                   82

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     at different temperatures.  Greatest walleye weight gain occurred
     at a temperature of 20 C.  1^, conversion weight gained per unit
     time to ration size, was 0.143 at 20 C, 0.127 at 16 C,  and 0.136
     at 12 C.  At 4, 8, and 12 C the maintenance requirement varied
     slightly (33.25-45.70 cal/g/week).  At a cycled temperature (16-
     8 C) for a period of 4 weeks the requirement was 40.2 mg/g/week.
     Between 20 C and 32 C the amount of energy consumed by  the fish
     was similar.

26.  Kennedy, William A.                               Descriptors
     No date (approx. 1935).  Report on the            WALLEYE
            migration of pickerel due to tern-          ONTARIO
            perature changes.  Unpub. MS, 15 p.        DISTRIBUTION
            In Univ. Toronto, Great Lakes Inst.
            Libr.
     It was observed that as the water warmed, walleyes in Lake
     Nipissing, Ontario moved to deeper waters, the larger fish
     migrating first.  It was found that the walleyes do not penetrate
     the thermocline which would entail a sudden change of temperature.

27.  Nelson, William R.                                Descriptors
     1968.  Reproduction and early life history of     SAUCER
            sauger, Stizostedion canadense. in         S. DAKOTA
            Lewis and Clark Lake.  Trans. Amer.        SPAWN
            Fish. Soc. 97(2): 159-166.                 INCUBATION
    .Sauger in Lewis and Clark Lake spawn upstream near the  Fort Ran-
     dall Dam when water temperatures reach 5.6-6.1 C.  The  incubation
     period at an average water temperature of 8.3 C was approximately
     21 days.
                                 83

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28.  Nelson, William R., Norman R. Hines, and          Descriptors
        Lance G. Beckman                               WALLEYE
     1965.  Artificial propagation of saugers and       SAUCER
            hybridization with walleyes.   Prog.         S.  DAKOTA
            Fish-Cult. 24(4): 216-218.                 INCUBATION
     Walleye and sauger brood stock were collected in the  Missouri
     River between April 15-29, when the spawning run started.  The
     temperature during the collection period ranged from 3.9 C to
     8.3 C.  The fish were placed in ponds which had a temperature
     range from 6.1 C to 12.8 C and were allowed to ripen  both nor-
     mally and with carp pituitary injections.  Fertilized eggs were
     then placed in hatching jars where water temperatures ranged
     from 10.0 C to 12.2 C when the eggs began hatching.   Walleye eggs
     reached the eyed stage in 8 days and began  hatching in 13 days.
     Sauger eggs began hatching in 9 days and continued through the
     14th day.

29.  Niemuth, Wallace, Warren Churchill,  and           Descriptors
        Thomas Wirth                                   WALLEYE
     1959.   The walleye, its life history, ecology,    WISCONSIN
            and management.  Wise. Conserv. Dept.      SPAWN
            Pub. 227, 14 p.                            INCUBATION
     The walleye spawning migration begins in Wisconsin when the water
     temperature reaches 3.3-6.7 C.  Spawning reaches a peak when
     temperatures are 8.9-10.0 C, although spawning has been observed
     between the temperatures of 6.1 and 17.2 C.  Walleye  eggs hatch
     in 26 days when the water temperature is 4.4 C, 21 days when the
     water temperature is from 10.0-12.8 C, and  in 7 days  with a mean
     water temperature of 13.9 C.
                                 84

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30.  Payne N. R.                                       Descriptors
     1964.  The life history of the walleye,            WALLEYE
            Stizostedion vitreum vitreum (Mitchill),    ONTARIO
            in the Bay of Quinte.  M.A.  Thesis,         YEAR-CLASS
            Univ. Toronto, Toronto, Ont.  40  p.         STRENGTH
     In lake Ontario walleye spawning commences  when the water tempera-
     ture reaches above 3.3 C and is completed by the time the water
     temperature is 10.0 C.  There is a strong indication that there is
     a relationship between April air temperatures and the size of
     year-classes of walleyes in the Bay of Quinte.   All strong year-
     classes occurred in the years when the April mean air temperatures
     were above normal.  Weak year-classes were  produced in the two
     years when the April mean temperatures were subnormal.  But also
     there were weak year-classes produced in 1949,  1953, and 1958  when
     April mean temperatures were above normal.   It was concluded from
     these facts that 1) above normal temperatures at spawning time
     are required for the production of a strong year-class, 2) sub-
     normal April mean temperatures result in the development of weak
     year-classes, and 3) above normal temperatures alone are not suf-
     ficient to cause better than average spawning success.  It was
     also suggested that it is feasible that May and June temperatures
     also are of some importance in enhancing or nullifying the effect
     of April temperatures.

31.  Priegel, Gordon R.                                Descriptors
     1963.  Walleye nursery.  Wise. Conserv.  Bull.     WALLEYE
            28(2): 6-7.                                WISCONSIN
                                                       SPAWN
     Walleye spawning in Wisconsin occurs in mid-April when the water
     temperatures approach 5.6 C.

32.  Priegel, Gordon R.                                Descriptors
     1966.  Lake Puckaway walleye.  Wise. Conserv.     WALLEYE
            Dept., Res. Rep. 19, 22 p.                 WISCONSIN
                                                       SPAWN
                                 85

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     Active walleye spawning occurs in the Montello River, Wisconsin
     when water temperatures reach 5.6 C.

33.  Priegel, Gordon R.                                Descriptors
     1968.  Lake Winnebago cousins.  Wise.             WALLEYE
            Conserv. Bull. 33(2): 24-25.               SAUCER
                                                       WISCONSIN
                                                       INCUBATION
     Walleye eggs will hatch in 21 days at water temperatures of 10.0-
     12.8 C   while sauger eggs will hatch in 13-15 days at the same
     temperature.

34.  Priegel, Gordon R.                                Descriptors
     1969.  The Lake Winnebago sauger.  Age,           SAUGER
            growth, reproduction, food habits          WISCONSIN
            and early life history.  Wise. Dept.       SPAWN
            Nat. Res., Tech.  Bull. 43, 63 p.           INCUBATION
     In 1965 sauger spawning occurred between May 2-9 when the tem-
     perature ranged from 6.1-9.4 C.   In 1966 the water temperature
     ranged from 7.2-10.0 C but no spawning activity was observed.  In
     1967 spawning occurred from April 24 to May 6 when the water tem-
     perature ranged from 7.8-11.1 C.  In a fish hatchery sauger eggs
     hatched in 13-15 days at a water temperature of 10.6 C.

35.  Priegel, Gordon R.                                Descriptors
     1970.  Reproduction and early life history        WALLEYE
            of the walleye in the Lake Winnebago       WISCONSIN
            region.  Wise. Dept. Nat. Res., Tech.      SPAWN
            Bull. 45, 105 p.                            INCUBATION
     In the Lake Winnebago region, Wisconsin, walleyes were observed
     spawning when water temperatures ranged between 2.2-15.6 CJ
                                                               !   i
     During peak spawning periods water temperatures were 5.6-7.8 C.
     The following tables show the temperature (C) criteria for spawn-
     ing and incubation of walleyes and eggs in the Lake Winnebago
                                  86

-------
    region:
          	Range of water temperature (C)	
             Spoehr's Marsh    Fox River Marshes    Lake Winnebago
          During   During    During    During    During    During
          spawning egg de-   spawning  egg de-   spawning  egg de-
    Year	velopment	velopment	velopment
    1960 5.6-12.2 7.2-18.9  4.4-12.2  5.6-15.0
    1961 2.2-10.0 2.2-15.6  3.3-10.0  6.7-16.7
    1962 2.2-12.2 2.2-15.6  5.6-10.0  5.0-15.6
    1963 5.6-12.2 2.2-12.8  4.4-11.1  6.7-14.4
    1964     -        -      5.6-10.0  4.4-15.6  5.6-11.1  5.0-12.8
    1965 6.1-8.9  5.0-14.4  5.0-14.4  5.6-15.6  5.6-7.8   5.6-10.0
    1966 4.4-8.3  4.4-11.1  4.4-13.3  6.7-15.0  6.7-10.6  6.1-10.6
    1967 4.4-11.1 6.7-13.3  6.1-15.6  6.1-17.8  3.9-7.8   4.4-10.6
    In the  Lake Winnebago region,  cold weather prolonged the  spawning
    activity over an  extended period  of time.  It was never inhibited.
    Most rapid embryo development and short  incubation periods were
    associated with daytime temperatures  above 10.0  C and high mini-
    mum water temperatures that did not fall below  7.2 C for  any
    extended length of time.  No correlation between water  temperature
    and embryo survival was found.

36. Rawson, D.S.                                      Descriptors
     1957.  The life history and ecology of the         WALLEYE
            yellow walleye, Stizostedion vitreum.       SASKATCHEWAN
            in Lac la Ronge, Saskatchewan.  Trans.      SPAWN
            Amer. Fish. Soc. 86(1956): 15-37.          DISTRIBUTION
     It was  suggested that water temperature appeared to be the  con-
     trolling influence for the walleye spawning run.  No  spawning
     activity was observed in water temperatures  below 3.3  C.  The
     main spawning run in Lac la Ronge took place at a temperature of
     4.4-5.6 C.  Active spawning was observed between 7.2-10.0 C.   No
     evidence was found that walleyes selected,  or moved into, water of
     any particular temperature range during the summer. However, it
                                 87

-------
     was found that walleyes were active in the range from 15.0-18.3 C.
     It was suggested that it was unlikely that temperature preference
     was the reason for movement into deeper water, since it was found
     that August water temperatures at 5 to 10 meters were usually
     between 16.1-18.3 C and the surface temperature rarely exceeded
     18.9 C.  An alternative reason for movement into deeper water
     was suggested to be the pursuit of food organisms such as ciscoes.

37.  Regier, Henry A., Vernon C. Applegate, and        Descriptors
        Richard A. Ryder                               WALLEYE
     1969.   The ecology and management of the          SAUCER
            walleye in western Lake Erie.  Great       LAKE ERIE
            Lakes Fish.  Comm. Tech. Rep. 15, 101 p.    DISTRIBUTION
     Walleye reportedly prefers a temperature of about 21.1-22.2 C in
     summer, but some resident populations in rivers (Illinois) tol-
     erate water temperatures as high as 30 C for extended periods.
     From all available information it appeared to the authors that
     light  intensity is a more important factor in determining depths
     selected by walleyes in the summer than water temperature.  Based
     on the geographical distribution of saugers and walleyes, it was
     suspected that saugers are less tolerant to low temperatures and
     slightly more tolerant to high temperatures than the walleye since
     saugers occur further southwest and do not occur as far north.

38.  Schumann, George C.                               Descriptors
     1964.   The effect of abnormal temperatures on     WALLEYE
            the spawning and developmental success     WISCONSIN
            of eggs from the North American walleye.   SPAWN
            Transl. from Osterreichs Fischerei, May
            1964(5): 85-87, by Dieter N. Busch,
            U.S.  Bur. Comm. Fish., Sandusky, Ohio.
     In northern Wisconsin it was found that the walleye consistently
     spawns at water temperatures from 5-10 C with the largest walleyes
     reaching the spawning grounds first.  When temperatures quickly
                                 88

-------
     warm up in the spring causing early spawning activity then followed
     by a cold spell, the walleyes leave the spawning grounds before
     spawning is completed.  It was found that the younger, smaller
     female walleyes were capable of spawning later when water tempera-
     tures warmed up again.  Since the complete ripening of eggs is
     earlier for the larger walleyes, the eggs in the smaller females
     do not suffer the same delay when unfavorable weather conditions
     postpone spawning.

39.  Smith, Lloyd L., Jr., and Richard L. Pycha        Descriptors
     1960.  First-year growth of the walleye,          WALLEYE
            Stizostedion vitreum vitreum (Hitchill),   MINNESOTA
            and associated factors in the Red Lakes,   GROWTH
            Minnesota.  Limnol. Oceanogr. 5(3):
            281-290.
     An attempt was made to correlate first-year growth of walleyes in
     Red Lakes, Minnesota with air degree-days above 45 F and air
     degree-days above 50 F for the following months: 1) May, June,
     July; 2) May, June, July, August; 3) July, August; 4) August; 5)
     August, September; 6) September; and 7) the last two weeks in
     July, August, and September for a 17-year period, 1940-1956.  They
     all showed a positive correlation with growth of young walleyes,
     but none were significant below the 15% level.

40.  Spinner, John                                     Descriptors
     1968.  Environmental effect on the spawning       WALLEYE
            run of northern pike and walleye in the    IOWA
            upper Mississippi River.  Proc. of North   SPAWN
            Central Warm-Water Fish Culture Work-
            shop, Iowa Coop. Fish. Unit, 1968: 9-12.
     Walleye spawn in the upper Mississippi River when temperatures
     are 7.8-8.9 C.  For management purposes it was suggested that
     peak of walleye egg taking is when the temperature reaches 8.9-
     11.1 C.  Tests were made on walleye eggs taken from the Mississippi
                                 89

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     walleyes.  Eggs were held at a constant temperature of 12.2 C; by
     the 10th day eggs are eyed and start hatching in 20 days.

41.  Steucke, Erwin W.                                 Descriptors
     1968.  Optimum temperatures for hatching          WALLEYE
            northern pike and walleye eggs.             WISCONSIN
            Proc. North Central Warm-Water Fish        INCUBATION
            Culture Workshop, Iowa Coop. Fish.
            Unit, 1968: 32-34.
     Walleye eggs were incubated at different test temperatures
     ranging from 10.0-23.9 C.  The temperature maintenance during the
     test was +0.28 C.  At 19.4 C, 67% of the eggs hatched.  Walleye
     eggs were then incubated at 21.7 C and 23.9 C.  These hatched in
     5 days but died immediately after hatching.  It was concluded that
     16.7-19.4 C was the best temperature for hatching walleye eggs.
     It was also concluded that based on 32  F,  it took an average
     number of 238 degree-days for walleye eggs to hatch.

42.  Walburg, Charles H.         .                     Descriptors
     1972.  Some factors associated with fluctuation   SAUCER
            in year-class strength of sauger, Lewis    S. DAKOTA
            and Clark Lake, South Dakota.  Trans.      INCUBATION
            Amer. Fish. Soc. 101(2): 311-316.          YEAR-CLASS
                                                        STRENGTH
     Saugers spawned in the Missouri River when water temperatures
     reached 6.1 C.  At an average water temperature of 8.7 C the
     embryo incubation period for saugers is 21 days.  It was found that
     June reservoir water temperature, along with water level,fluctua-
                                                             '   i
     tion over the spawning grounds and the reservoir exchange rate
     account for 86% of the variability in year-class strength.  Fewer
     fish were lost when June water temperatures averaged near 21 C.
     At cooler temperatures the growth was slower and fry were more
     subject to current loss in the discharge.
                                  90

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                 INDEX
WALLEYE (STIZOSTEDION VITREUM VITREUM)
1
9
15
22
29
36
2
10
16
23
30
37
4
11
17
24
31
38
5
12
18
25
32
39
7
13
20
26
33
40
8
14
21
28
35
41
    SAUCER  CSTIZOSTEDION CANADENSE)
 6       8      10      16      19      27
28      33      34      37      42

BLUE PIKE (STIZOSTEDION VITREUM GLAUCUM)
 3      10
                   91

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
  EPA-660/3-75-017
                             2.
             3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
 Temperature  Effects on Eggs and Fry  of  Percoid
 Fishes
             5. REPORT DATE
               July 1974 completion date
             6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)

 Lloyd L. Smith,  Jr.  and Walter M. Koenst
             8. PERFORMING ORGANIZATION REPORT NO.
9 PERFORMING ORGANIZATION NAME AND ADDRESS
 Department of  Entomology, Fisheries and  Wildlife
 University of  Minnesota
 St Paul MN 55101
             10. PROGRAM ELEMENT NO.

               1BA021
             11. CONTRACT/GRANT NO.
              R-800704
12. SPONSORING AGENCY NAME AND ADDRESS
 U.S. Environmental Protection Agency
 National Water  Quality Laboratory
 6201 Congdon  Boulevard
 Duluth MN 5580A
             13. TYPE OF REPORT AND PERIOD COVERED
              Final	
             14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
      Temperature effects on the early  life history stages of the walleye (Stizostedion
 vitreum vitreum (Mitchill)) and sauger (Stizostedion canadense  (Smith))  were examined.
 Walleye eggs and fry were exposed to six temperatures (6-21 C)  for effects on fer-
 tilization, incubation, and fry survival.   Mature sauger were held and eggs were
 fertilized at four temperatures (9-18  C).   Both species were incubated at  6-21 C.
 Sauger fry survival was also tested at 6-21 C.   Optimum fertilization temperatures
 were 6-12 C for walleye and 9-15 C for sauger.   Optimum incubation temperatures were
 12-15 C for both walleye and sauger.   A sharp drop or rise in temperature  had no great
 effect on walleye fry and juvenile survival except when the upper lethal or lower
 lethal temperature was approached.  Optimum temperature for juvenile walleye and sau-
 ger growth was  22 C.   Upper lethal temperatures for walleye juveniles were determined
 for acclimation temperatures at 2 C intervals between 8-26 C.   The upper lethal tem-
 perature of walleye juveniles was 27.0-31.6 C,  depending on acclimation.   The upper
 lethal temperature of sauger acclimated  to 10-26 C was 26.6-30.4 C.  There was little
 temperature difference (1-2 C) between 100% survival and no survival.
17
                               KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.lDENTIFIERS/OPEN ENDED TERMS
                           c.  COSATI Field/Group
 Sauger*, walleye*, environmental effects*,
 growth rates*, fish  eggs*,  fish larvae*,
 juvenile fishes, growth stages, water
 pollution effects, cold resistance, heat
 resistance
  temperature tolerance,
  acclimation
18. DISTRIBUTION STATEMENT

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       99
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