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ARTIFICIAL PROPAGATION OF LAKE STURGEON,
ACIPENSER FULVESCENS (RAFINESQUE),
UNDER HATCHERY CONDITIONS IN MICHIGAN
Eric Robert Anderson
A thesis submitted in partial fulfillment
of the requirements for the degree of
Master of Science
School of Natural Resources
The University of Michigan
August 1984
Committee members
Dr. W. C. Latta, Chairman
Dr. James S. Diana
ACKNOWLEDGEMENTS
This study was funded and supported by Michigan's
Living Resources Program and the Michigan Department of
Natural Resources (MDNR), Institute for Fisheries Research.
I would first like to extend my sincere gratitude to
Dr. William C. Latta for chairing my thesis committee and
providing me the opportunity to study lake sturgeon. His
enthusiasm and assistance contributed greatly to the success
of this project. I would also like to thank Dr. James
S. Diana for his useful contributions to this thesis and
throughout my years in the School of Natural Resources at
The University of Michigan. I wish to thank Dr. Karl
F. Lagler for giving me the opportunity for graduate study
in the School of Natural Resources and for guidance and
encouragement early in my graduate career. I greatly
appreciated the statistical advice and friendly nature of
Dr. Gary W. Fowler. Dr. Lee A. Fuiman also provided help
and advice with the analysis.
The Wiscons in Department of Natural Resources kindly
donated fertilized lake sturgeon eggs and assisted in many
aspects of this study, which were greatly appreciated and
vital to the projects completion. I would also like to
thank Mr. Fred P. Binkowski, Center for Great Lakes Studies,
University of Wisconsin, for providing useful information
during various stages of research.
I am grateful to the employees of the Institute for
Fisheries Research who have been more than Colleagues during
ii
the past 3 years. I am indebted to James R. Ryckman, Kelley
D. Smith, Richard D. Clark, Jr., Paul W. Seelbach, and
George B. Beyerle for their generous assistance throughout
this study. I would also like to thank Mrs. Barbara
Lowell, and Ms. Barbara Gould for their help and friendship
during my years at the Institute, and to Mrs. Grace Zurek
for her preparation of this manuscript.
My sincere thanks go to the entire staff at the Wolf
Lake State Fish Hatchery for their support, friendship, and
guidance throughout the study. Special thanks also to James
Copeland, Tom Coles, John Hnath, and Judy Zischke. My good
friends Michael P. Herman, David G. Gallery, and Chris Starr
provided assistance above and beyond the call of duty, and
made my stay at the "hatch" more enjoyable. Thanks go to
the maintenance staff at Wolf Lake, who constructed and
tirelessly maintained the rearing facility for this study.
I greatly appreciated the (MDNR) staff in District 5
for their superlative effort in obtaining spawning adult
sturgeon. Specifically, I would like to thank Harold
Miller, Lyle Hollenbaugh, Brian Hoxie, Keith Readmond, Gary
valientine, Jim Holser, and Heather Kanalos.
Bill Lyons and the Wolverine Power Supply Cooperative
kindly restricted flow from the upper Black River at Kleber
Dam to facilitate capture of adult Sturgeon during spawning.
Conservation officers James Rubin and Eugene Elsenheimer
variously assisted in the egg take. Special thanks to
iii
Conservation Officer Edward Pike for his continued concern
and assistance throughout the study.
Fisheries Habitat Biologist Mason Shouder readily
answered my many questions on the topic of sturgeon, and
assisted in many facets of this project. District Fisheries
Biologist Steve Swan was also instrumental in coordinating
the field work, and was very supportive through the project.
Dick Poynter, Biologist in Charge, of Oden State Fish
Hatchery, also assisted during the egg take and was much
appreciated.
I would also like to extend my sincere gratitude to my
close friends who helped throughout this project. Mr. Chris
L. Johnsrude helped in many aspects of this study, and
carefully reviewed rough drafts along the way. Mr. Bill
Barense always provided support when needed. Walter and
Jessie Janeczek collected important temperature data and
kindly provided me a "home away from home" at Black Lake.
Boyd and Doris Crist, as well as all the folks on Five Mile
Point were very supportive and friendly. I extend my
fondest thanks and love to my parents, Bob and Jackie, and
to my siblings, Kurt and Jill, for their encouragement and
support throughout my life.
Finally, I would like to thank my wife, Becky, for her
love, patience, and understanding during this research.
iv.
TABLE OF
ACKNOWLEDGEMENTS . . . . . . .
LIST OF TABLEs . . . . . . .
LIST OF FIGURES . . . . . . .
ABSTRACT . . . . . . . . . . .
INTRODUCTION . . . . . . . . .
CULTURAL METHODS . . . . . . .
Capture of adult lake sturgeon
Collection of milt . . . .
Egg Collection . . . . .
Fertilization of the eggs .
Incubation of the eggs . .
Hatching . . . . . . . . .
Feeding . . . . . . . . . .
EXPERIMENTAL METHODs . . . . .
Analysis . . . . . . . . .
RESULTS O © © O © © e © © O O
Survival © O © © O O O e ©
Growth O © O © O © O Go O O
DISCUSSION © o © © © © © © © o
Survival . . . . . . . . .
Growth Q © O Q O º "O O Q ©
Culture schemes . . . . .
LITERATURE CITED . . . . . . .
CONTENTS
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Table
l.
LIST OF TABLES
Percent survival (weekly) of lake sturgeon
fed natural diets over 9 weeks. . . . . . .
Percent survival (weekly) of lake sturgeon
fed Biodiet under weaned and direct methods.
Percent survival (weekly) of lake sturgeon
fed Oregon Moist Pellets, under weaned and
direct methods. . . . . . . . . . . . . . .
Mean total lengths (mm) each week for
sturgeon raised under a variety of diets.
Ninety-five percent confidence limits, as
calculated using a pooled standard error
from each group, are given for those samples
with n greater than one . . . . . . . . . . .
Mean total lengths (mm) each week for
Michigan sturgeon raised under a variety of
diets. Ninety-five percent confidence
limits, aS calculated using a pooled
standard error from each group, are given
for those samples with n greater than one. .
Mean total lengths (mm) each week for
Wisconsin sturgeon raised under a variety of
diets. Ninety-five percent confidence
limits, aS calculated using a pooled
standard error from each group, are given
for those samples with n greater than one . .
Mean weights (g) each week for sturgeon
raised under a variety of diets. Ninety-
five percent confidence limits, aS
calculated using a pooled standard error
from each group, are given for those samples
with n greater than one . . . . . . . . . . .
Mean weights (g) each week for Michigan
sturgeon raised under a variety of diets.
Ninety-five percent confidence limits, as
calculated using a pooled standard error
from each group, are given for those samples
with n greater than one . . . . . . . . . .
Page
l 4
15
l6
l 8
19
20
2l
22
vi
10.
Mean weights (g) each week for Wisconsin
sturgeon raised under a variety of diets.
Ninety-five percent confidence limits, as
calculated using a pooled standard error
from each group, are given for those samples
with n greater than one . . . . . . . . . . .
Mean values for survival (weeks) and growth
rates (mm/week) for all lots of sturgeon fed
a variety of artificial diets. Growth rates
are from only those sturgeon that survived
at least through the third week of the study
period. . . . . . . . . . . . . .
vi i
23
26
Figure
l.
LIST OF FIGURES
Collection site for lake sturgeon on the
upper Black River, Cheboygan County,
Michigan, 1983. . . . . . . . . . . . . . . .
The relationship between mean body length (L)
in mm and mean body weight (W) in g for
Michigan and Wisconsin sturgeon from
individual lots fed natural diets throughout
the 9-week study. . . . . . . . . . . . . . .
vi i i
Page
25
ABSTRACT
Eggs and milt were collected from spawning adult lake
sturgeon (Acipenser fulvescens Rafinesque) from the upper
Black River, Cheboygan County, Michigan, on l9 May 1983.
Eggs, obtained by cesarean-section, were fertilized by the
dry method, using milt stripped from males and collected by
syringe. Lake sturgeon eggs collected from the Fox River in
Winnebago County, Wisconsin, were fertilized and donated by
the Wiscons in Department of Natural Resources. Fertilized
eggs were incubated in standard McDonald hatching jars.
Artificial and natural diets were presented to groups
of experimental sturgeon, and survival ana growth were
measured for each group. Natural diets were zooplankton and
aquatic annelids; artificial diets were Biodiet and Oregon
Moist Pellets. Both direct and weaned feeding were tested.
Sturgeon fed natural diets throughout the study showed
highest survival (45–90%) and growth rates (approximately
7.6 mm/week) for all groups tested. Michigan and Wiscons in
sturgeon fed natural diets showed similar mortalities during
the 9-week study, however, wisconsin fish showed
significantly higher growth rates (8.18 mm/week) than
Michigan sturgeon (6.92 mm/week). In contrast, fish fed
artificial diets did not survive 9 weeks and had decreased
growth rates (approximately 4.7 mm/week). The exception WaS
one weaned group fed Biodiet, which showed growth rates
similar to fish fed natural diets, but with a survival of
only 3.7%.
ix
INTRODUCTION
Lake Sturgeon (Acipenser fulvescens Rafinesque) were
once abundant throughout the entire Great Lakes region.
Factors such as overfishing, poor water quality, and the
damming Of their spawning rivers have been largely
responsible for their decline (Harkness and Dymond l36l;
Scott and Crossman l973). The lake sturgeon is currently
classified as threatened (l276) by the Michigan Department
Of Natural Resources and rare by the United States
Department of Interior (1977).
During the late l800's, several attempts were made to
propagate the lake sturgeon artificially in the Great Lakes
region (Post l890; Meehan 1909; Leach l820). Early attempts
were largely unsuccessful for several reasons (reviewed by
Binkowski lºS0). Locating ripe males and females at the
same time was perhaps the greatest problem. Also, males
were reported to be more abundant than females during the
spawning migrations. Stripping the sturgeon of eggs by the
conventional pressure method was generally unsuccessful.
Further, obtaining a successful hatch was also a problem,
due to the adhesiveness and susceptibility of eggs to fungal
infestations. If eggs were successfully hatched, the fry
soon died as no suitable food source was known (Leach 1920).
Attempts at culturing the lake sturgeon were largely
discontinued from 1926 to 1979, when Wisconsin Department of
Natural ReSOur CeS biologists successfully reared lake
sturgeon to a plantable size (Czeskleba l'979).
The purpose of this study was to evaluate several diets
and feeding techniques for survival and growth of young
Sturgeon. The diets tested were two artificial diets,
Biodiet and Oregon Moist Pellets (OMP), and a natural diet.
The feeding methods tested were weaned and direct feeding.
In addition, several other ancillary objectives related to
Culture of Sturgeon were: (1) locate a spawning population
in the State of Michigan where adults could be easily
captured, (2) collect eggs and milt from spawning adults
without harming them, due to their rare and threatened
status in Michigan; (3) work out the proper fertilization
techniques, (4) hatch the eggs in a hatchery and rear the
young to a plantable size.
CULTURAL METHODS
Capture of adult lake sturgeon
Adult lake sturgeon were captured on their spawning
migration during the spring of lS83 using large, long-
handled dip nets. The sturgeon were captured on the upper
Black River, a tributary of Black Lake, Cheboygan County,
Michigan. The sturgeon were captured on 13 May 1983 at the
first set of rapids directly below Kleber Dam (Fig. l).
Water temperature at the time of capture was le. l C. The
Wolverine Power Supply Cooperative retained the water behind
the dam to make the sturgeon more vulnerable to our nets.
Lowering the water level did not appear to have an effect on
their spawning activity. Males and females were easily
distinguishable in the shallow, clear water. Females were
LOWER
BLACK RIVER
i
ſ
i
UPPER
BLACK
RIVER
RED BLACK LAKE
T BRIDGE
Collection
Site
!/
Ž KLEBER
DAM
Figure l. Collection site for lake sturgeon on the upper
Black River, Cheboygan County, Michigan, l 983.



considerably larger than males, and We re typically
surrounded by two to three males. Once a sturgeon was
netted, it was brought to shore and transferred to a
stretcher for collection of eggs or milt.
Collection of milt
The male sturgeon were processed first since it is
possible to store milt "dry" on ice in graduated cylinders
for several hours (Ginzburg l'972). Once a fish was netted,
it was taken to shore and placed ventral side up in the
stretcher, its head inserted into a sewn-in burlap sack to
calm the fish. The burlap sack was kept wet at all times to
prevent the gills from becoming desiccated. The stretcher
was supported by two saw horses to prevent movement of the
fish and to raise the stretcher to a comfortable working
height. The area surrounding the vent was dried off
completely. Milt, released by gently stripping the fish,
was drawn into a 50-cc syringe. After three to four
strippings, the milt was transferred to a dry graduated
cylinder and stored in an ice chest until needed. The
sturgeon was then returned to the river unharmed. Care was
taken to insure that no water came into contact with the
milt at any state prior to fertilization, as the milt
becomes activated in water. Milt was collected from four
males and held on ice for approximately 30 minutes before
UlS 6 e
Eqq collection
On 13 May 1983, 2. l L of eggs (39,900) were collected
from two of four Sturgeon, spawning below Kleber Dam. As a
back-up egg source for this study, the Wiscons in Department
of Natural Resources donated l. 9 L of lake sturgeon eggs
(36, 100). The Wisconsin eggs were collected from adults
captured below Eureka Dam, the Fox River, during late April.
The eggs were counted using the Von Bayer method (Leitritz
and Lewis l876). Both the Wiscons in and Michigan sturgeon
eggs measured l3,000/L.
FOUlr Michigan female sturgeon were captured and
evaluated for ripeness by palpation of the abdomen and
visual inspection of their eggs. Usually once a female
Sturgeon was handled, the sphincter muscles surrounding the
vent contracted, making stripping impossible. As a result,
a cesarean-section technique was used to remove eggs without
harming the fish. The technique WalS developed in
California for the white sturgeon (Acipenser transmontanus),
and later applied to the lake sturgeon in Wisconsin
(Binkowski and Czeskleba l'980).
Once a suitable fish was captured, it was placed in the
stretcher and the area surrounding the vent was dried, as
the eggs also become activated in water. Using a heavy
surgical scalpel, a 3.8 to 5.0-cm incision was made
approximately 10 cm anterior and to the left of the vent.
Of the four female sturgeon Cesarean-sectioned, only minimal
bleeding was observed in one female. Once the incision was
made, the fish was rotated dorsally allowing the eggs to
flow from the incision into a l2-quart stainless steel
mixing bowl. If the eggs were ripe, they flowed freely from
the incision. Care was taken to keep water from entering
the stainless steel bowl before fertilization. When the
desired amount of eggs was collected, the incision was
closed with 3-0 dissolving suture material. A cutting
needle was used, as the sturgeon's epidermis is very tough.
A suture clamp or needle holder was used to properly
manipulate the needle. A standard mattress pattern was
chosen using l/8-inch spaces between sutures. Once the
incision was closed properly, the sturgeon was returned to
the water. Usually a brief recovery period was necessary,
holding the fish facing into the Current . Previous
telemetry studies, conducted by the Wiscons in Department of
Natural Resources, have shown no mortality associated with
the cesarean-section technique. In all cases the incision
healed (Folz, et al. 1983)
Fertilization of the eqqs
Once eggs and milt were collected, the fertilization
process was begun as soon as possible, usually within 5
minutes. The dry method of fertilization was used. Milt
was added "dry", directly to the eggs contained in the bowl
and mixed for approximately 10 seconds. River water was
then stirred into the mixed eggs and milt, and the solution
was allowed to sit for several minutes. At approximately 4
minutes post-fertilization, sturgeon eggs become extremely
adhesive, clumping together and making them difficult to
handle. To alleviate this problem, bentonite clay powder
was added at that time. The bentonite Clay powder was
suspended in water to a "milk-shake" consistency prior to
use. Two Cups of the bentonite mixture were used per lz-
quart pan. Once added, the mixture was stirred gently by
hand for about lo minutes, or until the adhesiveness was
eliminated. The eggs were then allowed to sit for
approximately l hour to water harden, and were then rinsed
clean, packed in plastic bags within styrofoam coolers, and
transported to the hatchery.
Incubation of the eqqs
The fertilized eggs were transported from the Black
River site to the Wolf Lake State Fish Hatchery, near
Kalamazoo, for hatching and rearing. The water temperature
was le. l C on-site and did not fluctuate during transport to
the hatchery.
Standard McDonald hatching jars were used for incubation
of both the Wiscons in and Michigan Sturgeon eggs. Several
days prior to hatching, the Michigan eggs were placed in
vertical-flow incubators to contain larvae once they
hatched, while Wiscons in eggs were left in the hatching
jars. Flow rates through the McDonald incubators were held
at 7.5 L per minute, while the flow was reduced to 3.8 L per
minute when the vertical-flow incubators were in use. The
water temperature was held constant at 15.0 C and the eggs
began hatching in 9 days. Hatching was completed within 24
hours.
During the incubation period, the eggs were treated
with formal in on alternate days for lò minutes to prevent
fungal infection. During the latter part of incubation,
formal in treatments of the Michigan eggs were discontinued
due to sucker fry being held within the same water system.
As a result, approximately 28% of the eggs were lost to
fungus. The Wiscons in eggs also were attacked by fungus and
approximately 24% of these eggs were lost.
When removed from the female sturgeon, most of the eggs
were very dark in color (green-black) with a small buff
colored spot (the germinal vesicle) visible on one pole.
Once eggs were water hardened, they began to change color,
progressively turning lighter until hatching, when they were
almost clear. After the eggs cleared, hatching usually
occurred within 36 hours. Approximately 76% (27,500) of the
Wiscons in eggs and 72% (28,600) of the Michigan eggs
hatched. Upon hatching, the larvae were transferred from
the vertical-flow incubators into holding tanks.
Hatching
At hatching the lake sturgeon larvae were approximately
l.0 cm in length. Some of the larvae had developed gills
and eyes at time of hatching while others had not. From
hatching until yolk-sac absorption, the larvae swam
Constantly, and Were very negatively phototactic.
Approximately 20 days post-hatch their behavior changed and
they became positively phototactic and less active. This
behavior pattern coincided with yolk-sac absorption and
exogenous feeding.
Feeding
Prior to the diet study, the fry were fed zooplankton,
mainly Daphnia pulex and various stages of copepods, first
introduced several days prior to yolk-sac absorption.
Zooplankton were collected twice daily from a local lake
with a plankton net. During the first lo days of feeding,
the zooplankton was screened through Nitex (333 microns) to
permit only the smallest zooplankton to enter the tanks.
Sturgeon were dissected daily to determine the onset of
exogenous feeding. The yolk sac was fully absorbed at lS-19
days post-hatch. At 23 days post-hatch, approximately 40%
of the fry examined had begun to feed. At 28 days 70% of
the sturgeon examined had zooplankton in their stomachs.
After the lC-day screening period, zooplankton were added
directly into the tanks, as the fry were large enough to
feed on the largest zooplankton. The fry fed most actively
during the evening hours, and were often observed feeding
from the surface and water column. Nitex screens were used
at the ends of the raceways to prevent the zooplankton from
being washed out of tanks. After the sturgeon were feeding
well on the zooplankton, the diet study was started. At
approximately 16 days post-hatch (Michigan sturgeon), and 31
days post-hatch (Wisconsin sturgeon) the fry were
transferred to new tanks for the diet study.
10
EXPERIMENTAL METHODS
The fiberglass tanks used were 2.7 m in length, 51 cm
in width, and had a depth of 30 cm. Each tank was set up as
a flow-through system, and held l, 100 L of heated spring
water. The temperature was held constant during the study
at lS. 4 C with a flow rate of 7.5 L/min/tank.
On 5 June, the surviving fry were counted into the
tanks in preparation for the diet study which began the
following day. Michigan and Wiscons in sturgeon were kept
separate during the study. Three samples of 2,000 sturgeon
each were randomly collected to determine average weight so
that handling time of fry would be minimal. Eighteen tanks,
containing approximately 2,000 sturgeon fry (ll.4 g) each,
were set up for the diet study.
Two artificial diets commonly used in commercial
hatcheries were tested against a natural diet, and evaluated
for sturgeon survival and growth. Both OMP and Biodiet are
semi-moist pellets and were expected to be more palatable
(acceptable) to the sturgeon than a standard dry diet.
Additionally, neither diet had previously been tested on a
large scale culturing lake Sturgeon. Appropriate sizes of
Biodiet and Oregon Moist Pellets were tested against a
natural diet, composed of zooplankton and later an aquatic
annelid, Lumbriculus variegatus. Two methods of feeding
were used with the artificial diets, direct and weaned.
Sturgeon that were fed under the direct method were abruptly
switched to the artificial diet at the beginning of the
ll
experiment. The sturgeon being fed according to the weaned
method continued on decreasing amounts of zooplankton for lS
days. OMP was used in six tanks, three weaned and three
direct. Biodiet was also fed to six tanks, three weaned
and three direct. The natural diet was fed to six tanks.
Each tank was assigned a specific diet, and randomly
assigned a position in the hatchery building. Pure cultures
of Michigan or Wiscons in sturgeon were then randomly placed
in each tank.
The artificial diets were presented using Loudon
automatic feeders suspended above the tanks. The feed was
released into the tanks at lº-minute intervals from 3:00
P.M. to 5:00 A.M., at a rate of lo g per day per tank. Beer
(1982) showed frequent night feedings enhanced acceptance of
artificial pellets for white sturgeon. The artificial diets
were fed to excess. The natural diet was presented twice
daily, morning and evening, combining both the zooplankton
and annelids, until 17 June when only worms were used. The
WOI. IſlS provided Were eaten readily, amounting to
approximately lb.0 ml (170 g) per day to each tank initially
and increased to 300 ml ( 340 g) per day from 15 July until
10 August. However, fish did not appear to be satiated at
these levels.
Mortality (number of dead sturgeon) and water
temperature were recorded daily. Length and weight of
experimental fish were measured weekly. For this, 30 live
Sturgeon were randomly selected from each tank and
l2
anesthetized using MS-222 (l. l; lo, 000) for 60 seconds. The
fish were measured individually to the nearest mm (total
length) and weighed (as a group of 30) to the nearest g.
Measurements were not taken from dead sturgeon.
Analysis
Mortality was calculated by subtracting the daily
number of dead sturgeon from the total number of
surviving
sturgeon, dividing by the grand total and summing by weeks.
The data were analyzed as a binomial distribution (daily
number living or dead), expressed as percent survival
(Snedecor and Cochran l971) (Tables l through 3).
Length data were used to examine growth that occurred
during the study. Growth rate was evaluated as the slope of
the body length-time relationship based on mean values for
weekly samples since growth appeared to be strongly linear
for experimental fish (see also Monaco, et al. 1981),
COVA) was used to examine
Analysis of covariance (AN
differences in growth rates between sturgeon fed different
diets and between Michigan and Wisconsin sturgeon
natural diets. The level of significance was set at a
0.05 for all tests.
The data were analyzed using the
statistical package at T
Guire 1976).
this of
associated wit
al problem
potenti
occurred
growth rate is that high mortality rates that
during the initial part of the study may have selectively
smaller (starved) fish from being included in the size































13
measurements. This may wholly account for apparent growth
in lots that only survived through the initial weeks of the
study, and possibly inflate growth rate estimates somewhat
for the remaining lots (see Tables 4 through 9).
RESULTS
Survival
Survival, expressed here clS cumulative percent
survival, was greatest in the natural diet tanks (Table l).
For the Michigan sturgeon fed natural diets, survival to 9
weeks was 74.73 + 24.54% (mean #2 standard errors), whereas
Wiscons in sturgeon had 53.77 it 8.4% survival.
Biodiet weaned was the only artificial diet tank that
had survival through the 9 weeks of the experiment (3.7%,
Table 2). Most of the sturgeon that fed on artificial diets
died before the fifth week of the study (Tables 2 and 3).
Therefore no useful conclusions were drawn from comparisons
of their survival.
Growth
Overall, the six lots of sturgeon fed natural diets
grew from 26.18 mm (mean total length) and 0.07 g (mean body
weight) to 84.31 mm and 2.26 g during the 9-week study
period (Tables 4 and 7). The three lots of Michigan fish,
initially 26.45 mm and 0.07 g., grew to 80.31 mm and 1.96 g
(Tables 5 and 8). Results from analysis of covariance
(ANCOVA) showed that rates of growth (in length) for these
three lots were not significantly different (P = 0.3265;
l4
Table l. Percent survival (weekly) of lake sturgeon fed
natural diets over 9 weeks. -
Tank 7 ll 17 18 19 20
Source (MI) (MI) (WI) (WI) (WI) (MI)
(N) 2,048 l, 981 2,002 2,627 2, 370 2, 667
Week
l 99.0 99.2 82.8 64. l 88.5 95.3
2 96.7 97. 1 79.8 59.8 81 .. 7 78.4
3 92.9 89.2 72.8 57.1 76. 1 72. 0
4 92. l 88.8 68.0 51. 7 69.8 68.2
5 91.5 87.9 64.4 50. 0 66.8 64. 2
6 91. 0 86.2 60.4 4.7. 9 62. 1 56. 7
7 90.0 84.9 58.5 46.3 60.6 53. 0
8 90.0 84.4 57.7 45.9 59.7 51.5
9 89.7 84. l 56.8 45.4 59. 1 50. 4
15
Table 2. Percent survival (weekly) of lake sturgeon fed
Biodiet under weaned and direct methods.
Biodiet (weaned) Biodiet (direct)
Tank l O l2 l4 l6 2l 23
Source (MI) (WI) (MI) (MI) (MI) (WI)
(N) 2, 003 2,005 l, 620 l, 834 2, 322 2, 002
Week
l 97. O 77. 4 9.7. 9 94.8 98.2 82.8
2 92.8 67 - 7 95. 2 25.3 l6.6 O
3 0 55.9 89.0 2.8 2.5
4 2.2 20. l 0. 7 0.3
5 O 4.2 0.4 0.2
6 4. 1 0.3 0.1
7 3. 8 0.2 0
8 3. 7 O
9 3. 7
l6
Table 3. Percent survival (weekly) of lake sturgeon fed
- Oregon Moist Pellets, under weaned and direct
methods.
OMP (weaned) OMP (direct)
Tank 13 15 24 6 8 22
Source (WI) (WI) (MI) (WI) (WI) (MI)
(N) 2, 180 2, 362 l, 979 l, 997 2,000 l, 933
Week
l 70.5 65.4 96.9 78. 0 8l. 0 97.9
2 62.6 43.5 95.4 8. 7 0 25. l
3 39 - 0 31. 9 87. 0 O 2.8
4 0.4 0 50.4 O
5 0.2 0.4
6 0 0.2
7 0
l 7
6.92 mm/week). The three lots of Wisconsin sturgeon grew
from 25.92 mm and 0.06 g to 88.31 mm and 2.55 g during that
time (Tables 6 and 9). Growth rates among these fish also
were not significantly different (ANCOVA, P = 0.1432; 8.18
mm/week). Differences between Michigan and Wisconsin
sturgeon fed natural diets were found to be highly
significant (ANCOVA, P × 0.00005) for the 9-week period.
Fish from one tank being fed an artificial diet
(Biodiet weaned, Michigan sturgeon) survived for the
duration of the study period and showed growth similar to
Michigan sturgeon fed natural diets. Growth rates for the
four lots of Michigan sturgeon (three natural and one
artificial, Biodiet weaned) Were found to be not
significantly different (ANCOVA, P = 0.2257; 7.08 mm/week).
Because survival was very poor for many lots fed
artificial diets, only lots with survival through week 5
were compared for differences in growth rates. This left
only Michigan lots to be included in the analysis: 2
Biodiet direct, l Biodiet weaned, and l OMP weaned. The 2
lots of sturgeon fed Biodiet direct grew from 23.91 mm to
47.88 mm by the end of week 6 (Table 5). There were no
significant differences in growth rates between these two
lots (ANCOVA, P = 0.3298; 4.79 mm/week). Growth rates were
significantly different between fish fed Biodiet weaned
(7.6l mm/week, P × 0.00005) and OMP weaned (4.55 mm/week, P
= 0.0098) (ANCOVA, P = 0.0171). Growth rates were also

l8
Table 4.
Mean total lengths (mm) each week for Sturgeon raised under a
Ninety-five percent confidence limits, as
variety of diets.
calculated using a pooled standard error from each treatment
group, are given for those samples with n greater than one.
Diet
Oregon Moist Pellet Biodiet Natural
Direct Weaned Direct Weaned
24. 59:0.59 26. 48+0.59 24.34+0. 60 25. 42+0.59 26. L8+0.59
28. l3+0.62 27. Ll:0.59 28.50+0. 60 26 - 7.6+0.59 28.68+0.59
28.66+0.64 28. 59:EO. 59 29. 53+0. 60 29.23:0. 60 38.9l:0.59
33.33+0.6l 35.06:0. 64 37. 99:EO. 6l. 46. 10+0.59
4l. 60+0.83 42. 45+0.67 50. O6+0.62 52 - 31:0.59
50.33+l. 29 47 - 88+0.69 56.66+0.62 6l. 24+0.59
62. 66+0.62 69. O7+0.59
74.26+0.62 75 - 89:EO. 59
8l. 84+0.59 84.31:0.59
l9
Table 5. Mean total lengths (mm) each week for Michigan sturgeon raised
under a variety of diets. Ninety-five percent confidence
limits, as calculated using a pooled standard error from each
treatment group, are given for those samples with n greater
than One.
Diet
Oregon Moist Pellet Biodiet Natural
Week Direct Weaned Direct Weaned
l 24. 10+0.62 27.00+0.62 23.91:0. 60 25. O3+0. 60 26.45+0. 60
2 28. 13+0.62 28.43+0.62 28.50+0. 60 26 - 73+0. 60 28.73:EO. 60
3 28.66+0. 64 28.93:0.62 29. 53+0. 60 27. 66+0. 62 37.34+0. 60
4 32. l.2+0.62 35. 06:0. 64 38.13+0.62 44. 74:0.60
5 4l. 60+0.84 42. 45+0.67 50. 06:0.62 50.57+0. 60
6 50.33+l. 29 47. 88+0.69 56.66+0. 62 58.07+0. 60
7 62.66+0. 62 64. OliO. 60
8 74.26+0. 62 72.99:0. 60
9 8l. 84+0.60 80.31+0.60
20
Table 6. Mean total lengths (mm) each week for Wisconsin sturgeon
raised under a variety of diets. Ninety-five percent
confidence limits, as calculated using a pooled Standard
error from each treatment group, are given for those samples
with n greater than one.
Diet
Oregon Moist Pellets Biodiet Natural
Week Direct Weaned Direct Weaned
l 24.84+0. 60 26.22+0. 60 25. 20+0.62 26. 20+0.62 25. 92+0. 60
2 26. 45+0.60 26.83:0.62 28. 64+0. 60
3 28. 43+0.60 30. 80+0.62 40. 49+0. 60
4 37. 33+0.69 37.00+0.95 47. 46+0.60
5 54 - 05:0. 60
6 64. 49+0.60
7 74.14+0.60
8 78. 80+0. 60
9 88.31:0.60
2l
Table 7. Mean weights (g) each week for sturgeon raised under a variety
of diets. Ninety-five percent confidence limits, as calcu-
lated using a pooled Standard error from each treatment group,
are given for those samples with n greater than one.
Diet
Oregon Moist Pellet Biodiet Natural
Week Direct Weaned Direct Weaned
l 0.049+0.071 0.097+0.071 O. O89:EO. O.71 0.076+0. O71 0. O7+0.042
2 0.050 O. O.82+0. O71 0.095+0.208 O. O65+0. O71 0. O7+0.042
3 O. loC) 0.072+0. O71 0.085+0.208 0.082+0.208 0.25+0.042
4 0.160+0.208 O. l73+0.208 0.235+0.208 0.4li:0.042
5 0.260 0.318+0.208 0.523 0.58+0.042
6 0.466 O. 235+0.208 O. 716 0.95+0.042
7 l. 136 l. 34+0.042
8 l. 640 l. 75+0.042
9 2. 280 2.26+0.042
22
Table 8.
Mean weights (g) each week for Michigan sturgeon raised under
Ninety-five percent confidence limits, as
calculated using a pooled Standard error from each treatment
group, are given for those samples with n greater than one.
a variety of diets.
Diet
Oregon Moist Pellet Biodiet Natural
Week Direct Weaned Direct Weaned
l 0.043 O. l8l 0.063:EO. 208 O. O66+0.208 0.07+0.071
2 0.050 0.056 0.094+0.208 0.083+0.208 0.08+0.071
3 O. loo O. loſ) 0.085+0.208 O. O70+0.208 0.22+0.071
4 O. l.20 0.173+0.208 0.220 0.40+0.071
5 0.260 0.318+0.208 O. 523 0.53+0.071
6 0.466 0.235+0.208 O. 716 0.83+0.071
7 l. l.26 1. 17+0.071
8 l. 640 l. 6lit0.071
9 2. 280 l.96+0.071
23
Table 9. Mean weights (g) each week for Wisconsin Sturgeon raised under
a variety of diets.
Ninety-five percent confidence limits, as
calculated using a pooled Standard error from each treatment
group, are given for those samples with n greater than one.
Diet
Oregon Moist Pellet Biodiet Natural
Week Direct Weaned Direct Weaned
l 0.053+0. 208 0.055+0. 208 0. l40 0.096 O. O6+0. O71
2 0.094+0.208 0.030 O. 06:EO. O71
3 0.058+0. 208 0.093 0.27+0.071
4 0.200 0.250 0.42+0.071
5 0.63+0.071
6 l. O7+0.071
7 1.58+0.071
8 1. 89+0.071
9 2.55+0.071
24
significantly different between fish fed Biodiet weaned and
fish fed Biodiet direct (ANCOVA, P = 0.0022).
The relationship between body length and body weight
for the six lots of sturgeon fed natural diets is provided
in Figure 2. Further, Figure 2 shows the length-weight
relationship over the 9-week study was similar among
juvenile Michigan and Wiscons in sturgeon.
Thus, the major result of the feeding experiments is
that of those diets tested, natural diets were far superior
to the artificial diets in promoting survival and growth in
juvenile lake sturgeon. Data from lots that did not survive
through the fifth week of the study are not included in the
above evaluation of diet effects on growth. However,
consideration of mean number of weeks for which lots showed
any fish surviving, together with mean growth rates for
those lots surviving at least through the third week, may
indicate the relative effectiveness of the diet types and
methods used in this study. Of the two artificial diets
tested, Biodiet consistently showed higher survival and mean
growth rates than fish fed OMP (Table lC). When comparisons
are made between sturgeon fed according to the weaned and
direct methods, the weaned method appears to have promoted
higher survival, and in one lot of Michigan fish fed Biodiet
weaned, growth rates were similar to those observed for
Michigan fish fed natural diets. Generally, lots of fish
fed artificial diets under the direct method had poor
25
3.0
sº O
º O
amº O
-
2.0 — AA
2- sº A
O) º . Ae
N- º $
IE * A
O) * A •
QD sº
> I A*
1.0 — A &
I A
• *"
-
an Å O A Michigan
dº A** • Wisconsin
- A
0.01–º -I-I-I-I-I-I-I-I-I I-
20 3O 40 50 60 70 80 90 100
Length (mm)
Figure 2. The relationship between ITle a ſh body length (L) in
mm and mean body weight (W) in g for Michigan and
Wisconsin sturgeon from individual lots fed natural

diets throughout the 9-week study.
26
survival and decreased growth rates relative to fish fed
according to the weaned method.
Table lC. Mean values for survival (weeks) and growth rates
(mm/week) for all lots of sturgeon fed a variety
of artificial diets. Growth rates are from
only those sturgeon that survived at least
through the third week of the study period.
Diet Biodiet OMP
Method
Of Survival Growth rate Survival Growth rate
feeding in weeks mm/week in weeks mm/week
Direct 4.67 4 - 79 2.00 2. 28
Weaned 5. 00 5. 63 4. 67 3. 05
DISCUSSION
The effects of two artificial diets (OMP and Biodiet)
and a natural diet (zooplankton and aquatic annelids) and
feeding techniques on survival and growth were evaluated for
hatchery-reared lake sturgeon to explore the possibility of
a continued cultural program in Michigan. Eggs and milt
were collected from spawning adults, fertilized, hatched,
and reared to a plantable size. Overall, sturgeon fed
natural diets survived and grew well, as expected from
previous studies (Binkowski l980). In contrast, sturgeon
27
fed artificial diets generally did not survive or grow well
(also see Binkowski and Czeskleba l'980).
Survival
Survival of lake sturgeon was greater than 45% at the
end of the study for all six lots of sturgeon fed natural
diets. Of these, Michigan sturgeon consistently had higher
survival than Wiscons in sturgeon in the initial weeks of the
study, and a higher total survival during the 9-week study
period (Table l). The differences in initial mortality
appear to account for the differences in overall mortality
(Tables l to 3), suggesting experimental fish were
differentially responding to handling or conditions of newly
assigned tanks rather than the diets presented during the
study.
In contrast, survival of lake sturgeon fed artificial
diets was very poor (Tables 2 and 3). Comparisons between
these lots are restricted to those that showed some survival
through the fifth week of the study, which leaves 4 lots of
Michigan fish. Only l of the 12 lots fed artificial diets
had survivors by the end of the study period (Table 2).
Thus, a Michigan lot fed Biodiet weaned showed 3.7% survival
after 9 weeks. This alone suggests that Biodiet weaned may
be the most effective artificial diet tested here. However,
the lot that survived through week 9 was the only one of
three lots fed Biodiet weaned that had any survival (only
3.7%) past the fourth week. Fish fed Biodiet direct and OMP
weaned had no survivors by the eighth week of the study
28
(Tables 2 and 3). It thus appears that of the artificial
diets tested, Biodiet weaned may be the most effective for
rearing sturgeon to a plantable size.
Growth
Growth rates (calculated as changes in length over
time) were compared among experimental fish to further
examine the effect of different diets. As done for survival
effects, only those lots of sturgeon that survived through
the fifth week of the study were included in these
comparisons.
Michigan and Wiscons in sturgeon fed natural diets
exhibited strong growth throughout the 9-week study period.
Growth rates of Michigan and Wiscons in sturgeon fed natural
diets were 6.92 mm/week and 8.18 mm/week, respectively,
similar to those reported for successfully cultured white
sturgeon (Acipenser transmontanus) (Monaco et al. 1981). The
only lot fed an artificial diet (Biodiet weaned) that
survived throughout the study also showed strong growth in
those that survived (3.7% of the initial number). The
growth rate for this lot was not significantly different
from Michigan fish fed natural diets (P = 0.2257). The
other lots fed artificial diets showed much poorer growth.
Thus, fish fed Biodiet direct grew about 4.8 mm/week and
fish fed OMP weaned grew about 4.6 mm/week.
Culture schemes
The advantages of using an artificial diet to culture -
fish are reviewed by Hublou et al. (1959). Many cultured
29
fish can now be reared entirely or partially on artificial
diets without supplementary natural diets at a particular
stage in their life (Hastings and Dickie l972). The
majority of cultured species that accept these diets are
either carnivores or omnivores (Ghittino l872). Salmonids
are cultured extensively and reared entirely on artificial
diets. First-feeding larvae are most commonly fed a semi-
moist "starter" diet, such as Biodiet, and are progressively
moved to larger pellets as the fish grow. There are many
species of fish that require a natural diet during the first
portion of their life that can be directly switched or
weaned to an artificial diet at a certain size. For
example, striped bass (Morone saxatilis) require natural
diets during early life stages before being weaned to
artificial diets (Lewis and Heidinger lº&l).
This study demonstrates lake sturgeon Carl be
successfully reared from eggs under hatchery conditions if
fed natural diets. Further, lake sturgeon do not accept the
artificial diets used here if presented at the time of yolk-
sac absorption (direct method) or if accompanied by natural
diets for an additional lS days (weaned method).
In other experiments, researchers have been successful
in weaning small numbers of lake sturgeon onto Biodiet after
the fish were approximately lb.0 to l80 mm in length (Kim
Graham, Missouri Department of Conservation, personal
communication). Experiments conducted by Monaco et
al. (1981) have produced similar results for white sturgeon
30
fed OMP; however, only a small percentage (20–30%) accepted
the diet. Copeland (lº 70) experimentally fed OMP to a small
number of lake sturgeon and was unsuccessful at rearing them
on this diet. A number of the other artificial diets have
been tested on lake sturgeon by Binkowski (1980), with
limited success.
The successful culture of several species of sturgeon
using ponds is well established in the Soviet Union (Bardach
et al. 1972 ). Sturgeon culture in North America, however,
remains largely experimental (Buckley and Kynard l38l; Smith
et al. 1980). The few attempts to utilize pond culture to
raise lake sturgeon have been unsuccessful, probably due to
high temperatures and a Tl overabundance of aquatic
macrophytes, rather than limited food since zooplankton was
available (Copeland l370, Czeskleba l'979). These
possibilities can be readily evaluated. The problem of
rearing lake sturgeon on artificial diets is yet to be
solved as the sturgeon do not accept the currently available
pellets well. Additional work is needed to more fully
explore the potential for rearing lake sturgeon on
artificial diets.
3l
LITERATURE CITED
Bardach, J. E., J. H. Ryther, and W. O. McLarney. 1972.
Aquaculture--the farming and husbandry of freshwater
and marine organisms. Wiley-Interscience, New York,
New York, USA.
Beer, K. 1982. Enthusiastic operation on west coast begins
commercial sturgeon hatching. Aquaculture Magazine
8 : 4–5.
Binkowski, F. P. l.980. An investigation of the methods and
techniques for the artificial propagation of lake
Sturgeon, Acipenser fulvescens (Rafinesque). Center
for Great Lakes Studies, University of Wisconsin,
Milwaukee, Wisconsin, USA.
Binkowski, F. P., and D. G. Czeskleba. l.980. Methods and
techniques for collecting and culturing lake
sturgeon eggs and larvae. Wiscons in Department of
Natural Resources, Madison, Wisconsin, USA.
Buckley, J., and B. Kynard. l 981. Spawning and rearing of
shortnose sturgeon from the Connecticut River.
Progressive Fish-Culturist 43: 74-76.
Copeland, J. 1970. Experimental sturgeon rearing, l070.
Michigan Department of Natural Resources, Wolf Lake
State Fish Hatchery, Kalamazoo, Michigan, USA.
Czeskleba, D. G. l.279. Activities in dry feeding of cool
water species, l079. Wiscons in Department of
Natural Resources. Wildrose Hatchery, Wildrose,
Wisconsin, USA.
Folz, D. J. , D. G. Czeskleba, and T. F. Thuemler. 1983.
Artificial spawning of lake sturgeon in Wisconsin.
Progressive Fish-Culturist 45: 231-233.
Fox, D. J., and K. E. Guire. l976. Documentation for MIDAS
3rd edition. Statistical Research Laboratory, Ann
Arbor, Michigan, USA.
Ghittino, P. 1972. The diet and general fish husbandry.
Pages 540 - 637 in J. E. Halver, editor. Fish
Nutrition. Academic Press, New York, New York, USA.
Ginzburg, A. S. 1972. Fertilization in fishes and the
problem of polyspermy. Israel Program for
Scientific Translations Ltd. Jerusalem.
32
Harkness, W. J. K., and J. R. Dymond. l 96 l'. The lake
Sturgeon: the history of its fishery and problems
of conservation. Fish and Wildlife Branch, Ontario
Department of Lands and Forests. Ontario, Canada.
Hastings, W. H., and L. M. Dickie. 1972. Feed formulation
and evaluation. Pages 327–370 in J. E. Halver,
editor. Fish Nutrition, Academic Press, New York,
New York, USA.
Hublou, W. F., J. Walls, T. B. McKee, D. K. Law, R. O.
Sinnhuber, and T. C. Yu. l959. Development of the
Oregon Pellet diet. Technical Paper No. 1213.
Oregon Agricultural Experiment Station, Astoria,
Oregon, USA.
Leach, G. C. l.920. Artificial propagation of sturgeon.
Part I. Review of sturgeon culture in the United
States. Report of the U.S. Fishery Commission
1919: 3–5.
Leitritz, E., and R. C. Lewis. 1976. Trout and salmon
culture (hatchery methods). Fisheries Bullet in l84.
State of California, Department of Fish and Game,
Eureka, California, USA.
Lewis, W. M., and R. C. Heidinger. 1981. Tank culture of
striped bass. Report Of Fisheries Research
Laboratory. Illinois Striped Bass Project IDC F-26-
R, Southern Illinois University.
Meehan, W. E. 1909. Experiments in sturgeon culture.
Transactions of the American Fisheries Society
39 : 85–91.
Monaco, G., R. K. Buddington, and S. I. Doroshov. 1981.
Growth of white sturgeon (Acipenser transmontanus)
under hatchery conditions. Journal of the World
Mariculture Society l2: ll3–121.
Post, H. l890. Sturgeon: experiments in hatching. Trans-
actions of the American Fisheries Society lº: 36–40.
Scott, W. B. , and E. J. Crossman. 1973. Freshwater fishes
of Canada. Bullet in 184. Fisheries Research Board
of Canada, Ottawa, Ontario, Canada.
Smith, T.I., J. E. K. Dingley, and D. E. Marchette. 1980.
Induced spawning and culture of Atlantic sturgeon.
Progressive Fish Culturist 42:147-150.
Snedecor, G. H. , and W. G. Cochran. 1971 . Statistical
methods. Iowa State University Press, Ames, Iowa,
USA.
UNIVERSITY OF MICH IGAN
||||||||||
3 9015 97
THE UNIVERSITY OF MICHIGAN
DATE DUE

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