United States
Environmental Protection
Agency
Environmental Research
Laboratory '*"— -
Duluth MN 55804
Research and Development
EPA-600/S3-82-051 Oct. 1982
Project Summary
Factors Influencing
Growth and Survival of White
Sucker, Catostomus
commersoni
Walter M. Koenst and Lloyd L. Smith, Jr.
Growth responses of the white
sucker, Catostomus commersoni.
were examined in relation to the
influence of temperature, body size,
season, daylength, light intensity,
food ration level and food quality.
Sucker growth was maximum at a
temperature range of 19-26°C,
depending upon experimental
conditions. Fish reared under low light
intensities grew an average 43%
faster than those reared under
unshaded conditions. Growth on
various diets was best on live tubificid
worms presented over sand substrate
> tubificids (no soil substrate) >
frozen Daphnia > Oregon Moist
pellets > Glencoe Mills pellets. The
optimum temperature for growth on
excess rations of live tubificids was
25°C and was 19°C on restricted
rations (1.5% fish body dry weight).
Maximum specific growth rate
decreased nearly four-fold over a size
range of 12 to 175 g, but no
difference in optimum temperatures
was found. Fish of the same
approximate size grew twice the rate
in the spring as compared to other
times of the year. Photoperiod
showed little influence on growth
rate, but fish exposed to shorter
daylength showed a marked increase
in time to achieve a maximum growth
rate.
The ultimate upper incipient lethal
temperature (UUILT), determined by
slowly increasing (0.5°C/day)
acclimation temperature to death,
was 32.5°C for juvenile white suckers
and 31.5°C for adults. The UUILT was
2-3°C higher than the upper lethal
temperatures measured by the
classical approach involving the direct
transfer technique.
This Project Summary was
developed by EPA's Environmental
Research Laboratory. Duluth, MN, to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information
at back).
Introduction
The purpose of the present study was
to investigate the growth and mortality
rates of juvenile and adult white
suckers under different temperature
regimens as related to body size,
season, daylength and ration level.
Preliminary studies were conducted to
determine conditions that maximize
growth prior to initiation of
experimental studies. The upper lethal
temperatures of suckers of different
sizes were estimated by the direct
transfer method as well as by slowly
raising the acclimation temperature
0.5°C/day until death occurred.
Small and large juveniles and adult
white suckers were tested in this
project. Growth rates were determined
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at two-week intervals as a function of
season (daylength and light intensity),
food type (two kinds of commercially
available fish food pellets, frozen
Daphnia and live tubificid worms), and
temperature. Five ration levels were
given at all temperatures to determine
food conversion efficiency. Upper
lethal temperatures were determined
by direct transfer and by slow
acclimation methods for each size
group of fish.
Conclusions
1 The growth optimum varied from 19-
26°C for juvenile white suckers
depending on experimental
conditions.
2. Growth of fish was best when reared
without any discernible currentflow.
3. Growth of fish reared under shaded
conditions was increased by an
average of 43% over those reared
under unshaded conditions.
4. Maximum growth was observed at
25°C on excess rations (9.11% fish
body dry weight) and at 19°C on
restricted rations (1.5%). Best
growth was observed with live
tubificid worms presented over a
natural sand substrate. Growth on
various diets decreased in the
following order: tubificids (sand
substrate) > tubificids (no soil
substrate) > frozen Daphnia >
Oregon Moist pellets > Glencoe
Mills pellets. Maximum gross food
conversion efficiency was 26% at
22°C and 3.0% ration level of
tubificids.
5. Maximum specific growth rate
decreased nearly four-fold over a
size range of 12 to 175 g. Optimum
temperature for growth was not
influenced over this size range. The
weight exponent (slope of the log-log
plot of specific growth rate versus
body weight) for this size range was
-0.45 which decreased when
smaller fish were included in the
growth rate-body weight relation-
ship.
6. Fish of a common size had a two-fold
increase in maximum growth rate in
spring compared to other seasons.
There was no difference in growth
rate between summer and winter
fish under a 15hL-9hD photoperiod.
Maximum growth occurred at 26°C
in summer, and at 24°C in winter
and spring tests.
7. Daylength changes had no
significant effect on maximum
growth rate or optimum temperature.
However, attainment of maximum
growth under test conditions was
increased from 2 to 4 weeks when
fish were reared under 15hL-19hD
and 9hL-15hD photoperiods,
respectively, in a winter test.
8 The highest UUILT (32.5°C) was
achieved by slowly raising the test
temperature 0.5°C/day until death.
UUILT measured in this way was
consistently 2-3°C higher than that
measured by the classical approach
involving the direct transfer of fish
from an acclimation temperature to
a series of lethal levels. The upper
incipient lethal temperature (UILT) is
dependent upon acclimation up to
the maximum level (UUILT).
9. The UUILT for newly hatched larvae,
swim-up larvae, juveniles, and
adults were 28.2, 30.5, 32.5, and
31.5°C, respectively.
Recommendations
1. Investigators should run series of
preliminary tests to optimize culture
conditions prior to measurement of
physiological optima for each
species. Control of light intensity in
bioassays with nocturnal or deep-
water organisms is especially
encouraged
2. Growth of white suckers on live
tubificids should be compared to
growth on natural components in
their diet including live Cladocera
and macroinvertebrates.
3 Future bioenergetic studies should
cover a broader biokmetic range of
temperatures to include the lower
and upper limits of zero net growth.
4. The large variation in measurement
of the physiological optima and
UUILT for one species reported
herein suggests that the temperature
criteria data base be critically
evaluated before any literature
values are adapted to field problems
(i e , 31 6a demonstrations)
5 Field validation of the laboratory data
base on temperature criteria is
needed to confirm the best test
procedures
Walter M. Koenst is with the Department of Entomology, Fisheries and Wildlife
of the University of Minnesota, St. Paul, MN 55108; Lloyd L. Smith. Jr.
(deceased).
Kenneth C. F. Hokanson is the EPA Project Officer (see below).
The complete report, entitled "Factors Influencing Growth and Survival of White
Sucker, Catostomus commersoni," (Order No. PB 82-221 474; Cost: $7.50,
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Monticello Ecological Research Station
Environmental Research Laboratory—Duluth
U.S. Environmental Protection Agency
Box 5OO
Monticello, MN 55362
ft U.S. GOVERNMENT PRINTING OFFICE. 1982-559-017/0847
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Information
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