EPA-660/3-73-019
January 1974
Ecological Research S
Early Life History and Feeding of
Young Mountain White fish
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
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was consciously planned to foster technology
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2. Environmental Protection Technology
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This report has been assigned to the ECOLOGICAL
RESEARCH series. This series describes research
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provides the technical basis for setting standards
to minimize undesirable changes in living
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EPA-660/3-73-019
January 1974
EARLY LIFE HISTORY AND FEEDING OF
YOUNG MOUNTAIN WHITEFISH
By
Clair B. Stalnaker
Robert E. Gresswell
Utah State University
Logan, Utah 84322
Project 18050 DPL
Program Element 1B1021
Project Officer
Richard E. Siefert
National Water Quality Laboratory
Environmental'Protection Agency
Duluth, Minnesota 55804
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20102 - Price 95 cents
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EPA Review Notice
This report has been reviewed by the Environmental
Protection Agency, and approved for publication.
Approval does 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 recommendation for
use.
ii
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ABSTRACT
Study of the early life history of the mountain whitefish (Prosopium
williamsoni) was conducted in the Logan River, and under controlled
laboratory conditions in the Utah Water Research Lab and USU Fisheries
Laboratory. Culture methods were also developed.
Spawning behavior was observed in the field and in the laboratory.
In the Logan River spawning occurs from mid-November to mid-December
during the dusk hours.
Hatching success of whitefish eggs was studied in the field by weekly
collections from five areas. Total mortality to hatching was 92%.
Larval whitefish appeared in quiet areas along the river by early March.
Fertilized eggs were incubated in the lab under controlled temperatures
of 42, 45, and 48 F (5.6, 7.2, 8.9 C). In the river at ambient
temperatures from 1.7 - 6.1 C the eggs began hatching in approximately
79 days and continued for 23 days. At 45 F (7.2 C) they began in 52
days and continued for 23 days, and at 48 F (8.9 C) they began at day
45 and continued for 30 days.
Growth of larval whitefish in two areas of the Logan River showed
differences in total length and weight increases. These differences
can be partially explained by their temperature experience of accumulated
degree-days above 31 F. The water temperatures were consistantly
higher in the one area in which the young fish emerged two weeks earlier
both sampling years. Length-weight relationships were established.
Growth of larval whitefish at three different temperatures (6, 9, 12 C)
was examined in the laboratory. Data collected was analyzed by factorial
analysis and a simple linear model for predicting growth was developed.
Stomach analysis and field observation show that the larval whitefish
begin feeding at 14-15 cm and remain near the bottom. Chironomid
larvae were the major food item of age-0 fish ranging from 65.5-90%
of total monthly diet. Peak feeding activity occurred in late afternoon
and early evening.
Larval whitefish were raised in the lab under various temperature
regimes and diets. Starved fry were held at temperatures from
2-14 C at 2 degree intervals. All of the fish held at 8, 10, 12 and
14 C were dead by day 77, 50, 29 and 12 respectively. Between 78
and 92% survived at 2 to 6 C for more than 80 days. Larvae were
fed dry trout feed, Oregon Moist Pellet, mosquito larvae and brine
shrimp. Total mortality rates varied from 15% for 3 months on
brine shrimp to 98% in 1.5 months on Oregon Moist Pellets.
iii
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CONTENTS
Section
I
II
III
IV
V
VI
Page
VII
VIII
IX
Conclusions
Recommendations
Introduction
Study Area
Objectives
Spawning Behavior
Methods
Results and Discussion
Secondary sex characteristics
Spawning periods
Light intensity
Spawning success
Spawning Act
Natural Egg Mortality
Methods
Results and Discussion
Growth and Development of Larvae and
Juveniles in Natural Environments
Methods
Results and Discussion
Food Habits of Larvae and Juveniles
in Natural Environments
Methods
Results and Discussion
Whitefish Culture
Methods
Propagation
Survival
Growth
Diet
Temperature
Results and Discussion
Egg Incubation
Survival
Mortality
Growth-Diet
Growth-Temp erature
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FIGURES
PAGE
1 MAP OF THE LOGAN RIVER, SHOWING STUDY SECTIONS, 5
1969-1972
2 PATTERNS OF GRAVEL SUBSTRATE IN THREE LIVING 8
STREAM AQUARIA, 1971
3 LARGE FEMALE READY TO SPAWN; NOTE SWOLLEN ANAL 11
REGION. MALE WITH TUBERCLES IS SEEN AT LOWER LEFT
4 FISH SHOWING LATERAL STRIPES; NOTE CENTER PAIR 11
EXHIBITING LATERAL DISPLAY
5 MEAN VELOCITIES AND MEAN NUMBER OF EGGS RECOVERED 16
FROM LOGAN RIVER, 1971 INCLUDING 95% CONFIDENCE
INTERVALS WITH RESPECT TO STREAM POSITION
6 MEAN NUMBER OF EGGS RECOVERED AND 95% CONFIDENCE 17
INTERVALS WITH RESPECT TO VELOCITY, LOGAN RIVER, 1971
7 MEAN TOTAL LENGTH (mm) AND 95% CONFIDENCE INTERVALS 21
FOR AGE 0 MOUNTAIN WHITEFISH, FIRST DAM (AREA 1) AND
THIRD DAM (AREA 2), LOGAN RIVER, UTAH, 1970
8 MEAN WET WEIGHT AND 95% CONFIDENCE INTERVALS FOR AGE 0 22
MOUNTAIN WHITEFISH, FIRST DAM (AREA 1) AND THIRD DAM
(AREA 2), LOGAN RIVER, UTAH, 1970
9 TOTAL LENGTH AND DAILY INSTANTANEOUS RATE OF INCREASE 23
IN WEIGHT FOR AGE 0 MOUNTAIN WHITEFISH, FIRST DAM
(AREA 1) AND THIRD DAM (AREA 2), LOGAN RIVER, UTAH, 1970
10 TOTAL TEMPERATURE EXPERIENCE OF AGE 0 MOUNTAIN 24
WHITEFISH, EXPRESSED AS CUMULATIVE DEGREE-DAYS ABOVE
32 F AND 0 C, FIRST DAM (AREA 1) AND THIRD DAM
(AREA 2), LOGAN RIVER, UTAH, 1970
11 LENGTH-WEIGHT RELATIONSHIPS OF 399 AGE 0 MOUNTAIN 25
WHITEFISH FROM 12.5 mm TO 112 mm TOTAL LENGTH, LOGAN
RIVER, UTAH, 1970-71. THREE STANZAS ARE SHOWN WITH
THEIR RESPECTIVE REGRESSION EQUATIONS
12 SCHEMATIC DIAGRAM OF AUTOMATIC BRINE SHRIMP FEEDER 31
13 MOUNTAIN WHITEFISH EGG INCUBATION PERIODS AT THREE 34
CONTROLLED TEMPERATURES AND AMBIENT LOGAN RIVER
TEMPERATURES, 1969-1970.
vi
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FIGURES
PAGE
14 SURVIVAL OF UNFED WHITEFISH LARVAE AT THREE TEMPERATURES 35
(°C), 1970-1971
15 SURVIVAL OF UNFED MOUNTAIN WHITEFISH LARVAE AT VARIOUS 36
TEMPERATURES, 1971-1972
16 GROWTH OF MOUNTAIN WHITEFISH LARVAE FED DIFFERENT DIETS, 39
1971
17 GROWTH OF MOUNTAIN WHITEFISH LARVAE FED DIFFEREND DIETS 40
DURING SIX MONTHS AFTER HATCHING, 1971
18 GROWTH OF MOUNTAIN WHITEFISH LARVAE AT THREE 41
TEMPERATURES («C), 1972
vii
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TABLES
No. Page
1 Fertilization percentages in different tanks,
velocities, and substrate types, during 1972 12
2 Calculated F values for individual comparisons of
eggs recovered and physical characteristics of
Logan River, 1971 18
3 Whitefish eggs recovered from Logan River, 1971 19
4 Length-weight relationships for three-length ranges
of Age-0 mountain whitefish, Logan River, Utah, 1970-71 26
5 Number of organisms and their percentages of the monthly total
(in parentheses) from 238 Age-0 mountain whitefish taken
concurrently with drift samples, Logan River, Utah 1970-71 28
6 Number of organisms and their percentages of the monthly
totals (in parentheses) from 19 drift samples taken
concurrently with Age-0 mountain whitefish collections,
Logan River, Utah 1970-71 29
7 Length of incubation period (start to end of hatching),
length of hatching period (days), and peak period of
hatching (days after fertilization) 33
8 Survival of unfed mountain whitefish larvae at 42, 45, and
48 F in the NR-Z Lab and at ambient Logan River
temperatures in the Water Lab, 1970-1971 37
9 Survival of unfed mountain whitefish larvae at 2, 4, 6, 8,
10, 12, and 14 C, 1971-1972 37
10 Mortality of whitefish larvae cultured in the laboratory,
1971 38
11 Monthly mean (range) length in mm of larval whitefish at
three different temperatures, 1971-1972 42
12 Abbreviated factorial analysis of factors affecting
larval whitefish growth at three different
temperatures, 1971-1972 43
13 Abbreviated regression analysis of factors affecting
larval whitefish growth at three different temperatures,
1971-1972 43
viii
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SECTION I
CONCLUSIONS
1. Male and female whitefish developed tubercles and lateral stripes.
Females were discernible from males when nearly ready to deposit their
eggs, at this time they became swollen in the anal region.
2. In all cases, spawning occurred between late October and mid-
December in lab and Logan River.
3. Spawning was observed during periods of decreasing light intensity
at dusk. No spawning was observed after dark.
4. Total egg mortality was found to be 92% over the 106 day incubation
period in the Logan River. Hatching extended over approximately 43 days.
5. Differences in total length, weight, and daily instantaneous
growth coefficients over time can be explained by temperature
experience express as accumulated degree days above 0.5 C.
6. Larval mountain whitefish began feeding at lengths of 14-15 mm
before yolk was completely absorbed. Chironomid larvae was the major
food item for Age-0 fish (65.5% to 90% of total monthly diet).
Mean food size increased with fish size until fish reached 55 mm
total length and stabilized near 3 mm for whitefish of 60-112 mm.
Peak feeding occurred late afternoon and early evening decreasing after
23:00 hrs. Feeding did not resume until after 8:00 hrs.
7. Unfed whitefish larvae survived up to 63 days at 5.6 C. Survival
decreased with increase in temperature.
8. Whitefish larvae survived at higher rates (85%) and grew best
on brine-shrimp diets. Dry food diets and Oregon Moist pellets
produced lowest survival and growth.
9. Mean monthly growth increments increased with temperature.
Time and temperature interaction was significant with the following
model predicting growth increments for 1971-72 experiments.
y = 21.55 + .104 x + .012 x^ x when y = length in mm x^ = time
in days and x_ = temperature in °C.
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SECTION II
RECOMMENDATIONS
This project was limited to field and laboratory study of the
spawning behavior, and growth of larval and juvenile mountain
whitefish. Culture methods and egg incubation time in the laboratory
were described. It was not within the scope of this study to
fully determine developmental time and frequency of deformations for
whitefish embryos from fertilization to hatch and from hatch to
yolk-sac absorption when incubated at different temperatures.
It is recommended that such laboratory studies be carried out.
Environmental requirements for the whitefish are poorly known,
particularly the effect of temperature change at all life history
stages. Since the mountain whitefish inhabits waters potentially
and actually receiving thermal effluents it is further recommended that
laboratory studies be initiated to determine the upper and lethal
threshold temperatures for mountain whitefish embryos, larvae,
juveniles and adults.
The effects of prespawning temperature experience on maturation and
viability of gametes should be determined as well as growth rates
of larval and juvenile mountain whitefish within their range of
temperature tolerance.
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SECTION III
INTRODUCTION
Information is needed by water-quality control agencies on the long-
range effects of sub-lethal concentrations of pollutants on fishes
throughout their entire life history. In order to obtain this infor-
mation under controlled laboratory conditions, fish must be cultured
from the time of egg fertilization to sexual maturity and spawning.
Little is known about the environmental requirements of many fish
species during the early life history stages when larval fish shift
from endogenous (yolk) energy reserves to exogenous (food organism)
energy sources.
The mountain whitefish (Prosopium williamsoni) is a common river
fish in the western United States and is listed by the Duluth Water
Quality Laboratory as one of the species on which studies are
recommended.
This study began March 28, 1969 and continued through December, 1972.
During this time field observations were made in the Logan River
on spawning behavior and natural mortality of whitefish eggs. Larvae
and adult whitefish were taken as were drift samples of macroinr
vertebrates. Controlled laboratory experiments investigated development
of eggs and growth of young whitefish under different temperature
regimes and diets. Field data provided baseline information with
which to compare behavior, development, and growth under laboratory
conditions.
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SECTION IV
STUDY AREA
Logan River
Logan River begins in Franklin County, Idaho, and flows in a
southwesternly direction into Cache County, Utah, joining the Bear
River west of Logan, Utah. The watershed includes approximately
225 sq. miles (583 sq. kilometers) of mountainous limestone, dolomite,
and shale. Advanced weathering of base materials probably accounts
for the high alkalinity of the waters. The watershed has an average
yearly precipation of about 30 inches (76.2 cm) of which 60 percent
is snow. The major water source for the river is springs. River
temperature seldom exceeds 60 F (15.6 C) during the summer. Dissolved
oxygen is usually at or near saturation throughout the canyon.
Sigler (1951) reported an average discharge of 247 cfs at the
mouth of the canyon (first dam), with peak flows in May or June and
low flows in February. There are three power and irrigation im-
poundments on the river upstream from the City of Logan. No upstream
fish-passage facilities are in operation. The backwaters of the
impoundments have extensive shoals of silt deposits, creating nursery
areas for young-of-the-year mountain whitefish, (Prosopium williamsoni)
brown trout (Salmo trutta) and mottled sculpin (Cotus bairdi).
Field observations of egg mortality were conducted on five 600
meter sections of the Logan River (Fig. 1). Sections 1-4 were
located above the Spring Hollow campground impoundment (third dam) .
Sections 1 and 2 ran through DeWitt campground in a relatively
undisturbed stretch of river with pool and riffle areas. Sections
3 and 4 were in a channelized portion of the river immediately
above the third impoundment. Section 5 was located above the first
impoundment. This section had also been channelized and was
characterized by high gradient and large rock substrate. These
areas represented known spawning areas of the mountain whitefish.
Laboratory facilities
Two wet labs were utilized during this study. One was located in
the basement of the Natural Resources-Zoology building utilizing
dechlorinated tapwater at approximately 11 C. To provide various
incubation temperatures water was cooled to 4.5 C in a Min-0-Cool \J
and then heated with conventional heater-thermoregulators to the
desired temperatures.
The other facility was in the Utah Water Research Lab, located along
the Logan River. Water supply for this lab was the Logan River
which reached minimum temperatures of 1-2 C.
_!/ Manufactored by Frigid Units Inc., Toledo, Ohio.
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UTAH
*
i
;
STUDY SECTIONS
IDAHO
HM
UTAH
KILOMETERS
i
2
4 6 8 10
Figure 1. Map of the Logan River, showing study sections, .1969-1972.
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SECTION V
OBJECTIVES
The objectives of this study were to:
a) Describe spawning habitat and behavior of mountain whitefish.
b) Describe water temperature regimes and hatching times of
mountain whitefish eggs in natural environments.
c) Describe water temperature regimes for growth and development
of larval and juvenile mountain whitefish in natural
environments.
d) Describe food habits of larval and juvenile mountain whitefish
in natural environments.
e) Develop feasible methods to culture mountain whitefish in
the laboratory from time of egg-fertilization to end of
first 6 months of life.
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SECTION VI
SPAWNING BEHAVIOR
Methods
The spawning behavior of the mountain whitefish was studied in the
field and in the laboratory. The field studies were conducted from
October, 1971 through December, 1971 and the laboratory studies from
October through December, 1971 and 1972.
The field studies were conducted in sections 1 and 2. Observations
were made by using snorkel, mask, and wet suit. Photographs were
taken with a Nikonos underwater camera. Light intensity data was
measured with a selenium cell and galvanometer; the readings were
taken at or near the water surface and converted to langleys.
Laboratory studies were conducted at the Utah Water Research Laboratory,
Logan, Utah. Three living stream aquaria measuring 56 cm wide x
38 cm deep x 147 cm long (inside measurements in the fish holding
compartments) were used in 1971. River water was flushed through
these tanks at 200 gallons/hour (.0002 m3/sec.). This flow not only
regulated water chemistry, but also kept the temperature regime near
that of the river. Lighting was from over-head windows. Although
the light intensity was lower indoors, the daily light pattern was
essentially the same as outside. Gravel was placed in the aquaria
to simulate the river bed substrate. Three sizes of gravel were
used; pea gravel, 2-5 cm rock, and 10-15 cm rock. Three patterns
of gravel combinations were set up to determine substrate preference
(Fig. 2).
Three adult whitefish, 1 female and 2 males, were placed in each tank.
The fish were fed aquatic insects collected from the Logan River. The
data recorded in 1971 in the laboratory and in the field included
time of day spawning occured, description of spawning activities, and
light intensity measurements. In the field, notes were recorded
after every ten to fifteen minutes of observation with the snorkel gear.
In 1972, field observations were terminated and more intensive
laboratory studies were conducted. Three large round tanks were
used in addition to the three living stream aquaria. The round
tanks were 1.5 m in diameter and 79 cm deep. A glass sided
portion of the main flume at the Utah Water Research Laboratory was
utilized. This section measured '7.3 m by 2.4 m with a water
depth of .9m. Screens were used at each end of the windowed
section to confine the fish.
Two round tanks and two living stream aquaria were provided with two
types of gravel for substrate, coarse and fine. One of each type
tank was left bare. The round tank allowed unlimited swimming space
(in circles) and much greater velocities of water flow. Again,
river water was used with lighting from windows at near natural
conditions.
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IO-l5cmROCK
PEA GRAVEL
2 - 5 cm ROCK
IO-l5cmROCK
PEA GRAVEL
2-5cmROCK
DIRECTION OF FLOW
Figure 2. Patterns of gravel substrate in three
living stream aquaria, 1971.
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The flume was not situated near windows; therefore, a deck of plywood
and canvas was fitted to exclude all light from the work area of the
laboratory. A curtain was also hung in front of the windows. To
simulate natural lighting, a series of flourescent lights, and a
series of incandescent lights with timers and automatic dimmers were
used. This system was utilized because it eliminated the abrupt
change from darkness to light and vice-versa (Drummond and Dawson, 1970).
Flourescent lights were placed in three groups to turn on or off at
fifteen minute intervals with the incandescent sequence set at
twenty minutes. This provided a dawn and dusk sequence of approximately
1 hour.
The substrate used in the flume was 5-10 cm rock. Originally a
velocity of 30 cm/sec was planned, but fish drifting downstream had
trouble freeing themselves from the screen; therefore a velocity of
14 cm/sec was used. This provided sufficient velocity for orientation,
and was slow enough for the fish to maintain position.
Twenty adult whitefish were placed in the flume. There were 5
known males and 5 females in this group. Five adults (3 males and
2 females) were placed in each of the round aquaria and three adults
(1 female and 2 males) were placed in the living stream aquaria.
Spawning behavior was observed in the flume through the glass window.
Descriptions of the spawning activities were dictated onto a
taperecorder. Light intensity and time of day were recorded during all
courtship and spawning activities. The day length was altered to
determine if light was a major factor in the time of spawning.
Both still photographs and 16 mm movies were used for recording
the spawning sequence.
The spawning success (or failure) in the round aquaria and the living
streams was compared with bottom type and velocity. Percent
fertilization of eggs spawned was the criterion of spawning success.
The location of the eggs in relation to bottom type was recorded.
Results and Discussion
Secondary Sex Characteristics. As the spawning season approached,
the whitefish developed tubercles on their scales and lateral stripes.
McAfee (1966) found that neither sex became highly colored but the
males developed snouts and (prominent body tubercles while females
developed only smaller tubercles. In a study on the Bow River,
Banff National Park, tubercles were found on the males only
(Vladykov, 1970). The presence of stripes on mountain whitefish
had not been reported by other authors, however, Normandeau (1969)
found that the round whitefish (Prosopuim cylindraceum) does develop
orange to red coloration on the belly and other areas during
breeding.
Fifty-six mountain whitefish were collected from the Logan River and
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examined in the fall of 1971 for sexual dimorphism. Both males and
females had well developed tubercles. Lateral stripes were prominent
on fish that were currently spawning. Long snouts were present on
a few fish. Females were discernable from males only when they
were nearly ready to deposit their eggs; at this time they became
swollen in the anal region (Fig. 3). The lateral stripes consisted
of a dark back with a light dorsal lateral band, a dark lateral
band, and a light ventral side (Fig. 4). The stripes were present
only when the fish were ready to spawn and were more prominent in
the evening than the morning.
Spawning Periods. The mountain whitefish in the Logan River began
courtship activities on October 14, 1971. Spawning was taking place
on November 1, and by November 11, had peaked. Some courting, but
no complete spawning was observed on December 12. All activity
occurred in the evening over rocky areas in the river in pools and/or
deep riffles.
The whitefish held in the lab during the fall of 1971 developed at a
slower rate than the fish in the wild. Stripes and tubercles were
evident on November 1 and spawning did not begin until November 8 and
lasted until December 22. The time lag may have been due to the
handling and captivity.
During the fall of 1972, the whitefish held in the flume developed
tubercles and stripes by November 7 and also began courting on that
date. Complete spawning was first observed on November 11. The
last complete spawning was observed on December 5, but some courting
continued until December 12.
Light Intensity. During 1971 field studies, courting activity began
when the light intensity decreased to .023-.009 langleys. Spawning
took place as the light further decreased to .003-.0013 langleys.
Spawning was observed until intensities of .00026 langleys were
reached. Sexual activity may have occurred at lower light levels as
it did in the laboratory, but visibility was poor.
The laboratory observations in 1971 revealed similar trends, but were
somewhat altered because of overhead lights in the surrounding work
area. Spawning in the lab always began after the overhead lights
were turned off which would coincide with the start of the evening
decrease in light. Courting began at a light level of .00075-.0000023
langleys and spawning occurred at .00045-.0000011 langleys. The
lowest light level at which activity was observed was .0000010.
Although the light intensities were much lower than field data, the
pattern was basically the same.
In the fall of 1972, the light data revealed the same sequence. Courting
was first observed as the light decreased from a maximum of .0059 ;
to .0003 langleys. However, courting and spawning usually did not begin|
until .00094 langleys was reached. Spawning was observed at a light
level of .002-.00000038 and occurred until total darkness.
10
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Figure 3. Large female ready to spawn; note swollen anal region. Male
with tubercles is seen at lower left.
Figure 4. Fish showing lateral stripes; note center pair exhibiting lateral
display.
11
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The time of the onset of dusk was altered to determine if a decrease
in light was the triggering machanism for sexual behavior. On
November 21, 1972, the lights were left on all night at full intensity
(.0059 langleys). There was no sexual activity that night. At
13:45 hrs on the 22nd courting began in full light and continued
until 21:37 hrs. Spawning occurred after 30 hours of full light.
The lights were left on until the evening of the 24th when the lighting
was returned to a normal schedule. No sexual activity occurred during
the period from 22:00 hrs on the 22nd till 17:30 hrs on the 24th
when the fish began sexual behavior during a standard evening light
schedule. This was repeated the morning of December 2 until the
evening of December 5 when the fish spawned during a normal evening
schedule. On December 4, from 22:35 hrs until 22:47 hrs there were
four incomplete courting activities, but the fish did not spawn or
start large scale courting until returned to an evening schedule.
On November 20, 1972, the evening schedule was conducted at 15:00 hrs
instead of 17:00 hrs. The whitefish began courting at 15:00 hrs, 2
hours ahead of the normal schedule.
Spawning Success. Spawning behavior and spawning success were altered
depending on the type of aquaria used. Observations during 1971 both
in the field and in the lab, indicated that the mountain whitefish
needed room to swim about. In the Logan River pairs and groups were
seen swimming 15 to 20 feet upstream during courtship. Observations
in the living stream aquaria indicated that the spawning sequence was
altered. Fish were seen swimming violently against the glass side, and
then settling to the bottom. In 1972, three 5 foot diameter circular
tanks were used as well as the 24 foot long glass-sided flume.
These provided more swimming space.
Spawning success in 1972 was greater in the round aquaria and the
flume than in the living stream aquaria (Table 1). Spawning
success was measured by the percentage of fertilized eggs.
Table 1. Fertilization percentages in different tanks, velocities,
and substrate types, during 1972.
Holding Tank Velocity Substrate % Fertilization
Living Stream
Living Stream
Living Stream
Round Tank
Round Tank
Round Tank
Flume
0.0 ft/sec
0.0 ft/sec
0.0 ft/sec
0.52 ft/sec
0.44 ft/sec
0.49 ft/sec
0.48 ft/sec
% coarse-% fine
% coarse-% fine
Bare
Bare
% coarse-^ fine
% coarse-^ fine
10 cm Rock
0.0
0.0
1.4
32.8
1.9
41.4
23.1
12
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One of the round aquaria produced only 1.9% success. This was due to
placing 5 female whitefish and no males in the tank originally.
The females deposited their eggs anyway. Later, several males were
added and some success was realized, but the spawning season was
nearly over. The other two round aquaria produced 32.82% and 41.44%
fertilization. The flume had 23.1% success. The spawning success
in the living stream aquaria was 1.41% in the bare tank and 0% in the
other two. The female in the living stream did not deposit her eggs.
All three tanks had both females and males.
The percentage of eggs retrieved from the coarse gravel vs. the fine
gravel was also different. In the round aquaria, 66% of the eggs
were collected from the coarse gravel of one tank and 85% from another.
In the living stream 83% of the eggs were collected from the coarse
gravel area. However, the 5-10 cm rock had more space between the
rock to catch and hold the eggs. None of the eggs in the living
stream aquaria were fertilized indicating the eggs were deposited without
sexual interaction of the fish present. During the 1971 observations,
fish in two of the three living stream aquaria did spawn successfully,
and the eggs appeared evenly distributed although no quantitative
measurements were made. This may have been a result of the limited
space such that if the eggs were deposited in one area, swimming
motions would relocate the eggs.
More research is needed on choice of spawning sites. Most authors
agree that the whitefish prefers gravel to rocky areas of rivers.
Brown (1952) stated that there was no selection of bottom material,
the fish spawned in riffels or next to strong currents. Some lake
dwelling populations spawn in lakes and not in the tributaries
(McAfee, 1966). This would indicate a substrate preference since
silted areas would suffocate eggs. However, the 1972 laboratory
experiments indicated little if any substrate preference. More
eggs were found in coarse material but agitation by currents and
swimming fish would tend to relocate the eggs into the coarser
material. The whitefish also spawned successfully in aquaria with
bare bottoms. In the Logan River, whitefish have never been observed
to spawn in the impoundments, they apparently moved into the river
channel orienting to the current. Observations with snorkel gear
revealed whitefish in the main channel and brown trout dominating the
quiet pockets. Since they spawned at low light levels when visibility
was poor, the orientation to the current may have been the greater
stimulus over substrate size for choice of spawning sites.
Description of Spawning Act
Brown (1952) gave the most complete report of mountain whitefish
spawning. He observed whitefish spawning at night by using a light to
observe fish in shallow water. Brown gave the following account: the
whitefish would hold their position in the current and come together at
intervals until all were in contact. They would then settle to the
bottom for 2-4 seconds and then move apart. There were no rapid
13
-------
or violent body motions. In 1972 and 1971, whitefish in the Logan
River and in the laboratory displayed a definite but simple courtship,
and then swam rigidly upstream for up to twenty feet in groups of
2-7 fish. One fish, presumed to be a male, would approach another
fish, there would be a nudge or lateral wavering , and the pair would
swim away. Other fish would join them, and the group would settle
and emit sex products and then split apart. Eggs were deposited when
the fish darted to the bottom and quivered rigidly with fins erected.
Sometimes the swimming upstream was very rapid and at other times
quite slow. At times the group would immediately swim to the
bottom without darting upstream, but during the actual deposition
of eggs, the group always moved upstream. Brown (1952) also reported
whitefish spawning after dark. In 1971 at DeWitt campground on the
Logan River, an attempt was made to observe the fish after dark
with a light. The fish were extremely shy of the light and no
spawning was observed. Fish in the flume during 1972 spawned at very
low light levels but no evidence of spawning in total darkness was
found. Since there was not a 24 hour survelence on the tank, they
may have spawned at night. This study found the fish spawning during
the evening dusk sequence.
14
-------
SECTION VII
NATURAL EGG MORTALITY
Methods
2
One square foot(.l m ) samples were collected weekly with a
Surber sampler from five sections on the Logan River. Each week
the samples were collected 3 meters downstream from the previous
samples. Four sample sites, A, B, C, and D, were spaced evenly
across the river at each station, from south to north, yielding
20 samples per week.
A snorkel, wet suit, and face mask were used to increase sampling
efficiency. Sampling began on November 30, 1971 when spawning
activity was decreasing. Sampling terminated on April 20, 1972
when no eggs were found.
The method of least squares was used to fit a linear regression line
to the data using log transformation of the total number of eggs
recovered on each sampling date. By plotting days on the abscissa,
the slope of the fitted line was the daily instantaneous mortality
rate. This was expanded over the entire incubation period and
converted to the total mortality.
Data on the bottom type, water velocity, water temperature, relative
position in stream, and stream depth were recorded in conjunction
with the egg samples. Comparisons were made among these variables
and the number of eggs (eggs/ft. lm^). Bottom type was analyzed by
grouping the substrate into size groups. Depth, velocity, and
bottom type were compared among study sections and positions across
the river. Analysis of variance for a completely randomized design
was conducted.
Results
2
Since the number of eggs/ft varied with location, the study
sections and the position across the stream were examined for differences.
The water depth was greatest in Section 1 and shallowest in Sections 2
and 5. Sections 3 and 4 were median in depth. Sections 2 and 5 were
swiftest and sections 4, 3 and 1 were slowest. Bottom type also
changed in the different sections. Section 5 had the coarsest
substrate and section 4 had the finest with 1, 2, 3 being median.
Water velocity tended to be greater in the middle of the stream
(Fig. 5). The substrate size did not very with position.
Velocity, section, and position were the most important factors related
to the number of eggs recovered (Table 2). Bottom type and depth
seemed to have little or no effect. The velocity tended to be highest
at midstream, where the concentration of eggs was also greater (Fig. 5 & 6)
15
-------
1.2
1.0
u
0>
CO
O
O
0.8
0.6
0.4
0.2
/ 1
EGGS
VELOCITY
i i
\
*
\
*
J- \
30
25
20
15
z
c
s
TO
m
O
-n
m
O
-*>
i-t-
IS)
10
B C
STREAM POSITION
Figure '5. Mean velocities and mean number of eggs recovered
from Logan River, 1971 including 95% confidence intervals with
respect to stream position.
16
-------
30 -
CM
20
O
o
LU
li.
o
00
2
Z>
<
UI
10
I
I
I
0.0-0.5 0.5-1.0 1.0-1.5 1.5-2.0
VELOCITY (ft/sec)
2.0 +
Figure 6. Mean number of eggs recovered and 95% confidence
intervals with respect to velocity, Logan River, 1971.
17
-------
Table 2. Calculated F values for individual comparisons of eggs
recovered and physical characteristics of Logan River, 1971.
Comparison
2
Eggs/ft vs. section
Eggs/ft^ vs. position
Eggs/ft, vs. depth
Eggs/ft2 vs. velocity
Eggs/ft vs. Bottom type
Depth vs. position
Velocity vs. position
Bottom type vs. position
Depth vs. section
Velocity vs. section
Bottom type vs. section
4.777*
3.865*
1.0496
11.902*
.396
1.147
7.674*
.155
32.45*
6.989*
25.231
* Significance at 0.05 level.
Skindiving observations and electrofishing indicated that mountain
whitefish tended to be in the higher velocity pools and channels
while trout generally preferred the quieter areas along the banks.
Section 4 was the only area that differed significantly in the number
of eggs collected. Section 4 had the combination of the lowest
velocity and the finest substrate particle size. This may have made
it less desirable as a spawning site.
By March 8, 1972, larval whitefish were observed in quiet areas near
the river banks. The samples collected on March 22, 1972, contained
very few eggs indicating increased hatching activity. Because
increased rate of hatching would influence calculated mortality
rates, March 15, 1972 was the last sampling date used for mortality
estimations (Table 3).
The daily instantaneous mortality rate was -0.024. The total mortality
for the estimated 106 day incubation period was 91.88%. By April 20,
1972, no eggs were found in the samples, indicating that the duration
of the hatching period was approximately 43 days.
Mortality of the eggs may have been due to incomplete fertilization,
predation by insects and fish, and mechanical damage from agitation.
Predacious insects of the Tipulidae and Plecoptera were observed in
the bottom samples. Brown trout, whitefish, and sculpin, were
observed eating eggs during collections. Since no redd is formed,
the eggs may be jostled and damaged by the current.
18
-------
Table 3. Whiteflsh eggs recovered from Logan River, 1971.
Sampling Date
11-30-71
12-7
12-14
12-21
12-28
1-5-72
1-12
1-20
2-1
2-8
2-15
2-22
2-29
3-7
3-15
3-22
3-30
4-6
4-20
Total No. Eggs
771
596
398
301
273
194
200
198
129
127
112
92
71
52
48
8
3
2
0
Mean/ft2
38.55
29.8
19.9
15.05
13.65
9.7
10.0
9.9
6.45
6.35
5.6
4.6
3.55
2.60
2.67
.44
.16
.17
0
19
-------
SECTION VIII
GROWTH AND DEVELOPMENT OF LARVAE AND JUVENILES
IN NATURAL ENVIRONMENTS
Methods
Mountain whitef ish larvae and fry were collected by dip nets and
fingerlings with a direct-current backpack shocker from the backwaters
of the First and Third Dams of the Logan River. Collections were
made at 10-14 day intervals (except during spring runoff) from March 1970
to September 1970 and again during March 1971. Fish were preserved
in 10% formalin. Total and fork lengths were measured to the
nearest 0.5 mm. Wet weight was measured to the nearest 0.005 gm.
Means and 95% confidence intervals were calculated for each sample
and growth curves were fitted by inspection.
Results and Discussion
The mountain whitefish collected from the two backwater areas showed
large differences in total length increase (Fig. 7), weight increase
(Fig. 8), daily instantaneous growth coefficients (Ricker, 1968) and
the pattern of these rates over time (Fig. 9). These differences
can be partially explained by the temperature experience expressed
as accumulated degree-days above 0.5 C, of the fish from the two areas
(Fig. 10). Water temperatures were consistantly higher in First Dam
than in Third Dam. The young fish emerged approximately two weeks
earlier in First Dam than Third Dam in both years. Fish reached
approximately 50 mm total length at the end of 3 months and nearly
100 mm after 6 months growth.
All fish were pooled to establish a length-weight relationship for
age 0 mountain whitefish in the river. A scatter diagram .of log-weight
against log-length indicated three different relationships (Fig. 11) .
Linear regressions were fitted by the method of least squares. The
slope of the first was 4.3333, the second 3.4437, and the third
2.8043 (Table 4). The transition from the initial stanza to the
second stanza occurred at a total length of approximately 17 mm.
This may reflect the change from endogenous (Yolk) to exogenous
nutrition. The transition from the second to third stanza was less
certain and appeared to be between 50-60 mm total length. Average
condition factors were based on the formula
K(TL) = WeiSht - X 105
Total length (mm)3
20
-------
N>
I2O
100
80
X
o
^
U
60
040
20
Area 2
MARCH APRIL
MAY
JUNE
JULY
AUGUST
SEPT.
Figure 7. Mean total length (mm) and 95 percent confidence intervals for Age 0 mountain
..whltefish, First Dam (area 1) and Third Dam (area 2), Logan River, Utah, 1970.
-------
APRIL
MAY
JUNE
JULY
AUGUST
SEPT.
Figure 8 . Mean wet weight and 95 percent confidence intervals for Age 0
mountain whitefish, First Dam (area 1) and Third Dam (area 2), Logan
River, Utah, 1970.
22
-------
to
UJ
£.08
o
Lul
UJ
co
< .06
LU
CC
O
It-
CD
LU
.04
DC
CO
s
I
g
.02
20 40 60
TOTAL LENGTH (mm)
80
100
Figure 9. Total length and daily instantaneous rate of increase in weight for Age 0
mountain whitefish, First Dam (area 1) and Third Dam (area 2), Logan River, Utah, 1970.
-------
"3600 r
0
CM
ro
OJ
§
CD
<2400
crt
Q
I
Ul
iLl
a:
o
UJ
Q
UJ
O
2000
O
o
O
1500 U
O
00
I
1000 gj
OL
-------
20.0
10.0
5.0
E
o
1.0
io.5
UJ1
0.1
0.05
0.01
Log W = -4.6704 +2.8043 Log TL
R= 0.995
Log W =-5.7726+ 3.4437 Log TL-
R= 0.998
Log W=-6.8603+4.3333 Log TL
R= 0.928
10
20 30 40 50
TOTAL LENGTH (mm)
70
90
no
Figure 11. Length-weight relationships of 399 Age 0 mountain whitefish
from 12.5 mm to 112 mm total length, Logan River, Utah, 1970-71.
Three stanzas are shown with their respective regression equations.
25
-------
Table 4. Length-weight relationships for three total-length ranges of Age-0 mountain whitefish,
Logan River, Utah, 1970-71.
Total-Length Range and , ,
Length-Weight Regressions-
Correlation
Coefficient
(R)
Standard Error
of the Mean
Regression Mean
Square Error
from approximately 50.0 to 112.0 mm total length (end of study period)
Log @ = -4.6704 + 2.8043 Log TL 0.995 0.0067 0.0006
Average Condition
Factor
«TL>
from hatching to onset of active feeding (approximately 12.5-17.0 mm total length)
Log W = -6.7603 + 4.3333 Log TL 0.928 0.0052 0.0022
from 17.0 to approximately 55.0 mm total length
Log W = -5.7726 + 3.4437 Log TL 0.998 0.0131 0.0012
0.503
0.758
0.917
I/ where W = wet weight in grams, TL = total length in millimeters.
2/ a slight (5 mm) overlap of data was used to calculate the second and third stanzas.
-------
SECTION IX
FOOD HABITS OF LARVAE AND JUVENILES
IN NATURAL ENVIRONMENTS
Methods
Stomach contents from 238 fish (12.5 to 112 mm total length) were analyzed
for food habits. In larvae and post-larvae, the entire contents of the
alimentary canal was examined. In the fingerlings, only the cardiac
stomach anterior to the pyloric sphincter was examined. Organisms
were sorted taxonomically, counted, and measured to the nearest
0.1 mm. Nineteen drift samples were taken concurrently using a
drift sampler of an original design described and pictured by
Brown (1972). The drift samples were preserved in 5% formalin and
after sorting the organisms were preserved in 70% ethyl alcohol. The
stomach contents were compared to the organisms found in the drift
in order to get an idea of what the fish were taking compared to
what was available.
Results and Discussion
Observations of larval and fingerling mountain whitefish indicated
that they remain near the bottom while feeding, moving laterally
or vertically only to capture prey. The young fish may occasionally
seize food organisms directly from the substrate but usually capture
organisms which are drifting in the current. Whitefish larvae
began feeding at a total length of 14-15 mm, before complete
absorption of the yolk.
Chi-square analysis indicated no difference in food habits of
fish from the different collection areas (P < .01). Chironomid
larvae were the major food item of the Age-0 mountain whitefish
ranging from 65.5% to 90% of the total monthly diet in numbers.
Chironomid pupae were second in importance (8%) then came Dytiscidae
larvae (1.6%), Ephemeroptera nymphs (1.6%) and Simuliidae larvae (1.1%).
As the young whitefish increased in size their feeding habits became
more diverse, although the percentage composition in numbers of
chironomid larvae in the diet remained above 80% (Table 5). Mean
food size increased with fish size until the fish reached 55 mm total
length then dropped and stabilized near 3 mm for whitefish 60 - 112 mm
total length.
Samples collected over 24 hr periods indicated that peak feeding
activity occurred in late afternoon and early evening. Numbers of
food items in stomachs decreased after 23:00 hrs and the young fish
did not resume feeding until after 8:00 hrs. Drift samples taken
concurrently indicated no change in available food (Table 6).
27
-------
Table 5. Number of organisms and their percentages of i:he monthly total (in parentheses) from 238 Age-0
mountain whitefish taken concurrently with dr;Lft samples, Logan River, Utah, 1970-71,
Item
Nemata
Oligochaeta
Cladocera
Ostracoda
Copepoda
Ephemeroptera
Plecoptera
K3
00 Hemiptera
Corixidae
Coleoptera
Dytiscldae
Trichoptera
Diptera
Chironomidae
larvae
pupae
Simuliidae
Misc.
Acari
Miscellaneous
TOTAL NUMBERS
Number of fish
March '71
0
0
0
0
6(6.0)
3(3.0)
0
0
0
0
90(90.0)
0
1(1.0)
0
0
0
100
59
April '70
0
0
0
0
0
0
0
0
0
0
61(87.1)
4(5.7)
5(7.1)
0
0
0
70
11
May '70
0
0
0
0
0
2(2.3)
0
0
0
0
78(90.7)
0
6(7.0)
0
0
0
86
14
June ' 70
(1
(i
0
(i
1(0.5)
29(15.6)
C
c
0
3(1.6)
122(65.6)
15(8.1)
15(8.1)
0
0
1(0.5)
186
26
July '70
0
0
0
0
0
6(4.3)
0
0
0
0
Aug. '70
Ktr)i/
0
Ktr)
0
2(tr)
136(6.2)
3(0.1)
0
8(0.4)
24. (1.1)
99(71.7)1806(82.4)
24(17.4) 179(8.2)
9(6.5)
0
0
0
138
62
31(1.4)
0
Ktr)
Ktr)
2193
22
Sept. '70
Ktr)
3(tr)
0
4(tr)
Ktr)
89(1.5)
3(tr)
Ktr)
131(2.2)
14(0.2)
5183(87.3)
471(7.9)
29(0.5)
5(tr)
Ktr)
Ktr)
5937
44
TOTALS
2(tr)
3(tr)
Ktr)
4(tr)
10(0.1)
265(3.0)
6(tr)
Ktr)
139(1.6)
41(0.5)
7439(85.4)
693(8.0)
96(1.1)
5(tr)
2(tr)
3(tr)
8710
238
I/ (tr) less than 0.1.
-------
Table 6. Number 'of organisms and their percentages of the monthly totals (in parentheses) from 19 drift
samples taken concurrently with Age-0 mountain whitefish collections, Logan River, Utah, 1970-71.
to
vo
Item
Nemata
Oligochaeta
Cladocera
Ostracoda
Copepoda
Ephemerop tern
Flecoptera
Hemiptera
Corixidae
Coleoptera
Dytiscidae
Misc.
Trichoptera
Diptera
Chironomidae
larvae
pupae
adults
Simuliidae
Misc.
Acari
Miscellaneous
TOTAL NUMBERS
Number of samples
March '71
0
7(3.3)
0
37(17.3)
49(22.9)
14(6.5)
5(2.3)
0
2(0.9)
0
0
67(31.3)
7(3.3)
16(7.5)
6(2.8)
1(0.5)
2(0.9)
1(0.5)
214
7
April '70
0
1(2.6)
0
0
0
1(2.6)
0
0
0
0
0
25(64.1)
0
0
12(30.8)
0
0
0-
39
1
May '70
1(1.6)
17(26.6)
0
0
0
2(3.1)
0
0
0
0
0
39(60.9)
1(1.6)
0
4(6.2)
0
0
0
64
1
Juno ' 70
3(9.4)
4(12.5)
0
0
6(18.8)
3(9.4)
0
0
0
2(6.2)
2(6.2)
8(25.0)
0
0
2(6.2)
2(6.2)
0
0
32
2
July '70
1(14.3)
0
0
0
1(14.3)
0
0
1(14.3)
1(14.3)
0
0
3(42.8)
0
0
0
0
0
0
7
1
Aug. '70
4(1.6)
12(7.5)
2(0.8)
0
2(0.8)
27(10.8)
1(0.4)
0
2(0.8)
2(0.8)
3(1.2)
156(62.7)
12(4.8)
0
17(6,8)
3(1.2)
4(1.6)
210.81
249
2
Sept. '70
4(1.4)
21(7.5)
4(1.4)
0
55(19.6)
17(6.1)
2(0.7)
3(1.1)
5(1.8)
1(0.4)
6(2.1)
123(43.9)
10(3.6)
0
2(0,7)
5(1.8)
19(6,8)
311,11 .
280
5
TOTALS
13(1.5)
62(7.0)
6(0.7)
37(4.2)
113(12.8)
64(7.2)
8(0.9)
4(0.5)
10(1.1)
5(0.6)
11(1.2)
421(47.6)
30(3.4)
16(1.8)
43(4,9)
11(1,2)
25(2,8)
6(0.7)
885
19
-------
Methods
SECTION X
WHITEFISH CULTURE
Egg Incubation. Several adult whitefish were collected with
electrofishing gear in November of 1970 and 1971 and sex products
collected. The eggs were immediately fertilized using the "dry
method" (Lietritz, 1972) and placed in 7 egg hatching jars and 19
screened egg trays in the Utah Water Research Lab and into 16
screened trays in the NR-Z Lab. The eggs were incubated at ambient
Logan River temperature and at 45 F (7.2 C) in the UWRL and at 42 F
(5.6 C) 45 F (7.2 C) and 48 F (8.9 C) in the NR-Z Lab.
Lighting at the UWRL lab came from windows which kept the eggs and
larval whitefish in an ambient lighting pattern. The eggs and fry
reared in the NR-Z Lab were lighted by overhead flourescent lights.
The day length varied with research activities, but basically
followed the standard 8 to 5 workday.
Saprolegnia grew rapidly on the dead eggs in both laboratories and
was particularly bothersome on the trays. Eggs incubated in jars
were in continuous motion and the fungus growths were restricted to
the individual dead eggs. A 10-minute treatment with 20 ppm
malachite green proved to be highly effective in controlling the
fungus. Dead eggs were removed but not counted.
Survival. Whitefish larvae at birth have developed mouthparts and
begin feeding immediately if food is available. In natural
environments, however, food may not be present and the larvae must
exist on its yolk-energy reserves. In 1970-1971, fry were held
at ambient Logan River temperatures (36-45 F), 42, 45, and 48 F
until they died of starvation. In 1971-1972, this procedure was
repeated at 2,4,5,8,10,12, and 14 C. The later experiment was
terminated after 80 days.
Growth. An automatic feeder was developed to provide a continuous
supply of live brine shrimp to the whitefish fry and fingerlings.
This device was designed to remove the brine shrimp hatched in
brine with very little of the brine accompanying them into the fish
rearing tanks.
Brine shrimp eggs were hatched in tapered "Halvin" plastic bags hung
on a wall hook. Each bag was allowed to incubate at room temperature
48 hrs before being used, thus achieving about a 95% hatch of the eggs.
Air was bubbled through the medium during this time. On the third day
the intake tygon tubing was inserted down to the base of the
tapered bag. This tubing lead through a Buchler Polystaltic Pump
and then into the top of the fish tank. The air bubbler line to the ,
brine shrimp was attached to a solenoid valve (ASCO 8320 A 3). Both
the peristaltic pump and the solenoid valve were attached to a Tork-8001
timer with a delay-timer switch (Amf Model 533 032 0) between the Tork
and the pump (Fig. 12).
30
-------
I EL AY-TIMER
SWITCH
FISH TANK
TO AIR SUPPLY
Figure 12. Schematic diagram of automatic brine shrimp feeder.
31
-------
The timer could he set to feed the fish eyery forty-five minutes. At
this time the solenoid yalye was closed thus shutting off the air.
The pump did not turn on until eight minutes later giving the brine
shrimp a chance to settle and concentrate into the tapered end
of the "Halvin" bag.
The pump then switched on for seven minutes and pumped concentrated
shrimp from the bag to the fish tank. The pump was turned off and
the valve opened for thirty minutes. These time intervals could
be adjusted on the timer.
Time needed to maintain this device was about 30 minutes per day.
The intake tubes had to be transferred to a new set of Halvin bags
and fresh bags of brine shrimp eggs in brine were started. Thus
with a minimum of daily work live brine shrimp were supplied to the
fish throughout the day.
Brine shrimp are expensive and as the fish grow larger they require a
larger size food item. It was desirable to switch the fish to trout
pellets by introducing small amounts of dry trout feed into the
young whitefish's diet. Gradually the amount of dry food was
increased and the amount of brine shrimp was decreased until the
fish were entirely on a dry trout food diet.
Diet. After hatching, fry were placed into experimental containers
and fed four different diets: newly hatched brine shrimp; dry trout
diet of appropriate particle size; mosquito larvae; Oregon Moist
Pellet (OMP) trout feed; and a combination of dry food and brine
shrimp. Fish were measured and weighed periodically. The experimental
containers were suspended in the large min-o-cool units, and
water was circulated through each. This facilitated handling the
fish and cleaning the containers. As the larval whitefish grew
they were placed in min-o-cool tanks or circular tanks. Two
replicates of 50 fish each were fed three diets at 48 F for the first
4 months and at 52 F for the last 2 months.
Temperature. In 1970-1971, whitefish larvae were kept at 45
(7.2 C) and 48 F (8.9C) and fed comparable amounts of brine
shrimp (4-6 times daily to satiation) for three months. Comparisons
were made on the mean monthly increase in total length.
In 1971-1972, the above procedure was repeated for six months at
three different temperatures (6, 9, and 12 C). Two replicates
were maintained at each temperature, and a sample of five fish was
measured monthly and preserved in 10% formalin. Results were
analyzed using a mixed effects model of the factorial design
(Snedecor & Cochran, 1971). A model was proposed for significant
factors using stepwise multiple regression.
32
-------
Results and Discussion
Egg Incubation. Incubation periods ranged from 45-75 days at 48 F
(8.9 C) to 77-98 days at 42 F (5.6 C) in the NR-Z Lab (Table 7).
At the lower temperatures in the UWR LAB (Logan River water,
35-43 F), the incubation period was 80-120 days (Fig. 13).
Table 7. Length of incubation period (start to end of hatching),
length of hatching period (days), and peak period of hatching (days
after fertilization).
Length of Peak Period
Incubation Period Hatching Period (Days after
Temperature (F) (Days; Start to Finish) (Days) Fertilization)
I/
42-'
45
48^-//
(5.6 C)
(7.2 C)
(8.9 C)
Logan River (35-43)
77-98
52-76
45-75
80-120
21
24
30
40
83-87
59-63
49-55
I/ First 25 days at Logan River temperature (11/17-12/11): Mean = 39 F
21 First 7 days at Logan River temperature (11/16-11/22): Mean = 39 F
Survival. At 48 F unfed whitefish larvae lived 40 days before death
occurred. Fry at 45 F lived for 50 days, and those at 42 F, 63 days
(Fig. 14). At ambient Logan River temperatures (36-45 F), fry lived
41 days (Table 8). The shorter life span at the lower Logan River
temperatures may have been due to the fish being more active and using
more energy in the flow-through containers. Larvae in the NR-Z Lab
which were held on shallow screen trays were less active and rested
on the screen nearly all of the time, which reduced demands on food
energy reserve. Larvae removed and fed brine shrimp after 17, 24,
3.1 and 38 days of starvation readily took the food items and survived
and grew at satisfactory rates.
The survival experiments with unfed fry were repeated in 1972 at
2, 4, 6, 8, 10, 12, and 14 C (Fig. 15). In both tests increase
in temperature shortened survival. At 14 C all were dead within
12 days, whereas at 2, 4, or 6 C,80% or more were alive after 80
days (Table 9).
33
-------
(W
031
NOIiVZniiH3J INOHd SAVQ JO
001 08 09
10
tr
UJ
QL
cc
UJ
i'9-ri
9'9
I
m
-o
m
X
o
O
6'8
Figure 13. Mountain whitefish egg incubation periods at three controlled temperatures and
ambient Logan River temperatures, 1969-1970.
-------
70
60
50
40
30
20
10
V
5.6 7.2 8.9
WATER TEMPERATURE (°C)
Figure 14. Survival of unfed whitefish larvae at three temperatures
(*C), 1970-1971.
35
-------
100
x "X "xx.
» » ^ ..
\ **... ^
* «
% **«"«....,
\
\
\
12C
'I
1
hoc
\
«
\
V
V
*.
\
\ 8C
*
\
*
\
\
\
. I
10
20
70
80
30 40 50 60
NUMBER OF DAYS
Figure 15. Survival of unfed mountain whitefish larvae at various temperatures, 1971-1972.
-------
Table 8. Survival of unfed mountain whitefish larvae at 42, 45, and
48 F in the NR-Z Lab and at ambient Logan River temperatures in
the Water Lab, 1970-1971.
JL/ 20-170 fry per replicate
No. Days Alive
Temperature (F)
42 (5.6 C)
45 (7.2 C)
48 (8.9 C)
Logan River (36-45) £
No. Replicates
3
4
3
2-7. 2C) 3
Mean
63
53
40
41
Range
56-68
51-56
34-45
40-43
Table 9. Survival of unfed mountain whitefish larvae at 2, 4 6,
8, 10, 12, and 14 C. 1971-1972.
Temperature (C) No. Replicates
No. Days Alive
Mean Range
% Survival
After 80 Days
2
4
6
8
10
12
14
3
3
3
3
3
3
3
80?-
80*
801
75.5
49
28
10.5
80
80
80
74-77
48-;50
27-29
10-11
91.7
82.0
78.0
0.0
0.0
0.0
0.0
Experiment Terminated after 80 days.
Mortality. The equation Logg No - Log N = Z was used to compute
daily instantaneous mortality. Highest mortality was observed on the
mosquito larvae and OMP. For dry trout diet the total mortality
rate was 93% for the first 6 months of life and for OMP it was 98%
for 1.5 months. Lowest mortality was in the brine-shrimp-only lots
where 3 month mortality rate was 15%. In the combination diet
lots, total mortality rate was 44% for the first 6 months of
life (Table 10).
37
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Table 10. Mortality of whitefish larvae cultured in the laboratory, 1971.
Diet
Months
Mortality Rates
Total (a) Daily Inst. (Z)
Brine Shrimp
Mosquito Larvae
OMP
Dry Trout Diet
Dry Trout Diet
and Brine Shrimp
3
3
1.5
5
6
15%
93%
98%
93%
44%
0.17%
2.5%
8.9%
1.41%
0.83%
Growth-Diet. Larvae on dry trout diet did not grow during the first
month, began to grow slowly during the 2nd month (1mm) and the few
survivors which were remaining after this time grew at 4 mm/month. All
fish on the dry diet were dead by the end of the fifth month.
Growth on mosquito larvae was irratic during a 3 month test, being
better than that of fry on OMP diet but riot as good as those fed
brine-shrimp (Fig. 16). In other experiments the OMP and mosquito
larvae diet produced similar growth. Both groups were switched to
brine shrimp at the end of 3 months. The fry from the mosquito
diet did very well and at the end of six months had caught up with
the group on brine shrimp diet. The ones fed OMP when switched to
brine shrimp grew better but died after 4 months (Fig. 17).
Highest growth rates were observed on the brine shrimp diet and
the combination brine shrimp/trout food diet where larvae grew at
the rate of 18 mm/month for the first 3 months. During the later 3
months, larvae on brine-shrimp-only grew at approximately 1 mm/month
and those on the combination diet did not grow at all.
Growth-Temperature. During the 1970-1971 experiment, larval
whitefish raised at 48 F (8.9 C) exhibited a mean monthly growth
increment of 12 mm/month for three months. Fish at 45 F (7.2 C),
grew at 4.3 mm/month.
Differences in growth as measured by changes in total length also
appeared in the 1971-1972 experiment (Table 11). Mean monthly
growth increments were 4.95, 5.88 and 7.08 mm/month at 6, 9. and
12 C respectively (Fig. 18). Although the main effect of temperature
was not significant (a = 0.05), the main effect of time and the
interaction of time and temperature were significant at the 0.05
and 0.01 levels (Table 12). The effects of replicates within
temperature and the interaction of replicates within temperature
and time were also significant (a = 0.05).
38
-------
401
35
30
25
E
E
LU
20
15
10
Brine Shrimp
Mosquito Larvae
OMP
FEB
MAR
APR
MAY JUN
Figure 16. Growth of mountain whitefish larvae fed different
diets, 1971.
39
-------
E
E
x
Ul
70
60
50
40
30
20
10
Brine Shrimp
Mosquito Larvae
OMP
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
Figure 17. Growth of mountain whitefish larvae fed different diets during six months
after hatching, 1971.
-------
Ui
_J
g
60
50
40
3O
20
10
30
60
150
Figure 18.
90 120
NUMBER OF DAYS
Growth of mountain whitefish larvae at three temperatures (*C), 1972.
ISO
-------
2
The following model was developed with an R value of .90 (Table 13)
Y = 21.55 + .104 X1 + .012 X^
where: Y = length in mm
time in days = X..
temperature = X
0
Table 11. Monthly mean (range) length in mm of larval whitefish at
three different temperatures, 1971-1972.
Temperature (C)
Month 6 9 12
May 20.8 (19.5-21.5) 23.9 (22.5-25.0) 23.4 (22.5-25.0)
Jun 27.1 (24.5-29.5) 29.3 (28.5-33.0) 28.0 (24.5-31.0)
Jul 32.5 (28.5-35.0) 34.2 (30.5-37.5) 33.1 (30.5-39.0)
Aug 37.3 (34.5-40.5) 41.4 (33.5-46.0) 43.0 (34.0-53.0)
Sep 41.6 (38.0-44.5) 45.5 (41.5-51.0) 48.5 (42.0-49.5)
Oct 45.6 (41.5-51.5) 53.3 (46.5-62.5) 58.8 (48.5-65.5)
42
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Table 12. Abbreviated factorial analysis of factors affecting larval
whitefish growth at three different temperatures, 1971-1972.
Source of variation Degrees of freedom Mean square
Total
Temperature
Tank/Temperature
Time in days
Temperature X Time
Tank/Temperature X
Fish/Temperature X
in days
Time in days
Tank X Time
179
2
3
5
10
14
135
123.095
426.101^
147.873**
3793. 078A
62.164AA
18.461
6.612
A
Significant at the 0.05 level
**Significant at the 0.01 level
Table 13. Abbreviated regression analysis of factors affecting larval
whitefish growth at three different temperatures, 1971-1972.
Source of variation Degrees of freedom Mean square
Total
Time
Time
Model
Error
in days
in days X Temperature
170
1
1
2
168
111.051*
879.456A
1025.208
8460.671
11.650
Significant at the 0.05 level
43
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ACKNOWLEDGMENTS
The initiation of the project and collection of data on egg incubation
and culture methods was very ably carried out by Dr. Robert H. Kramer
former Unit Leader, Utah Cooperative Fishery Unit until his death
in December 1972.
Graduate students Larry Brown and Ross A. Smith conducted the research
on early life history, food habits and spawning behavior as thesis
projects in the Wildlife Science Department, Utah State University,
Logan, Utah.
The support of the project by the Environmental Protection Agency
and the help provided by Mr. Richard E. Siefert, the Grant Project
Officer, is acknowledged.
44
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LITERATURE 'CITED
Brown, C.J.D. 1952. Spawning habits and early development of the
mountain whitefish, Prosopium williamsoni (Girard), in
Montana. Copeia (2):109-113.
Brown, L. G. 1972. Early life history of the mountain whitefish
Prosopium williamsoni (Girard), in the Logan River, Utah.
Masters thesis Utah State Univ. 40 p.
Drummond, R. A. and W. F. Dawson. 1970. An inexpensive method for
simulating diel patterns of lighting in the laboratory.
Tran. Amer. Fish. Soc. 99 (2):434-435.
McAfee, W. R. 1966. Mountain whitefish, p. 299-303, In Inland
Fisheries Management, Alex Calhoun (Ed.) State of Calif.,
The Resources Agency, Dept. Fish and Game.
Leitritz, Earl. 1972. Trout and salmon culture (hatchery methods).
Fish Bulletin No. 107, State of California Dept. of Fish and
Game. 169 p.
Normandeau, D. A. 1969. Life history of the round whitefish,
Prosopium cylindraceum (Pallas), of Newfoundland Lake, Bristol
New Hampshire. Trans. Amer. Fish. Soc. 98(1):7-13.
Sigler, W. F. 1951. The life history and management of the mountain
whitefish Prosopium williamsoni (Girard) in the Logan River,
Utah Agri. Exper. Sta. Utah State Agri. Coll., Logan, Utah.
Bull. 347. 20 p.
Snedecor, G. W. and W. G. Cochran. 1971. Statistical methods.
Sixth ed. The Iowa State University Press. Ames, Iowa. 593 p.
Vladykov, V. D. 1970. Pearl tubercles and certain cranial
peculiarities useful in the taxonomy of coregonid general,
p. 167-194, In Biology of Coregonid Fishes. C. C. Lindsey and
C. S. Woods (Ed.) University of Manitoba Press.
45
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PUBLICATIONS
Brown. L. G. 1972. Early life history of the mountain whitefish
Prosopium williamsoni (Girard), in the Logan River, Utah.
M.S. thesis, Utah State University, Logan, UT 40 p.
Smith, Ross A., J. Anne Holman and the late Robert H. Kramer. Automatic
brine shrimp feeder. Progressive Fish Cult, (in press).
46
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
l.'Rer rt
w
4. Titlr
EARLY LIFE HISTORY AND FEEDING OF YOUNG MOUNTAIN
WHITEFISH
5. f. ..'jrtD.. -
6.
*. Pf-iormir Or gar' tatiott
Stalnaker, C. B. and Gresswell, R. E.
Utah State University
Logan, Utah 84322
12- Sponging Organize! .Environmental Protection Agency
or.,:--, ",-
18050 DPL
13, Type i ' Repor i
Perio^ Covered
Environmental Protection Agency report number, EPA-660/3-73-019/
ifi. Aijs-irsi, Early life history studies and development of culture methods of the mountaii
whitefish (Prosopium williamsoni) were conducted in the Logan River, and in the Utah Stat
.esearch Laboratory and USU Fisheries Laboratory.
Spawning was observed in the laboratory and in the Logan River from mid-November to
aid-December during dusk. At ambient river temperature from 1.7-6.1 C eggs began hatchin
after 79 days and continued for 23 days. Total mortality to hatch of eggs from weekly
collections from five areas was 92%. In the laboratory, at 7.2 C eggs began hatching in
52 days and continued for 23 days; at 8.9 C in 45 days and continued for 30 days.
Larval whitefish from two areas showed differences in growth due to temperature
experience. Growth was examined in the laboratory at 6, 9, and 12 C. A simple linear
nodel for predicting growth was developed.
Whitefish began feeding when 14-15 cm long, and fed near the bottom mainly on
Shironomid larvae.
Larval whitefish were raised at 2-14 C at 2 degree intervals, and were fed dry trout
Eeed, Oregon Moist Pellets, mosquito larvae, and brine shrimp. Starved fish died earlier
it higher temperatures; mortality ranged from 15% for 3 months on brine shrimp to 98%
Ln 1.5 months on Oregon Moist Pellets.
17a. Descriptors
*Life history studies, *Spawning, *Water temperature, *Fish behavior *Fish food organisms
Aquatic habitats, Fish eggs, Thermal pollution, Mortality, Hatching
^ 17b. Identifiers
Mountain whiteZish, *Culture methods, Fish growth, Logan River
17c. CO \VRRF :tld& Group 05C
13. Avail ab-.H
IS. Security C '-ass.
.^(Report)
20 Security Class.
(Page}
21. Av.bif
Page*
22, Price
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C. 2O24O
Richard E. Siefert
utiVc National Water Quality Laboratory, Duluth,
! Minnesota ~~^
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