The age, growth and food habits of the marine cottid Leptocottus armatus
by Edward Frederick Weiss
A thesis submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE in Fish and Wildlife Management
Montana State University
© Copyright by Edward Frederick Weiss (1962)
Abstract:
A study was made on the age, growth and food habits of the Pacific staghorn sculpin (Leptocottus
armatus) in the vicinity of Friday Harbor, Washington. The study was conducted during the summer of
1961. Otoliths were removed from 295 sculpins for the age and growth study. The otoliths are
generally elliptical in appearance with a moderately crenated outline. The otolith radius to total length
relationship for 272 sculpins was expressed by the equation Y = -16.9 + .642X and a correlation
coefficient of 0.974 After elimination of the 20 largest fish the relationship was expressed by the
equation Y = -10.0 + .601X and a correlation coefficient of 0.980. The average calculated lengths for
262 sculpins at the end of each succeeding year of life for ten years were 34, 55, 80, 101, 122, l48, 174,
200, 222, 228 mm., respectively. Calculated growth rate at the end of each year of life, except for the
ninth and tenth, is greater in older fish. Length-frequency data generally agreed with growth data. The
growth increment was determined to be uniform throughout the life of the sculpins sampled. A total of
182 stomachs was analysed for the food habits study. Amphipods were the most numerous items taken
by the sculpins and comprised the largest volume of material in stomachs of small specimens. Fish
made up the largest volume of food in stomachs from large sculpins. t
THE AGE, GROWTH AHD FOOD HABITS OF THE MARIHE COTTID
LEPTOCOTTUS ARMATUS
^7
EDWARD FREDRICK WEISS JR.
A thesis submitted to the Graduate Faculty in partial
fulfillment of the requirements for the degree
of
MASTER OF SCIENCE
in
Fish and Wildlife Management
Approved:
H e a d p m j o r jDe^artment
/fmahp-Examining Committee
Dean/ Graduate/Division
lM f ; r;-iII ,
I/
S
MONTANA STATE COLLEGE
Bozeman, Montana
June, 1962 .
iii
Acknowledgements
The author wishes to extend thanks to those who assisted in this
study.
Dr. C. J. D. Brown suggested and directed the investigation, and
assisted in the preparation of the manuscript.
Mrs. Evangeline Brown, Mr.
John Campbell, and several graduate students assisted with the collections.
The University of Washington Friday Harbor Laboratories provided laboratory
space and furnished the equipment for making collections.,
5
iv
Table of Contents
Page
Abstract . ................................. . . ...............
Introduction
.......... .....................................
Sampling areas . . . . . .
......................
. . . . . . .
Methods of collection and preservation . . . . . . . .
..............
I
I
2
. . . . . . . . . . .
2
Total body length-otolith relationship . . . .
Rate of growth . . . . . . . . . . ..........
Length-frequency distribution . ............
Validity of the age and growth determinations . . . . . . .
Length-weight relationship . . . . . . . . . . . . . . . . .
Total length and standard length relationship . . . . . . .
Maximum size
............
11
13
13
13
Stomach analysis ..................
\o -q o\
Age and growth . . . . . .
........
vi
14
. . . . . . . . . . . . .
l6
Literature cited . . . . . . . . . . . . . . . . . . . . . . . .
l8
Summary
. . . . . . . . .
..........
V
List of Figures
Page
Fig. I.
Fig, 2.
Fig. 3.
Fig. 4.
Otolith from a Pacific staghorn sculpin of 87 mm. total
length showing three annuli ..........................
4
Relationship between otolith length and otolith width
for Pacific staghorn sculpins collected near Friday
Harbor, Washington, 1961 . . . . . ..................
5
Relationship between otolith radius and total length of •
Pacific staghorn sculpins, 1961. The solid regression
line was calculated from data for 272 fish. The broken
regression line was calculated after omission of the 20
largest f i s h .......... ............................ .
8
Length-frequencies of three collections of Pacific
staghorn sculpins collected near Friday Harbor, Wash­
ington, 1961 . ......................................
12
vi
Abstract
A study was made on the age, growth and food habits of the Pacific
staghorn sculpin (Leptocottus armatus) in the vicinity of Friday Harbor,
Washington. The study was conducted during the summer of 1961. Otoliths
were removed from 295 sculpins for the age and growth study. The otoliths
are generally elliptical in appearance with a moderately crenated outline.
The otolith radius to total length relationship for 272 sculpins was ex­
pressed by the equation Y * -16.9 + .642X and a correlation coefficient of
0.974. After elimination of the 20 largest fish the relationship was ex­
pressed by the equation Y » -10.0 + .601X and a correlation coefficient of
O.98O. The average calculated lengths for 262 sculpins at the end of each
succeeding year of life for ten years were 34, 55* 80, 101, 122, l48, 174,
200, 222, 228 mm., respectively. Calculated growth rate at the end of each
year of life, except for the ninth and tenth, is greater in older fish.
Length-frequency data generally agreed with growth data. The growth in­
crement was determined to be uniform throughout the life of the sculpins
sampled. A total of 182 stomachs was analysed for the food habits study.
Amphipods were the most numerous items taken by the sculpins and comprised
the largest volume of material in stomachs of small specimens. Fish made
up the largest volume of food in stomachs from large sculpins.
tA
-I-
Introduction
The age, growth and food habits of the Pacific staghorn sculpin
(Leptocottus armatus Girard) were investigated from June to September,
1961- This study was carried out at the University of Washington Friday
Harbor Laboratories located on San Juan Island, Washington.
All collect­
ions were made along the shores of this island, which provides suitable
habitat for this species.
No age growth investigations and only one stomach analysis study of
marine sculpins have been found in the literature.
Mitchell (1953) ana­
lyzed the stomach contents of three species of tidepool sculpins in Cali­
fornia.
Several investigations have been made concerning age, growth and
food habits of the freshwater sculpin Cottus bairdi.
Bailey (1952) in­
vestigated the age, growth and food habits of this species in Montana and.
Zarbock (1951) made a similar study in Utah.
Koster (1937) and Daiber
(1956) reported its food habits in New York while Dineen (1951) investigat­
ed this species in Minnesota.
Northcote (195^) compared the food habits of
Cottus asper and Cottus rhotheus in British Columbia.
Description of the Sampling Areas
The Pacific staghorn sculpin was most abundant on clean sandy areas
.of the intertidal zone,
The collecting areas on San Juan Island were:
False Bay, on the southwestern side, which is generally protected from
direct wave action, and North Bay, on the eastern side, which is exposed
to constant wave action.
Bottom materials in the collecting areas were
primarily sand and gravel.
Sea lettuce (Ulva) and eelgrass (Zostera) were
-2-
the most abundant aquatic plants present in these areas.
The Pacific
staghorn sculping when disturbed, utilized the aquatic plants for conceal­
ment, but preferred the open, sandy areas at other times.
While it was
the most abundant fish collected in the sampling areas, the shiner perch
(Cymatogaster aggregate) and starry flounder (Platichthys stellatus) were
also abundant.
A considerable number of other species was taken less
frequently.'
Collection and Preservation of Samples
Most sculpins less than 150 mm. in total length were collected with a
15 foot "common sense" seine.
Larger sculpins evaded this seine, and were
captured with a 30 foot bag seine moved rapidly parallel to shore, with
the operator at the outer end remaining about ten feet in advance of the
other.
Many sculpins of all sizes were also collected by applying rotenone
to small areas near eelgrass beds.
Sculpins from which otoliths were taken and those used for stomach
analysis were measured while fresh.
were preserved in 10$ formalin.
Those used for length-frequency study
The relationship between total lengths of
fresh and preserved sculpins was determined for $0 specimens under 100 mm.
in total length and 75 over 100 mm.
Conversion from fresh total length
(Y) to preserved total lengths did not exceed .$84 Y and therefore no
corrections were applied to preserved fish.
Age and Growth
Otoliths were studied from 295 specimens.
These were removed by
.
" 3 ‘
making an oblique cut from immediately posterior to the orbits to the be­
ginning of the vertebral column.
The top of the skull was then raised and
the two exposed otoliths of the saccuius were removed with a forceps.
These were the only otoliths used in this study.
The otoliths of the Pacific staghorn sculpin are generally elliptical
in outline with the ventral edge more flattened than the dorsal (Fig. I).
Smaller otoliths have narrower and more pointed anterior projections than
the larger ones.
The lateral surface of the otolith is slightly concave,
while the.mesial surface is convex with the sulces acusticus along its
longitudinal axis.
The margin-of the otolith is moderately crenated.
Oto­
liths ranged from 1.5 to 11.2 .mm. in length and 1.0 to 5*5 mm. ..in width.
Growth of the structures appears to be uniform (Fig. 2).
Generally, the core of most otoliths consisted of a small, opaque
center, surrounded by a translucent band.
The core of larger otoliths was
usually composed of an enlarged translucent area with an opaque band im­
mediately outside the core.
The otoliths have translucent rings that alternate with opaque zones
outside the core (Fig. I).
The translucent rings are narrower than the
opaque ones and occur near the edge of otoliths collected during June.
These are interpreted to represent winter growth or annuli while the opaque
zones are summer growth.
Otoliths were gently rubbed between the thumb and forefinger to remove
adhering tissues, and then stored in vials.
preserved in 5
The majority of otoliths were
glycerin and water to which a few crystals of thymol were
-U-
Fig. I.
Otolith from a Pacific staghorn sculpin of 87 mm. total length
showing three annuli.
-5-
«
BC
Ili
Y -.150 ♦
.469 X
lUJ
a
z
z
H
Q
£
Z
O
IO
OTOLITH
Fig. 2.
LENGTH IN MI LLI METERS
Relationship between otolith length and otolith width for
Pacific staghorn sculpins collected near Friday Harbor,
Washington, 1961.
-6-
added.
However, some were stored in xylene.
Ho major difference was
noted in otoliths stored in two -media at the end of five months.
Preserved
otoliths, with their concave surfaces directed upwards, were placed in a
blackened dish and immersed in glycerin.
A Cyclospot illuminator was
positioned to allow the light to strike the otolith perpendicular to the
concave surface.
Magnification ranged from 15 to 45X.
A translucent band
was considered to represent a true annulus only if it were continuous, or
nearly so, around the entire otolith.
The first annulus was often in­
complete and narrower than other annuli.
Annuli were sometimes difficult
to distinguish due to increased thickness and opacity in otoliths from
larger sculpins.
Large otoliths were cleared by immersion in pure creosote
for.a period of from 12-24 hours.
Otoliths that were crystalline or par­
tially so, or those exhibiting "multiple rings" of the type described by
Frost (1945) were discarded.
The paired otoliths from each sculpin showed
95$ agreement in ages.
Total Body Length-Otolith Relationship: Otolith measurements were
made in millimeters by use of an ocular micrometer while the otolith was
positioned as described above.
Measurements were made from the center of
the core of each otolith, along the longitudinal axis to the anterior edge,
and the distances to each successive annuli and to the anterior edge of the
otolith were recorded.
The distance from the core of an otolith to its
anterior edge is hereafter referred to as otolith radius.
Variations in the
number of fish used in the tables resulted from discarding otoliths which
could not be read and measured with confidence.
-7-
The otolith radii in millimeters were plotted against the correspond­
ing total lengths in millimeters and a line fitted to the data by the
method of least squares.
-16*9 mm. (Fig. 3).
This line was found to intercept the Y axis at
The regression coefficient for the data was calculated
to be 0.974.
Inclusion of the small sample of sculpins over 200 mm. in total length
(20 fish comprising 7 -»4$ of the total number used in the calculations) was
thought to cause the intercept value to be low.
A new regression line was
calculated from the data after elimination of larger sculpins and was found
to intercept the Y axis at -10.0 mm.
calculated to be 0 .980.
The new regression coefficient was
This compares favorably with the value of 0.969
determined by Sneed (1950) for catfish spines»
The low intercept value for the data including the larger.sculpins was
apparently caused by an inadequate number of large fish in the sample
and/or by a differential sexual mortality causing a change in sex ratio at
the greater lengths.
These data could also represent a true curvilinear
relationship rather than the assumed rectilinear as described above.
Rate of Growth:
The age was assessed and growth rates were determined
for 262 Pacific staghorn sculpins.
Calculations to determine lengths at the
end of each year of life were made with the aid of a nomograph similar to
that described by Carlander and Smith'(1944).
These calculations were
based on a rectilinear relationship between otolith radius and body length
and included a correction factor of -10 mm. (Fig. 3)*
Calculated lengths
have been expressed for each age group and as grand averages for all groups.
-8-
400
IN M I L L I M E T E R S
Y-16.9 + .642 X
TOTAL
LENGTH
Y M O O +.601 X —
400
OTOLITH
Fig. 3.
RADIUS
x IOO
IN
MILLIMETERS
Relationship between otolith radius and total length of Pacific
staghorn sculpins, 1961. The solid regression line was calcu­
lated from data for 272 fish. The broken regression line was
calculated after omission of the 20 largest fish.
-9-
The grand average calculated lengths for the sculpins at the end of
each succeeding year of life for ten years were 3^, 55, 80, 101, 122, 148,
174, 200, 222, and 228 ram., respectively (Table l).
Growth rate was
greatest in the first year, but thereafter did not decline appreciably
until after the ninth year.
Small samples of age group X probably result­
ed in some error in this range.
The calculated growth rate at the end of each year of life, except
for the ninth and tenth, is greater in older fish.
This relationship
appears to be a reversal of Lee rs phenomenon and indicates that the early
year classes grew faster than more recent ones.
due to two or more factors.
This would seem to be
The larger core of the otoliths from older
sculpins may have caused the first annuli used in the growth calculations
IV?
to be a greater distance from the center of the otolith core. This would
result in an apparent increase in the average calculated length for the
first year class of each successive age group.
However, this would not
explain the reversal of Lee's phenomenon in the other year classes unless
the larger core of the otoliths from older sculpins completely obscures
the first annuli.
The uniform increase in calculated length at the end of
any selected year for successive age groups indicates that neither of these
factors would completely explain the reversal of. Lee's .phenomenon,,
/, /
1
Length-Frequency Distribution: A length-frequency study was made' on
2734 specimens collected during the following periods: 1190, June 18 to
June 30; 388, July 26 to August 3; 1156 , August 7 to August 26.
A length
interval of 5 mm. was used in preparing the frequency polygon (Fig. 4).
Table I.
Age
group
Ho.
fish
18
60
36
51
b9
20
12
8
5
3
Av.
length
capture
b9
67
97
115
133
159
191
207
231
2U6
■
Year of life
_______________ _____ _________ :____
k
6
I
2
3
5
30
32
53
31 • 55
54
33
35
55
35
59
36
57'
60
37
38 . 62
38
63
7
8
10
9
80
Qk
83
100
100
100
106
105
86
114
78
78
80
118
119
127
130
85
105
137
134
l4l
148
151
165
170
172
181
195
226
155
184
207
200
215
228
OT-
I.
II
'III
IV
V
VI
VII
VIII
IX
X
Average calculated total lengths and growth increments (millimeters) of sculpins col­
lected in 1961 in Puget Sound, near Friday Harbor, Washington.
Grand
average
length
Incre­
ment
,Humber
of fish
262
34
;•
:
55
80
101
122
148
174
200
222
228
34
21
25
21
21
24
26
26
22
4
262
244
184
148
97
48
28
16
8
3
-11-
Age group I showed a mode at 35 mm. in the June collections, 50 mm. in
the July and 60 mm in the'August „
Age group II showed modes at JO, 65,
and 75 mm.respectively for the same collecting periods.
Age group III
showed a mode at 90 mm. in the July collection while age group IV indi­
cated modes at 105, 115 and H O mm. for the three collecting periods.
.Validity of Age and Growth Determinations: The time of annulus for- .
:
mation for otoliths from the Pacific staghorn sculpin was not established,
but it was assumed that this occurred sometime shortly before June 18.
There was evidence that the translucent bands in otoliths from this
sculpin represent true annuli.
Calculated lengths of young fish as de­
termined from the otoliths of older sculpins should nearly approximate
tht empirical lengths of young fish of the same assigned age at the time
of capture.
The calculated length of age group II at the end of the
second year of life slightly exceeds the measured length, of age group I
at the time of capture (Table I).
Similarly, the calculated growth to
the third annulus of age group III exceeds the average measured length of
age group II.
This relationship exists for all except age group X and
this probably resulted from the small samples of age groups IX and X.
Further substantiation of the age and growth determinations would
require that there be agreement between modes of length-frequency dis­
tribution and the average calculated lengths for each year of life.
Com­
parison of the average calculated lengths for sculpins at the end of one
and two years of life (Table l) with the length-frequency distribution for
June collections (Fig, 4) indicates satisfactory agreement.
Comparison of
the mean actual lengths at capture for the sculpins assigned to age groups
-12 —
JUNE, 1961
FREQUENCY
1190 FISH
JULY, 1961
3 8 8 FISH
AUGUST, 1961
1156 FISH
TOTAL
Fig. 4.
L E N GT H
IN
MI LLI METERS
Length-frequencies of three collections of Pacific staghorn
sculpins collected near Friday Harbor, Washington, 1961.
-13-
I, II, and IV with the length frequency distributions for July and August
collections also gave satisfactory agreement, .Age group III showed a
mode in the July collections which agreed with the mean actual length at
capture for that group.
Length-Weight Relationship; The relationship between fresh total
lengths and weights was obtained for 108 sculpihs collected at various
periods throughout August, 1961.
The length-weight data were fitted to
the equation W =. CL where W = weight in grams,. C ® a constant, and L s
length in millimeters.
The resulting equation expressed in logarithmic
form was log W » -5.243 + 3 .134(log L).
A calculated length-weight curve
was prepared which satisfactorily fitted the empirical length-weight
values, except for sculpins over 190 mm. in total length.. This discrep­
ancy may be,explained by the fact that only four fish larger than 190 mm.
were available for the calculations.
Total Length and Standard Length Relationship; The relationship be­
tween total lengths and standard lengths of fresh seulpins. was determined
forslOO specimens (total lengths 30-220 mm.).
A line fitted to the data
by the method of least-squares was represented by the equation Y ® -3.068
+ 6!.-883X where Y «® standard length and X = total length in millimeters.
Maximum Size: The largest sculpin collected during this study was
taken in the False Bay area.
length.
This was a male of 272 mm. fresh total
The largest specimen obtained was a female of 337 mm. preserved
total length which was collected by Dr. C. J. D. Brown in the summer of
i960.
Clemens and Wilby (1961) report that, the sculpin may reach 12
inches in length.
Food of the Pacific Staghorn Sculpin
Two separate collections, totaling 109 fish, were -obtained' from
False Bay, one on August 11 and another August 26, 1961, for the food
analysis study.
On June 2U and August 11, 1961, collections were made
from North Bay totaling 73 fish, most of which were less than 75 mm.
total length.
All collections were made in the afternoon.
Sculpins were measured while fresh and the body cavity was injected
with 40% formalin.
All fish were then preserved in 10$ formalin.
No
sculpins were observed.to regurgitate when preserved, and no food was
found loose in the storage container at later times.
Sculpins were slit from the isthmus to the anus and stomachs were re­
moved by cutting the esophagus at the posterior end of the oral cavity and
breaking off the intestine at the pyloric valve.
The stomachs were slit
open and the contents were placed in 70$ alcohol before examination.
organisms were generally classified to order.
Food
Most of the fish were
identified to species.
Numbers and volumes of food in individual stomachs were not determin­
ed because of the small quantities involved.
Total numbers and total vol­
umes were determined for each of three length groups, 25-50 mm., 51-150
mm., 151-240 mm. respectively (Table II).
Total volumes were found by
displacement in 70$ alcohol.
Amphipods were the most numerous items in the stomachs of all three
size groups.
Polychaetes were next most frequent in the small and medium
size groups.
Stomachs from the large size group showed fish to be the
/ •
Stomach contents of 182 sculpins taken near Friday Harbor, Washington, l$6l.
Percent of rtotal
volume of all foods
Total volume of
organisms in
milliliters
I!
Percent of total
number of foods
h
Cl CU
Av. number-of org­
anisms in stomachs
containing'them
O
Percent of,total
volume of all foods
-p S
O <H
Total volume of
organisms in
milliliters
/'
H
Cd CQ
Td
O 0
+1
Total length of fish
151-240 mm.
(21 stomachs)
3.30 1.10 2 8 . 9 0.34 t A 5.0 8.1 0.47 5.6 0.8 '1.0
93.70 2.30 60.5 3.80 81.7 3.4 5.5. 6.60 78.1 2.2 2.8
0.10
0,8
0.14
5.2
0.24
2.8
0.1
0.1
0.5
' 0.10
0.20 5.2 o . o 4 0.8 1.6 2.6 0.38 4.5 11.8 15.2
0.02
o „o 4
o .o 4
0.8
0.6
0.05
0.02 o . o 4 0,10 2.6 0.17 4.0 46.6 75.5 0.71 8 . 4 59:0 76.0
1.2
3.4
0.4
1.9
0.10
2,6
3.4 5.5'
0.4
0.3
I
Polychaeta
Amphipoda
Isopoda
Decapoda
Mollusca
Fish
Miscellaneous
Unidentified
Total length of fish
51-150 mm.
(108 stomachs.)
Percent of total
Ivolume of all foods
Total volume of
organisms in
milliliters
Percent of total
number of foods
A v . number of org­
anisms in stomachs
containing them
Total length of fish
25-50 mm.
(53 stomachs)
A v . number of org­
anisms in stomachs
containing them
Table 2»
0.15
4.20
0.04
Oo 06
I
H
XJl
I
-16second most numerous items, followed closely by polychaetes and decapods,
Amphipods comprised the largest volume of food in sculp ins of the
small size group while polychaetes were second-in importance.
Fish made
up the largest volume in sculpins o f .the medium and large size groups,
Polychaetes were volumetrically second in importance for the medium size
group and decapods occupied this position in stomachs from the large size
group.
The contents of the miscellaneous category were mainly aquatic
vegetation, but some sand, hydrozoans and other items were present.
Thirty-six fish were removed from stomachs during this study.
Thirty
of these were Pacific staghorn seulpins, five were pleuroneetids and one
was a shiner perch.
Summary
1.
The age, growth and food habits, of Pacific staghorn seulpins
collected near Friday Harbor, Washington were investigated during the
summer of 1961.
2.
Otoliths were removed from 295 seulpins and stored in one of
two media, glycerin and water or xylene, with satisfactory results.
3.
The otoliths of this sculpin are generally elliptical in outline
with a moderately crenated edge.
4.
The relationship between otolith radius and total length was ex­
pressed as a straight line with an intercept at -16.9 mm. total length and
a correlation coefficient of 0 .97^»
5«
The straight line expressing the relationship between otolith
radius and total length after elimination of the 20 largest seulpins had
-17-
an intercept of -10,0 ram, total length and a correlation coefficient of
0 .980.
6 o Back calculations based on otolith measurements and employing a
correction factor of -10.0 mm. gave average lengths at each annulus as
■follows;
annulus I, 3k mm. j
V, 122 mm.;
VI, 148 mm.;
11, 55 mm.;
VII, 17^ ram.;
III, 80 mm.;
VIII, 200 mm.;
IV, 101 ram.;
IX, 222 ram.;
X, 228 mm.
7»
Growth increments were uniform throughout the age groups sampled.
8 . The calculated length at the end of each year of life was greater
in older fish, which is a reversal of Lee's phenomenon.
9«
Comparison of length-frequency data with calculated lengths and
actual lengths of sculpins supported- the validity of the age and growth
determinations.
10.
The length-weight relationship for 108 sculpins was expressed by
the equation log W ® -5-243 + 3«134(log L).
11.
The equation Y = -3.068 4- O.883X represents the relationship be­
tween, total length (X) and standard length (Y) of 100-fresh fish.
12.
’ The largest sculpin obtained was a female of 337 mm» preserved
total length.
13.
An analysis of 182 sculpin stomachs showed amphipods to be most
frequently taken.
14.
Araphipods comprised the largest volume of food in stomachs from
small sculpins, but fish made up the greatest volume of food in large
sculpins,
15«
The Pacific staghorn sculpin was the most common fish found in
- 18-
the stomachs examined.
Literature Cited
Bailey 5 Jack E.. 1952. Life history and ecology of the sculpin Cottus
hairdi punctulatus in southwestern Montana. Copeia5 (4): 243-255"*
Carlander5 Kenneth D. and L. L. Smith5 Jr. 1944. Some uses of nomo­
graphs in fish growth studies. Copeia5 (3): 157-161.
Clemens 5 W. A. and CL V. Wilhy. 1961. Fishes of the Pacific Coast of
Canada. Bulletin No. 68 (second edition) of the. Fisheries Research
Board of Canada. Ottawa5 Canada. 443 pp.
Daiher5 F. C. 1956. A comparative- analysis of the winter feeding hahits
of two henthic stream fishes. Copeia5 (3 ): 141-151.
Dineen 5 C. F. 1951° A comparative study of the food habits of Cottus
hairdi and associated species of Salmonidae. Amer. Midi. Wat .5
46(3 ): 640-645.
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