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a1 URAL HISTORY

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STATE OF ILLINOIS

Adlai E. Stevenson, Governor

DEPARTMENT OF REGISTRATION AND EDUCATION
C. Hobart Engle, Director

An Inventory of
fae FISHES OF JORDAN CREEK,

Vermilion County, Illinois este

R. Weldon Larimore

Quentin H. Pickering

Leonard Durham

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An Inventory of THE FISHES OF JORDAN CREEK, Vermilion County, Illinois

R. Weldon Larimore, Quentin H. Pickering, and Leonard Durham*

Many streams and small rivers transect the up-
land prairies of Illinois. Most of them drain rich
agricultural lands and are strongly influenced by the
farming practices of surrounding areas. Some have
been dredged. Probably all of them receive large
amounts of surface water during periods of heavy
tainfall. Usually the runoff water carries a heavy
silt load, which causes the streams and rivers to
become very turbid for a period of days or weeks.
In some parts of Illinois, the streams are fed main-
ly by springs, in others mainly by drainage tiles.

A considerable number of these streams and
small rivers support large populations of fishes,
including several species of importance to anglers.
In some parts of Illinois, stream fishing is a com-
mon practice, but in most of the state itis confined
to a comparatively few individuals who are some-
what secretive about the sources of their catches.
Consequently, the average Illinois angler thinks of
fishing in terms of lakes.

Most of the fishery investigations on the
smaller streams of Illinois have considered princi-
pally the distribution of species as related to the
stream habitat (Forbes & Richardson 1920;
Thompson & Hunt 1930). The concept of managing
the stream habitat and the fishes of a stream for
the improvement of angling has received
little consideration.

As a preliminary to the development of fish
management techniques for small streams, an inten-
sive study of the fishes of Jordan Creek, a tributary
of the Salt Fork of the Vermilion River in Vermilion
County, east central Illinois, was begun in July,
1950. This study has been almost continuous since
that time. The material included in this report is
largely an analysis ofan intensive inventory of the
fish population made between July 25 and
September 5, 1950.

Acknowledgments

The investigation reported here is part of the
fisheries program of the Illinois Natural History
Survey and has been jointly supported by the
Survey and the Illinois Department of Conservation.
Dr. George W. Bennett supervised the organization
of the project and offered valuable suggestions for

this report. Mr. Sam A. Part, Superintendent of
Fisheries, Department of Conservation, co-operated
in this program by arranging for funds to aid
the investigation.

Methods and Procedure

Field operations on Jordan Creek were begun
by a crew of two or three men during the last week
in July, 1950. Beginning at the mouth of the creek,
the crew worked each pool and riffle with an elec-
tric apparatus that stunned but did not kill the fish.
As the crew moved upstream, the pools were num-
bered and described. Continuous sampling was
stopped at a distance of 4.02 miles above the
stream mouth because sample collections indicated
that few if any game fish were present above
this point.

The electric apparatus for stunning the fish
was operated from a portable 115-volt alternating
current generator. At the beginning of the opera-
tion, two hand-carried electrodes were used in a
manner described by Shetter (1947). Later an elec-
tric seine, a modification of that described by Funk
(1949), was used in all collecting. This electric
seine, 21 feet in length, allowed a complete sweep
of the stream, fig. 1, except in a few especially
wide pools. The difference in efficiency of these
two fish shockers was not determined. The elec-
tric seine, however, was faster to use because it
was effective over a greater area at one time.
Stunned fish were picked up in dip nets. The
quartter-inch mesh of the nets largely determined
the minimum size of fish collected.

Game and pan fishes that were stunned by the
electrical current and collected were kept alive in
tubs and later released at the points of capture.
Prior to release, the total length of each of these
fish was recorded, scale samples were taken, and
one or more fins were clipped for later recognition
of the fish. Fin marks were changed at intervals
of about a quarter mile of streamdistance. Weights
were taken of enough specimens to determine the
length-weight relationship for each species and to
allow an estimate of the weight of the fish that
were only measured for lengths. Fish other than
those considered as game and pan species were

*R. Weldon Larimore, Assistant Aquatic Biologist, Illinois Natural History Survey; Quentin H. Pickering, at time of inventory,
Technical Assistant, Illinois Department of Conservation; Leonard Durham, at time of inventory, Technical Assistant, Illinois

Natural History Survey.

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Fig. 2. -- Map of the Jordan Creek study section, indicating the limits of the eight divisions andthe open and wooded areas, 1950.

removed from the stream, placed immediately in
chipped ice, and brought to the laboratory for iden-
tifying, counting, and weighing. Fifty-two separate
collections were made in this initial inventory.

After the initial inventory had been completed
on September 5, 1950, the 4-mile length of stream
under intensive study was marked off into eight
divisions for further investigation of the stream it-
self and of the fish found in each division. As the
divisions were set up, no pool was split; each pool
was entirely within a single division. Fortunately,
the lower seven divisions could be made equal in
length (0.53 mile each), as determined from topo-
graphic maps and aerial photographs. Since these
lower seven divisions were each slightly over one-
half mile in extent, the eighth division of the
4-mile length was shorter than the others, only
0.31 mile in length. Deeper water and shade under
a concrete road bridge that marked the upper limit
of this last division attracted a concentration of
fishes at that point. The fish populations cen-
sused in this division, even though modified by the
shorter length of the stream and by the bridge,
were compared with the populations in the
other divisions.

During the months of September, October, and
November, 1950, many pools were reworked once to
several times. The same procedures were followed
as were used during the initial census, except that
the fishes returned to the stream were marked with
numbered opercular tags. By repeated censuses of
certain pools, much information was gathered con-
cerning fish movements and the effects of removing
a large percentage of the forage fish population.
The fish taken in these repeat censuses are not
included in the original tabulations, tables 2-9.
However, several additional species collected
duting the fall months are included in the species
list, table 1, and in the discussion of species.

Description of Drainage Basin

Jordan Creek, a warm-water stream 11 miles
long, drains a glaciated area of 10.6 square miles
in the southern part of Vermilion County. During
the Glacial Epoch, at least two ice sheets, the
Illinoian and the Wisconsin, covered this region.
The more recent Wisconsin glacier largely deter-
mined the topography and soils. The source of
Jordan Creek is in a part of Vermilion County that
was left as a flat, marshy area by the last
glaciation. The soils ofthis flat area are primarily
of two types: Drummer clay loam and Brenton silt
loam (Wascher, Smith, & Smith 1938). These soils

were formed under slough-grass and prairie-grass
vegetation. Because of the poor natural drainage
ofthis flat land, the upper half of Jordan Creek was
dredged to improve the drainage and make these
soils suitable for farming.

The stream flows northward out of this flat
land into an area of rolling to rough topography.
Here the stream has not been dredged. In this
lower part of Jordan Creek is the 4-mile study
section, which is divided naturally into two con-
trasting habitats of about equal lengths: a lower,
wooded area and an upper, open area.

Lower, Wooded Area.-- This area, which in-
cludes the first 2 miles above the mouth of Jordan
Creek, covers the lower four divisions of the study
section, fig. 2. Here the rough, rolling land through
which the stream flows has scattered ridges of
glacial materials and frequent outcroppings of
bedrock.

In this area Jordan Creek falls an average of
24 feet per mile. Flowing rapidly across the ex-
posed edges of underlying rock strata as it nears
the Vermilion River, the stream forms more frequent
pools and steeper riffles than in the upper area.
Besides the siltstone, sandstone, and shale that
comprise the bedrock, gravel is a predominant
bottom material. Sand and silt bottoms are not
common. Midway in this lower, wooded area, the
volume of stream flow is approximately 18.6 cubic
feet per second at average water levels.

Heavy vegetation covers most of the stream
banks in the lower area, fig. 3. American elms,
sugar maples, silver maples, cottonwoods, syca-
mores, and many other large trees shade the water.
Even away from the wooded creek margins there
are extensive stands of hardwood timber. Farming
is limited primarily to stock raising on permanent
pastures. Vance silt loam is the common soil type
in the lower half of the study section (Wascher,
Smith, & Smith 1938). This soil erodes easily, so
that plowing is limited to a few flat areas and small
garden plots.

Upper, Open Area.--The upper half of the
study section, which is in open farm and pasture
land, includes the 2 miles of stream in the upper
four divisions, fig. 2. The topography of this area
is flat to rolling. Generally only 10 to 15 feet of
soil covers the bedrock, but there are no out-
croppings except in the bed of Jordan Creek. The
stream has cut through the overlying soil, so that
its gradient and bottom materials are determined
largely by the bedrock.

In this area, in contrast to the wooded area,
the stream flows over the flat surfaces of rock
strata and only occasionally cuts entirely through

Fig. 3. -- A part of the lower, wooded area of Jordan Creek, showing steep riffles, short, rocky pools,
and dense, shading vegetation.

Fig. 4. -- A long pool in the upper, open area of Jordan Creek.

a layer. The open area has fewer steep riffles than
the wooded area. The pools are long and quiet,
fig. 4. The stream gradient averages 9.7 feet per
mile and there is a flow of about 12.9 cubic feet
per second at average water levels. Even though
bedrock and coarse gravel comprise the dominant
bottom materials, there are extensive accumulations
of sand and silt in the long pools.

Catlin silt loam is the predominant soil type
(Wascher, Smith, & Smith 1938) in the upper half of
the study section. This soil does not erode easily
and it is suitable for alfalfa, clover, corn, and soy-
beans. The land is farmed rather intensively and,
even though about one-third of it is in permanent
pasture, there are few trees. Most of the stream
in this half of the study section is exposed to
direct sunlight, fig. 4, being shaded in only a few
places by groups of cottonwoods and American
elms or low, overhanging shrubs.

The sharp contrast between these two habitats,
figs. 3 and 4, affords an opportunity to evaluate the
influence of various environmental conditions on
the stream fauna. The situation produced by these
very different habitats is unusual in that features
ordinarily associated with lower parts of streams--
low gradient, long pools, and slow current--are
characteristic of the upper, open area, whereas the
more typical upstream features are found in the
lower, wooded area.

Composition of the Fish Population

Quantitative data on the fish population of
Jordan Creek, as given below and in tables 2-9,
include only those fish actually collected during
the initial census (July 25 through September 5,
1950); no estimates are given of the numbers missed
in collecting, and no attempt is made to evaluate
the population during other times of the year.

After a period of high water in the fall of
1950, several species were taken that were not
represented in the first inventory. These species
are included in the list of 40 species, table 1, and
mentioned in the discussion of families. The
common names of fishes are used throughout the
discussions. These names, as well as the sci-
entific names in table 1, are those suggested by
the American Fisheries Society (1948), except as
indicated otherwise.

Tables 2-7 are set up to show the distribution
of most species in the study section. The species

_in each table are arranged in descending order of

weight represented in the take; those represented
by only a few specimens are not included. Since

attempts have been made to classify streams on
the basis of the fish family that dominates them--
as bass streams, sucker streams, or minnow
streams--the distribution patterns of families are
also considered and then asummary is given, tables
8 and 9, for the five most abundant families.

In the brief discussions of species that follow
in systematic order, the distribution of fishes in
the study section is considered in relation to four
primary ecological factors--stream gradient, amount
of water shaded, dominant bottom material, and use
of the surrounding land. Table 10 is a summary of
this relationship.

Sucker Family

The suckers varied more in abundance in the
several divisions of the stream than either the
minnows or sunfishes, table 8. The actual number
of suckers collected in each division of the stream
was approximately inversely proportional to the
stream gradient, whereas the actual weight seemed
to be related to the number of larger pools in each
division. In relation to the other families of
fishes, the suckers increased in abundance from the
mouth of the stream up through Division 4 but
decreased progressively farther upstream, table 9.
The distribution of each sucker species is dis-
cussed in the following paragraphs and summarized
in table 2.

Quillback.--Fish of this species showed a
preference for the soft mud bottoms and slow
currents of the upper, open part of the stream. Of
167 specimens taken in seven collections, all but
1 were from the open area and 104 of these were
from Division 8. The single specimen from the
lower half of the study section was exceptional
also in being the only specimen over 1 year of age.

White Sucker.-- The larger individuals of this
species were taken in relatively deep pools, partic-
ularly associated with rock ledges and moderate
current. They usually attempted to avoid the
electrical shock by swimming ahead but seemed
especially sensitive to the electric current when
forced to turn into the effective field. The fisher-
men around Jordan Creek catch this sucker during
the spring months and value it highly as a
food fish.

Hog Sucker.-- By weight, the hog sucker was
the most abundant fish in Jordan Creek. The young
fish of this species were found in shallow riffles,
whereas the adults usually were taken just below
tiffles in gravel-bottomed pools of moderate depth.
The hog sucker and the white sucker frequently
occurred together in collections but usually were

. Table 1.-- Common and scientific names of the fishes collected in Jordan Creek, 1950. Most
names used are those given in Special Publication No. 1 of the American Fisheries Society (1948).

Common Name

SUCKER FAMILY
Ouillback
White sucker
Hog sucker
Creek chubsucker
Spotted sucker
Golden redhorse

MINNOW FAMILY
Carp
Creek chub
Hornyhead chub
Rosyface shiner*
Redfin shiner
Common shiner
Spotfin shiner*
Sand shiner
Suckermouth minnow
Silverjaw minnow*
Fathead minnow
Bluntnose minnow
Stoneroller

CATFISH FAMILY
Black bullhead
“Yellow bullhead
Stonecat
Brindled madtom*

PIKE FAMILY
Grass pickerel

KILLIFISH FAMILY
Starhead topminnow

PERCH FAMILY
Blackside darter*
Logperch
Johnny darter
Rainbow darter
Orangethroat darter*
Fantail*

Greenside darter*

SUNFISH FAMILY
Smallmouth black bass
Largemouth black bass
Warmouth
Green sunfish
Bluegill
Orangespotted sunfish
Longear sunfish

Rock bass

Scientific Name

CATOSTOMIDAE
Carpiodes cyprinus (Le Sueur)
Catostomus commersonnii (Lacépéde)
Hypentelium nigricans (Le Sueur)
Erimyzon oblongus (Mitchill)
Minytrema melanops ( Rafinesque)

Moxostoma erythrurum (Rafinesque)

CYPRINIDAE
Cyprinus carpio Linnaeus
Semotilus atromaculatus (Mitchill)
Nocomis biguttatus (Kirtland)
Notropis rubellus (Agassiz)
Notropis umbratilis (Girard)
Notropis cornutus (Mitchill)
Notropis spilopterus (Cope)
Notropis deliciosus (Girard)
Phenacobius mirabilis (Girard)
Ericymba buccata Cope
Pimephales promelas Rafinesque
Hyborhynchus notatus (Rafinesque)
Campostoma anomalum (Rafinesque)

AMEIURIDAE
Ameiutus melas (Rafinesque)
Ameiutus natalis (Le Sueur)
Noturus flavus Rafinesque
Schilbeodes miurus (Jordan)

ESOCIDAE
Esox vermiculatus Le Sueur

CYPRINODONTIDAE
Fundulus notatus (Rafinesque)

PERCIDAE
Hadropterus maculatus (Girard)
Percina caprodes (Rafinesque)
Boleosoma nigrum (Rafinesque)
Poecilichthys caeruleus (Storer)
Poecilichthys spectabilis Agassiz
Poecilichthys flabellaris (Rafinesque)
Etheostoma blennioides Rafinesque

CENTRARCHIDAE
Micropterus dolomieu Lacépede
Micropterus salmoides (Lacépéde)
Chaenobryttus coronarius (Bartram)
Lepomis cyanellus Rafinesque
Lepomis macrochirus Rafinesque
Lepomis humilis (Girard)

Lepomis megalotis (Rafinesque)
Ambloplites tupestris (Rafinesque)

*Not given in the American Fisheries Society list; from Hubbs & Lagler (1947).

Table 2. -- Number and weight (in pounds) of each of the species of suckers collected, 1950, in each
of the eight divisions of Jordan Creek, and the total number and total weight of each species collected in
all divisions combined.

not abundant in the same pools, indicating a
difference in habitat preferences. Like the white
sucker, the hog sucker showed a tendency to move
ahead of the shocker. Occasionally it was able to
dash through the electrical field without becoming
completely incapacitated. When stunned, it would
sink to the bottom rapidly and for this reason was
often difficult to collect.

Creek Chubsucker.--Fish of this species
appeared in only 11 collections in the study area.
Upstream above the study area, they were more
abundant; 2.5 times as many specimens were taken
in two short upstream sample stations (each 200 feet
long) than were collected in the entire study area.

Spotted Sucker.--Only one specimen of this
species was collected. It was taken in Division 3
after a heavy rain in October and presumably had
moved up the stream from the Salt Fork River, where
the species was rather abundant.

Golden Redhorse.-- This species was rep-
resented in 79 per cent of the collections, but 95
per cent of the specimens were taken from the soft-
bottomed, slow-flowing waters in the open area.
They were usually in small schools of four to six
individuals. All but 27 of the redhorse collected
were of the 1950 brood (young-of-the-year) and
only 4 of the 27 were unquestionably of adult size.

Minnow Family

The minnows were the dominant fish family in
the Jordan Creek study area, comprising 75 per
cent of the total number and 38 per cent of the

There was a

total weight of all fish collected.
marked increase in their numbers from the wooded
to the open area, table 8; the wooded area yielded
30 per cent, the open area 70 per cent, of the total
number collected. The increase in weight was not
so evident, indicating that the minnows from the
wooded area were larger inaverage size than those
from the upper, open area. In each division the
minnows were more numerous than the fish of all
other families combined, and only in Division 4
was their weight exceeded by the fish of any other
one family--by the suckers and the sunfishes, table
9. In this division the stoneroller, which comprised
39 per cent of the weight of all minnows collected,
was at its lowest level of abundance, table 3. Of
the 13 species of minnows present in the study
section, 3 species--the stoneroller, the homyhead
chub, and the bluntnose minnow--made up 73 per
cent of the total weight of this family.

Carp.--One immature specimen taken in
Division 4 was the only representative of this
species in our collections.

Creek Chub. -- Individuals of this species were
taken in all but one collection. Their numbers
increased progressively upstream, whereas their
average size decreased.

Hornyhead Chub. -- This species was the second
most abundant minnow by weight and was rep-
resented inevery collection. The larger individuals
were found at the upper ends of fairly deep pools,
usually in constricted riffles having currents of
moderate velocity.

Rosyface Shiner.-- Although this minnow was

Table 3.--Number and weight (in pounds) of each of the 10 most abundant species of minnows
collected, 1950, in each of the eight divisions of Jordan Creek, and the total number and total weight of

each species collected in all divisions combined.

Hornyhead
Chub

Stoneroller

Division

CON DU SEWN rFH

All

divisions

Division

Common Sand
Shiner Shiner

ONKDUNBWN eH

All

divisions

16.13 | 2,344

+ Less than 0.01 pound.

common in the Salt Fork River, only one specimen
was collected in Jordan Creek. It was taken in
Division 3 after heavy fall rains. Forbes &
Richardson (1920) called this species Notropis
tubrifrons and recorded it as being present in
Illinois only in the Mississippi River drainage of
the northern third of the state. Thompson & Hunt
(1930) did not record it from Champaign County.

Redfin Shiner. -- This minnow was rather scarce
in Jordan Creek collections, even though it is
generally abundant in the smaller, slow-flowing
streams of the Wabash River drainage in central
Illinois.

Bluntnose

9,830 89.26 | 2,071 43.34 7,098 | 35.94 | 2,960

Suckermouth

in narrow but

Creek
Chub

Silverjaw

Minnow Minnow

4.11

17.07 5,159

Redfin
Shiner

Spotfin
Shiner

Common Shiner.-- The weight and number of
minnows of this species decreased progressively
upstream. Eighty-seven per cent of the weight
was taken in the wooded area. The greatest
numerical abundance was in Division 1 and was
associated with shade, rocky riffles, and short,
shallow pools. The larger individuals were found
moderately deep riffles with
swift currents.

Spotfin Shiner. -- This species, Notropis spilop-
terus, and a very similar species, N. whipplii, were
both present in the Salt Fork River, but only the
former was collected in Jordan Creek. It showed a

decided preference for the slow-flowing, soft-
bottomed pools of Divisions 7 and 8.

Sand Shiner. -- The sand shiner showed a sharp
change in abundance between the wooded and open
areas, with 99 per cent of the individuals coming
from the upper, sunny area. Notropis volucellus,
which closely resembles the sand shiner, was
presentin the Salt Fork Riverbut was not collected
in Jordan Creek.

Suckermouth Minnow.--Minnows of this species
were most abundant in divisions of the wooded
area and were associated with a steeper gradient
and harder bottom than are found farther upstream.
They were usually collected in riffles of moderate
current and depth.

Silverjaw Minnow.-- The weights and numbers
of minnows of this species increased in an
upstream direction. There was a distinct rise in
abundance from the wooded area to the open area;
86 per cent of the specimens were collected in the
open area. Moore, Pollock, & Lima (1950) pointed
out that this minnow is morphologically adapted to
tolerate intense light over a bright sandy bottom.

Fathead Minnow.--One specimen of the fat-
head was collected in Division 3 following high
water stages during the fall. Forbes & Richardson
(1920) reported that in Illinois this species is
ptactically limited to the Mississippi River drain-
age, as they collected it from only four localities
in the headwaters of the Embarrass River of the
Ohio River drainage. Gerking (1945) had few
tecords for it in western Indiana.

Bluntnose Minnow.-- This, the second most

numerous minnow in the study section, appeared in
every collection. The greatest numbers were taken
in quiet waters over soft bottoms in the open area.
Its abundance was inversely proportional to the
steepness of the stream gradient.

Stoneroller.--In number the stoneroller was
the most abundant fish in the study section; in
total weight it was exceeded by only the hog
sucker. Minnows of this species, present in every
collection, seemed to prefer narrow, shallow pools
with gravel bottoms and rapid currents.

Catfish Family

The four species belonging to this family
comprised a relatively small part of the total fish
population of the Jordan Creek study section,
table 9. These species, table 4, can be separated
into two groups, based on habitat preferences: (1)
the bullheads, which seek mud banks along larger
pools, and (2) the stonecat and madtom, which in-
habit rocky areas of moderate to swift currents.
Because of differences in habitat preferences of
the species represented and because of great
differences in average size of individuals of these
species, there was comparatively little correlation
between the numbers and the weights of catfish
taken in the eight divisions, table 8. The yellow
bullhead made up 86 per cent of the total weight of
representatives of the family.

Black Bullhead.-- Four specimens of this
species were collected. They were taken in three
collections, each of which included yellow bullheads.

Table 4.-- Number and weight (in pounds) of each of the species of catfishes collected, 1950, in
each of the eight divisions of Jordan Creek, and the total number and total weight of each species

collected in all divisions combined.

Yellow Bullhead

Division
Number

ONIHNDMNHBWN PE

All

divisions

Stonecat

wig |e [ wei |

Black Bullhead

Brindled Madtom

0.16
0.04

Yellow Bullhead.-- This is the common bull-
head of Jordan Creek, and specimens were taken in
all eight divisions. Because of their dark color
and preference for cover along the stream bank,
yellow bullheads were difficult to collect with an
electric shocker. Most of the young-of-the-year
were found at the edges of shallow riffles. The
largest individual collected was 9.7 inches in
length and weighed 0.55 pound.

Stonecat. -- Fish of this species were collected
in only the fourlower divisions of the study section,
where generally they were found under stones in
the larger riffles.

Brindled Madtom.-- The madtom was taken in
eight collections. Six of these collections also
contained the stonecat. The madtom was restricted
to rapids of the lower area, occurring in only
Divisions 1 and 2.

Darter Family

The numerical abundance of darters in relation
to the other families of fishes, table 9, was directly
proportional to the steepness ofthe stream gradient.
The actual numbers and weights of darters collected
in each division, table 8, was influenced largely
by the abundance of the four common species, table
5. For example, the greatest weight of darters was
recorded for Division 1, where the large green-
side darter was abundant.

Blackside Darter. -- Only six specimens of this
darter were taken. These were in separate collec-
tions and all were from the wooded area, in water
of moderate depth and velocity.

Logperch.--One specimen was taken in a
shallow, sandy pool in the upper area.

Johnny Darter.-- This species was found in
somewhat deeper waters than were the other darters
and, because of this, it was more difficult to
collect with the electric shocker. It was taken in
greatest numbers in the upper three divisions,
where it was associated with sandy bottoms.

Rainbow Darter.--The abundance of this
darter decreased progressively upstream. It was
most numerous in the larger, steeper riffles of the
wooded area.

Orangethroat Darter.--This species closely
resembles the rainbow darter in appearance, but
its distribution in Jordan Creek was strikingly un-
like that of the rainbow, fig. 24. Orangethroats
increased in numbers upstream; 85 per cent of the
specimens were taken in the upper, exposed area.
Usually they were found either just above, below,
or at the edges of the riffles and not so frequently
in the most rapid currents. ‘

Fantail.-- This was the most numerous darter
in Jordan Creek. It was commonly taken at the
edge of, or just above, riffles and was more nu-
merous in the upper half of the study area than in
the lower.

Greenside Darter.-- Rapid, rocky riffles were
the characteristic habitat for this darter, which was
more abundant in the wooded part of the study area
than in the open part.

Sunfish Family

By weight, fish of the sunfish family appeared
to be about equally distributed between the lower,
wooded area and the upper, open area; by number,
71 per cent were taken in the open area, table 8.
This lack of weight-number consistency was the

Table 5.-- Number of each of the species of darters collected, 1950, in each of the eight divisions of ©
Jordan Creek, and the total number of each species collected in all divisions combined.

Division

ONDUBWN rE

All
divisions

: a
NIoWRRHHE ND

wi
NI
aS
PS
(j=)

0 Oe EEC aS oo |,

Table 6. -- Number and weight (in pounds) of each of the species of sunfishes collected, 1950, in each
of the eight divisions of Jordan Creek, and the total number and total weight of each species collected
in all divisions combined.

Longear Smallmouth | Rock
bie,” Sunfish Black Bass Bass
Division | .
Number Weight Number Weight Number Weight
= |
1 69 3.32 | 48 4.99 14 SY
72 Sil 6.62 62 16.91 12 5.04
3 87 6.41 50 WAS? 3 0.97
4 201 11.92 53 13.58 1 0.35
5 451 16.75 52 9559 --- ees
6 371 14.97 61 9.67 --- eis
7 384 12.86 19 122, --- ----
8 361 | 1229 24 3.64 --- Shs
All
divisions 2,015 85.14 369 72.33 30 10.08
] |
Green ; Largemouth
Sunfish Bluegill Black Bass
Division | i Se!
; Number | Weight Number Weight Number Weight
1 19 0.58 : 3 0.06 -- ----
2 10 0.37 il 0.16 -- ----
3 13 0.33 10 0.20 -- ----
4 51 13> 32 0.82 -- ----
5) 101 2393 13 0.34 11 0.81
6 66 1292 25 0.63 15 0.49
7 28 0.76 6 0.16 9 0.43
8 30 0.82 > 0.15 6 0.51
All |
divisions 318 ait 9.06 101 2-52 41 2.24
L

tesult of great differences in size and abundance
between the bass and the other sunfishes. The
bass were relatively few in number and large. The
other sunfishes were numerous and small, In
Division 1, both the total number and the total
_ weight percentages of the sunfish family were low,
table 8, because of a scarcity of pools. In
Divisions 2, 3, and 4 the percentages of total

pools, steeper gradient, and more cover than were
present in the upper area. The adults were taken
usually in the deeper water of pools where there
was such cover as boulders or root-masses. The
young, however, were found most often in or near
the riffle areas.

Largemouth Black Bass. -- The largemouth was
taken only in the upper, open area, where the low

_ number were comparatively low while those of total

_ weight were high. In these divisions were found

_ most of the larger bass, table 6.

Smallmouth Black Bass.--By weight, 67 per
; cent of the fish of this species were collected in
_ the lower area, associated with more shade, deeper

stream gradientand absence of shade produced long
warm pools with only moderate currents.
Warmouth.-- Two specimens were taken in
Division 5 during fall recheck censuses. Since this
species was not present in the earlier collections,
it seems likely that these two specimens came from

a stone quarry that was connected with the head-
waters of Jordan Creek during high-water periods.

Green Sunfish.-- This fish, as collected in
Jordan Creek, was too small to interest anglers.
It was found in slow-flowing pools, especially
along the shallow edges where grasses and roots
provided cover. Its abundance was inversely re-
lated to the stream gradient.

Bluegill. -- Although the bluegill was collected
in all divisions of the study section, it was not
abundant anywhere in Jordan Creek. Usually
regarded as a pond fish, the bluegill showed a
preference for long, shallow pools with reduced
current velocity. Few specimens collected were
of sizes desired by anglers. Only four were 5
inciies or more in length.

Longear Sunfish.--This was the most abundant
sunfish in Jordan Creek. In total weight collected,
it was surpassed by only the hog sucker and the
stoneroller. Its abundance increased sharply from
the wooded area to the open area and seemed to be
inversely related to the stream gradient. Sixty-
seven per cent of the total weight of this fish was
taken in the open area.

Orangespotted Sunfish.--Only one specimen
(3.8 inches in total length) was collected. It was
taken in Division 4.

Rock Bass.-- The rock bass was collected in
only the lower, wooded area. Although not abundant
in Jordan Creek, it was reputed to be a favorite
fish with local sportsmen. Only 2 of 30 rock bass
collected were less than 6 inches lony.

Miscellaneous Families

Two families were represented in Jordan Creek
by single species: the pike family by the grass
pickerel, the killifish family by the starhead top-
minnow. Neither species was abundant in the 1950
collections, table 7.

Grass Pickerel.--Only 16 specimens of this
fish were collected, of which 14 were from the
slow-flowing pools of the open area. Thompson &
Hunt (1930) found fewer fishes in collections
containing grass pickerel than in those which did
not include this pickerel. No scarcity of minnows
was observed in the Jordan Creek collections that
contained grass pickerel.

Starhead Topminnow.--This topminnow showed
a definite preference for the slow-flowing pools of
the upper area; only three specimens were taken in
the wooded area.

Association of Species

The association of fishes of Jordan Creek was
studied in the relationship of families to eachother
and in the relationship of various species to
ecological characteristics of the stream, as discus-
sed in preceding paragraphs and summarized in
tables 8, 9, and 10, It was further studied by com-
paring the distribution patterns of the most common
species throughout the eight divisions of the study
area, figs. 6-24. Species having similar patterns

Table 7.-- Number and weight (in pounds) of grass pickerel and starhead topminnow collected, 1950,
in each of the eight divisions of Jordan Creek, and the total number and total weight of each species

collected in all divisions combined.

Grass Pickerel

Starhead Topminnow

Division

Number “| Weight Number Weight

il af 1 0.21 -- ---
2 1 0.20 -- ---
3 -- -- 1 +
4 -- --- 1 +
5 5 0.23 6 0.03
6 4 0.66 5 0.02
7 4 0.14 8 0.04
8 1 0.04 23 0.11
All

divisions 16 1.48 44 0.20

+ Less than 0.01 pound.

}

Table 8.-- Five most important fish families collected in Jordan Creek, 1950, and, for each family,
the percentage of its total number and weight (in pounds) collected in each of the eight divisions; also,
for each family, the total number and weight of fish collected.

Suckers Minnows Catfishes Darters Sunfishes
=
ae te Per | Per Per Per | Per | Per Per | Per Peror|tosPer
Division Cent Cent Cent | Cent | Cent | Cent | Cent | Cent Cent | Cent
of) «|| of of OE Wil often: Defies eh Ge 4 berek ieceke of of
Number | Weight | Number | Weight Number | Weight Number | Weight | Number | Weight
| Ss
1 4.07 AZT 8.51] 11.90] 18.47 | 11.92 15.20 | 15.99 5:52." 46:98
2 6.07 14.85 6.41 12.66) 10.36 1A2 9.35 | 14.48 6.33 | 16.04
3 723 14.07 5.035) 812-37 6.31 | 10.98 9.15 14.30 5.67 | 11.38
4 10.27 19.41 6.83) | ©. 9.25 $.995)\ 23E54 T6E ||} 9:18 | 41279) |p 35:46
5 18.62 13.00} 15.84 | 16.34] 10.36 | 14.85 | 13.43 | 14.56 | 21.84 16.77
6 24.30 £6:$2)}:- 20218 >] 13.22 4.05 BAD 15.26 10.19 | 18.71 15.26
% 15.64 AOR O He 9452065) 043-00) 0015.32) 8233 14.12 10940 1a 15 SE ee SD
8 13.81 SAD) ott 35| ©1E28 +) 25.23 j| 21014 15.88 10235: || 14:82¢:|='9!60
[=
number 3,984 31,032 222 “e 3,060 2,875 -
= +
Total
weight
a
pounds 158.30 231.76 18.12 | | 11.88 181.41

Table 9.-- Five most important fish families collected in Jordan Creek, 1950, and the percentage
each represented of the total number and weight (in pounds) of all fishes in each of the eight divisions
and in all divisions combined.

Darters Sunfishes

eerie Per Per Per Per Per Per Per
Cent Cent Cent Cent Cent Cent Cent
of of of of
Number Number i

ONKDUBRWN eH

divisions

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ret

of distribution--that is, those increasing or de-
creasing in abundance in the same divisions of
the stream--were considered associated, either with
each other or with similar or related ecological
factors. The association of several species was
measured statistically.

The fish collections included a large pro-
portion of the fish population present in each part
of the stream censused, and so data on the indi-
vidual species lend themselves to statistical
treatment. The usual statistical measures of
association based on the presence or absence of
a species were of no significance in the treatment
of these data, because most of the abundant fishes
were taken in all 52 collections. Coefficients of
correlation (r) between figures involving distribu-
tion of the various species were calculated to give
indices of association. In species of the darter
family and in three species of minnows, the indices
were based on numbers of individuals, in all other
species on total weights. In order to reduce the
number of mathematical calculations and make the
size of the samples as nearly uniform as possible,
the analyses were based on the total collections
from each of the eight divisions rather than on
separate collections. Each of the correlation co-
efficients is simply a mathematical expression of
the degree of similarity between the distribution
patterns of the species being compared; the figures
do not explain or measure. any other relationship
between the species.

Because the smallmouth black bass was the
fish most sought after by Jordan Creek anglers,
particular attention was given the fish communities
with which it was associated. Its distribution was
compared with that of each of several other abun-
dant species, table 11.

Table 11.-- Coefficient of correlation (r) for
the weight distribution of the smallmouth black
bass and that of nine other species of fishes in
the eight divisions of Jordan Creek, 1950.

Species I
Hog sucker 0.85
Hornyhead chub 0.62
Common shiner 0.56
White sucker )-2)5)
Stoneroller 0.04
Green sunfish 0.01
Longear sunfish -0.18
Golden redhorse -0.22
Creek chub -0.73

A graph, fig. 5, was prepared to show the
telative abundance of the smallmouth and the other
main groups of fishes in aseries of 24 pools ranked
as good, mediocre, or poor on the basis of the
weight of bass they contained. A high bass pop-
ulation seemed to be associated with a high per-
centage of suckers anda low percentage of minnows.
The percentages of sunfishes (exclusive of small-
mouth bass) and miscellaneous species were fairly
constant in this series of pools, dropping off only
slightly where the minnows were dominant. A
direct relationship between bass and suckers and
an inverse relationship between bass and minnows
probably reflected the habitat preferences of
these fishes.

The smallmouth, fig. 6, and the hog sucker,
fig. 7, had a similar weight distribution, being most
abundant in Division 2 and generally decreasing in
their abundance upstream. The highest correlation
of the smallmouth (r =0.85) was with the hog sucker
and is significant at the 1 per cent level. These
species have similar distributions in Illinois. The
high degree of association in Jordan Creek probably
is best explained by the preference of both
for hard-bottomed pools.

The hornyhead chub, fig. 8, had a weight
distribution pattern in the study section somewhat
similar to that of the smallmouth black bass, al-
though the weight of the chub was greatest in
Division 3 and the weight of the smallmouth was
greatest in Division 2. The correlation coefficient
of 0.62 between the weights of these species is
somewhat high but not significant.

The abundance of the longear sunfish, fig. 9,
teached a peak in Division 5 and decreased at
stations upstream and downstream from Division 5.
Gerking (1949) suggested that the presence of the
longear sunfish was antagonistic to the smallmouth
black bass in three streams that he surveyed.
Antagonism between these species did not seem to
prevail in Jordan Creek. There was a negative
correlation (r =-0.18) between the weight of the
smallmouth and that of the longear sunfish, but it
is not significant. However, the negative correla-
tion (r =-0.73) between the weight of the small-
mouth black bass and the weight of the creek chub
is significant. This strong negative correlation
teflects the upstream increase of the chub and the
difference in habitat preference between the two
species. The creek chub, which is a headwater
form, showed a gradual increase in numbers in the
upstream stations, but in weight it had an irregular
distribution pattem, fig. 11. The graph for this
chub and that for the hornyhead chub indicate these
fish are of smaller average sizes progressively up-

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LHOISM 1WW1LOL JO LN39D Y3d

PER CENT
40

PER CENT
FIG. 6—SMALLMOUTH BASS FIG. 9-——LONGEAR SUNFISH

TOTAL NUMBER— 369 a0 TOTAL NUMBER— 2,015
TOTAL WEIGHT— 72.33 LB. TOTAL WEIGHT— 85.14 LB.

30 30

NUMBER
~~

20 20 / x

i
“.numBer

——
=—_—

PER CENT
40

PER CENT
FIG. 7—HOG SUCKER FIG. 1|O.—BLUNTNOSE MINNOW

TOTAL NUMBER—2, 358 29 TOTAL NUMBER—7, 098
TOTAL WEIGHT— 96.20 LB. TOTAL WEIGHT—35.94 LB.

30 30

-\~- NUMBER
Ca

20 20

PER CENT
50

PER CENT
FIG. 8—HORNYHEAD CHUB 50

TOTAL NUMBER—2, O71
TOTAL WEIGHT— 43.34 LB.

FIG. Il— CREEK CHUB

TOTAL NUMBER—2,960
TOTAL WEIGHT— 17.07 LB.

40 40

30 30

NUMBER -~
mG
NUMBER
a

20 20

\ 2 3 4 5 6 7 8 | 2 3 4 5 6 Th 8
DIVISION OF STUDY AREA DIVISION OF STUDY AREA

Figs. 6-11. -- Distribution (in per cent) of the number and weight of each of six species of fish
collected in the eight divisions of the Jordan Creek study area, 1950.

stream. The bluntnose minnow, fig. 10, which
showed a general increase in numbers up to
Division 6, dropped off in the last two divisions;
it had a distribution very similar to that of
the longear sunfish.

Figs. 12-17 present an interesting picture of
the succession of fishes in Jordan Creek. The rock
bass, fig. 12, the stonecat, fig. 13, and the brindled
madtom were present in only the fast, rock-bottomed
pools of the lower area and showed a general de-
crease in the upstream stations of this area.

The common shiner, fig. 14, was present in all
eight divisions but showed a general decrease of
weight and number in the upstream divisions. Al-
though we are more interested in the weight than in
the number of a species, an interesting correlation
(r =0.78) was found between the number of small-
mouth black bass and the number of common
shiners. In Illinois the common shiner has a
pattern of distribution similar to the patterns of the
smallmouth and the hog sucker; all are scarce in
the southern part of the state and increase
in abundance northward.

The smallmouth black bass generally is
found in smaller streams than the largemouth, and
when these species occur together the smallmouth
is usually more abundant upstream than the large-
mouth. In Jordan Creek this situation was reversed;
the largemouth was taken in only the upper area,
fig. 15, and the smallmouth more abundantly in the
lower, fig. 6. As was mentioned previously, Jordan
Creek is unusual in that the upper area has more
characteristics typical of larger streams--slower
currents, larger pools, and softer bottoms--than has
the lower area. To some extent this situation has
caused for some of the fish a reversal of the dis-
tribution typical for a stream of the size of
Jordan Creek.

The sand shiner, fig. 16, silverjaw minnow,
fig. 17, and spotfin shiner were much more abundant
in the upper area than in the lower. The
distributions of the numbers of these three species
were correlated. The silverjaw minnow and the
sand shiner had a correlation coefficient of 0.96,
which was the highest correlation calculated. The
spotfin had a correlation coefficient of 0.75 with
the silverjaw, 0.67 with the sand shiner. These
associations probably are explained by the fact
that these three species have a preference for the
soft bottoms of sand and silt in the upper area.

The general pattern of distribution of the
white sucker, fig. 18, was bimodal, with a low in
Division 5 and peaks in Division 4 and Division 6.

‘20

The general distribution of the bluegill, fig. 19,
was somewhat similar to that of the white sucker.
However, bluegills usually were collected near the
banks with cover, whereas white suckers were
collected in the open water ofthe pools. The green
sunfish, fig. 20, reached its peak of abundance in
Division 5, in which the bluegill and the
white sucker were low in abundance. The white
sucker had a higher correlation coefficient with
the smallmouth black bass than did the green
sunfish.

In comparing the distribution of the stoneroller
with that of the white sucker, figs. 21 and 18, it
was discovered that in the divisions of the stream
where the numberand weightof the stoneroller were
high those of the white sucker were low, and vice
versa. However, these two bottom feeders probably
do not compete in their habitats, since the stone-
toller was found in faster and more shallow water
than the sucker. The yellow bullhead, fig. 22, had
an irregular distribution in Jordan Creek, with only
a general increase in abundance in the upstream
stations. The large adults of this species were
found at the edges of pools where the water was
deep and where the banks were covered with grass
or roots. The young of the golden redhorse, fig.
23, showed a definite preference for the softer
bottoms of the upper area. The correlation
coefficient for the weights of the golden red-
horse and the smallmouth black bass was
not significant.

In relative abundance, the greenside and rain-
bow darters were replaced upstream by the fantail
and the orangethroat darter, fig. 24. Trautman
(1930) noted differences in habitat preferences of
the rainbow darter and the orangethroat darter.

In the Jordan Creek study section, the rainbow
had a correlation coefficient of 0.76 (significant
at the 5 percent level) with the greenside, of -0.85
with the fantail, of -0.55 with the orangethroat, a
species very similar in appearance to the rainbow
and often confused with it. The greenside had a
correlation coefficient of -0.81 with the fantail, of
-0.60 with the orangethroat. The orangethroat had
a correlation coefficient of 0.88 with the fantail.

The rainbow and the greenside showed a pref-
erence for the larger and faster rapids, whereas
the orangethroat and the fantail showed a pref-
erence for the smaller and slower rapids.

The associations and succession of darters |
are due to steep, swift rapids with large boulders ©
in the lower area and less turbulent, gravel riffles
in the upper area.

PER CENT

FIG. 12.— ROCK BASS
50

TOTAL NUMBER—30

TOTAL WEIGHT— 10.08 LB.

PER CENT
50

FIG. 13.— STONECAT

TOTAL NUMBER— 45
TOTAL WEIGHT—1.81 LB.

PER CENT FIG. |4—COMMON SHINER

30 TOTAL NUMBER— 826
TOTAL WEIGHT—16.13 LB.

NUMBER
Ss EN
10 x

1 2 3 4 5 6 Uf
DIVISION OF STUDY AREA

PER CENT

50 FIG. 15.—LARGEMOUTH BASS

TOTAL NUMBER—4I
TOTAL WEIGHT— 2.24 LB.

NUMBER
30

PER CENT
50

FIG. 16.—SAND SHINER

TOTAL NUMBER— 2,344
TOTAL WEIGHT— 8.15 LB.

NUMBERS
30

PER CENT FIG. 17.—SILVERJAW MINNOW

30 TOTAL NUMBER—5, I59
TOTAL WEIGHT— 16.38 LB.

NOE xc

| 2 3 4 5 6 T 8

DIVISION OF STUDY AREA

Figs. 12-17. -- Distribution (in per cent) of the number and weight of each of six species of fish

collected in the eight divisions of the Jordan Creek study area, 1950.

PER CENT
40

PER CENT
50

4
DIVISION OF STUDY AREA

FIG. 18.—WHITE SUCKER

TOTAL NUMBER— 413
TOTAL WEIGHT—38.79 LB.

FIG. 19.—BLUEGILL

TOTAL NUMBER—lOI
TOTAL WEIGHT— 2.52 LB.

FIG. 20.—GREEN SUNFISH

TOTAL NUMBER—318
TOTAL WEIGHT—9.06 LB.

"
BER GEN G. 21—STONEROLLER .

40 TOTAL NUMBER—9, 830
TOTAL WEIGHT—89.26 LB.

PER CENT

to FIG. 22—YELLOW BULLHEAD .

TOTAL NUMBER—I55
TOTAL WEIGHT—I5.53 LB.

30 if

NUMBERS

PER CENT
50

FIG. 23.—GOLDEN REDHORSE

TOTAL NUMBER—1,024
TOTAL WEIGHT—17.95 LB.

40
30

l 2 3 4 5 6 7 8 ;
DIVISION OF STUDY AREA !

Figs. 18-23. -- Distribution (in per cent) of the number and weight of each of six species of fish
collected in the eight divisions of the Jordan Creek study area, 1950. i

RK X So
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S252

OSS?

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os
SS

SRK

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OO
OOS
SSO

PER CENT OF TOTAL NUMBER

4
DIVISION OF STUDY AREA

Ses Oe
ZR
e,

x89

Fig. 24. -- Distribution (in per cent) of the four most numerous darters in the eight divisions of the

Jordan Creek study area, 1950.

Discussion

Jordan Creek was found to have an abundant
fish population, not only from the standpoint of
total number and weight but also from that of
variety of species. The abundance of fish was
probably related to the fertility of the lands drained
by this creek, whereas the number of species re-
flected the variation in the stream habitat.

A natural division of the study area into
a rough, wooded area downstream and a flat to
tolling, open area upstream facilitated the relating
of fish distribution to ecological conditions. The
lower area showed more typical upstream charac-
teristics than did the upper area withits long, slow-
flowing pools. This reversal of upstream-down-
stream conditions tended to emphasize the specific
factors influencing fish distribution.

Several species (rock bass, stonecat, brindled
madtom, and blackside darter) were restricted to
the lower area, whereas other species (largemouth
black bass, sand shiner, spotfin shiner, and star-
head topminnow) occurred abundantly only in the
upper area. The number and weight of the common
shiner decreased progressively upstream; the
number and weight of the silverjaw minnow de-
creased progressively downstream. The distribu-
tion of several species (white sucker, stoneroller,
bluegill, green sunfish, and yellow bullhead) seemed
to be influenced by specific habitats not restricted
to either the upper or lower areas. A few species
were represented by only one or two specimens and

were considered only temporary residents of
Jordan Creek.
Species with similar general distribution

patterns in the study section may have different

habitat preferences and be influenced by different
specific environmental factors. For example, the
rock bass andthe stonecathad very similar general
patterns of distribution, figs. 12 and 13; but the
tock bass inhabited deep, shaded pools and the
stonecat swift, rocky areas, fig. 25.

It was usually difficult to distinguish the
factors that actually defined the habitat for each
species. Stream gradient, amount of shaded water
surface, dominant bottom materials, and the use of
surrounding lands appeared to influence the dis-
tribution of Jordan Creek fishes. But it should be
kept in mind that the fishes were actually in-
fluenced by more specific environmental factors.
The abundance of the bluntnose minnow, for
example, varied inversely with the stream gradient
but its distribution may actually have been governed
by some more definite factor determined by stream
gradient, such as velocity of flow, size of pools,
steepness of riffles, kinds of bottom materials, or
the associated food organisms.

Summary

1. The fish populationin acontinuous section
of Jordan Creek was censused with an electric
shocker to form a basis for further investigation of
the fishes of this small, warm-water stream.

2. The 4-mile study section was separated in-
to eight divisions, each approximately one-half
mile in length. The lower four divisions were in a
rough, wooded area. Here the stream was composed
of short, hard-bottomed pools and steep riffles.
The four divisions above this wooded area were in
open, sunny, farm and pasture land. Here the
stream gradient was low, resulting in long, slow-
flowing pools.

3. In the eight divisions of the study area,
the numbers and weights of fish taken were
tabulated for each species and for each family of
fishes. Particular attention was given the relation-
ship between the distribution of the fishes and the
characteristics of the habitat.

4. Forty species of fishes comprised the
population. The minnows made up 75 per cent of
the total number and 38 per cent of the total weight
of all fishes. Sunfishes were second and suckers
were third in total weight. By number the stone
troller was the most abundant species and by
weight it was second to the hog sucker.

5. The distribution of species appeared to be
strongly influenced by four primary factors of the
habitat: stream gradient, shading of water surface,

dominant bottom materials, and use of sur- .
rounding land.

6. The smallmouth black bass, the favorite
fish with Jordan Creek anglers, had a distribution —
by weight similar to that of the hog sucker. There —
was a direct correlation in weight between bass |
and suckers in individual pools and an inverse ©
relationship in weight between bass and minnows,

7. Certain species (rock bass, stonecat) were |
found only in the wooded area, with a high gradient, —
wheteas others (largemouth black bass, sand ~
shiner) were abundant only in the slow-flowing :

pools of the upper, open area.

Literature Cited

American Fisheries Society
1948. A list of common and scientific names F

of the better known fishes of the United

States and Canada. Am. Fish. Soc. —

Spec. Pub. 1. 45 pp. E

}

Forbes, Stephen Alfred, and Robert Earl Richardson
1920. The fishes of Illinois. (Second ed.) —
Illinois Natural History Survey, Urbana.

cCxxxvi + 357 pp.

Funk, John L.
1949. Wider application of the electrical
method of collecting fish. Am. Fish.
Soc. Trans. for 1947, 77:49-60.

Gerking, Shelby D.
1945. The distribution of the fishes of
Indiana. Ind. Dept. Cons. and _ Ind.
Univ. Invest. Ind. Lakes and Streams |
3(1):1-137. |

Gerking, Shelby D.
1949. Characteristics of stream fish popu- |
lations. Ind. Dept. Cons. and Ind.

Univ. Invest. Ind. Lakes and Streams

3(7):283-309.

Hubbs, Carl L., and Karl F. Lagler j
1947. Fish of the Great Lakes region. &
Cranbrook Inst. Sci. Bul. 26. xi+186pp. _

Moore, Geo, A., Harold R. Pollock, and Donna Lima i
1950. The visual cells of Ericymba buccata ~
(Cope). Jour. Compar. Neurol. 93(2): i

289-95. |

a Vee

>
~

elias

24
.

Fig. 25. -- Quiet pool, in foreground, typical of the Jordan Creek pools in which rock bass and small-
mouths were found in 1950. In swift, rocky areas, like the riffle in the background, stonecats, madtoms,

and rainbow darters were taken.
25

Shetter, David S.
1947. The electric “shocker” and its use in

Michigan streams. Mich. Cons. 16(9):
8-10.

Trautman, Milton B.

1930. The specific distinctness of Poe-
cilichthys coeruleus (Storer) and Poe-
cilichthys spectabilis Agassiz. Copeia
1930(1):12-3.

Thompson, David H., and Francis D. Hunt
1930. The fishes of Champaign County, Ill,

Wascher, Herman, R.S. Smith, and L.H. Smith
Nat. Hist. Surv. Bul. 19(1):5-101.

1938. Vermilion County soils. Ill. Ag. Exp.
Sta. Soil Rep. 62. 36 pp.

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