Bulletin


STATE OF ILLINOIS

DEPARTMENT OF REGISTRATION AND EDUCATION

DIVISION OF THE

NATURAL HISTORY SURVEY
THEODORE H. PRISON. Acting Chief

Vol. XIX. BULLETIN Article I.

The Fishes of Champaign County
A Study of the Distribution and Abundance

of Fishes in Small Streams

BY

DAVID H. THOMPSON
and

FRANCIS D. HUNT

PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS

URBANA. ILLINOIS

SEPTEMBER. 1930



STATE OF ILLINOIS

DEPARTMENT OF REGISTRATION AND EDUCATION

M. F. Walsh, Director

BOARD OF NATURAL RESOURCES AND CONSERVATION
M. F. Walsh, Ch.airmaii

William Trf.lease, Biolof/y John W. Alvord, Engineering

Hf.xry C. Cowles, forestry Charles M. Thompson. Ref<rescnting

Edson S. Bastin, Geology the President of the Vnix'crsity of

William A. Noyes, Chemistry Illinois

STATE NATURAL HISTORY SURVEY DIVISION

Theodore H. Prison, Acting Chief

H. C. Oesterlixc. Ilditor

Jeffersons Printing & Stationery Co.

Springfield. Illinois

t!l30

3310S—1200



TABLE OF CONTENTS

Introduction 5

Description of the area 5

Description of the streams 7

Methods' and equipment 14

List of species, with analytical keys and data on distribution and

abundance 17

Type habitats 34

Abundance and number of kinds 39

Relation of distribution and abundance to stream size 41

Headwater fishes 47

Relation of soil fertility to growth and abundance of fishes 48

Effects of pollution on growth, distribution, and abundance of fishes 50

Other environmental factors affecting distribution and abundance 58

Effect of fish-eating species on abundance 58

Some observations on morphological adaptations 58

Migration, isolation, and changes in distribution 60

Association of species GG

Summary "^^

Distribution maps '^

Appendix ^°

Index to names of species '^





Volume XIX Article I

THE FISHES OF CHAMPAIGN COUNTY*
A Study of the Distribution and Abundance

of Fishes in Small Streams

David H. Thompson and Francis D. Hdnt

A careful account of the local and general distribution of the fishes

of Illinois, their relations to their environment, and the function and

relative importance of each species in the general system of aquatic life,

was presented twenty years ago in a comprehensive work by Forbes and

Richardson^, which was based primarily on a state-wide ichthyological

survey. In the present study the general methods employed in the

former survey have been applied intensively to a small area, Champaign

County, and use has been made of special methods which yield results

more strictly quantitative. Inasmuch as there exist among the small

stream systems of this county faunal differences comparable to those

found among large stream systems, not only in Illinois but elsewhere as

well, the intensive study of this restricted area has made it possible to

formulate in a more precise manner some of the general conclusions

previously reached by other workers on the distribution and abundance

of fishes. The use of quantitative methods of collecting has made it pos-

sible also to arrive at new conclusions based on such data as may have

passed unnoticed in a less detailed study or in streams too large to apply

such methods.

Description of the Area

Champaign County is located in the east-central part of Illinois and
is crossed by the 88th meridian and the 40th parallel. Measuring approxi-

mately 36 miles from north to south and 27.5 miles from east to west,

the county has an area of 988 square miles. The topography varies from
flat to slightly rolling land, the variations being due to two causes

—

glacial action and stream erosion. The average altitude is about 710
feet above sea level ; a maximum of 860 feet is reached on the Cham-
paign moraine and a minimum of 6.30 feet where the Salt Fork leaves

the county.

•This study was carried on and completed under tlie direction of the late
Stephen Alfred Forbes.

1. Forbes, S. A., and R. E. Richardson. "The Fishes of Illinois." Final
Report.? of the Illinois Natural History Survey, Vol. HI, 1909.

[5]



6 Illinois Natural Historv Surxt^y Bllletix

During the Glacial Period, Champaign County was covered by two
ice sheets, the Illinoian and the Early \\'isconsin ; and the othenvise
monotonous topography of the county is broken by their terminal
moraines, which commonly rise 50 to 100 feet above the intermorainal

tracts, vary from one-half mile to three or four miles in width, and
usually form the boundaries between the several drainage basins (Fig. 1).

As the Early Wisconsin sheet receded, the various parts of the county
were uncovered in the following order : first, the lower part of the

SANGAMON BASIN %
•'''' SALT FORK

BASIN

,^..t LITTLE

""^'icVERMILION

EMBAKHA3S V^B.gN

%^22

Fig. 1. Sketcli map of Cliampaigii CoiiiUy, .'iliowiiig water-
sheds (dotted liiK-s), .glacial moraines (cross-hatch-

ing), and umisiially fertile area (stippling).

Sangamon basin ; ne.xt, the Kaskaskia and Embarrass basins : then the

upper Sangamon, Salt Fork, and Little \^ermilion basins : and lastly,

the basin of the Middle Fork of the \'ermilion. The general aspects

of the topography now are the same as at that time, and there has been

no subsequent change in the hook-u]i of the drainage systems.'- There
are no outcropSi of rock in the county, as it is covered with a layer of

boulder clay ranging from 95 to 300 feet in thickness.^

2. Personal communication from Dr. M. M, Leighton, Chief, Illinois State
Geological Survey.

3. 111. Aw. E\p. Sta. Soil Repoi I No. 18, •'Champaign County Soils," 1918.



Fishes of Champaign County 7

The soils of Chamj^aign County are fertile and, taken as a whole,

are more uniform than those of other counties of the state. Dark
upland prairie soils make up 92 percent of the area of the county, and
upland timlier soils an additional 5 percent. Of the 92 percent of upland

prairie, soils, 72i is brown silt loam and 18 is l^lack clay loam. Almost
all of the upland timber soil is yellow-gray silt loam. The water-table

in the county lies 45 to 60 inches beneath the surface and is generally

more uniform in depth than in other counties.*

There is an area of about 50 square miles in the eastern part of the

county in which the soil has a different history from that of the rest of

the county and is unusually fertile. This area is drained by the East

Branch of the Salt Fork and lies north of the town of St. Joseph. (See

Figure 1.) The soil of this area was formed under water, and until

this part of Illinois was settled, it was a marsh in which water-fowl

abounded. Later, when ditches were dug, the marsh was reduced to a

few ponds, and more recently it has been drained completely, but the

organic matter that had accumulated under water has not leached away.

The soil is highly calcareous and therefore rich in available plant foods;

nodules of calcium carbonate occur throughout it and render it more
alkaline than other soils of the county. An unusually rich fish fauna

was found in the streams of this area, as will be shown in a later section.

W'eather records for the past 26 years have been kept by an ob-

server of the United States Weather Bureau at Urbana. The Weather
Bureau station is near the center of the county and has an altitude of

743 feet. The mean annual temperature for the 26 years is 51.2° F.

and the mean annual rainfall 34.26 inches. The mean temperature for

1928 alone was 51.4° F. and the total rainfall 32.96 inches.

The mean monthly temjjeratures for 1928 and for the past 26 years

are as follows

:

Jan. Feb. Mar. Apr.

1928 27.5 32.2 39.6 46.8

Ave. 26 yrs. 25.9 27.7 40.2 50.4

The mean monthly rainfalls for 1928 and for the past 26 years are

as follows

:

.\ug. Sept. Oct. Nov. Dec.

2:11 3.65 2.34 1.88 2.53

.i.44 2.98 2,38 2.13 2.20

Description of the Streams

Six streams have their headwaters in Champaign County: the San-

gamon River, the Salt Fork and the Middle Fork of the Vermilion

River, the Embarrass (pronounced Ambraw), the Kaskaskia (otherwise

known as the Okaw), and the little Vermilion. The headwaters of

4. Personal communication from Mr. K. A. Norton, Assistant Chief, Soil

Survey.

Alav



8 Illinois Natural History Survey Bllletix

these six streams interlace except as they are separated by glacial

moraines (see Figure 1 ) . The drainage area in square miles at the point
where each stream leaves the countv is as follows : Sangamon 388. Salt

Fork 307, Middle Fork 241, Embarrass 106, Kaskaskia 98, and Little

Fig. 2. Skctcli map ol Illinnis, showiiis the location of

Cliampaigii County with respect to stream systems. The
dotted line indicates the boundary of the unusually

fertile area discussed in the te.xt (pa.ae 50).

Vermilion 28. Other small streams flow out of the county, but they

soon join one or the other of these six larger ones. The relation of these

headwater streams to the larger streams of Illinois is shown in Figure 2.



Fishes of Champaign County 9

While fishes in the headwaters of the Salt Fork may be but 2 or 3 miles

overland from fishes in the headwaters of the Sangamon, they are more
than 1.200 miles apart by water.

Because of the essential flatness of the county, most of the smaller

streams have been straightened and deepened by dredging. This dredg-

ing has tended toward greater uniformity of environment but has not

changed apprecial^ly the kinds of fishes present nor their general dis-

tribution within the streams. However, dredging has an eflfect on the

minutiae of their distribution and, less obviously, on their abundance.

The c_\'cle of change may be summed up as follows

:

A brook meanders across a pasture with alternate gravelly rififles

and vegetation-bordered stretches of mud and sand ; is slowed down
as it enters pools about the roots of trees in a patch of woodland ; or is

Fig. 3. View of Sangamon River near Mahomet.

scattered into a dozen channels as it passes through a bit of marsh
choked with willows and cat-tails. Thus the stream is well difl^erentiated

into a variety of situations, each with its own characteristic fishes. A
dredging machine goes past and we have, instead, our brook flowing

along a fleep groove in the earth, with dirt |)iled in a high ridge on

each side, of uniform width and grade, and uniformly denuded of every

shred of vegetation. There are no more riftles. no shaded ])ools. but

only constantly flowing silt-laden water. Now, for a few weeks or

months, our fishes become literally the "mere ghosts" of their former
selves. Owing to the lack of light thev all fade tf) a uniform paleness.

Since their food is destroved, their bellies shrink, and their heads assume



10 Illinois Natural History Sur\'ey Bulletin

a prominence disproportionate to their customary aspect. But soon the

process of redifferentiation begins. Gravelly riffles begin to form, with
long stretches of sluggish water between. A few rains scoop out deep
holes where the channel is narrowed by bridge abutments. Small drifts

of debris furnish cover for fishes that .seek it. and offer a richer spot

for the beginnings of rooted vegetation than naked glacial till. In a year
or two we see a heavy growth of weeds on the banks of the ditch and
overhanging the water. A little later a sprinkling of willow and cotton-

wood appears, and in the water a fringe of Elodca, water cress, water
smartweed, MyriophyUum. and many other coarse aquatic plants. At
the end of 20 or 30 years we find that our brook is again something
like its former self. It has gravelly riffles, meanders back and forth

within its narrow confines, is choked by dense beds (jf aquatic plants.

Fis. 4. \ic :1 Kaskaskia River ntar rmiulvillc

At some places it is open to the sky, but at others it is thickly overhung
by an ever-crowding thicket of willows and other small trees. Deep,

shaded pools are also found about the roots of these newly grown trees.

The vegetation checks the flow of water ; the ditch fills u]i with silt from
the fields ; and then the dredging machine comes plodding up the stream

again.

Dredge ditches showing this cycle of change are numerous in the

county, and examples of all the different stages can be found within a

single stream system such as the Kaskaskia. When the hshes of an
old ditch are compared with the fishes of a new ditch, no outstanding

difference is seen except that certain vegetation-loving forms, such as

the pirate-perch and the grass pike, are temporarily absent in the new



Fishes of Champaign County 11

ditch. As for the rest of the fishes, we get aljout the same numbers and
about the same proportion of the different species.

The slope of headwater streams in the county is commonly 10 to

15 feet per mile. Farther downstream the usual slope is 3 to 5 feet

per mile. While the slope of one stream may be somewhat greater than

that of another of the same size, the result is not to produce new kinds

of aquatic environment but only to vary the proportion of uniform
rififles and uniform sluggish reaches. The three larger undredged
streams of the county, the Sangamon, the Middle Fork, and the Salt

Fork, are very similar and offer to fishes almost exactly the same variety

of habitats.

The kind of bottom which a stream has in Champaign County is

primarily a function of the rate of flow of the water. The stream

Fig. 5. View of Camp Creek near Seymour.

channels are cut in glacial till, which is made up of particles of many
sizes, from clay whose particles are 0.0002 inch or less in diameter up to

boulders 2 feet across. Owing to the sorting power of water, nothing

but rocks and boulders will lie found in the swiftest water: jiebbles

and rocks on ordinary riffles; gravel and sand in smoothly flowing

stretches ; while the silt and clay is carried along and dropped in deep,

wide places and eddies and wherever the movement of the water is

checked. The kind of bottom determines very largely the kind and
amount of food organisms for fishes and is thus an important factor

in their distribution. While rate of flow and kind of bottom are closely

related causally, more fishes seem to distribute themselves more of the

time according to current than according to kind of bottom.



12 Illinois Natural History Surn'ey Bulletin

Both direct and indirect evidence has been accumulated which
shows that in streams of the same size there occur parallel variations

in physical characteristics, such as temp)erature, dissolved oxygen,

hydrogen-ion concentration, turbidity, ice conditions, flood conditions,

kind of bottom, depth, vegetation, and available fish food.

Permanency of flow is a factor of prime importance to the fishes

of small streams. The point above which a stream is reduced to a

series of shrunken pools in dry weather varies from 2 to 10 square

miles of drainage area, depending on the lay of the land, kind of soil,

drainage improvements, etc.

Stream size, in this paper, has been expressed in square miles of

drainage area. A calculation based on the average annual rainfall, as

measured by the U. S. \\'eather Bureau at Urbana, and on the average

run-off of various county streams, as measured by Mr. R. A. Norton,

engineer of the U. S. Department of Agriculture, gives an average

annual flow of almost exactly one cubic foot per second per square mile.

This may be used as a rule of thumb to translate statements of drainage

area (square miles) directly into terms of average annual flow (cubic

feet per second), since the two are numerically equivalent. From the

point of view of this paper a precise statement of the average annual

flow of the various streams would be valueless l>ecause it represents a

stage of water which is attained only occasionally as a stream is rising

to, or receding from, a flood. The actual flow for all but a very small

fraction of the total time is either more or less than the annual average.

Pollution b\' sewage, which is one of the most important
factors affecting the variety and abundance of fishes in certain streams

of the county, will be discussed sejiarately (pp. 50-57).

The oxygen content of unpolluted streams in Champaign County
varies from al^out 6 parts per million up to super-saturation due to the

production of oxygen by chlorophyll-bearing plants in sunlight.

The pH varies from 6.5 to 8.3. with most readings between 7.2

and 7.8.

The turbidity, naturally, is extreme during freshets; but during
ordinary or low stages of water, small objects on the bottom commonly
can be seen through a foot of water in winter and 3 to 6 inches in

summer, the comparative clearness in winter probablv being due in part

to the inactivitv of the fishes and the lesser development of the plankton.

The clearest stream in the county is the most heavily polluted part

of the Salt Fork, and its clearness is probablv due to the almost complete
absence of fishes. Accurate measurements of turbidity were made at

the beginning of this study but were soon discontinued because in many
cases the roiliness was directly traced to ditching machines, bridge
building, livestock wading in the water, and other temporary dis-

turbances.

Temperatures in local streams vary from freezing in winter to

90°F. in unshaded stretches in mid-summer, although the variations,

of course, are not quite so abrupt nor so great as in the air. Most fishes

are sedentary and do not feed or grow much when the water is at or
near the freezing point. The growing season for most of the local fishes

is probably about seven months—from sometime in March or earlv April

until October or early November. Usually for a month during every



Fishes of Champaign County 13

winter, the streams are completely frozen over except for the riffles,

and on the more slowly moving stretches ice may form to a thickness

of 12 or more inches. In summer, there is great variation in the temper-

ature of the water at dilTerent places in the streams, depending on the

amount of shade.

The Middle Fork, the Salt Fork, and the Sangamon, before leaving

the county, form narrow flood plains which may reach a quarter-mile

or more in width. At ordinary or low stages of water each of these

streams flows between steep earth banks, 4 to 8 feet below the flood

plain, but at least once each year the water rises 10 or 15 feet and covers

the flood plain.

The common coarse aquatic plants of the county have been ob-

served, and specimens have been identified by Mr. L. R. Tehon, Botanist

for the Illinois Natural History Survey. A list follows

:

Ctadophora glomerata—streamers attached to stones of riffles and rapids of the

larger streams.

Cladofihora crispata—forming mats in quieter water of streams and ponds.

Fissideiis Julianus—moss. On top of submerged rocks in the swiftest water of

the Middle Fork and Sangamon.

Equisctum hicmale—horse tail. On ditch banks, etc.

Typha latifolia—common cat tail. In mud and shallow water at the headwaters

of small streams.

Sparganium sp.—bur reed. In mud and shallow water along small streams.

Potamogeton americanus, P. hcterophyllus, P. costcvijoUus, and P. pjisillus—Sub-

merged in small flowing streams.

Sagittaria heterophylla—arrow leaf. Mudd\' banks of streams.

Elodea canadensis—In small flowing streams.

Grasses and sedges of various species. In and along streams.

Scirptis validus, S. fluviatills. and S. atrovircns—bull rushes. In and along streams.

Lcmna minor—duck weed. Floating and on muddy margins.

Spiradcla polyrhiaa—duch weed. Floating and on muddy margins.

Juncus spp.—rushes. On muddy banks of streams.

Salix spp.—willows. Along streams of all sizes.

Rmnex crispus—common dock. In or near the water in many situations.

Rumex verticillaius—swamp dock. In swampy places.

Polygonum Hydropipcr—water smartweed. Abundant in sluggishly flowing streams

and ditches of small size.

Nymphaca advena—yellow water lily. In sluggishly flowing pools.

Ranunculus aquatilis—butter cup. Muddy banks.

Radicnla Nasturtinm-aqiiaticum—water cress. Small flowing streams.

Callitriche sp.—water starwort. Small flowing streams.

Jtissiaea diffusa—primrose-willow.

Myriophyllum heterophylhim—squirrel tail. .Shallow water and muddy banks of

small streams.

Dianathera amcricana—water willow. Gravelly and rocky shallows and shores

of small swift rivers.

Ccphalanthus occidcntalis—button bush. Swampy flats along the larger streams

the county.

Ambrosia trifida—giant ragweed. Fertile banks and flood plains.

Bidens jrondosa, B. cernua, and R. spp.—Spanish needles, beggar's ticks. Along

streams.



14 Illinois Katlral History Sirvey Bii.letin

Methods and Equipment

In planning this quantitative study of Champaign County fishes it

was foreseen that the important sources of error would Hkely arise in

the collection of the fishes and the distribution of the samples. As has

been stated before, all of these streams are small, with depths ranging

from an inch to 3 feet at ordinary stages of water. Most kinds of

fishing api^aratus are highly selective and particularly so if any move-
ment or other reaction of the fishes is necessarv- for their capture. It

was decided that a single piece of fishing apparatus would give most
uniform results, and for this a "common-sense" minnow seine was
chosen, 10 feet long and 4 feet wide, with meshes 1,6 inch square. Of
the 132 collections 127 were made with this seine, and the other 5 with

an inch-mesh seine, 75 by 6 feet, which took only larger fishes. In
subsequent treatment of the data the collections made with the latter

seine were properly weighted and made to apply only to the larger

fishes. Several years of experience with small seines in many knnds of

situations, as well as continual estimation and measurement of the area

covered per haul, indicated that in such small streams, with the same
persons fishing in the same manner, a 10-foot minnow seine took fishes

efficiently from 10 square yards, a 12-foot minnow seine from 15 square

yards, and a 30-foot minnow seine from 50 square yards. The 75-foot

inch-mesh seine used was estimated to include lOlD stjuare yards. The
1/6-inch mesh used in this study took fry of the smallest sizes identi-

fiable.

Another factor of great importance in making such quantitative

studies of fishes is the skill and efficiency with which the equipment is

used. The success of this i^hase of our work is due to the ingenuity and
skill of the jimior author in gathering up, not a few of the fishes, but

almost all of them from a given area. Without someone who, through
long experience, is thus ah'e to collect fishes from the different situa-

tions efficiently, it would he ]iractically useless to attempt quantitative

work.

The collections are distributed over all the seasons of 1928 from
early spring to late autumn, and for this reason the data not only present

the average of a year's collecting but also indicate many instances of

changes in detailed distribution of species.

While an attemjit was made to do the collecting at ordinary stages

of water, it nevertheless hai)])ened that the collections in some streams

were made at higher stages and, hence, at considerably greater dilutions

than in others which were abnormally low. The order of the stream
systems according to their average stages of water when the collections

were made, from greatest dilution to greatest concentration, is as fol-

lows: (1) Embarrass, (2) Kaskaskia, (3) Salt Fork, (4) Little

Vermilion, (5) Sangamon, (6) Middle Fork. Differences in number
of fishes per unit area due to differences in dilution may be as much as

50 to 7S per cent between the extremes, that is, between the Embarrass
and the Middle Fork stream sv.stems.



Fishes of Champaign- County IS

An effort was made to make collections as closely as possible pro-

portional to water area. The following tabulation shows the number

of collections and the total area collected over in streams of different

sizes

:

Stream size



16 Illinois Natural History SuR\'Ey Bulletin

more than 40 square yards. Before statistical treatment of the data

was begun, all collections were reduced to numbers per 100 square yards.

One of the reasons for doing this intensive work was to permit

a direct comparison with earlier collections made in Champaign County.

This county was collected over at that time as thoroughly as any other

part of the state, with collections distributed as follows : 1 in 1882, 3 in

1885, 1 in 1892, 2 in 1898, 22 in 1899, 3 in 1900, and 8 in 1901. The
distribution of both recent and older collections by stream systems is

as follows

:

Stream system

Square miles of

drainage area

in the county

Number of collections

1882-1901 1928

Salt Fork

Sangamon
Embarrass

Kaskaskia

Middle Fork

Little Vermilion

346



Fishes of Champaign County 17

large and offered no difficulty in identification and which were returned

to the water. Notes made in the loose-leaf field hook were removed

daily, and later typed in triplicate, as is our regular procedure for field

notes. The laboratory identifications were entered on the hack of each

page of the notes.

Within a day or two after the collections were made they were

sorted and identified in the lalaoratory liy the junior author and checked

by the senior author. JMr. R. E. Richardson kindly checked many doubt-

ful specimens and all of several doubtful and variable species. His help

in this respect lends confidence in comparisons to be made with earlier

collections which he identified. At the present time there is an un-

identified residue of only 2 or 3 juvenile specimens.

The data were tabulated on large sheets of co-ordinate paper with

half-inch squares. Across the top of each table were column headings

for accession number, location, date, drainage area, depth, width, rate of

flow, kind of bottom, submerged non-living cover (such as brush, logs,

debris, etc. ) . aquatic vegetation, shade, turbidity, temperature, the factor

used to reduce actual numbers of fishes taken to numbers per 100 square

yards, and finally the names of the 74 species of county fishes. In these

columns were tabulated the field data and numbers of each kind of fish

in each collection. The collections were arranged in the order of their

upstream-downstream occurrence in each stream. In the columns under

the names of the fishes, the actual numbers taken and the calculated

numbers per 100 square yards were entered. Horizontal and vertical

totals were made and checked against each other. These tables were

then used as the basis for all subsequent calculations and are preserved

in the files of the Illinois Natural History Survey.

LIST OF SPECIES, WITH ANALYTICAL KEYS AND DATA

ON DISTRIBUTION AND ABUNDANCE

The following list of the species of fishes taken in Champaign
County is presented especially for the use of collectors in this area. For

the sake of conformity the scientific names and the general arrangement

are the same as in "The Fishes of Illinois" by Forbes and Richardson

(1909) except that some of the common names have been changed to

conform with local usage. An appendix (page 98) lists those Cham-
paign County fishes which have revised names in Jordan's "Manual of

the Vertebrate Animals of the Northeastern United States" 13th

edition, 1929. Notes have been added in some cases for the convenience

of the collector.

The data shown here are based on 132 quantitative cfillections made
in 1928 which included 28,905 specimens, with the addition of three

species {Ictiohus bubahis, Hybopsis storerianus , and Eihcostoma

jcssiac) represented bv single s])ccimens taken in the earlier collections

of the Illinois Natural History Survey, and two other readily recognized

large species (AuquiUa clirxsvpa and Lcplops nlivaris) taken by anglers

in 1928.



18 Illinois Natibal History SrR\"Ey Bulletin

The habitat numbers refer to an ecological classification of Cham-
paign County streams and fishes which follows Cpages 34-39). Several

habitat numbers following the name of a species indicate that it occurs

most frequently in the first habitat, and so on. with its least frequent

occurrence in the last habitat. i\Iaps are appended showing the local

distribution of all species represented by ten or more specimens in the

collections of 1928. An explanation of these maps is given on page 71.

The distribution of a species is described as "restricted" when it is

absent from one or more of the stream systems in which its preferred

habitat or habitats generally occur. In labelling certain species as

"restricted," it has been necessary to take into account the number of

specimens collected, since by random sampling it is within the realm

of probability that a few specimens of a rare species may be taken in

one stream system and not in others in which they may nevertheless

occur. The word "restricted" used in connection with these species

implies a spotty distribution and a high degree of isolation.

The following analytical keys to the Champaign County fishes have
been adapted directly from the Forbes and Richardson keys, hut a

few minor modifications have been made, mostly within the family

Cafosfoinidac.

KEY TO THE FAMILIES OF CH.\MP.\IGX COUXTY FISHES

a Dorsal fin with no spines, or with only 1. Pelvic fin without

spine.

b Head naked.

c Body scaled (scales small and obscure in the eel). Head
without barbels or with not more than 2 or 4.

d Gill membranes free from the isthmus, i. e., split far

forward and meeting in an acute angle.

e Lateral line present. (Moon-eye) — Hiodontidae

ee Lateral line wanting. Last rays of dorsal fin much
elongated. (Gizzard-shad) — Dorosomidae

dd Gill membranes more or less broadly joined to the

isthmus, not meeting in an acute angle.

f Pelvic fins wanting. Body eel-shaped. (Eel) _ Anguillidae

ff Pelvic fins present. Body not eel-shaped.

g Pharyngeal teeth niuncrous and comb-like. Mouth
fitted for sucking. Lips more or less thick and

plicate or papillose. (Suckers) — Catostomidae

gg Pharyngeal teeth fewer than 8 on each side. Lips

tliin and never plicate or papillose. Dorsal fin

of not more than 10 rays. (Minnows) __ Cyprinidae

cc Body and head naked. Eight long barbels about the

mouth. (Catfishes) ._ .._ _— Siluridae

bb Head scaled. Body completely scaled.

h Lateral line present. Front of head shaped like a duck's

bill. (Pike) _ Esocidae

hh Later.-il line w.Ttiting. Moulh small and upturned. (Top-

minnow ) _ — ~ — — - Poecilidae



Fishes of Champaign County 19

aa Dorsal fin with more than one spine. Pelvic fin with a spine.

i Insertion of pelvic fins distinctly nearer the anal fin than

the throat. First dorsal separated from the second and
composed of 4 weak spines. (Silverside) Atherinidae

ii Insertion of pelvic fins distinctly nearer the throat than the

first soft ray of the anal.

j Vent in front of pectorals. (Pirate-perch) Aphredoderidae

jj Vent normal.

k Anal spines 3 to 10. (Sunfishes) Centrarchidae

kk Anal spines one or two.

1 Lateral line not extending onto the rays of the caudal

fin. ( Dan ers) _ Percidae

11 Lateral line extending onto the rays of the caudal fin.

(Sheepshead) _..___ Sciaenidae

Family HIODONTIDAE—The Moon-eyes

Hiodon fcrgisits—]Moo:i-eye ; toothed herring.

1 coll. 1 spm. Habitat 9.

Family DOROSOAIIDAE—The Gizzard-shad

Dorosottia. ccpcdiaiutm—Gizzard-shad; hickory shad.

2 colls. 17 spins. Habitat 9.

Family ANGUILLIDAE—The Eels

Anguilla chrysypa—Eel.

One reported taken in 1928 from the Embarrass River

above Villa Grove.

Family CATOSTOMIDAE—The Suckers

Key to the Genera

a Dorsal fin elongate, with 25 to 40 developed rays.

b Distance from eye to lower posterior angle of preopercle

about -H of that to upper corner of gill-cleft. Subopercle

broadest at its middle, sub-semicircular. (Buffaloes) —...Ictiobus

bb Eye about equidistant between upper corner of gill-cleft

and the lower posterior angle of preopercle. Subopercle

broadest below its middle, subtriangular. (Carp-suckers) Carpiodes



20 Ilunois Natural History Survey Bulletin

aa Dorsal fin short, with 9 to 18 developed rays.

c Lateral line more or less incomplete or wholly wanting.

Scales large and unifornilj- distributed, 30 to 50 in lat-

eral line.

d Lateral line entirely wanting at all ages. Mouth sub-

inferior, somewhat oblique. Young with wide, black

lateral band breaking up into about six dark blotches in

adults. (Chub-sucker) Erimyzon
dd Lateral line more or less developed in adults. Mouth

inferior, horizontal. One dark squarish spot in center of

each scale. (Spotted sucker) Minytrema
cc Lateral line complete and continuous.

e Scales small and crowded anteriorly. The number in

the lateral line 55 to 110 (Except C. nigricans for

which see below ee). (Suckers) Catostomus

ee Scales large and nearly equal all over the body, 40 to 55

in the lateral line.

f Air-bladder in two parts. Scales 48-55 in lateral line.

(Hog sucker) Catostomus (Hypentelium) nigricans

ff Air-bladder in three parts. Scales larger, 40 to 50 in

lateral line. (Red-horses) __ _ Moxostoma

Key to the Sfccics of Ictiobus

a Mouth large, oblique. Upper lip about on level with lower

margin of orbit. Angle of mandible with horizontal more

tha n 40° _ - cjrprinella

aa Mouth smaller, little oblique. Level of upper lip about mid-

way between chin and lower margin of orbit. Angle of

mandible with horizontal slight, less than 20°

b Back scarcely elevated. Depth 3 to 3}4 in length. Body
of adults subcircular at front of dorsal— — ._ urus

bb Back elevated. Depth 2;/, to 2f^ in length. Body strik-

ingly compressed in adults - — bubalus

Ictiobus cypriiiclla—Red-mouth buttalo ; big-mouth buffalo.

1 coll. 3 spms. Haliitat 9.

Ictiobus urns—Mongrel buffalo : round buffalo.

1 coll. 1 spm. Habitat 8.

Ictiobus bubalus—Small-mouth buft'alo ; high-back buffalo.

One taken in 1901 in Sangamon River. See Forbes and
Richard,son (1909).

Key to the Sf'eeies of Carpiodes

a Distance from anterior nostril to end of snout less than diam-

eter of eye. Snout blunt, squarish at tip. Profile of head

flattish or slightly concave. Eye large. 3M to A'A in head._

aa Distance from anterior nostril to end of snout greater than

diameter of eye. Snout pointed at tip. Profile of head con-

vex. Eye small, A^i to 5J<S in head— —

difformis

.. velifer



Fishes of Champaign County 21

Carpiodes diffoniiis—Blunt-nosed river carp.

4 colls. 30 spms. Habitat 9.

Carpiodes velifer—Quillback ; silver carp.

9 colls. 13 spms. Habitats 8, 6, 9.

Erimy::on sucetta oblongus—Chub sucker ; sweet sucker.

48 colls. 196 spms. Habitats 1, 5, 4, 6, 8, 9.

Minytrcma melanops—Spotted sucker ; striped sucker.

5 colls. 18 spms. Habitats 9, 8, 5.

Key to the Species of Catostomus

a Head transversely convex above. The orbital rim not ele-

vated. Scales in lateral line, 60 or more, crowded and

smaller anteriorly _ _ _ commersonii

aa Head broad, depressed, transversely concave between the

orbits. Scales nearly equal all over the body, not crowded

anteriorly, 48 to 55 in the lateral line _._ nigricans

Catostomus coniiiicrsonii—Black sucker; fine-scaled sucker.

65 colls. 644 spms. Habitats 8, 5, 6, 9, 4, 2, 7.

Catostomus nigricans—Hogsucker ; stone-roller.

27 colls. 64 spms. Habitats 7, 8, 6, 5.

Key to the Species of Moxostoma

a Folds of lower lip more or less broken up into papillae.

b Head short, 4^ to Syi in body. Caudal fin pink to bright

red outward. Base of scales dark, giving a cross-hatched

appearance. Developed dorsal rays 12 or 13 _ breviceps

bb Head longer, 3J4 to 4J/^ in body. Mouth large. Developed

dorsal rays 14 to 16. Back elevated. Color silvery Anisurum
aa Lips strongly plicate. Head 4 to 4J/2 in body. Caudal gray-

ish olive to lemon. Outer margin of scales with dark

stippling. Mouth large. Developed dorsal rays 12 to 14.

Back scarcely elevated. Color bronze above lateral line..._ aureolum

Moxostoma anisurum—White-nosed sucker.

One adult taken in September. 1929, from Sangamon
River five miles above Mahomet.

Moxostoma aureolum—Common red-horse; white sucker.

22 colls. 1 14 spms. Habitats 8. 9. 7, 5, 6.

Moxostoma breviceps—Short-headed red-horse ; red-tail.

6 colls. 11 spms. Habitats 8, 9, 6.



22 Illinois Natural History Slrvey Bulletin

Family CYPRINIDAE—Thc :\Iinnows and the Carp

Key to the Genera

a Dorsal fin elongate. Dorsal and anal fins each with a

strong serrated spine. Teeth molar or submolar. (Carp) „. Cyprinus

aa Dorsal fin short. No spines in fins. Teeth not molar.

b Intestine more than twice length of body. Peritoneum

usually black, brown, or dark gray. Generally mud-eaters.

c Intestine spirally wound around air-bladder — — Campostoma

cc Intestine not wound around air-bladder.

d Scales before dorsal 12 to 16 in number, not crowded Hybognathus

dd Scales before dorsal small and considerably crowded,

22 to 25 in number __ _ _— _ Pimephales

bb Intestine less than twice the length of body. Peritoneum

usually pale. Generally carnivorous, or partly so.

e Maxillary without barbel.

f Mouth extremely small and upturned, the angle with

vertical formed by its cleft less than 40° — —Opsopoeodus

ff Mouth horizontal or more or less oblique, the angle

with vertical formed by its cleft usually more than 40*^.

g Abdomen behind ventral fins with a sharp keel-like

edge over which the scales do not pass. Body

much compressed. Anal fin long, its rays 12 to 14

gg Abdomen behind ventrals never sharply keeled, but

rounded and fully scaled. Form various, elongate

or fusiform, or more or less compressed.

h First (rudimentary") ray of dorsal club-like, cov-

ered with thick skin, and separated from second

ray by a distinct membrane — —
hh First (rudimentary) ray of dorsal slender and bony

and closely attached to second.

i Lips normal, nowhere conspicuously thickened.

Mouth subterminal, more or less oblique,

j Lower portion of head rounded, not swollen,

and W'ithout externally visible mucus chan-

nels - -

jj Lower portion of head with an appearance

of being swollen. The suborbitals, inter-

opercles, and dentaries with greatly dis-

tended mucus cavities, appearing externally

as transverse vitreous streaks -^

ii Lower lip with two lateral fleshy lobes, sepa-

rated at the middle by the more or less horny

and knob-like chin. Scales rather small. 40

to 60 in lateral line

ee Maxillary with a barbel at or near its extremity (sometimes

quite small and difficult to make out, especially in preserved

specimens").

k Barbel on upper side of maxillary and distinctly in front

of its iiosterior tip. Mouth exceptionally large, maxil-

lary 2.4 to 2.8 in head. Scales 50 to 60

-Abramis

Cliola

- NotropiB

Ericymba

Phenacobius

Semotilus



Fishes of Ciiampaiun County 25

kk Barbel terminal on the maxillary, situated in the axil

formed at meeting of upper and lower lip-grooves.

Maxillary more than 2.8 in head. Scales 35 to 45 in

lateral line _ _ Hybopsis

Cyprinus carpio—Carp ; European carp.

9 colls. 15 spins. Habitats 8, 9.

Camposfoina aiioinaluin—Dough-belly ; stone roller.

64 colls. 1146 spms. Habitats 6, 7, 8, 2, 1, 4, 5.

Hybognathus iiuclialis—Silvery minnow.
9 colls. 68 spms. Habitats 5, 8, 6, 7. Restricted to Kas-
kaskia River basin. Found among submerged vegetation,

brush, and other cover.

Key to the Species of Pimephales

a Body short and stout, depth 3 to 4 in length. Lateral line

more or less incomplete _ promelas

aa Body moderately elongate, depth 4 to 5 in length. Lateral

line complete ._ notatus

Pimephales promelas—Fathead miiinow ; black-head minnow.
19 colls. 103 spms. Habitats 8, 6, 4. Restricted to San-

gamon River basin. Found in quieter water of perma-
nently flowing streams.

Pimephales notatus—Blunt-nosed minnow.
110 colls. 6440 spms. Habitats 4, 5, 2, 6, 8, 1, 7, 9.

Opsopoeodus cmiliae—Snub-nosed minnow.
1 coll. 2 spms. Habitat 5.

Abramis crysoleucas—Golden shiner ; bream.

41 colls. 401 spms. Habitats 5, 8, 6, 3, 2, 4, 7. Almost
invariably found among vegetation or other cover.

Cliola vigilax—Bullhead minnow.
4 colls. 24 spms. Habitat 8. Restricted to the Sangamon
River and the East Branch of the Salt Fork. Found in

shallow, quiet water with mud bottom and no vegetation,

cover or shade.

Key to the Species nf Notropis

a Anal rays typically 7 or 8, occasionally 9 in two compressed

forms (see bb below), in which however, scales before dor-

sal are not over 17, and no black spot is present at base of

first dorsal rays.

b Eye moderate, 2% to 2% in head, always less than 4.

Body not usually much compressed, the body gently

and broadly rounded in front of dorsal fin. Scales not

closely imbricated.

c Eye 3 or more in head. Small, usually less than 2J^
inches.



24 Illinois Natural History Survey Bulletin

d Scales before dorsal large, 12 to 15 in number.
e A black stripe along sides through eye to end of

snout. Chin white, ilouth small, nearly horizontal cayUga
ee A dark vertebral streak, and a plumbeous lateral

band more or less distinct posteriorly. Mouth more
or less oblique. Lateral line distinctly decurved

anteriorly __ _ blennius

dd Scales before dorsal smaller, 17 to 19 in number.
Mouth inferior. Lips rather thick gilberti

cc Eye very large, 2% to 2-54 in head. Dark lateral stripe

not developed anteriorly. Some dusky color on chin

at tip. Length 3 inches illecebrosus

bb Eye small, 4 to 5 in head in adults. Body more or less

distinctly compressed, the back sharply rounded in front

of dorsal fin. Scales closely imbricated. Adults with

depth 3J/2 to 4 in length. A more or less distinct black

blotch on last membranes of dorsal whipplii

aa Anal rays 9, 10, 11, or 12.

f Dorsal in front of or over ventrals. Exposed portions of

scales of flanks notably deeper than long. A broad dark

vertebral streak. Aanal rays 9 to 10, usually 10 comutus
ff Dorsal fin behind ventrals. Scales roundish, the exposed

portions not notably deeper than long.

g Scales loosely imbricated, those before dorsal in 1.^ to

17 series. No black spot at base of dorsal.

h A dark vertebral streak. Anal rays 9 or 10 pilsbryi

hh Vertebral streak very narrow and usually faint. Snout

blunt. Maxillary equal to eye_ __ atherinoides

gg Scales closely imbricated, about 30 series in front of

dorsal. A black spot usually evident at front of base

of dorsal. Anal ravs 10 to 12, usuallv 11 umbratilis

Notropis cayiif/a atrocaiidalis—Cayuga minnow.
1 coll. 1 spin. Habitat 8.

Notropis hlcnnius—Straw-colored minnow.
44 colls. 1573 spms. Habitats 8. 6. 7, 5. 1.

Notropis gilberti—Gilbert's minnow.
5 colls. 53 spms. Habitats 6. 8. 5. Restricted to Sanga-
mon River basin. Found in shallow, quiet water over
sandy bottom.

Notropis illecebrosus—Big-eyed minnow.
2 colls. 8 spms. Habitat 7. Restricted to ^liddle Fork
River. Found below raiiids among stalks of the water
willow, Diaiitliera aiiiericaim.

Notropis ti'hipplii—Steel-colored minnow : silverfin.

53 colls. 1994 spms. Habitats 8. 7, 6. 4. 2. 5. Found on
or near riffles and briskly moving water. Strong
swimmer.



Fishes of Chamtaign County 25

Notropis contutiis—Shiner ; horned shiner.

54 colls. 2618 spms. Habitats 5, 6, 7, 8, 4. 2, 9. Found
abundantly in Sangamon. Middle Fork, and Kaskaskia
River basins. A few specimens taken in Salt Fork Basin.

Very closely associated with Hyhopsis bciituckieiisis.

Notropis pilsbryi—Pilsbry's minnow.
6 colls. 17 spms. Habitats 5, 6.

Notropis athcrinoidcs var.—Shiner.

3 colls. 21 spms. Habitat 7. Restricted to Middle Fork
River.

Notropis uinhratUis atripcs—Blackfin minnow.
69 colls. 1108 spms. Habitats 6, 5, 8, 7, in about equal

frequency. Shows preference for vegetation or other

cover.

Ericxuiba buccata—Silver-mouthed minnow.
79 colls. 3519 spms. Habitats 2, 6, 5, 8. 7, 4. Found
most often and in largest numbers over sand bottom.

Phenacobiiis iiiirabilis—Sucker-mouthed minnow.
24 colls. 102 spms. Habitats 8, 6, 7, 5.

Scinotiliis atroiiiaciilatiis—Horned dace ; creek chub.

101 colls. 2873 spms. Habitats 4, 2, 1, 6. 5, 8, 7, 3.

Key to the Sfccics of Hybopsis

a Upper jaw decidedly inferior, lying below the projecting

snout. Preorbital much narrower than eye. No nuptial

tubercules. Upper jaw reaching eye.

b Size small, 2 to 3 inches when adult. Dorsal fin inserted

over origin of ventrals, usually a little nearer caudal

l)ase than tip of snout. Dark lateral stripe. Color

silvery. Upper jaw 3.6 to 4.6 in head _ amblops

bb Size large, 4 to 10 inches when adult. Dorsal fin inserted

distinctly in advance of ventrals, decidedly nearer snout

than caudal base. Color silvery without a dark lateral

stripe. Upper jaw 3.2 to i.7 in head _ _._ . . storerianus

aa Upper jaw almost terminal. Snout rather conical. Pre-

orbital much wider than eye. Nuptial tubercles very

strong. Large fishes with the aspect of Semotilus— kentuckiensis

Hybopsis auiblops—Big-eyed chub: silver chub.

8 colls. 40 spms." Habitats 8, 6. Restricted to Middle
Fork, Salt Fork, and Embarrass rivers.



26 Illinois Natural History SuR\xy Bulletin

Hybopsis storeriamts—Storer's chub.

One taken in 1899 in Middle Fork River,

and Richardson (1909j.

See Forbes

Hybopsis kenttickicnsis—Hornv head ; Kentucky chub.

46 colls. 1221 spms. Habitats 5, 6, 7, 8, 4, 9. Found
closely associated with Xotropis coniutus in Sangamon,

Middle Fork, and Kaskaskia River basins

Family SILURIDAE—The Catfishes

Key to the Genera

a Adipose fin with its posterior margin free.

b Premaxillary band of teeth without lateral backward ex-

tensions. Anal rays 17 to 35, including rudiments.

c Bony bridge from occiput to dorsal fin complete. Tail

deeply forked _ _ — — — Ictalurus

CO Bony bridge from occiput to dorsal fin broken. Caudal

fin typically rounded, truncate or slightly emarginate . —Ameiurus

bb Premaxillary band of teeth with a backward extension

on each side. Anal rays 12 to 15 including rudiments- — Laptops

aa Adipose fin adnate to the back, continuous with the caudal

and separated from it only by a notch.

d Premaxillary band of teeth with lateral backward ex-

tensions, as in Leptops. Skin thick tough, and

villose, not translucent „ — — Noturus

dd Premaxillary band of teeth truncate at the ends, as

in Ameiurus. Skin thinner than in d, smooth or very

finely villose, sometimes translucent— — Schilbeodes

Ictalunis pnnctatus—Channel cat ; fiddler.

8 colls. 10 spms. Habitats 8, 9.

Key to the Sl'fi-ii-s of Ameiurus

a Anal rays 24 to 27, including rudiments, usually 25 or 26.

Caudal fin rounded posteriorly. Margin of anal fin a

straight line -._ — — -

aa Anal rays 17 to 20, usually 18 or 19, including rudiments.

Caudal fin always evidently emarginate. Margin of anal

fin a curve — — — —

natalis

melas

Ameiurus natalis—Yellow bullhead.

15 colls. 28 spms. Habitats 5, 6, 8.

Ameiurus melas—Black bullhead; horned pout.

13 colls. 1704 spms. Habitats 3, 5, 8, 9. Schools of

youns; found in haliitats 3, 5.



Fishes of Champaign County 27

Laptops olivaris—Mud-cat : yellow cat ;
goujoii.

One 24 pound spni. taken August 1928 in Sangamon River

by Mr. Homer Bales.

Notiirus flaviis—Stonecat.

5 colls. 12 spms. Habitat 7. Found under rocks on riffles.

Key to the Species of Schilbeodes

a Anterior and posterior edges of pectoral spine entire, or

the anterior edge very slightly roughened near tip. Jaws

equal. Adipose fin continuous with caudal, the notch being

absent or faint, never acute. Color purplish olive to dark

brownish, without noticeable specking. Three dark streaks

on sides _ — —
aa Pectoral spine with distinct posterior serrae, which are re-

curved and in length more than 1/3 the diameter of spine.

Notch between adipose and caudal fins always more or

less acute.

b Pectoral spine short, 3 in head, the posterior serrae not '/z

diameter of spine. Notch between caudal and adipose

fins usually shallow. Color light brown, sometimes

faintly mottled. A large squarish spot of lighter

color on back before dorsal and a smaller cresentic one

behind it _

bb Pectoral spine longer, less than 2 in head, its posterior

serrae strong and in length nearly equaling diameter of

spine. Notch between adipose and caudal fins deep and

acute. Color grayish with black specks and larger

blotches. Four saddle-like blotches on back, the last

but one extending upon adipose fin to its edge

gynnus

exilis

Scltilbcodcs gyriiius—Tadpole cat.

7 colls. 14 spms. Habitats 8, 6.

River basin.

Restricted to Salt Fork

Schilbeodes exilis—Slender stonecat.

3 colls. .3 spms. Habitats 8, 7.

Schilbeodes luiiints—Brindled stonecat.

1 coll. 44 spms. Habitat 8. Restricted to Salt Fork
River basin.

Fawilv ESOCWAE—The Pikes

Esox veniiicitlafiis—Grass pike; little pickerel.

26 colls. 63 spms. Habitats 8, 5, 6. Found among sub-

merged vegetation or other cover, anrj in the shade of over-

hanging bu.shes.



28 Illinois X'atural History Slrvev Bulletin

faiuily POECILJWAE—lhe Killifishes

Fimduhis notaliis—Top minnow.
44 colls. 151 spms. Habitats 8, 5. 6. Found most often

near aquatic vesjetation. Swims commonly with back

touching the surface film.

Family ATHERINIDAE—The Silversides

Labidcstlics sicculns—Brook silverside.

3 colls. 27 spms. Habitat 8. Restricted to the Salt Fork
River basin.

Family APHREDODERIDAE—lhe Pirate-perch

Aphredodenis sayanus—Pirate-perch.

12 colls. 167 spms. Habitats 5, 8. Restricted to San-

gamon, Embarrass, and Kaskaskia River basins. Found
among living vegetation or other cover.

Family CENTRARCHIDAE—The Sunfishes

Key to the Gexera

a Dorsal fin little longer than anal, if any, its length 1 to 1.4

times length of anal hase. Anal spines 5 to 8 in number.

b Dorsal spines 5 to 8 (occasionally 9 or even 10) (Crap-

pies) _- _ — Pomoxis

bb Dorsal spines 11 to 13. Anal spines 6, rays 10 or 11.

( Rock bass) _ — —Ambloplites

aa Dorsal more than twice length of anal. Anal spines 3.

c Body comparatively short and deep, depth in adults as a

rule more than 2/5 of length. Dorsal fin not deeply

emarginate, the shortest spine behind middle of fin more

than 2/3 height of longest. Operculum entire behind,

not emarginate, more or less prolonged in a bony process

or flap with a rounded posterior margin.

d Tongue and pterygoids with teeth. Maxillary reaching

past pupil { Warniouth bass) — Chaenobryttus

dd Tongue and pterygoids toothless. Maxillary in most

species short of middle of orbit (to middle in L.

cyanellus). Pectorals never reaching beyond vertical

from base of anal. Opercular flap \vithout red, or if

red is present, with the color forming a border and

not a roundish spot. (Sunfishes, and the bluegill) Lepomis



Fishes of Chajii'aigx County -29

cc Body comparatively elongate, depth about 1/3 length.

Dorsal fin deeply emarginate, the shortest spine behind

middle of fin from 1/3 to Yz height of longest. Oper-

culum ending in two flat points. (Black basses) -Micropterus

AV.v to the Species of Pomoxis

a Dorsal spines typically 6, rarely 5 or 7.- Color light, the dark

markings tending to form vertical bands annularis

aa Dorsal spines typically 7 or 8, rarely 6, 9, or 10. Color

dark, spotted, the dark markings not forming vertical bands sparoides

Pomoxis aitiiiilaris—White crappie.

2 colls. 2 spms. Habitat 8.

Pomoxis sparoides—Black crappie.

3 colls. 7 spms. Habitats 9, 8.

Auibloplitcs nipcsfris—Rock bass; goggle-eye.

1 coll. 1 spm. Habitat 8.

Chaenohryttus gulosus—Warmouth bass.

2 or 3 spms. collected in recent years near the outlet of

Crystal Lake from which they had ]3robably escaped.

Key to the Species of Lepomis

a Black opercular spot borne by the stiff bony upper posterior

angle of the operculum, which is plainly distinguished from

a flexible (fleshy or membranous) border of different

(usually lighter) color.

b Mouth large and cheek not very deep, the maxillary 1/5 to

^ longer than the distance from the lower margin of

the orbit to the lower posterior corner of the preopercle.

In life with blue spots and vertical bars of dusky.

Margin of ear-flap coppery to purplish. Cheeks with

wavy blue lines __ _ ~ —cyanellus

bb Mouth smaller and cheek deeper, maxillary about equal

to or less than distance from lower margin of orbit to

the lower posterior corner of preopercle. Many scales

of sides with squarish light-colored areas (bronze or

purplish in life), these forming more or less distinct

longitudinal rows. Rest of body dusky olive miniatus

aa Portion of opercular flap bearing black spot very thin and

flexible.

c Bony portion of operculum terminating in front of tlie

middle of the black opercular spot, which is confined

chiefly to the broad pale (pinkish in life) membranous
(not osseus) border. In life olive with orange spots.

Cheeks and operclcs with wavy broken lines of rusty

orange. No black blotch at Ijase of last dorsal rays humilis



30 Illinois Natural History Survey Bulletin

cc Bony portion of operculum continued backward as a thin

and flexible osseo-membraneous flap, which is all or

nearly all black, the longitudinal bone-striae being visi-

ble through its enshcathing epidermis.

d Gill-rakers short and weak, their length not over 1/6

eye. No black spot at base of last dorsal rays. Olive

with blue and orange spots and wavy vertical streaks

of emerald. Cheeks with wavy lines of emerald —megalotis

dd Gill-rakers rather long and slender, their length nearly

1/3 of eye. A black blotch at base of last dorsal

rays. Life color olive, with purplish luster —pallidus

Lcpomis cycmcllus—Green sunfish.

38 coHs. 121 spms. Habitats 3. 5. 6. 2. 8. 7. 4. Usually

found among vegetation or other cover.

Lepoinis Miniatus—Carman's sunfish.

1 spm. collected in 1928 near the outlet of Crystal Lake,

from which it had probably escaped.

Lepoinis megalotis—Long-eared sunfish.

39 colls. 154 spms. Habitats 8, 5. 6. 4. 9. About 20

adults observed building nests and spawning in the Little

Vermilion River at the Champaign-\'ermiHon County line

on August 2. 1928. The stream at this point is a dredge

ditch with 3 to 10 inches of water and a muddy gravel

bottom.

Lepoinis Iiiiinilis—Orange-spotted sunfish.

13 colls. 35 spms. Habitats 8. 2. 5, 6. Restricted to San-

gamon, Salt Fork, and Middle Fork River basins.

Lepoinis pallidus—Bluegill.

1 spm. taken in 1928 near the outlet of Crystal Lake, from
which it had jiroliably e.scaiied.

Key to tlic Species of Micropterus

a Mouth moderate, the maxillary never extending beyond

eye, usually a little short of back of orbit. Scales on

cheeks in about 17 rows. Young more or less barred or

spotted, never with a black lateral band — - dolomieu

aa Mouth verj' large, the maxillary in the adult extending past

back of orbit. Scales on cheek large, in about 10 rows.

Young with a blackish lateral band „ salmoides

Micropterus dolouiicii—Small-mouthed black bass.

16 colls. 44 spms. Habitats 8, 7, 6. 9. Usually found

near subiucrged lirush or logs. Good swimmer. Commonly
jumps clear of water when disturbed.



Fishes of Champaign County 31

Microptcrus sahnoides—Large-mouthed black bass.

3 colls. 4 spms. Habitats 8, 6. It has been noticed that

where this species is found in creeks there is usually a

good growth of the water willow, Dianthcra auicricana.

Not so active as M . dolomieu.

Faiiiilv PERCIDAE—The Darters

Key to the Genera

a Pre-maxillaries not protractile, free only at the sides, con-

nected in front with the skin of the forehead, from which

they are not separated by a cross groove.

b Cranium not compressed or much elevated back of eyes,

its elevation not more than 1/3 of its breadth. Body
as a rule more or less slender and little compressed,

subcylindrical or fusiform. Depth in length as a rule

6 or more. Spring males ordinarily without red or other

gaudy coloration.

c Cranium broad between the eyes, the interorbital space

4 to 4.7 in head. Snout pig-like. Darters of large

size, reaching a length of 6 inches. (Log perch)

cc Interorbital space narrower, S.5 to 9 in head. Small

fishes, ordinarily not over 4 inches in length. Body
moderately slender, the depth as a rule about 6 in

length (sometimes 7)

bb Cranium more or less compressed and elevated back of

eyes, fl" shaped, its elevation as a rule noticeably more
than 1/3 (to less than J4) its breadth (except in E.

flabellare which has a low spinous dorsal and spring

males without gaudy coloration). Fishes with usually

more or less compressed and comparatively shortened

bodies, the depth in length as a rule less than 6. Spring

males usually with brilliant red, blue, or green colora-

tion.

d Lateral line not noticeably flexed upward anteriorly

dd Lateral line conspicuously flexed upward anteriorly, its

direction parallel with line of back (least distance be-

tween lateral line and middle of back in B. fusiformis

about J4 depth of body at same point) _

aa Premaxillaries protractile, i. e., a groove separating them
from the skin of the forehead.

e Groove separating premaxillaries from forehead inferior,

not visible except from below. Maxillary adnate to the

preorbital for most of its length, nearly immovable.

Anal spines 2

-Percina

..Hadropterus

Etheostoma

-Boleichthys

..Diplesion



32 Illinois Natural History Survey Bulletin'

ee Groove separating prcniaxillaries from forehead superior,

easily visible from in front and above. Maxillary sep-

arated by groove from preorbital for its entire length.

Anal spine single.

f Anal fin much smaller than soft dorsal. Body mod-

erately slender, depth not over 7 in length. Not

hyaline in life — — — _ Boleosoma

ff Anal fin almost as large as soft dorsal. Body extremely

slender, depth in length 8 to 10. Body hyaline in life Ammocrypta

Pcrciita caprodcs—Log perch.

2 colls. 4 spms. Haljitat 7.

Key to the Sf-eeies of Hadropterus

a Gill membranes not broadly united at the isthmus, distance

from tip of snout to angle formed by their union scarcely

exceeding that to back of orbit. Color pattern longi-

tudinal, the sides marked with a median row of blotches

or a moniliform band, above which are longitudinally dis-

posed marblings. Cheeks scaled _ __ _ — — aspro

aa Gill membranes united at isthmus in a broad curve, least

distance from muzzle to free margin of gill membranes

1.2 to l.S times that from muzzle to back of orbit. Head
very slender and -snout long and pointed. Lateral

blotches small and as a rule faint. A very small central

caudal spot -- phoxocephalus

Hadroptcnis aspro—Black-sided darter.

24 colls. 45 s]ims. Habitats 8. 5. 6. 7. Often found

among- ac|uatic vegetation or other cover.

Hadroptcnis phoxocephalus—Sharp-nosed darter.

8 colls. 12 sj-ims. Habitats 8, 7, 6.

Diplcsioii !<h-iiiiioidcs—(ireen-sided darter.

10 colls. 149 simis. Habitats 7. 8. 6. Restricted to 'Middle

Fork, Salt Fork, and Emliarrass River basins. Found on

swiftest riffles.

Key to the S/^eeies of Boleosoma

a Lateral line complete or nearly so. Pyloric caeca 6. Cheeks

and breast typically naked, sometimes more or less scaly— nig^nim

aa Lateral line absent on posterior half of body. Pyloric caeca

3. Cheeks and opercles, and usually breast, closely scaled camurum

Boleosoma- nifjnmi—Jo^i'mv darter.

S2 colls.' 90.^ Slims. i-Taliitats 8. 5, 0, 2. 4. 7.



Fishes of Champaign County 33

Boleosoma camunim—Snub-nosed darter.

1 coll. 1 spm. Habitat 5.

Aminocrypta pellucidn—Sand darter.

2 colls. 19 spms. Habitat 8. Restricted to Middle Fork
River. Found buried in sand above ri.lfles.

A_Vv to the Species of Etheostoma

a Lateral line usually complete, occasionally 2 to 6 pores lack-

ing. Gill membranes joining broadly across the isthmus zonale

aa Lateral line always more or less incomplete, the number
of pores lacking usually 10 to 30, rarely as low as 5.

b Spinous dorsal fin not exceptionally low, its height as a

rule 75 to 90 per cent of height of soft dorsal. No
enlarged dark humeral scale.

c Cheeks and opercles scaled. Brown bars on sides jessiae

cc Cheeks naked. Opercles scaled. Spring males with

alternating red and blue bars coeruleuin

bb Spinous dorsal fin as a rule less than 60 per cent height of

soft dorsal. An enlarged dark humeral scale more or

less conspicuous. Gill membranes broadly connected.

Dorsal spines each ending in a fleshy knob in the male .flabellare

Etheostoma zonale—Banded darter.

8 colls. 85 spms. Habitats 7, 8. Restricted to the San-
gamon River.

Etheostoma jessiae—
One spm. taken in 1901 in Sangamon River. See Forbes
and Richardson (1909).

Etheostoma coerulenm—Rainbow darter.

32 colls. 497 spms. Habitats 6, 7, 8, 5, 4. Not found
in the Kaska.skia Basin.

Etheostoma flahellare—Fan-tailed darter.

14 colls. .34 spms. Habitats 7, 8, 6. Restricted to San-
gamon, Embarrass, Aliddle Fork, and Salt Fork River
liasins. Fotuid under and around rocks on riffles.

Boleichthys fiisiformis—
1 coll. 1 spm. Habitat 6.

Family SCIAENIDAE—The Drums

Aplodinotiis gntnniens—Sheepshead ; white perch ; drum.
3 colls. 10 spms. Habitats 9, 8.



34 Illinois Natural History Sur\xy Bulletin

Type Habitats

Habitat numbers given in the preceding s])ecies list refer to the fol-

lowing classification of tyjie habitats as found in the streams of Cham-
paign County. In the selection of these type habitats we have chosen

those stream situations which occur repeatedly and have made them
correspond, in as far as possible, with what appear to be natural sub-

divisions in the distribution of the fishes. It is, of course, to be under-

stood that a stream is a continuum and does not break abruptly from
one situation into another. There are marked differences in the details

of the environment in these type haliitats and corresponding differ-

ences in the detailed distribution of the fishes.

Type Habitat 1

]'crval Rifulets

Commonly draining / to 2 square miles. Flowing for a few weeks in sprin?

and for shorter periods following heavy rains. Completely dry throughout most

of the year. One to six inches deep. Six inches to four feet wide. They are

often so small that they can be dammed hy one's hand. The substrate is of ex-

posed subsoil with an accumulation of loam in the depressions. Occasional short

stretches of sand bottom may occur depending on the kind of soil being eroded.

There are no characteristic bottom muds nor gravelly or rocky riffles. There is

usually considerable dead vegetation in the form of drifts of leaves, dead weeds.

sticks, cornstalks, grass, etc. No living vegetation except for occasional pieces

of sod. The aquatic animal food present for fishes is restricted almost entirely

to water isopods. A considerable number of terrestrial animals are washed in and

also serve as food. The typical species of this habitat are as follows

:

Lrimyzcn sucrtta obloiunis, young

Pinicplwli's notatus, young
i Sciiwtihis atroiiiaciilatiis, young

Caiiihostoina anoiiuiliim. young

The above fishes are known to feed extensively on mud and organic debris. The

yoimg of a few other species may occur in small numbers.

Type Hahilat 2

Kettle Holes at Moiiflis of Tile Drains

Commonly draining from 1 to 7 square miles. There is a flow throughout

the year but it is often reduced to a trickle. Usually 10 to 25 feet wide and I'j

to 4 feet deep. Water temperature not exceeding 65°F. in summer and seldom

freezing in winter. Very clear. No aquatic vegetation except filamentous algae.

Bottom usually of clay, rock, gravel, and sand. No characteristic dark-colored

5. On the afternoon of July 2S, 1929, two of these kettle holes were visited ami
temperatures tal<en. On that afternoon tlie air temperature in tlie shade varied
around fl.')°F. The temperaturo of one was fi-l.-f^F. and the other 62,6°F. The
water tem]>er,ature as it came from tlie two tiles was 62.8*'F. and 61.3**F., re-
spectively.



Fishes of Champaign Cou.vtv 3S

bottom muds. No cover except a little overhanging grass and some submerged

trash, dead leaves, and weeds. Very little available aquatic animal food apparent.

Grasshoppers and other terrestrial insects fall into the water and probably fill an

important place in the dietary of the fishes. No shade. The typical fishes in

these situations are as follows

:

Ericymba huccata, adults

Semotihts atromnciilatiis, adults and young

Piinefhales notalus, adults

Catostomus coinmcrsonii, young

Campos10)'>a anoinalinn. adults and young

When the tile outlet is sufficiently low some of these fishes, notably Ericymha and

Scmotiliis, will ascend the tile for considerable distances where they may feed on

subterranean amphipods and isopods.

Type Habitat 3

O.vboiv Ponds along Small Streams

Commonly draining l-i to 1 square mile. Flowing during wet weather. Flooded

by adjacent stream during freshets. Usually wide, shallow ponds with a bottom

of deep, soft, black, mucky mud. Much dead and decaying vegetation. Usually

with emergent coarse aquatic vegetation of Saygittaria, smartweeds, buUrushes,

docks, etc. In summer with heavy growths of blanket algae and duck weeds.

Seldom shaded ; water extremely warm in summer weather. Freezes almost to

bottom in winter. Numbers of frog tadpoles of several species can often be found.

Small crayfishes numerous. An abundance of a large variety of aquatic animal

food. The typical fishes are as follows

:

Aiiiciiinis mclas. adults and young

I.cponiis cyaiiclliis, adults and young

Esox vcrmiculatu!:, adults and young

Abrawis crysolcucas, adults and young

Occasional young specimens of other species are also found. The conditions of

these small oxbow ponds are sometimes approximated in the upper ends of dredge

ditches and there the above fishes are also found.

Type Habitat 4

Permanent Headzvatcr Streams

Commonly draining 2 to 10 .square miles. Reduced during drouths to mere

trickles running from one shallow depression to another, One inch to one foot

deep and six inches to si.x feet wide. Substrate usually of exposed subsoil but

occasional gravelly riffles and beginnings of characteristic bottom muds are seen.

Shaded by a luxuriant growth of cattails, grasses, weeds, willows, and other shrubs

and small trees. Water cool. No submerged coarse aquatic vegetation. May
have some duck weed and filamentous algae in summer. Available aquatic animal

food for fishes not abundant. Numbers of dragon fly and damsel fly nymphs and



36 Illinois Natural History Sur\xy Bulletin-

water striders and other bugs. Much food probably falls from the overhanging

vegetation. The typical fishes in this situation are

:

Scmotilus alroinaculalus, adults and young

PiincphaUs notatns, adults and young

Sometimes the fish population consists entirely of Scmotilus. At other times a

few specimens of other species may also be found.

Type Habitat 5

Stretches of Shallow, Sluggish ll'ater

Found in both dredged and undredged streams with a drainage area of 5 to

40 square miles. Reduced to long quiet pools in dry weather. Three to twenty

feet wide and yi to 2J/ feet deep. In summer the water is relatively warm and

is turbid. In winter covered with heavy ice. The bottom is characteristically

of dark mud with an admixture of small amounts of sand, gravel, rock, and sticks.

The banks are usually steep and drop off quickly to an almost uniform depth.

There is characteristically a growth of a variety of submerged and emergent coarse

aquatic vegetation, and the channel often is literally choked with beds of water

smartweed. Small amounts of shade are furnished by overhanging grass and

weeds and a few willows. A variety of aquatic animal foods is present in fair

abundance, with Hexagenia nymphs near first place. Crayfishes are common
and often are extremely abundant. The typical fishes in this habitat are

:

Calcstomns commcrsonii, adults and few young

Notrof'is conuitus. adults and young

Hyhnpsis kenlitckioisis. adults and young

Scip.otiius atromactilatus, adults and young

Abrnmis crysolcucas. adults and young

Erimyzon succtia obhiigiis, adults and young

Eso.r vermiculatns, adults and young

Fuiiduhis iwtntus. adults and young

Piiitel^hnlcs notatns. adults and young

Aphrcdodcrtis sayanus, adults and young

Lc/'oiius mcgalolis. adults and young

Lcpninis cyaiirlhts. adults and young

Bolcosoma niqnim. adults and young

Small numbers of other fishes arc re.aularly taken. This is one of the mere

important fish habitats inasmuch as it occurs commonly in Champaign County and

supports a large population of a variety of fishes.

Type Habitat 6

Gravelly and Sandy Riftles and Stretches

Drainage area 8 to -40 square miles. One to 12 feet wide and 1 to 8 inches

deep. May be a few feet lon.g or several himdrcd yards long. Kither in dredged

ditches or in natural streams that loop and meander. Small flow in dry weather.



Fishes of Champaign County 37

Bottom of gravel or sand, more commonly of both. Often with pebbles ranging

up to two inches or more in diameter. Mud along banks and in shallow depres-

sions. Exposed roots of willow, brush, and overhanging sod and grass and shore

vegetation. Sometimes there are small amounts of coarse aquatic vegetation.

Moderate amounts of aquatic animal food. The typical fishes are:

Catostomus nigricans, young and few adults

Campostoma anomaluni. adults and young

Semotilus atiomaculatus, adults and young

Notropis whipplii, adults and young

Catnstomns cotnmersonii, young

Notropis cormittis, adults and young

Hybopsis kentitckiensis, adults and young

Pimcphalcs notatns. adults and young

Ericymba bnccata, adults and young

Notropis nmhralilis atripes, adults and young

Boleosoma nigrum, adults and young

Etheostomn coernlcuni, adults and young

Etheostoma fiabeUarc, adults and young

Moxostoma aureolum, young

Carpiodes vclifer, young

Smaller numbers of other fishes are regularly taken.

Type Habitat 7

Rocky Rapids and Riffles

Draining 40 to 400 square miles. Depth 2 to 15 inches. Width 5 to 40 feet,

very swift except during very low stages of water. Commonly 10 to 100 yards

long. Bottom of rocks from the size of eggs up to boulders and loose trap rock

interspersed with solidly packed gravel and sand. Occasional logs and brush in

water along edges. Rocks overgrown with spreading growths of algae, diatoms,

bryozoa, etc.. and often serving as anchors for long streamers of Cladophora. An
abundance of animal food, consisting principally of small mollusks and immature

stages of may flies and caddis flies. This situation occurs in both dredged and

natural streams. There are usually trees and shrubs on the banks, which partially

shade the water. The typical species of this habitat are

:

Catostomus nigricans, adults

Phcnacnbins mirabilis, adults and young

Ictalnrns punctatus, young

Etheostoma flabcllare, adults and young

Etheostoma sonale, adults and young

Hybopsis kcntuckicnsis, adults and young

Notropis cornutus, adults and young

Notropis lihipplii, adults and young

Hybopsis amhlops, adults and young

Pcrcina caprodes, adults

Diplcsion blcunioidcs, adults and young

Noturus f.az'us, adults and young



38 Illinois Natural History Survey Bulletin

Small numbers of other fishes taken under certain conditions. The fishes of this

situation are mostly adapted to hiding behind and under rocks or other objects

that break the full force of the current. These species are seldom seen swimming

except for sudden spurts of speed from one stopping place to another. They hold

their position rather by avoiding the full force of the current and clinging than

by excellence of swimming.

Type Habitat 8

Moderately Deep, Smoothly Flozciiig Stretches

Draining 40 to 400 square miles. Depth 1 to 4 feet. Width 20 to 50 feet.

Current sluggish during periods of low water. Bottom of sand and gravel with

mud along the banks. No coarse aquatic vegetation. Usually with no overhang-

ing grass or weeds. Commonly shaded by trees on the banks. Roots of trees

often exposed and offer hiding places for sunfishes. Numerous drifts of brush

and logs and stumps commonly accumulated in places where a large tree has fallen

in. The banks usually drop off steeply to a uniform depth. Moderate amounts

of a variety of animal foods. Mussels of several species numerous. The typical

fishes of this situation are

:

Mo.xostoma aurcoltiin. adults

Moxostoma brcviccps. adults

Carl^wrles vetifcr, adults

Catostomits commcrsonii, adults

Catostomtis nigricans, adults

Micrpj^lcrux dolomicn. adults and young

Pniiw.ris atunilaris, adults and young

Pititcf<lialcs notatus, adults

Notropis btcnnius. adults

Notrnpis ivhipplii, adults

A^otropis conuitiis. adults

Hyhopsis kcnturkicnsis. adults

Ictalurus punclahis, adults and young

Lcpoiuis cyanclhis. adults and young

Lcpomis megnlotis. adults and young

Lcpoiin<: Inniiilis. adults and young

Other fishes are also taken in smaller numbers.

Type Habitat 9

Long. Deep Pools

Draining 100 to 400 square miles. Width 40 to 75 feet. Depth 3 to S feet.

There is less fluctuation of the physical environment of this habitat than any other

small stream situation. Mud bottom with more or less gravel and water-logged

sticks. Mud banks. Usually with partly submerged logs and brush along banks.

Partly shaded by trees. Sometimes turbid. No aquatic vegetation except for

water bloom and duck weed in late summer. U.sually with aquatic animal food



Fishes of Champaign County 39

in the form of small mollusks, Tubificid worms, and chironomid larvae. The typ-

ical fishes are

:

Aplodinotns grunnicns, adults and young

Dorosfliiia ccf'cdiannm, adults and young

Carfiodcs diffonnis, adults

Moxostoma anreolum, adults

Mo.vostoma hrcviccf^s, adults

Microptcnis salmoidcs, adults and young

Ictiobus cypfincUa, adults and young

Cyprinus carhio, adults and young

Catcstomus commcrsonii, adults

Poinoxis sparnidcs, adults and young

Ictahiriis I'liiictalus, adults

.-linciunis iiiclns, adults

Other large fishes are taken in smaller numbers. Scanty numbers of smaller

kinds of fishes are taken regularly. Snapping turtles are found here most often.

Painted turtles numerous. This situation is the winter quarters of most of the

larger fishes.

Abundance and Number of Kinds

In the present quantitative collections a total of 28,905 fishes were
taken from a total water area of 9,535 square yards or 1 .97 acres—about

15,000 per acre, or 3 per square yard. The total weight of these fishes

was estimated at 300 pounds, or about 150 pounds per acre for the

county streams as a whole. This average weight of fish flesh per acre

has no obvious relation to the annual yield of food fishes or to the annual

increment.

On the basis of some fragmentary data on the rate of growth of

Champaign County fishes and on a general knowledge of the size and
relative numbers of the different age groups of the principal species, one
may venture a guess that the annual increment, or turnover, of fish flesh

is something less than one-half of the total 150 ]wunds per acre.

In this area food and game fishes may be taken only by hook-and-
line, and minnows may be taken for bait with small minnow seines. In

general, the fishes in this county are too small to be attractive to many
anglers, and the weight of the fishes taken from the water by man is

surely a very small percentage of the annual increment. In these streams

we probably have a close appro.ximation to an equilibrium, or a balance

wherein the annua! increase in fish flesh equals the annual decrease, and
that without undue influence or control by man. Most fishes in these

streams die of '"natural" causes—they may lie eaten at any period of

their life liy any one of a variety of predators such as carnivorous insects,

crayfishes, necturi, ttirtles, water and shore l)irds, or the mink. They
may be injured or stunted or destroyed Ijy any one of a long and impos-

ing list of specific fish diseases and parasites. Under certain conditions

their food may be exhausted or seriously depleted. Their ambient medium
may dry up or get too hot or freeze .solid or be deficient or unsuitable

in a number of other ways. Cotnpared with these vicissitudes an occa.s-

ional worm on a hook is a minor hazard.



40 Illinois Natural History Sl"r\xy Bllletix

Some recent work of Dr. H. J. \'an Cleave and Mr. H. C. Markus
on the life histor\- of the blunt-nosed minnow. Piiiicphalcs )Wtatus, in

this area suggests that females and males of this species do not exceed
2 and 3 years in age, respectively. The implication is that they die fol-

lowing their first spawning period. (Aincr. Xat. 63: 530-539. 1929.)
Of those species which occur both in these small streams and in the

large rivers of Illinois the average size is much less in the small streams.

Such size differences among the suckers and red-horses are obviously

due to migration, since these fishes ascend the small streams and spawn
and then descend. Size differences may also be due to slower growth
or greater relative elimination in the small streams. In any case it seems
probable that the annual "turn-over" in fish flesh is greater in these

small streams than in the larger rivers.

Eight of the thirteen families of fishes in Champaign County are

represented by single s])ecies. The remaining five families are represented

by species as follows: Catfishes 8, Suckers 12. Sunfishes 11. Darters

12, Minnows 23. In point of weight the sucker family (Catostoiiiidae)

takes first place, furnishing somewhat more than half of the total

weight of fishes taken. About three-fourths of this total weight of the

sucker family was contributed by the common, or black, sucker. Catos-
toiiius couuiicrsonU. which averaged 3 ounces in weight. In point of

numbers of individuals the minnow family ( Cypriiiidai- ) e.KCels. con-

tributing 23,347 of the total of 28.905 specimens taken. Of the 23
species of minnows taken, the following 9 species furnished 22,492
specimens.

Caiiipostonin auninalum Notropis connitits

Phncphalcs iiotatiis Notropis iniibrafilis atripcs

Scuiotiliis atroiiiacitlatiis Ericyiiiba biiccata

Notropis hlcnnius Hyhopsis kcnfiickiciisis

Notropis zdiipplii

Most of these are headwater species, generalized, both physiologically

and morphologically, and will be discussed more fuUv later.

To illustrate the wide range of abundance, one species is represented

by 6,440 specimens in one season's collecting, while 12 others are repre-

sented by single specimens each. Such ditTerences in abundance of the

various species as we find in this study are not satisfactorily explained

by one or a few factors, and it seems that an adequate explanation will

involve not only a complete and intimate knowledge of all the variable

factors of the lihysical environment but—what is more difficult—an

equally complete and intimate knowledge of the fishes themselves and of

their various responses to the environment. Any factor is important to

the extent in which it limits the life and abundance of any kind of fish.

And. as a corollar}', all factors are important at least as they exceed cer-

tain threshold limits.

Considerable information and oliservation on individual species, to-

gether with the (|uantitati\o data, make possible a rather critical analysis

of some of the factors affecting fish distribution and abundance. En-
vironmental factors known to be of importance in these small streams

are: volume of water; dejith of stream: rate of flow: pennanency of

stream (/. <., whether or not it is reduced to jiools in dry weather) : sub-

merged vegetation, sb.ade, ami other cover : kind of bottom : temperature



Fishes of Champaign County 41

variation
: fertility of soil of drainage basin

;
pollution ; and catastrophe

(unknown factors which destroy or drive out whole species from within
one or more stream systems). Biological factors known to be of im-
portance are: migration, activity in winter (metabolism), morpholog-
ical adaptation, physiological adaptation, diet, size, habit (e. g., sedentary
or active ) .

disease, introduction of new kinds, association of species in-
dependent of the environment, association of species showing prefer-
ence for same environment, predator-prey relationship, and modern
and primitive groups.

Rel.\tion of Distribution and Abundance to Stream Size

All of the kinds of fishes with which we are dealing exhibit fre-
quencies which vary with stream size in a very consistent and definite
manner for each species. Small streams flowing into large streams
have no more large-stream fishes than do small streams that increase
slowly over many miles of length. It can be shown that some species
which reach greatest numbers at certain points in a stream also reach
greatest numbers in other streams at points with the same drainage area,
without reference to distance from headwaters or from the mouth. In
certain species the entire population is confined to a certain stream size
with very narrow limits, while other kinds may occur in all sizes of
streams but show abundances which fluctuate aliout a certain stream
size as a mode. The young of some of the sjaecies of suckers have
their greatest frequency in smaller streams than do the adults. In most
fishes, other than the suckers, both the young and the adults occur most
abundantly in the same size of stream.

Forbes and Richardson (1909) expressed the relation of stream
size to the distribution of the diflferent species by the relative frequency
of occurrence in larger rivers, smaller rivers, and creeks. In their sys-
tem of classification all of the streams of Champaign County would prob-
ably come under the general heading of creeks. Hankinsoii" used a sim-
ilar method. Shelford', in considering this same subject of distribution
of fishes in streams, has brought out most of the principal facts of the
problem. One of the more important points he states is "that the dif-
ferent fish communities are closer together in the smaller streams."

Several methods for expressing in a statistical manner this greater
pro.ximity of fish communities in the smaller streams were tried. It

was found that the most satisfactory method was to consider the streams
in classes in which each class is twice the preceding class, that is, in a
geometrical progression. Since the streams studied here varied in drain-
age area from 0.7 up to 378 square miles, they fell very conveniently
into ten classes beginning with 0.5-1.0 and ending with 256-512 square
miles. The validity of this method of classification is indicated in Fig.

6 where the number of species per collection and the number of fishes

per square yard have been plotted from data given in the tables mentioned
on page 17. As is commonly the case, the ends of the curves are
based on smaller numbers of determinations and, hence, are more vari-

6. Hankinson, T. L., "Distribution of Fish in the Streams Aljout fliarlcston,
Illinois." Trans. 111. Acad. Sci.. 6:102-113, 101.3.

7. Shelford, Victor E.. "Ecological Succession. I. Stream Fishes and the
Method of Physiog^raphic Analysis." Biol. Bui. 21:9-34, 1911.



42 Illinois Natural History Sur\-ey Bulletin

able. In order to smooth the curves the three classes at each extreme
have been averaged and plotted, so that we now have points on the cur\'es

representing approximately equal numbers of observations. The fact

that these two biological functions of stream size give curves that approx-
imate straight lines is good empirical reason for assuming that this is

the correct method for comparing the life of streams of widely varying

sizes. There is the further convenience that the distribution of the

collections in the different size classes is fairly uniform: whereas, if ten

arithmetical classes of 0-40, 40-80, 80-120, etc.. had been used, more
than two-thirds of the total number of observations would have fallen

in the 0-40 class. It seems that this method of tabulation may be advant-

ageously extended in biological studies to compare the range of adapt-

ability of different species to different stream sizes, varying from the

smallest we have mentioned here up to, let us say. the size of the Miss-

issippi at New Orleans. If, for example, we find that the sjKJonbill cat

NuMDtH OF XJerenMINATJONJ AvtVAfttD



Fishes ok Champaign County 43

Thus, in the case of Er'unyzon succctta oblougiis, the chub sucker, which
occurs generally in all the stream systems, there are on an average 6.0
individuals per 100 square yards in streams with 8-16 square miles of

drainage area ; while in the case of Hybognatlnis luichalis. the silvery

minnow, which is restricted to the Kaskaskia River basin, there are on
an average 5.6 individuals per 100 square yards in streams with 8-16

square miles of drainage area and none dsrzclicrc.

Table I. SUCKERS

—

Average Numbers per 100 Square Yards.

Species
Drainage area of stream in square miles at point of collection

0.5 1 2 4 8 16 32 64 128 256 512

Erimyzon succetta oblongus 29.4



44 Illinois Natural History SfR\-EV Bulletin

Table IV. OTHER MINNOWS AND THE CARP-
PER 100 Square Yards.

-Average Numbers

Species



Fishes of Champaign County 45

Table VII. DARTERS

—

Average Number per 100 Square Yards.

Species
Drainage area of stream in square miles at point of collection

0.5 1 2 4 8 16 32 64 128 256 512

Boleosoma nigrum 1.0

Etheostoma coeruleum*
Hadropterus aspro
Etheostoma flabellaret

Boleosoma camurum
Diplesion blennioidest

Boleichthys fusiformis

Hadropterus phoxocephalus
Etheostoma zonaleg

Percina caprodes
Amraocrypta pellucidajl

5.9



46 Illinois Natural History Scrvey Bllletix

charging certain volumes of water. (4; The kinds and proportions of
food available to fishes in streams of diflferent sizes vary widely, and
there are parallel variations in the distribution of many fishes which
are restricted to certain food materials.

As shown in Figure 6 (page 42 j. the number of species of fishes

per collection increases downstream. In one way this may seem to con-
tradict Shelford's general statement that "communities" are closer to-

gether in small streams than in large ones, Ijut it is explicable on the
basis that the comparatively few species in the headwaters are generalised
fishes, able to live and thrive under widely varving conditions. (A fuller

discussion of these headwater fishes is given in the following section.)

Then, too, the pluralit}' of species downstream is largelv due to species

present in small numbers, except locally, in "niches" in the "mosaic" of

the aquatic environment, where they find food and shelter without com-
petition or invasion by larger, more numerous, or more generally dis-

tributed kinds.

The graph in Figure 6 also shows that the actual number of fishes

per unit area decreases downstream. But with this decrease of number
of fishes downstream there is a corresponding increase in the average
size of the individuals, so that, other factors being equal, the total amount
of fish flesh per unit area is probably almost constant. This apparent
constancy of the amount of fish flesh per unit area is a fact of practical

importance and is readily applical)le to many fisheries problems, but it

is also not without its philosophical interest. The life of streams is

ultimately made up of rain water and non-living nutritive substances

derived from the soil. This ])rospectivel}-living material is "crystall-

ized out" in the form of bacteria and other lower forms of plant life,

very much as a salt is crystallized out of a supersaturated solution when
the process is started by the addition of a crystal of the salt : and this

"crystallization" goes on until an equilibrium is established. The bacteria

and other lower forms of plant life which are nourished by non-living

material are the beginning of a long chain of organisms, each feeding

on the one before, and their interrelations approaching an equilibrium.

Fishes commonly are the end of this food chain in water. The efficiency

with which each stage in the chain utilizes the preceding one varies wide-

ly. The bacteria and other lower forms of plant life probably are effici-

ent in utilizing non-living nutritive material, and they in turn are appar-

ently utilized efficiently by the common ]ilankton organisms, but beyond

this point a discrepancy arises. Some deterniinations made by Mr. R.

E. Richardson, on the relation of the fish \iel(l of Rock River to the

yield of plankton there, have showed that the fish yield represented the

efficient utilization of only a fraction of one jier cent of the available

plankton, although comparison of careful and detailed quantitative de-

terminations of the yield of the small bottom animals ujion which most

fishes feed with the yield of fishes shows no large discrepancy. The
greatest inefficiency, or discrepancy, is undoubtedly between the plank-

ton and the small bottom animals. For the latter can take only such

plankton as comes to them on the bottom : they cannot forage in the

plankton-laden water flowing liy overhead. Obviously, what is needed to

make our streams more productive in fish is a new link in the food chain

between plankton and the small bottom invertebrates.



Fishes of Champaign County 47

Headwater Fishes

A few kinds of fishes car. withstand the rigorous conditions of ex-

treme headwaters, but these few species are aJnindant in numbers of

individuals. These species are

:

Erimyzon siiccfta oblongiis—Chub sucker
Caloslonnts coiiniicrsoiiii—Common sucker
Cainpostouia annuiahtui—Dough-liellv

PimcphcAcs notatus—Bhmt-nosed minnow
Sciuoiiliis afroiiiaciilaliis—Horned dace
Ericyinba buccata—Silver-mouthed minnow
/Ibrauiis crysolcncns—Golden shiner

Aiiiciiints iiielas—Black bullhead

These fishes must withstand water temperatures in summer up to

and exceeding 90'F. while living in pools so shrunken that the fish pop-
ulation is more than 10 times ordinary concentrations. In summer and
early autumn they must withstand wide daily variations in temperature.
In winter their ambient medium is largely converted into ice. In both
winter and summer they may be called upon to endure lack of o.xygen,

excess of carbon dio.xide, or extremes in hydrogen-ion concentration. At
any season there may be torrential rains or sudden thaws that can in a

single hour change their environment from a hot, stagnant pool or ice-

covered ditch to a flood of muddy trash-laden water or a temporary pond
in a field. When the water subsides, all the old landmarks may be gone,

or the channel may have been shifted or filled up or cut deeper. Most
other fishes, if called upon to meet such a crisis in the dead of winter

with the water temperature at freezing, would be so torpid and sluggish

in their movements that they would either be washed tail-first down-
stream or else be left stranded in some cornfield when the flood subsided.

The supply of animal food for headwater fishes is probably hap-

hazard at best and depends largely on terrestrial insects which fall into

the water in summer and on worms, insect larvae, etc., washed in by
rains. In headwaters plankton has not had time to develo]) and very

few kinds and scanty numbers of invertebrates are apparently able to

withstand the conditions. All of these fishes seem to have solved the

food question by having a very generalized diet. They all eat vegetation,

organic debris, or bottom ooze probably as occasion demands, and animal

food when they can get it, for none of them will refuse a bit of worm
in an aquarium or on a tiny hook.

These are generalized fishes, api^arently capable of meeting
all situations and reaching large numljers under conditions more rig-

orous than others can endure. They are generalized morphologically

and have a wide range of physiological adaptability. They are found
over a wider range of freshwater habitats than other fishes. They not

only tolerate pollution but in sizable streams can reach large numbers
to the exclusion of other species where pollution is moderate.

Morphological adajitation, degree of isolation, tolerance to pollution,

and other phases of the biology of these fishes are di.scus.sed in other

sections of this paper.



48 Illinois Natural History Survey Bulletin

Relation of Soil Fertility to Growth
AND Abundance of Fishes

This study was undertaken and carried on with the rather well

founded assumption that the streams of Champaign County oflfer an

unusual degree of uniformity of conditions. The data on abundance
and size of fishes, however, show a wide divergence between Spoon
River, or the East Branch of the Salt Fork, and the rest of the county.

The greater concentration of fishes found in Spoon River was not due

to a lower stage of water there than in the other streams : for all of the

16 collections in this stream were made at about an average stage of

water and were distributed as follows : 5 in July, 4 in August, and 7

in September. The total area covered in these collections was 817 square

yards, about 8 percent of the total area covered in our quantitative col-

lections throughout the county. The number of fishes taken from these

817 scjuare yards was 4,566, or more than 5 per square yard as against

the average of 3 fishes per square yard for the whole county. Thus,

on an average, fishes were twice as numerous here as in the county as

a whole. Again, the total weight of the fishes taken from this stream

was about 110 pounds, or i? percent of the total weight taken in the

county, although the number of individuals was only 16 percent of the

total number taken. That is, the individual fishes averaged from

2 to 3 times as heavy here as in the county as a whole. A compar-

ison of the average number of fishes per 100 square yards at various

points on the East Branch of the Salt Fork and its tributaries with aver-

age numbers at similar jwints for the county as a whole (except the

polluted part of the Salt Fork, where fishes are very scanty) is shown

in Table IX.

The 34 species taken in the East Branch of the Salt Fork consti-

tute a list somewhat longer than from similar numbers of collections in

other streams of the same size-range in the county. The greater num-

ber of specimens taken seems to account satisfactorily for the longer

list of species. A comparison of the average number of s]->ecies per

collection in this stream and in the county as a whole is given in Table X.

It is interesting to sec to what extent each of the different sjiecies

contributed to the increased number and size of fishes in this area. Of
the 34 species found in this stream, 25 occurred in abundances greater

than the average for the county as a whole, and 20 of the latter in abund-

ances greater than twice the average for the county as a whole. The

silver-mouthed minnow, Ericyiiiha hnccata. exhibited the greatest num-

erical preponderance over the average for the county, contributing 1 .480

of the 3.519 specimens of this species taken in the county. This pre-

ponderance is readily exiilained by its preference for a .sandy bottom, of

which this stream has much larger areas than are to be found elsewhere.

The horned dace. Sctiwtilus atrfliiiacuhUiis. here furnished 940 out of

its total 2.873 taken in the county, and the Johnny darter. Polrosouui

caiiuinuu. 309 out of 993. It should be noted that none of tlie species

of Notropis were more aliundant here than the average for the county

at large.

The increase of the total weight of fishes in this stream is even

more notable than the increase in numbers, being 4 to 5 times the aver-



Fishes of Champaign County 49

age for the county as a whole. The greatest increase in this weight was

shown hv the hlack sucker, CatosloniHS coiiiiiicrsnnii. which was not only

3/-- times as abundant here as in the county at large, but also averaged

alrout three times as large individually. The average size of a number

of other species is oloviously greater than in other streams.

The larger numlier and the larger size of fishes in this area indicate

that the conditions for survival and growth are more favorable here,

and it seems most prol^able that an increased food su]iply is the cause.

An examination of the stomach contents of a number of the lilack suck-

ers, CatostoniKS coiiiiiicrsoiiii. showed (|uantities of blackish mud and

Table IX. Abunpan-ce of Fishes ix Relation to Soil Fertility.

(Numbers per 100 square yards of water)

Stream size

(drainage

area in

sq. mi.).

Number of

collections.

Average of all

Champaign

County col-

lections except

polluted part

of Salt Forl<.

Average of

collections in

polluted part

of Salt Fork

(Disposal Plant

to County

Line).

Average of

collections in

East Branch

of the Salt

Fork where

the soil is

verv fertile.

0.5

1

2

4

8

16

32

64

128

256

512

5



50 Illinois Natural History Slrvey Billetix

ooze and little else. In this stream there were considerable amounts of

a variety of aquatic vegetation, ]:)erhaps no greater than are to be found
in other parts of the Salt Fork or in other streams, but of kinds lietter

adapted for supporting an abundance of animal food for fishes. Collec-

tions of the small bottom animals, while not quantitative, indicated a much
larger supply cf fish food.

An inquiry addressed to !Mr. E. A. Norton, of the Soil Survey.

brought the information that the soil of this region was unusually fer-

tile in plant foods, produced superior crop yields, and had a very dif-

ferent history from soils in the remainder of the county. This has

been discussed earlier (page 7).

The abundance of fishes in this stream is apparently reflected in the

fact that we took more adult snapping turtles. Chclxdm scrf'ciitiua. in

this stream than in all the rest of the county combined. This is signifi-

cant because the snapping turtle is almost, if not entirely, piscivorous

in its habit.

Champaign County is near the center of an area of several coun-
ties in which the soil is more fertile than in other parts of the state. This
area, as outlined by Mr. Norton, is shown in Figure 2. From it streams

flow outward in different directions—the Kaskaskia and Embarrass to

the south, the .Sangamon and ^lackinaw to the west, the ^"e^milion fa

branch of the Illinois) and the Iroquois to the north, and the Big \"er-

milion and the Little Vermilion (branches of the Wabash) to the east.

A casual examination of the distribution maps of Illinois fishes as given

ill the atlas accom])anying the volume by Forbes and Richardson (1909)
shows a decided preponderance of occurrences in this fertile area. A
small part of this jireponderance may conceivalily be explained by greater

numbers of collections in this area, but even so the occurrences are still

more numerous in this area. Moreover, as we have just seen earlier in

this section, if the number of occurrences is greater, the actual number
and size of fishes is greater still. It is interesting to note that the 2?

species of fishes which occurred in the East Branch of the Salt Fork
in numbers greater than the average for the county are the same sf'ccics

which show unusually high percentages of occurrences in this unusually

fertile general area as comjiared to the figures for the state as a whole.

Effects of Pollution on Growth. Distributiox, .\nd

Abuxdance of Fishes

When this study was liegun it was known in a general way, from

casual collecting during the past ten years, that certain streams in Cham-
paign County cariied pollution and that aquatic life in these streams was
more or less com]iletely altered thereby. Previous experience in aquatic

work outside the county had shown that household sewage, within cer-

tain limits, acts as a fertilizer and increases the productivity of a stream,

the fishes being of greater size, abundance, and variety—a result com-

parable to the effect of high fertility of soil just described in the East

Branch of the Salt Fork. The ]iresent study shows that an excess of

sewage results in decreases of number of kinds, abundance per unit area,

and average size of fishes. There is no lack of fertility or of plant and



Fishes oi- Champaign County 51

animal foods for fishes in these polkited streams, but the fishes cannot

tolerate the conditions or substances that result from the sewage or its

products of decomposition.

The most obvious and most important factor limiting fish life in

polluted waters is the deficiency of dissolved oxygen which occurs in

certain places and under certain conditions. Some work done a few

years ago on the oxygen requirements of fishes of the Illinois River*

showed that the number and variety of kinds of fishes taken by certain

uniform methods of fishing in the same area varied directly with the

amount of oxygen dissolved in the water. Furthermore, this variation

in relative abundance and number of kinds not only took place in re-

sponse to variations in the oxygen concentration near the lethal limit

but was. apparently, equally as effective near the saturation point of

atmospheric oxygen in water.

It is obvious that the size of fishes in these, as well as in other

small polluted streams, averages distinctly smaller than in clean streams.

Table X. Average Numbers of Species of Fishes per Collection.

(,The average number of individuals per collection was about 220.)

Stream Size



52 Illinois Natural History Survf.y Bulletin

In the Illinois River it has been shown that the carp average smaller

in the more polluted sections," and this difference in size was found to

be due to slower growth of the carp in those sections. In Champaign
County streams, however, there is no evidence that the difference in

size is due to slower growth ; it seems somewhat more probable that

the larger fishes are eliminated by low oxygen concentrations, since

they have a smaller ratio of respiratory surface lo liody size than do
small fishes.

The Salt Fork, which carries wastes from Urbana and Champaign,
the largest towns in the county, is obviously polluted over a greater
distance, and affords more complete information on the relation of

pollution to fishes, than other streams in the county.

For comparison of the polluted and unpolluted sections of the West
Branch of the Salt Fork, collections were made, at first, from approxi-
mately equal areas above and below the source of pollution, extending
from the point where the stream enters Crystal Lake Park to the bridge

just south of University Woods. In this distance the drainage area

increases from 59 to 76 square miles, the difference being due primarily

to the confluence of the Boneyard. The width, depth, rate of flow, and
kind of bottom are essentially the same throughout this distance, so

that the same variety of habitat is afforded above and below the source

of pollution, namely : long, smoothly flowing reaches, separated by
small rapids or riffles, and occasional "holes" three or more feet deep.

The results of quantitative collections made from 330 and 320 square

yards, respectively, above and l>elow the source of pollution, are shown
in Table XI. Other fishes known to have been taken from the stream

in Crystal Lake Park during the year are indicated as "-|-" in this

table. Most of the fishes taken below the Champaign-Crbana sewage
disjiosal plant were about the mouths of two tile drains.

The differences in the fish life above and below the outlet of the

sewage disposal plant are clearly due to conditions resulting from pollu-

tion in the lower section. The stream as it runs through Crystal Lake
Park and down to the mouth of the Boneyard is typical of the clean

dredge ditches of this region.

On May 10, 1928, at three points 1^. 3. and S}^ miles below the

outlet of the plant, where the above collections of fishes from the pol-

luted area were made, the stream had a nauseating odor perceptible on

the bridges above the water. The stream was then quite low, and the

weather was ordinary, warm. May weather. The rocks and other ob-

jects in the water at these three stations were covered with grayish or

brownish feathery or flocculent growths. There was a large amount

of light flocculent solid matter drifting in the water, sufficient to com-

pletely clog our seine when it was held in the current more than a few

seconds. In the quieter places along shore and behind drifts and large

objects, there were deposits of black sludge, varying from an inch to

several inches in depth, which gave oft' a strongly putrescent odor when
stirred up. Tubificid worms, which in numbers arc characteristic of

heavily polluted waters, were extremely abundant in the mud and sludge

along the shores and also among the gravel and sand in midstream.

9. Thompson, David H. "The Knothead Carp of the Ulinois River." III. X.it.

Hist. Surv. Bui., vol. 17 (art. 8), pp. 2S5-320, with II fls. 1928.



Fishes of Champaign County S3

On the riffles and in swift water there were considerable growths of

two plants tolerant of pollution

—

Cladophora glomcrata and Elodca

canadensis—which, together with Potaiuogcton pusilliis and one or two

others, are characteristic of the coarse aquatic vegetation of polluted

small streams of Illinois.

During the summer of 1928 there were heavy rains which largely

flushed out the accumulations of sludge and organic matter from the

stream bed, and the continuous operation of the disposal plant tended

to reduce further accumulations. When collections were made in Sep-

tember it was expected that the stream would appear cleaner and fishes

more abundant, but such was not the case. One small, blunt-nosed

minnow (Piiiicplialcs notatiis) and two very small green sunfish

(Lcponiis cyanelltis) were collected from a total water area of 90

square yards in the same jjlaces in which t'le spring collections were

made. There was no floating or drifting organic matter or sludge.

Table XI. Effects of Pollution in the West Branch of the Salt Fork.

Comparison of the kinds, numbers, and ma.ximum sizes of fishes taken from

appro.ximately equal areas of water in the West Branch of the Salt Fork above

and below the source of pollution on May 10 and 11, 1928. (See text, p. 52.)

Species

Notropis whipplii

Pimephales notatus

Semotilus atromaculatus

Notropis umbratilis atripes

Ericymba buccata

Campostoma anomalum

Abramis crysoleucas

Erimyzon siicetta oblongus

Catostomus commersonii

Esox vermiculatus

Lepomis megalotis

Lepomis cyanelkis

Lepomis humilis

Lepomis pallidus

Boleosoma
i

nigrum

Notropis blennius

Ameiurus melas

Labidesthes sicculus

Lepomis ininiatus

Etheostoma flabellare

Collection from

330 square yards

above source of

pollution.

Number
of fishes

+
320

22

71

126

5

74

3

6

1

12

7

3

1

6

+
+
+

Max. size

in inches

3.0

fi.l

2.5

2.3

4.8

5.1

5.4

9.8

8.0

4.3

5.1

2.3

4.6

1.2

Collection from

320 square yards

below source of

pollution.

Number
of fishes

1

1

1

18

2

Max. size

in inches

1.8

1.1

2.0

2.1

2.0



54 Illinois Natural History Survey Bulletin

such as was seen on May 10, and no large beds of sludge, but the sand
and the mud of the bottom and banks contained a large admixture of
black sludge with a putrescent odor and immense numbers of tubificid

worms. The stream gave off the same nauseating odor as was noticed

in May. The water was unusually clear for a stream in this region,

possibly from the lack of fishes that tend to stir up the sediment and
bottom muds, or else because of the agglutination and precipitation

of the silt by the abundance of microscopic organisms poured in bv the

disposal plant. Downstream from the disjxjsal plant outlet to a point

several miles below St. Joseph, there was a heavy growth of brown
diatoms : and for several miles below the confluence of the East Branch
of the Salt Fork, there were heavy growths of blue-green algae along
with the diatoms.

Collections made in September, 1928. from the West Branch and
the East Branch, at stations 1 J/2 miles above their confluence, yie'ded

in the West Branch 30 fishes, taken from about 105 square yards, all

of them belonging to four known tolerant kinds and having a total

weight of about three ounces—as against 437 fishes, of 25 kinds, taken

from 90 square yards in the East Branch and having a total weight of

about 15 pounds.
In January, 1926, when the sewage disposal plant had been in

operation about a year, a collection of fishes was made in the West
Branch of the Salt Fork at the bridge just south of University \\'oods

at the same place where the collections were made in the spring and
fall of 1928. At this time fishes were clearly more numerous than

they were found at any time in 1928. The number of kinds and the

maximum size were greater, and specimens were taken of the Johnny
darter, a species that has not been found since in the polluted section

of the West Branch, although it is more tolerant than other darters.

The 1926 data, though fragmentary, at least make it clear that four

years of operation of the sewage disposal plant have had no greater

effect than one year in cleaning up the stream.^"

Dr. T. H. Prison reports that, in the years 1912 to 1914, sunhsh,

bullheads, and suckers could be taken in fair numbers on hook and line

from the West Branch of the Salt Fork near the University Woods.
Collections made by the Natural History Survey in the \\'est Branch

of the Salt P'ork in the period 1882-1901 showed a number of species

not found in the 1928 collections, even though the latter collections were

twice as niunerous. In the older collections the white crappie and the

large-mouth black bass were taken, probably because they were planted

or had escaped from a fish hatchery which was then in operatioii in

Urbana. Besides these, the spotted sucker, common red-horse, sucker-

mouthed minnow, top minnow, brook silverside. and black-sided darter

have since disappeared, even from the stream above the source of pol-

lution. It so hapjiens that the stream above the source of pollution is just

at the upper limit of stream si.'-e in which all of them live, except perhaps

the last named : and since the stream below Urbana has become hcavilv

polluted, thev apparently have not been able to exist and m.aintain their

numbers cut off from the lower course of the stream.

UK Tn the past two years tlie plant lias been operated oontiniiously, an.i new
units li<T,ve been added whicb tend to reduce further the organic load of the stream.
A few cursory examinations made recently reflect these improvements, there being
a somewhat "greater variet>' and sfreater numbers of fishes, partieularlj- in the
lower course of the stream".—P. H. T. .luly 1. IdSO.



Fishes of Champaign County 55

Collections of Ijottom fauna and plankton were made in the West
Branch near the University \\'oods in IMay, 1929, and were identified

in the lal)oratory by Mr. Richardson. The bottom fauna collections were

made from clumps of Elodca canadensis growing in midstream and from
gravel and sand there. The most numerous animals taken from these

were two species of sludge worms, or Tubificidae. LhnnodrUus hof-

mcisteri and Tubifcx tubij'cx, which occurred in roughly 100 times the

numbers to be expected in ordinarily clean streams with gravel and

sand bottom. The presence of these sludge worms in such numbers is

indicative of a heavy load of organic matter in the water and, in general,

conditions which are distinctly pollutional. Small numbers of several

other species of small bottom animals also occurred in these collections,

but their value as indices of pollution has not lieen sufficiently studied.

One other thing was noticed which invariably indicates foul conditions—

•

the larvae of the sewage fly, Psychoda altcnmta. Furthermore, other

insect larvae found here were covered with colonial vorticellid protozoans

of the genus Epislylis. In unpolluted streams the insect larvae and other

small l)Ottom animals are habitually clean and free from incrusting micro-

organisms. The plankton sample taken here showed E/^istylis. Thiothrix,

and Rotifer tardus, all of which were probably washed down directly

from the sprinkling filter bed of the sewage disposal plant.

Determinations of the amount of dissolved oxygen in the polluted

section of the .Salt Fork, made at various times during the past two
or three years, showed amounts varying from saturation down to 3 or 4
parts per million. In those cases where a series of samples were taken

on the same day at different points on the stream the samples showing

least dissolved oxygen were taken near the outlet of the plant. Duplicate

samples taken on January 17, 1929, at a point IjA miles below the plant,

showed a biological oxygen demand of 51 and 56 parts per million. At
that time the plant was discharging at the rate of 2,700,000 gallons

per dav, and the effluent was diluted to 6 times that volume by the water

in the stream.

Occasional periods of oxygen deficiency are usually regarded as the

immediate cause of destruction of fishes by pollution. Evidence of this

came to hand in November, 1928, during other studies along the West
Branch of the Salt Fork from the bridge east of the Tuberculosis Sana-

torium down to Brownfieid Woods, points respectively lyi miles and

3 miles below the sewage disposal plant. In the early part of the month
the stream had been low and there were considerable accumulations of

sludge and putrescing organic matter along the shore and in the quieter

places. On the 14th and ISth of November, as a result of rains, the

water level rose and the sludge and organic matter were stirred up. At
this time the stream was black, smelled strongly putrescent, and had the

appearance of being septic. On the 16th and 17th the stream had sub-

sided and resumed its customary aspect. On these days several small

fishes were picked up freshly dead ; they were faded and had their

mouths agape and their opercies and branchio-stegals extended, showing

evidence of suH'ocation. Since lack of oxygen is the only well-known

means liy which pollution has its effect on fishes, it seems that lack of

oxygen must be at least the tentative explanation of the alisence of fishes

in this stream.



56 Illinois Natural History Sl'kn-ey Bulletin

The West Branch of the Salt P'ork from the sewage disposal plant

down to its confluence with the East Branch receives no tributaries other

than a few tile drains. In this stretch of about 12 miles the condition

obviously im]jroves. fishes become more numerous, of mure kinds, with

greater maximum size ; and the deposits of sludge, the nauseating odor,

and the other evidences of pollution decrease. It seems quite certain

that this improvement in the stream without much dilution is due to the

continuance and completion of biological processes of self -purification.

A collection made in September, 1928, about 2 miles below the con-

fluence of the East Branch and West Branch of the Salt Fork, showed
fishes in normal numbers, but 98 percent of them were of known tolerant

kinds, 92 percent being blunt-nosed minnows, silver-mouthed minnows,
and steel-colored minnows, which were feeding on the very heavy de-

velopment of diatoms and blue-green algae at this point. From Sidney

down to the county line, fishes occurred in about one-seventh of the

numbers normal to streams of this size. Apjjarently normal numbers
and kinds of fishes were taken just below the Homer Dam, but Richard-

son (1928) has shown that swift water, in general, offers unusual pro-

tection to species otherwise sensitive to pollution.

During the period 1919 to 1924. ;. c. before the sewage disposal

plant was put in operation, the writer collected fishes from time to time

in the two-mile stretch above the Homer Dam. Fishes taken then in-

cluded green sunfish, long-eared sunfish. suckers, bullheads, and several

kinds of minnows. When those collections are compared with collec-

tions made in the same place in 1928. no obvious increase in fishes is

apparent, although several car-loads of fishes have been planted there

since the dis]5osal plant was put in ojieration. There are reports of

crappies, carp, channel cat, bullheads, and many sunfish being taken above
the Homer Dam in 1916.

The number of species of fishes and the abinidance of each in the

polluted part of the Salt Fork, as compared with other streams of the

county, are shown in Tables IX and X.

The following list of fishes, arranged in order of decreasing toler-

ance to pollution in small streams, is based on observations in this and
other streams of comparable size

:

Semotilus atromaculatus

Pimephales notatus

Notroiiis umbratilis atripes

Ericymba buccata

Notropis whiiijilii

Aliramis crysoleucas

Lepomis cyanellus

Boleosotna nigrum
Cam]K)stoma anomalum
Erimyzon sucetta oblongus
Catostomus commersonii
Notropis cornutus

Hybopsis kentuckiensis

Notropis blcnnius



Fishes of Champaign County 57

The darters other than the Johnny darter seem to be most sensitive

to pollution. Almost all of these tolerant species find their greatest

development in headwater streams. These headwater species occur in

polluted large streams where they normally would not occur in such

numbers were the stream clean.

The Boneyard, a small creek flowing through Champaign and
Urbana and emptying into the West Branch of the Salt Fork about a half-

mile above the outlet of the sewage disposal plant, has been liadly pol-

luted with a miscellany of household and industrial wastes including oils,

gas liquors, tar, soap suds, rubbish, garbage, precipitates from water-
softening processes, drainage water from the streets, etc. This stream
is practically without fish, there having been reported within the past

few years a medium-sized black sucker, three or four very small chub
suckers, and a school of about a dozen small minnows. The effect of

the Boneyard water on the fishes of the stream below was not sepa-

rated from the effect of the effluent of the disposal plant in the present

study.

Copper Slough, a branch of the Kaskaskia, receives untreated sew-
age from the west part of the city of Champaign and is thereby so

grossly ])olluted for several miles down from its source that there was
no fish life at all in August, 1928, and even in its lower course there

were very reduced numbers of fishes. Dr. T. H. Prison reports that

some }ears ago black bullheads and horny-head chubs could be taken
where Route 10 now crosses Copper Slough.

Sewage from the village of Rantoul flows eastward about two miles

ill a ditch alongside the highway and empties into the East Branch of

the Salt Fork. It was noticed at the time of our first visit, in July,

that the ditch coming from the town (carrying undiluted sewage) stank

badly and was black with sludge, and that grayish growths of pollu-

tional protozoans or schizomycetes were abundant. The weather just

then was very warm, and by the time the sewage had reached the stream

the putrefactive processes were evidently nearly complete ; for the stream
below the mouth of this ditch was not septic, although there were ex-

tensive deposits of sludge and an obvious scarcity of the bottom animals

ordinarily found in clean streams. Fishes were abundant in the stream
below the mouth of the ditch, a quantitative collection made there show-
ing 1,866 per 100 square yards—a figure which compares well with

abundance figure for other headwater streams feeding the East Branch
of the Salt Fork. It should be mentioned, however, that 94 per

cent of the fishes in this collection were of known tolerant kinds.

The same place was visited again in November after the weather had
been near freezing for some days. Although the water level in the ditch

and in the stream was at approximately the same stage as in July, the

coolness had retarded the putrefactive processes so that they were, ap-

])arently, only well under way by the time the stream was reached : for

the stream itself was stinking and septic and entirely without fishes for

\y2 miles below the mouth of the ditch.

A few years ago many fishes were killed in a tributary of the San-
gamon as the result of jxillution by wastes from a canning factory near

Gibson Citv.



58 Illinois Natural History Sir\-ey Bulletin

Other Environ.mental Factors Affecting
Distribution and Abundance

Vegetation is a factor determining the abundance of most small-

stream fishes. The largest variety and greatest abundance of fishes

in individual collections were consistently found in situations with lux-
uriant growths of submerged coarse aquatic plants. The large number
of fishes in such places is certainly correlated with the large p^jpulations

of food organisms which these plants supjMrt. The presence or absence
of certain species, such as the pirate-perch, the golden shiner, and the

grass pike, is closely associated with the presence or absence of aquatic

vegetation.

Depth of water is an important factor in the distribution of many
fishes. The buffalo fishes, carp-suckers, gizzard shad, sheepshead, and
several of the sunfishes are found only in the deeper pools. Others, such
as the long-eared simfish, may occur in a stream of any size in the county
providing that the water is a foot or more in depth. In general, adult

fishes seek deeper water than young fishes, and large species more than

small species.

Kind of bottom and rate of flow of streams in Illinois generally

are casually related, and it is difificult to differentiate the effects of

these two factors on the distribution of fishes. Some species are

obviously more abundant on certain kinds of bottom than on others,

and a few are very .strictly limited to certain substrates, as is described

in various places in this paper. Our present data do not permit a criti-

cal comparison of total abundances of fishes on different kinds of bot-

tom, and no obvious consistent differences were ajiparent during the

course of the field work.

Effect of Fish-eating Species on Abund.vnce

The general decrease in number of fishes and increase in size of

individual fishes as we pass from the smaller to the larger streams may
be due, at least in part, to the larger number of fish-eating kinds in

the larger streams, such as the large-mouth and small-mouth black

bass and the channel cat. Our numbers of these kinds are too small to

make a statistical comparison. One of the most voracious of the typi-

callv small-stream fishes i.-; the grass pike. Excluding collections from

the polluted part of the Salt Fork, our 26 collections in which the grass

pike occurred averaged 2.49 fishes per square yard : and the remaining

86 collections, in which the grass pike did not occur, averaged 5.71

fishes per square vard—more than twice as many. The number of grass

pike producing this effect was quite small, averaging only 0.006 per

square yard. This relatively large effect of so few grass pike is under-

standable, however, because we have aquarium experiments which show

that a grass pike of average size can eat about one minnow per day.

Some Observations on Morptioi.ogicai. .Adaptations

Since the beginning of the science of biology-, close organic corre-

lation of the various parts and internal functions of an organism during

its life history has been so api^arent and so exact that workers in this

field are much given to tcleolog-ical ex]ilanations of these phenomena.



Fishes of Champaign County 59

Workers investigating the relations of organisms to their surroundings

are much more impressed by the similarity of the reactions of the dif-

ferent organisms in a given environment than by the similarity of mor-
phological adaptations found there. In this they are douljtlessly correct.

Morphological adaptation, however, should not be neglected or put aside

as vmimportant.
Among the small-stream fishes of Champaign County it has been

found that there is a readily recognizable and fairly close correspond-

ence between habit and structural adaptation, although there are many
exceptions. Non-adaptive structures, incongruities, elaborateness, and
uniformity of detailed structure are certainly not necessary from the

standpoint of the requirements of the environment : nevertheless, they

are the rule within the various races of animals and are intimately tied

up with the fundamental nature of living substance itself. The relative

importance of physiological as against morphological adaptations is a

dilemma that has been considerably clarified by recent findings in the

study of the manner of inheritance of the characteristics of living things.

It has been found that many morphological changes are inseparably as-

sociated with certain physiological qualities. It so happens that the

morphological changes are usually of trivial importance from the stand-

point of viability and usually involve such thin.gs as proportion of parts,

texture, color pattern, etc. The associated physiological qualities, on the

other hand, commonly involve such important things as number of eggs,

length of life, rate of development, viability at all stages, reactions to

stimuli, etc. If both the physiological and morphological changes are

of advantage they will survive. If both are disadvantageous they will

not survive. However, if one is advantageous and the other disadvant-

ageous the one will survive which has the greater selective value at

critical points in the life history, and the other will be carried along

willy-nilly because it is inseparably associated, even though it is unnec-
essary or even somewhat disadvantageous. The fact that hereditary

changes usually involve selective differences which are more often physio-

logical than morphological, gives a hint as to why animals show a better

physiological than morphological closeness-of-fit to the environment.
The fishes of Champaign County fall into three approximately

equal groups with respect to current : ( 1 ) Those that live in the faster,

shallower water and spend most of their time, not swimming, l)ut cling-

ing to the bottom or hiding behind or under objects which break the

force of the current. (2) Those that live in deeper and more sluggishly

moving water and spend most of their time swimming or floating but

not clinging or hiding. (3) Those that inhabit both kinds of places and
divide their time between clinging or hiding and swimming freely. As
these three groups of fishes are examined, certain morphological features

stand out as characteristic of each group.

The first group
—

"clinging" fishes—is typified by the hog sucker,

the darters, the red horses, the stone cats, and the tadpole cats. They
have a large head and a body that ta])ers from the head to the tail and
is roughly circular in cross-section : that is, they are slenderly conical.

They have large pectoral fins with which they cling or "crawl" on the

bottom. Their specific gravity is greater than that of other fishes. They
often show protective coloration by having their backs crossed by
dark bars.



60 Illinois Natural History Slrvey Bulletix

The second grou])
—"swimming" fishes—is typified by the gizzard

shad, the toothed herring, the sunfishes, and certain minnows such as

Notropis cormitus, N. uinbratilis, and A'. iMpplli. These fishes are

flattened laterally and tend to taper equally toward the head and tail from
the middle of the body. Their swimming habits are correlated with

large caudal fins and a specific gravity almost exactly the same as water.

These are the fishes that leap from the water. .Adults of several other

species have the body shape and swimming habit of this group, but

their young live in fast water and have the body shape typical of the

first group. An excellent e.xample of such a change in body shape and
habit is found in the silver carp, Cai piodcs vclifcr.

The third group
—

"generalized" fishes—has a body form typified

by the extreme headwater fishes, such as the blunt-nosed minnow, the

horned dace, the chub sucker, and the dough-belly. These fishes tend

to be circular in cross-section and to taper from the middle toward both

ends. They are commonly found in both still and fast water.

While there are many e.xceptions in one way or another to the above

classification, it still holds for most of the local fishes.

There are other local examples of structural adaptation correlated

with certain habits. F"i.shes that regularly feed from the surface, such

as the silverside (Labidesthcs siccidiis) and the top minnow (Fiiiiduliis

nofatus), have flat backs and upturned mouths. Larger fishes that hab-

itually live under flat rocks, such as the stone cat (Xotiirus flavits). are

dorso-ventrally flattened. Fishes that nuzzle the bottom and pr\- among
rocks for food, such as the various suckers and the sucker-mouthed
minnow (and elsewhere the sturgeons), have inferior, protrusible

mouths. There are three species of one genus (Ictiobiis) which are

bottom feeders but have clifterently formed mouths: the small-mouth

bufifalo has a .strictly inferior mouth, the mongrel buffalo has a mouth
tilted up at about 22° from the horizontal, and the red-mouth buffalo

has its mouth turned up at an angle of 45°. In late summer large num-
bers of red-nio'ith bufifalo have been seen sucking in the foam and float-

ing insects in the quieter eddies of Rock River, but never a mongrel or a

small-mouth buffalo. This observation is amply borne out by recent

Studies of the stomach contents of these three s]iecies.

MlGR.\TI0N, ISOL.XTION, .\XD Ch.WGES IX DlSTRIBUTIOX

The extremes of fish migration are represented by fishes taken in

Cham]iaign C<iuiity. As one extreme, there is the eel taken in the Em-
barrass River, which must have been spawned in the Sargasso Sea off

the coast of the Bermuda Islands, according to recent life-history work
on this species. As the other extreme, we have darters that live under

the rocks on riffles and may not have moved more than a few hundred
yards in many generations." The migration of most of our species,

however, is moderate.

11. A good in.st.inoe exemplifying this sedentary h.ihit came out during our
work on the Rock River. In 1927. after four years of collecting in the Rock River
basin, it seemed that our list of fishes was complete, at le.ist for the basin in

Illinois. I went to see two old fishermen, brothers by the name of McMillan, who
had made most of their living since boyhood by fishing one way or another in the
vicinity of Rockford. In order to facilitate conversation and .avoid difficulties of
different common names for the same fish and the same iMinmon name for different
llsiies, I took along the Survey's illustrated volume on the fishes of Illinois. We



Fishes of Champaign County 61

We have sufficient information to show migration for eight species

of suckers, the young of each of these species Ijeing regularly taken
much further upstream than the adults. As an example, the young of

the common red-horse were found most abundantly in streams draining

4 to 8 square miles, while the adults are known to reach their greatest

abundance in streams draining 1,000 or more scjuare miles. /. c. much
larger than any in Champaign County. The toothed herring and the
gizzard shad probably make migrations of about the same order in

larger streams, and the larger members of the sunfish family are prob-
ably capable of extended migration, although our data do not directly

indicate this. Among the minnows there are no clear examples of dif-

ferent distribution of the young and the adults in our streams, but a

certain amount of migration is indicated by the fact that headwater
minnows are regularly found in spring in small rivulets which at other

seasons dry up completely for one or more miles. None of our seven

species of catfishes gave evidence of any considerable migrations.

During 1928 and 1929, several anglers fishing in the Sangamon
River, both in Champaign County and Piatt County, have expressed sur-

prise at taking sheepshead in fair num1:)ers, a kind of fish which they

report had not been seen in the Sangamon before. This suggestion that

the sheepshead is a newcomer is sulistantiated by our findings. We took

ten specimens in the Sangamon within the county in 1928. Earlier

collections Ijy the Survey did not take the sheepshead from the Sangamon,
either in this courity or any place else along its entire length, although

this species was taken in the Illinois River and in several other streams

in the state. The specimens taken or seen in 1928 all weighed between

3 and 6 ounces—the same size, incidentally, at which the sheepshead

have been observed in thousands in May below dams on the Rock River

and below the head-gates of the Illinois-Mississippi Canal Feeder, at-

tempting to go upstream. The fact that the collections and reports of

sheepshead in the Sangamon in 1928 and 1929 are scattered over fifty

miles or more of stream, argues that these fishes have migrated upstream

from some point further down, rather than that they have been planted

locally in many places.

leafed through the book together, meanwhile checking the fishes they had seen
in the vicinity agrainst my sjtecies list for the river. T pointed to the picture of the
sculpin (Coitus ictalops) and remarked that they probahly had not seen it because
we had not taken it in our extensive program of collecting in the basin. The older
brother .spoke up and .said, "Yes. that's a doogy pawl. I call it that because it

looks like a fish by that name I used to catch \\hi'n I was a boy in Scotland."
He went on to relate that for many years they had made a business of catching
minnows foi^ the bait market in the small streams about Rockford and that there
used to be one place, and one place only, where they found the sculpin. This
place was in a small stream tributary to Sarver Creek, about seven miles north-
west f>f Rockfoi'd. They had first noticed it there some If) or 20 years previously,
and they had not been to the place for the past several years The younger
brother agreed to g(f with us next day and point out the place. When we arrived,
there was a rocky riffle aVjout 10 feet long in a tiny stream in a pasture. 'We set
our minnow net below the riffle, rolled some of the rocks over, and lifted out
3 or 4 sculpins. Then we seined just above the riffle, but got none. We seined
below the riffle and took five or six more sculpins. A few yards further down
we took none. Then we went on and seined over several himdred yards Init found
none. Persistently we seined in the vicinity of every bridge over this whole tiny
stream system, but no sculpins. For several weeks as we worked over the small
.streams of that part of the Rock River basin, we tried every likely riffle, many of
which were identical with the sculpin riffle, but nowhere did we find another
sculpin. When our sculpins were compared with others of the same species col-
lected in Indiana, they were found to 'lilTcr in several minor details of body contour
and minute structure. While the sculpin is in a different family of fi.shes from
the darters, it is of about the same size and in point of shape and haliit can best
be described as an exaggerated darter.



62 Illinois Natural History Scrvey Bulletin

There is another kind of migration that apjjhes to all our larger

fishes in Illinois streams and probably also to smaller kinds. In spring,

summer, and early autumn the larger fishes are found in all parts of the

larger streams ; some are in fast water, some in sinoothly flowing reaches,

some hiding among brush and vegetation, and some in the deep pools

of quiet water. As the water becomes cold with the approach of winter,

these fishes become sluggish and stop feeding, then retreat downstream

and join the fishes of the deep pools. In spring when the ice is gone

and the water is warmer, they ascend the stream and begin feeding. Our
investigations on Rock River have shown that the order in which the

different fishes come into the quiet pools and eddies is quite definite

and that the order in which they go out is the reverse of the order in

which they come in. Furthermore, those that come in first are generally

sluggish-water fishes ; next are those of moderate current ; and last are

those of the swift waters, such as the red-horses and the common suck-

er. In Rock River the wall-eyed pike may or may not retreat from the

fast water during winter. This pike is very active in its movements

all winter and feeds voraciously and is taken on the hook in swift water

every month in the year. The fishes soonest benumbed are those that

live in summer in the deep pools, such as the blunt-nosed river carp,

the sheepshead, the buffalo fishes, the quillback, the carp, and the gizz-

ard shad. The last-named fish seems particularly susceptible to cold,

being seriously winter-killed.

Fishes in the headwaters of the Salt Fork are but two or three

miles overland from fishes in the headwaters of the Sangamon, but as a

fish travels they are more than 1,200 miles apart. Such long distances,

doubtlessly, are traversed in a reasonable period of years by the larger,

abler, and habitually swimming species. The uniformity in contour,

color pattern, and morphological detail within such strong swimming

species as the suckers and the larger suntishes bears witness to frequent

interlireeding within the species and lack of isolation. On the other hand,

minnows, darters, and small species of other groups with feeble swim-

ming powers and with a tendency to spend most of their time in restrict-

ed habitats, such as under and around stones, among vegetation or other

cover, small eddies below riffles, etc., may he effectively isolated for

very long periods of time, esj^ecially if they are in dift'erent streams and

separated by many miles of water. Even in the same stream their dis-

tribution is "spotty" because they are sedentary or are adajited to limited

kinds of habitat.

It may lie possible, however, for some fishes to pass from one basin

to another, in such flat country as we have in Champaign County, dur-

ing prolonged periods of extremely wet weather. This is indicated in

the state distribution of the silver-mouthed minnow (Ericyinha buccata).

That this minnow should pass from one liasin to another is not at all

surprising, since we have already shown that it is an extreme headwater

si>ecies and will even ascend tile drains. The present data indicate that

interbasin passing does not occur unless it be among the extreme head-

water species. Among the isolated species in general, there is no evi-

dence of any extended migration during the spawning period.



Fishes of Champaign County 63

Among families of small fishes, ichth^'ologists have found local

races and varieties to be the rule. Among freshwater fishes commonly
inhabiting headwaters and other out-of-the-way "niches" in the environ-

ment, inordinately large numbers of species and varieties of minnows
and darters are recognized. While our Champaign County collections

have not yet been thoroughly studied with this in view, racial diliferences

in morphological detail have been found, as will be fullv reported in a

later paper. Several of these differences may be mentioned here : ( 1

)

The fan-tail darter in Champaign County is restricted to the Sangamon.
Salt Fork, and IMiddle Fork basins. Sixteen specimens from the San-
gamon and its tributaries each had 8 dorsal spines. Of 7 specimens

from the East Branch of the Salt Fork, four had 8 spines and three had
7 spines. Nine specimens from the Middle Fork and its tributaries each

had 7 spines. (2) The log perch taken in the Kaskaskia Basin have
a color pattern distinctly different from those taken from the ]\fiddle

Fork Basin. (3 ) The orange-spotted sunfishes of the Sangamon have

a body shape which differs markedly from those of the Salt Fork.

(4) Within certain small species there seem to be consistent diliferences

in the numbers of vertebrae between different stream systems.

A casual survey of the literature on geographical races among
motile animals gives the impression that isolation is a more effective

cause of racial differences within a species than is a difference in environ-

ment to which an animal may respond directly in one generation or be

gradually adapted over many generations. If this be true, the explana-

tion of geographical races is to be sought in terms of the properties of

the germplasm and of the growth of populations rather than in terms

of the response of the organism to the environment. Every species that

has lieen studied genetically has shown heritable variations of greater

or less degree. Furthermore, these heritable variations are continually

arising dc novo liy changes in the germplasm due to causes entirely un-

related, as far as is known, to ordinary variations in the physical environ-

ment. While most of these heritable variations are disadvantageous to

the animal and are rapidly eliminated, many of them are of indifferent

selective value and mav persist. Yet it is a significant fact that no

heritable variations have been found which are more viable and can

crowd out the "wild tvpe." This superlative position of the "wild tvpe"

suggests that it represents the highest possible combination of hereditary

factors affecting viability, and if so. variations in viability can occur

only in the downward direction.

It is common experience that a pojiulation of a species is at all times

heterogeneous, its degree of heterogeneity being dependent primarily on

the rate of origin of variations de novo as compared with the rate of

their elimination due to selectivity and the degree of inbreeding. The
degree of inbreeding is important because it is a common fact of all

population studies that the population of a species within an isolated

area at any one time is not descended from the entire population of

that species in that area, let us say several generations earlier, but from

a fraction of it. If. in anv generation, by chance, the parents of the

next generation are all homogeneous for some indifferently selective,

heritable variation which has arisen dc novo, then the character of the



64 Illinois Xatural History Survey Bulletin

whole population will have been changed without regard to the selective

value of the variations or environmental differences. Since these herit-

able changes arising dc novo are fixed in ]30])ulations by chance, the

proliability is infinitely small that the same changes will arise and be

fixed in isolated jjojjulations. Hence, as long as populations are isolated,

heritable differences from the original condition, and from each other,

will accumulate. If. however, interbreeding is occasionally ])ossible be-

tween partially isolated populations, their differences will tend to be

ironed out, likewise, by chance.

Of the 74 species taken within the county, there are 17 which have

been collected in sufficient numbers to avoid errors due to random samp-

ling and which are absent from one or more of the six stream systems.

Furthermore, these 17 kinds include only those species whose preferred

habitat and stream she are known to occur generally in the streams from
which they are absent. These species are listed below, together with the

stream systems in which they have been taken.

Sf'ccies Sircaiit Systems

Pimephales promelas ~ Sangamon

Hybognathus nuchalis Kaskaskia

Notropis gilberti Sangamon

Notropis atherinoides var Middle Fork

Notropis illecebrosus —Middle Fork

H.\bopsis amblops Middle Fork. Salt Fork, Embarrass

Cliola vigila.x Sangamon, Salt Fork

Schilbeodes gyrinus Salt Fork

Schilbeodes miurus — ~SaIt Fork

Lepomis humilis Sangamon. Middle Fork. Salt Fork,

Embarrass

Aphredodcrus .sayanns -Sangamon. Embarrass. Kaskaskia

Labidesthes siccnlns Salt Fork

Etheostoma coeruleum .\11 but the Kaskaskia

Etheostoma flabellare Sangamon, Middle Fork, Salt Fork

Etheostoma zonale Sangamon

Diplesion blennioides Middle Fork. Salt Fork. Embarrass

Ammocrypta pellucida -Middle Fork

As these fishes are examined to see what they have in common, we
find, first, that they are all small, the largest specimen among them be-

ing a Hybognathus nuchalis 3'4 inches long. More than half of them
are clearly sedentary in habit and spend most of their time hiding. All

of them are specialized ]ihysiologicaIly. since they are restricted to siiec-

ial kinds of habitats which are usually of discontinuous distribution.

Our findings on these fishes correspond, both in general and in detail,

with the data on their distribution in the state and in the county as given

by Forbes and Richardson in "The Fishes of Illinois." and with Han-
kinson's data in the "Distribution of Fish in the Streams about Charles-

ton, Illinois. "'-

12. Loc. cit.



Fishes of Chame-aign County 65

Since the streams of Champaign County are so similar and offer

the same variety of habitats, it may be assumed that the absence of one

of these species from a stream system is due to one of two things : either

that it may never have extended its range into that stream, or that it

may have been there formerly but is now absent as a result of some

catastrophe which wiped it out. Both of the.se explanations are nec-

essary to account for all the data. The first applies to Diplcsion blcnni-

oidcs, Notropis iUcccbrosus, and Schilbcodcs uiiurus, which are strictly

limited to the Wabash drainage in Illinois, and Ethcostoma aonalc, No-
tropis gUhcrti. and Piuicphalcs proiiiclas. which are limited to the Mis-

sissippi drainage. The second explanation covers certain changes in the

distribution of individual species in the county during the period l)e-

tween the earlier collections of the Survey and the present ones—changes

which indicate catastrophes of one kind or another; disease, an ex-

ceptionally cold winter or hot summer, pollution, predators, etc.

The most pron.ounced case of increase in abundance is found in the

horned dace (Scui'Otilus atromaculatus) in the Salt York. In the period

1882 to 1901 not a single specimen of this species was taken in the 25

collections of fishes made in this stream and its tributaries, but in 1928

it occurred in 48 out of our 52 collections in the same areas, which thus

contributed 1,547 of the total of 2,873 specimens taken this year in the

whole county. At the time of the earlier collections small hatchery

ponds were maintained in Urbana by the Illinois Fish Commission, and

they were stocked with a variety of fishes from various parts of the

state. A collection of fishes made in this hatchery by Professor Frank

Smith and Mr. R. W. Mills in November, 1898, included among a mis-

cellany of other fishes 3 specimens of the horned dace between 4 and 7

inches long. It seems very likely that individuals escaping or being

released from this hatchery into the \\' est Branch served as seed for the

stocking of the entire Salt Fork basin, which formerly did not contain

this species. The suitability of the Salt Fork as an environment for

horned dace is witnessed by their greater abundance in this stream at

present than in other parts of the county. It would have been most

interesting to follow their spread and multiplication in this system, to

see how closely their numbers conformed to the logistic curve of popu-

lation growth ; but without such evidence the length of time involved is

entirely problematical.

Another case of remarkable increase is that of the silver-mouthed

minnow (Ericyiiiba bnccata). No minnows of this species were taken

in the 8 collections made in May, 1901, in the Sangamon in Champaign

County, and only one was taken then in Piatt County; but during last

year silver-mouthed minnoAvs have been fourid in 26 of the 29 collec-

tions from that stream, which has thus furnished 1,547 of the 3,519

specimens taken from all the streams of the county.

Evidence indicating the recent appearance of the sheepshead in

the upiier Sangamon has already lieen presented.

These cases indicate clearly that certain fishes can fare well in places

other than their original habitats. With nKxlern transportation facilities

and fishes being carted hundretls of miles alive, both for stocking pur-



66 Illinois Natural History Slrvey Bulletin

poses and for bait, it seems certain that within a comparatively short

period evidence concerning the original distrilnition of fishes, as well

as racial distinctions, will be obliterated.

There is evidence that the small-mouth black liass is more abundant

in the Sangamon now than formerly. None of this species were taken

in the 8 collections made in 1901, but 12 of the 29 collections made
there in 1928 contained the small-mouth, and these 12 collections fur-

nished 35 of the 44 specimens taken this year in the whole county. It

also seems to have increased in the Middle Fork in the same perio<l ; for

none were taken in the 3 earlier channel collections while 9 were taken

in the 4 recent channel collections.

There is some evidence of decreases in the abundance of several

species. The silvery minnow (Hyhoqnathus michalis) was taken in 2

out of the 8 former collections in the Sangamon, but not at all in the

29 recent collections in the same stream. The spotted sucker (Miiiytrciiia

nielano/^s) was formerly taken in both the Sangamon and the Middle

Fork, but not at all in 1928. It is possible that the increase in small-

mouth Ijlack bass in these two streams may have had something to do

with the disappearance ot the above fishes.

A number of sjiecies formerly present in the stretch of the Salt

Fork between Urbana and the Homer Dam are now absent, obviously

because they are not tolerant to jiollution.

A few other species in other streams of the county may have changed

their range or abundance, or both, since 1901, but the earlier collections

were not extensive enough to justify statistical comparisons excejit in

the Salt Fork and the Sangamon.

The above observations on changes in distribution do not substan-

tiate the view that the fish life of a stream is a highly integrated whole

to which nothing can be added or subtracted without upsetting the

"balance."

Assori.Miox OF Speciks

Most instances of the associatior. of difl'erent s]iecies of fishes arc

explained satisfactorily l)y similar environmental preferences. This

phase of the ecology of Illinois fishes has been treated very comi^letely

and critically bv Professor T'orbes in "Fresh-water Fishes and Their

Ecology," and "(^n the Local Distribution of Certain Illinois Fishes:

an Essay in Statistical Ecology." In these pajiers he has presented co-

efficients of association of certain species with certain other si)ecies and

with certain environmental cliaracteristics. Tables of such coefficients

for importar.t food and game fishes and their assiKintes can be put to

good use in fornmlating principles for the efficient management of our

waters and in making recommendations for planting important fishes

in waters where they are not already present. In actual jiractice a liodv

of water in which planting is to be done would be inspected as to its

general features and the more abundant kinds of fishes noted. Desirable

kinds of fishes not already present would he selected for successful

planting from those showing high coefficients of association, el.sewhere.



Fishes of Champaign County 67

with fishes already present and with the general features of the aquatic

environment.

An instance of another order of association of species came to light

in the course of the present study, a new order of association that is

distinguished by its extreme exactness. It apjiroaches the order of cor-

rellation to be expected between males and females of the same species

and implies that at some stage in their life history the presence of both

species is necessary for the maintenance of a large population of either.

This new kind of asscciation was discovered in the relations of two
large minnows: the horny head, Hybopsis kcnfuckiensis; and the

shiner, Notropis conuitus. One or both of these minnows were taken

in 55 of the 132 collections in the county, and all but two of these 55

collections were made in three river systems—the Sangamon. Kaskas-
kia, and Middle Fork—the two exceptions being in the .Salt Fork basin.

Nntropis cornutiis occurred in 54 of these 55 collections and Hybopsis
kciitiickicnsis in 46 of them. To put it on the basis of number of indi-

viduals: 2,618 specimens of Notropis cornutus were taken in all, of

v.'hich 2,590 were in the same collections with Hybopsis kcntuckiensis

;

and of the 1,221 specimens of Hybopsis kcntuckiensis, 1,217 were taken

in collections with Notropis cornutns. The actual number of each of

these species in each of the 55 collections in which one or both were

taken during 1928 is shown in Table XII.

An inspection of the distribution maps of these two species indi-

cates that they both are restricted to certain systems very much as the

.seventeen other species which have been described earlier in this paper

as showing isolation. There are. however, several important points in

which these two fishes do not conform with the characteristics of other

species with a restricted distribution. All our other restricted fishes

are small (not exceeding 3j/i inches in length in this area) and either

sedentary in habit or restricted to certain limited types of environment,

liut these two are our largest minnov.'s, specimens of both having been

taken more than 6 inches in length. Furthermore, they are both strong

swimmers and are not sedentary in any sense of the word. Neither

are they restricted to any limited type of environment, both of them hav-

ing beeri found in almo.=t every type of stream environment in this area.

It is often mentioned in the literature that Notropis cornutus is a

typical small-stream fish while Hybopsis kcntuckiensis is more charac-

teristically found in large rivers. This difi^erence is not indicated by our

Champaign County data. Following is a tabulation of the average num-
bers of these two species per 100 square yards of water area in streams

whose sizes are expressed in square miles of drainage area

:

12 4 8 16 .32 64 128 256 512

h'ofrflpis cornutus W.O 25.0 8.8.8 64.3 132.6 141.0 31.7 35.8 10.8

Hybofsis kculiu-lnexsis 4.5 2.0 46.9 74.1 33.6 11.3 17.6 9.2

The largest sjiecinien of the shiner was taken in the same collection

as the largest chub' There is, moreover, a general correspondence

between the sizes of these two fishes in all our collections in the county.



68 Illinois Natural History Sur\xy Bulletin

The association of these two species is not obviously a predator-

victim relationship, because studies of their stomach contents show them
both to be omnivores, taking either plant or animal foods of a wide

variety. For many 3ears I have taken these two fishes in almost equal

numbers on trout flies and a variety of other baits on the riffles of Wild
Cat Creek near Lafayette, Indiana.

The degree of association of these two species in the state at large

does not appear so exact as in Champaigii County. One or both of them
occurred in 203 of the 1,800 collections of fishes reported by Forbes

and Richardson. Notropis cormitus occurred in 185. and Hybopsis
kiVtiuckiensis in 139, of those 203 collections. On the basis of numlDers

of individuals : 725 of the 855 specimens of Hybopsis kciitiickicnsis

taken in the state were taken in the presence of Notropis cormitus;

Table XII. Numbers of Hybofysis kcntuckicnsis and Notrof>is coniutus and

total of all fishes in Champaign County collections in which one or both of these

species occur. Arranged in order of decreasing stream size within each stream

system.

Hybopsis



Fishes of Champaign County 69

conversely, 2.184 of the 2,666 specimens of Nofropis corniifiis were
taken with Hybopsis kentuckiensis. The lower incidence of these two
species and the comparative smallness of the earlier collections would
tend to lower the probability that specimens of lioth would be included

in any given collection. However, the state-wide data does contain

some evidence that one of these species, particularly Notropis coniutus,

can occur in larger streams independent of the other.

The general distribution of Notropis cornutus is given bv Jordan
and Evermann^^ as,—^"Entire region east of the Rocky Mountains ex-

cepting the South Atlantic States and Texas : aluiost everywhere the

most abundant fish in small streams. Its variations are great, some of

them appearing like distinct species." The general distribution of Hy-
bopsis kentuckiensis is given as.

—
"Pennsylvania to Wyoming and Ala-

bama, on both sides of the Alleghenies ; everywhere abundant in the

larger streams, seldom ascending small brooks : western specimens
usually have the teeth in two rows. Variable."

Reports on the fishes of many other areas within the range of these

species clearly indicate a correspondence of the detailed distribution of

the chub with the shiner.

The explanation of why these two species show isolation in cer-

tain stream systems seems to be embodied in the nature of their associ-

ation. It may be that, while they are necessary to each other's exist-

ence at least to attain abundance, the necessity of their association ex-

tends over only a part of their life history, so that they can move into

other areas independently of each other. Whether or not they shall

occupy the new area, may then depend on the small probability that they

should both get there at the same time.

Summary

Champaign County, which is nearly level u|)land plain, embraces

the neighboring headwaters of six stream systems which diverge in

various directions, sending their waters into the tributaries of the

Wabash on the east and the Mississippi on the west.

Quantitative collections containing 28,905 fishes were made in

1928 from 132 l.icalities on these streams, and with these were com-
bined for study the product of 40 collections from this same area, made
in the course of a general survey of the fishes of the State in the period

1882-1901. The identity of the specimens from all these collections has

been determined, and the data of their distribution and abundance in

the different seasons and in the several habitats of each stream have

been organized to show factors affecting distribution. These two series

of collections, together with a few miscellaneous collections and reports

from Champaign County, include representatives of 74 species.

1.3. Jordan, David Starr, and Kvermann. Barton Warren: "Thc> Fishes of

North and Middle America." luilietin 47, Smithsonian In.ititution, V. H. .National

Mu.seum. ISflC.



70 Illinois Natural History SuRrey Bulletin

From the data of 1928 it appeared that the streams of the county

contained an average of three fishes per square yard of water, equiva-

lent to 15,000 fishes per acre, with a total weight per acre of about 150

pounds.

Data of temperatures and rainfall are given for 1928, when the

collections were made, and for the 26 years during which accurate ob-

servations have been recorded.

Dredging of the streams for farm drainage is common, and its

efifect on the fishes are temporarily serious : but erosion and the growth
of water plants and of stream-side shrubs and trees presently repro-

duce original conditions, so that the general effect of dredging is not

important.

The coarse aquatic plants of the waters of the county are listed

with statements as to the situations in which they occur.

Nine principal classes of habitats in Champaign County streams

are recognized, and the species of fishes most characteristic of each

are listed.

The number of fishes per unit area varies from seven per square

yard in extreme headwaters down to two per square }'ard in the larger

streams, Init this decrease in number of fishes downstream is more than

counterbalanced by an increase in the average size of the individual

fishes.

In comparing the range of stream sizes which different species

inhabit, it was found most satisfactory to throw the data on drainage

areas into size classes which increase as a geometrical jirogression. each

class being made twice the preceding class : for the numbers of fishes per

unit area and the numbers of species per collection, when plotted against

stream sizes on this scale, give curves that approximate straight lines

—

a good empirical reason for assuming that this is a correct method of

comparison.

Some species which reach their greatest abundance at certain jxiints

in a stream also reach their greatest abundance in other streams at

points with the same drainage area, without reference to distance from
source or mouth.

Some species are sharply limited to a certain stream size, while

others are more generally distributed but fluctuate about a certain stream

size as a mode.

Although the young and adults of most s]>ecies reach their greatest

abundance in streams of the same size, the you»g of certain sjiecies of

suckers regularly occur in smaller streams than do adults of the same
species.

Fishes of the e.xtreme headwaters are the hardiest, most tolerant

of pollution, and most nearly omnivorous.

Correlation between unusual fertility of soil and abundance, rate

of growth, and adult size of fishes is illustrated by an extraordinarily

productive tract drained by Spoon River which yielded twice as many
fishes to a given area and four to five times as many pounds of fish as

the average for the county.



Fishes of Champaicn County 71

The effects of pollution are illustrated by an extreme scarcity of

fishes—as for example, downstream from Champaign and Urbana, not-

withstanding the operation there of a modern sewage disposal plant

above which there were thirty times as many fishes per unit area and
four times as many kinds as below. (See footnote 10, page 54.

)

There are distinguished three types of morphological adajitation of

fishes to the size of streams and velocity of their flow.

Notwithstanding the close neighborhood of the headwaters of the

different stream systems and the similarity of their habitats and of

their drainage basins, the local distribution of their species is so re-

stricted that 17 species are wanting in from one to five of the six

stream systems of the county ; but examples are given of the ability of

species thus isolated to survive and multiply in other waters if they

gain access to them.

Attention is called to the indispensable importance of a knowledge
of the natural limitations of the distribution and survival of economic
species in different habitats, without which wasteful efforts will be made
to introduce desirable species where they cannot thrive.

Two species, Hybopsis kcntttckicnsis and Notropis coninttis, ex-

hibited an extraordinary and unexplained association, being found to-

gether in 99 per cent of the collections in which either one of them
occurred.

DISTRIBUTION MAPS

On the following pages distribution maps are shown for all species which

were represented by ten or more specimens in the collections of 1928. Circles

indicate places where collections were made in 1928, and triangles where collec-

tions were made in the period 1882-1901. The occurrence of each species is

indicated by the use of these symbols in solid black. (For index, see p. 99.)



72 Illinois Natural History Slrvey Bulletin



Fishes of Champaign County li

_?JS



74 Illinois Natural History Sl'rv-ev Bl-lletin



Fishes of Champaign County 75



76 Illinois Xatural History Sur\'EV Bvlletin



Fishes of Champaign County 77



78 Illinois Natural History Sur\-ey Bulletin



Fishes of CHAiirAicN County 79



80 Illinois Natural History Slrvey Bulletin-



Fishes of Champaign County 81

-JS



82 Illinois Natl-ral History Slr\-ey Bulletin



Fishes of Champaign County 83



84 Illinois Natural History Sirnxv Bulletin



Fishes of Champaign County 85



86 Illinois Natural History Survey Bulletin-



Fishes of Champaicn Couxty 87



83 Illinois Natural History Svrvey Bli.leti.v



Fishes of Champaign County 80



90 Illinois Xatural History Survey Bulletin



Fishes of Champaign County 91

—-J



92 Illinois Natural History Sur\-ev Bulletin-



Fishes of Champaign County 93



94 Illinois Natural History SfR\'Ey Bulletin



Fishes of Champaign County



96 Illinois Natural History Sur\-ey Bulletin



Fishes of Champaign County 97



98 Illinois Natural History Survey Bulletin-

APPENDIX

Revised Names of Champaigx Couxty Fishes

Xaines used b)- Jordan in "Manual
Names used by Forbes and Rich- 1 of the \'ertebrate Animals of the

ardson in "The Fishes of Illinois." Northeastern United States." 13th

1909. ed.. 1929.

Aiiguilla chrysypa Anguilla bostoniensis

Ictiobus cyprinella Megastomatobus cyprinella

Carpiodes vclifer „Carpiodes cyprinus

Catostomus nigricans - -. Hypentelium nigricans

Moxostoma breviceps „ Moxostonia macrolepidotum

Pimephales notatus Hyborhyiichus notatus

Abramis crysoleucas _......Notemigonus crysoleucas

Cliola vigilax _Ceratichthys vigilax

Notropis cayiiga __ Hybopsis hcterolepis

Notropis blennins Hybopsis deliciosus

Notropis gilberti Hybopsis dorsalis

Notropis illecebrosus - Hybopsis boops

Notropis whipplii Cyprinella wbipplii

Notropis cnrnutus Luxilus corniitus

Notropis pilsbr\i Hydrophlox zonatus

Notropis umbratilis atripes Lythrurus umbratilis cjanocephalus

Hybopsis aniblops Erinenuis hyalinus

Hybopsis storerianus Erinemus storcrianus

Hybopsis kentuckiensis Nocomis bigiittatus

Leptops olivaris Opladehis oli\-aris

Schilbeodes cxilis Rabida exilis

Scliilbeodts niiiirus Rabida miuriis

Fuiidulus notatns Zygonectes notatus

Lepomis c>anellus _Apomotis c\-ancllus

Lepomis miniatns Sclcrotis niiniatus

I^cponiis nicgalotis Xenotis niegalotis

Lepomis humilis .A.llotis humjlis

Lepomis pallidns Helioperca mcisor

Micrnptcrns salmoides Huro salmoidcs

Hadroptcnis phoxocephalus Alvordins plioxocephaliis

Hadroptcrns asnro Alvordins niaculatus

Diplesion blcnnioides ~ Etheostoma blcnnioides

Boleosoma camnrum Vaillantia caniura

Ammocrypta pcllucida „ -.Vigil pellncidus

Etlicnstoma zonale Nanostoma zonalc

Rtlicostnma jcssiae .Oligocephalns jessiac

Etheostoma cocnileuiTi _ _ _01igoceplialns coenilens

Etheostoma flahellare Catonotns flabellaris

Boleichthys fusiformis Hololcpis fnsiforniis



Fishes or Champaign County 99

INDEX TO NAMES OF SPECIES

Abrainis crvsolcucas, 34, 35, 36, 44, 47

S3, 56: Map 15, p. 79.

Aiiiblol^lilcs nipcstris, 29, 44.

Amciiin's mclas, 26, 35, 39, 44, 47, 53;

Map 31, p. 87.

Awciunis natalis, 26, 44; Map 30, p. 86.

Ainmocrvfta pelliicida, 33, 45, 64; Map
48, p. 95.

AngniUa chrysyfa, 17, 19, 45.

. ll'hrcdodenis sayanus, 28, 36, 45, 64

;

Map 38, p. 90.

AplodiiiDttis i/ninniens, 33, 39, 45 ; Map
52, p. 97.

Banded darter, see Eihcostoma sonalc.

Big-eyed chub, see Hybopsis amblops.

Big-eyed minnow, see Xolropis Ulccc-

brosiis.

Big-moutli buffalo, see Ictiubiis cvpriii-

c'.la.

Black bullhead, see Ainciunis mclas.

Black crappie, see Pomo.ris sparoidcs.

Blackfin minnow, see Notnipis iniibra-

tilis alripcs.

Black-head minnow, see Piiucphuics

proiiiclai.

Black-sided darter, see Hcidrol^lcrus

aspro.

Black sucker, s;e Caloshnniis cnnimcr-

sonii.

Bluegill, see Lcpontis pallidiis.

Bhmt-nosed minnow, see Piiiicplwlcs

noUjIiis.

Bhmt-nosed river carp, see Carpiodcs

diP'oiiitis.

Bnlcichtliys fusifornus. 33, 45.

Bolcosonia cavuinim, 33, 45, 48.

Boleosoma nigrum. i2, 36, i'/, 45, 53,

56; Map 47, p. 95.

Bream, see Abrainis crysolcucas.

Brindled stonecat, see Schilbcodes

niinnis.

Brook silverside, see Labidcstlics sic-

culus.

Bullhead minnow, see Cliola vigilax.

CampDstonni anonialnnt. 23. 34, 35, 37,

40, 43, 47. 53. 56; Map 11, p. 77.

Carp, see Cvprinns carfio.

Carfindcs difformis, 21, 39, 43; Map
2, p. 72.

CarHodc; vcliicr. 21, 37. 38, 43, 60;

Map 3, p. 72i.

Catnslomus commcrsonii. 21, 35, 36, 37,

38, 39. 40, 43, 47, 49, 53. 56 ; Map 6,

p. 74.

Caliistonius niijru-ans. 21, 37, 38, 43;

Map 7, p. 75.

Cayuga minnow, sec .\'<)lr(if>is cayiiga

alrocaudalis

Chacni'bryllus gulosns, 29, 44.

Channel-cat, see Ictalnnis piinclatns.

Chub-sucker, see Erimyson succlla ob-

longns.

Cliola vigilax. 2i, 44, 64; Map lo, p. 79.

Common red-horse, see Mo.votoina
anrcolutn.

Conmion shiner, see Notropis cornutus.

Common sucker, see Catostomns com-
mcrsonii.

Creek Chub, see Scniotitus atromacii-

lalns.

Cvpr.nus carpio, 23, 39, 44; Map 10,

p. 76.

Diplcsion blennioidcs, 31, 37, 45, 64, 05

;

Map 46, p. 94.

Dorosoma cepcdianum, 19, 39, 45; Map
1, p. 12.

Dough-belly, see Campostuma anoma-
lum.

Eel, see Anguitla chrysypa.

Ericvmba biiccata, 25, 35, 37. 40 ,44, 47,

48^ 53, 56, 62, 65 ; Map 24, p. 83.

£)(';)( v-c')/ siicctta oblongus, 21, 34, 30,

43, "47, 53, 56 ; Map 4, p. 73.

Esox z'cnniculatus, 27, 35, 36, 45, 53;

Map 35, p. 89.

Ethcostama cocrulcuin, 33, 37, 45, 64;

Map 50, p. 96.

Ethcostonia flabctlarc. 33. 37. 45, 53,

64; Map 51, p. 97.

Ethcoslonia jcssiae, 17, 33.

Ethcostonia zonale, 33, 37, 45, 64, 65

;

Map 49, p. 96.

European carp, see Cypriniis carpio.

Fan-tailed darter, see Eihcostoma jla-

bcllarc.

Fathead minnow, see Piincphalcs prom-
clas.

Fiddler, see Ictaturus pnnctalns.

Fine-scaled sucker, see Catostomns
commcrsonii.

Fnndulus notatus. 28, 36, 45, (.0; Map
3b, p. 89.

Carman's sunfish, see Lcpomis minialus.

Gilbert's minnow, see I^'olropis gitbcrti.

Gizzard-shad, see Dorosonm ccprdi-

aiinni.

Golden .shiner, see Abrainis crysolcnca.'-.

Goggle-cyc, see Ambloplilcs rnpcstris.

Goujon, see Lcptops olivaris.

Grass pike, sec Esox rcrmictilatiis.

Green-sided darter, sec Diplcsion l>lcn-

nioidcs.

Green sunfish, see Lcpomis cynncllns.

Iladroptcnis aspro, 32, 45 ; Map 44,

p. 93.

Iladroptcnis phoxoccphahis, 32, 45

;

Map 45, p. 94.

High-back buffalo, sec Ictiobus bubalus.



100 Illinois Natural History Survey Bulletin

Hiodoii lcri;isiis. I'J, 45.

Hogsucker, see Catoslomns nigricans.

Horned dace, see Scmotilus atromacu-
iatns.

Horned pout, see Aniciunis mclas.

Horned shiner, see Xotrnpis corniUus.

Horny-head, see Hybof^sis kcntucki-

cnsis.

Hybognalhus iiKihalis. 23, 43. 64, 66,

Map 12, p. 77.

HYbopsis ambln/'s, 25, 37, 44, 64; Map
27, p. 85.

Hvbopsis kciitiickicnsis. 26, 36, 37, 38,

40, 44, 56, 67, 68, 69, 71: Map 28,

p. 85.

Hybopsis storcriainis, 17, 26.

Iclalunis puiictatus. 26, 37, 38, 39, 44

;

Map 29, p. 86.

Ictiobiis biibaliis. 17, 20.

Ictiobus cypriiiclh. 20, 39, 43.

Ictiobus urns, 20, 43.

Johnny darter, see Bolcosotiw nigrum.

Kentucky chub, see Hybopsis kcnlucki-

cnsis.

Labidesthcs sicculus, 28, 45, 53, 60, 64;

Map 37, p. 90.

Large-mouthed black bass, see Microp-
Icnis saUnoidcs.

Lcpomis cxancUus, 30, 35, 36, 38, 44,

53, 56; Map 39, p. 91.

Lcpomis Iiumilis. 30, 38, 44, S3, 64;

Map 41, p. 92.

Lcpomis luciinlotis, 30, 36, 38. 44. 53

;

Map 40, p. 91.

Lcpomis miniatns, 30, 44, 53.

Lcpomis pallidiis. 30, 44. 53.

Lcptops olivaris. 17, 27, 44.

Little pickerel, see Eso.v zcniiicnhitiis.

Log percli, see Pcrcina caprodcs.

Long-eared sunfish, see Lcpomis mcga-
lotis.

Microptcnis doloiuicii. 30, 38, 44; Map
42, p. 92.

Microptcnis salnioidcs. 31, 39, 44; Map
43, p. 93.

Minvtrcnia mclonops. 21, 43, 66; Map 5,

p,-74.

Mongrel buffalo, see Ictiobus urns.

Moon-eye, see Hiodon tcrgisns.

Mci.rnstoma anisnnim, 21.

Mo.vostnma aurcolnni. 21, 37, 38, 39,

43; Map 8, p. 75.

Mo.vosloma brcviccps. 21, 38, 39, 43;

Map 9, p. 76.

Mud-cat, see Lcptops olivaris.

jVolropis athcriiioidcs. 25. 43, 64 ; Map
22, p. 82.

Nolropis Idcnnins, 24. 38. 40. 43. 53. 56;

Map 17, p. 80.

Kolropis cayuim otrocundidis, 24. 4.\

Notropis cornulus, 25, 36. 37, 38, 40,

43, 56, 60, 67, 68, 69, 71; Map 20,

p. 81.

Sotropis iiilbcrti 24, 43, 64, 65 ; Map
18, p. 80.

A'otropis illcccbrosus. 24, 43. 64. 65.

Xolropis pilsbryi. 25, 43 ; Map 21, p. 82.

A'otropis uinbralilis atrifcs, 25, 57, 40,

43, 53, 56. 60 ; Map 23, p. 83.

Notropis -cMpplii. 24, 37, 38, 40, 43. 53.

56, 60 ; Map 19, p. 81.

Xotiirus flavns. 27, 37, 44, 60; Map 32.

p. 87.

Opsopocodiis cmiliac. 23, 44.

Orange-spotted sunfish, see Lcpomis
Iiumilis.

Pcrcina caprodcs, 32, 37, 45.

Phcnacobius mirabilis, 25. 37, 44 ; Map
25, p. 84.

Pilsbr>'s minnow, see Xolropis pilsbryi.

Pimcplialcs nolatus, 23, 34. 35. 36. 37.

38, 40, 43, 47, 53, 56; Map 14. p. 78.

Pimcplialcs promclas, 23, 43, 64, 65;
Map 13, p. 78.

Pirate-pcrcli. see .Aphrcdodcrus sayaiius.

Pomo.ris annularis. 29, 38, 44.

Poino.i'is sparoidcs, 29, 39, 44.

Quillback, see Carpiodcs zctifcr.

Rainbow darter, see Etheostoma cocru-
Icum.

Red-moutli buffalo, see Ictiobus cxprin-

clla.

Red-tail, see Mo.vosloma brcziccps.

Rock bass, see .iiubloplilcs rupcstris.

Round buffalo, see Ictiobus urus.

Sand darter, see Ammocrypla pcllucida.

Schilbcodcs c.rilis. 27. 44.

Schilbcodcs oyrinus, 27, 44. 64: Map
33, p. 88.

Schilbcodcs iniurus. 27, 44, (>4. 65; Map
34. p. 88.

Scmotilus atromaciilatus. 2}. 34. 35. 3('\

37, 40, 44. 47. 48. 53. 56. (.5 ; Map 26,

p. 84.

Sharp-nosed darter, see Hadroptcrus
pho.voccplialus.

Sheepshcad, see .Aplodinotus grunnicns.

Shiner, see Xolrol>is athcrinoidcs.

Short-lieaded red-horse, see .\foxosfoina

brcviccps.

Silver chub, see fiybopsis amhiops.
Silver carp, sec Carl<iodcs '•clifcr.

Silvertin, see S'olrofts ^ihipplii.

Silver-nioutbcd minnow, see Rricymha
buccota.

Sil\ery minnow, see Hybofinalhus niiclt-

alis.

Slender stonccat. see .'Schilbcodcs exilis.

Sninll-incnitiicd black bass, see }ficrop-

lc"us dolomicu.



Fishes of Champaign County 101

Small-mouth buffalo, see Ictiobiis bit-

bali(S.

Snub-nosed :viinno\v, see Ohsopocodiis

cmil'we.

Spotted sucker, see Minytrema iiiclaiwps.

Steel-colored minnow, see Notropis

«'/i ipt>Ui.

Stonecat, see Xolunts flavus.

Stone-roller, see Calostomus nigricans.

Storer's chub, see Hybopsis storcrianus.

Straw-colored minnow, see Xolropis

blcnniiis.

Striped sucker, see Minytrema mcl-

ancps.

Sucker, see Catostnntus coinnicrsnnii.

.Sucker-mouthed minnow, see Phcnaco-

bius mirabilis.

Sweet sucker, see Eriniy::on sucelta

oblongns.

Tadpole cat, see Schilhcodcs gyrinus.

Toothed herring, see Hiodon tcrgisus.

Top-minnow, see Fundulus notalus.

Warmouth bass, see Chaenobryttus
gidosiis.

White crappie. see Ponwxis annuiaris.

White-nosed sucker, see Moxostoma
aiiisiiruin.

White perch, see Aplodinntiis gniunicns.

White sucker, see Moxostoma aurcolnm.

Yellow bullhead, see Ameinrus natalis.

Yellow cat, see Leptops olii'aris.