• 

• 

THE FOOD OF FISHES. 

BY S. A. li..,ORBES. 

For a clear conception of the general and intricate in­
terdependenc·e of the different forms of organic life upon 
the earth, one cannot do better than to st11dy thoroughl)­
the life of a per1nanent body of fresl1 water-a river or 
smaller stream, or, better than these, a lake. The animals 
of such a body of water are, as a whole, curiously isolated 
-closely related among themsel,res in all tl1eir interests, 
but so far independent of the life of the land about then1 
that if every terrestrial plant and animal were annihi­
lated it would doubtless be long~ before the g·eneral m11ltj­
tude of the inhabitants of the lake or stream v\7011ld feel 
the effects of tl1is e\rent in any very importa11t ,,ra:v~. 

Further, the g1 .. eater difficulty of comm11nication be­
tween the different parts of a water s3rstem as compared 
with the diffe1~ent regions of the land, is st1ch that the 
former are much the more sharply limited. There is very 
n1uch less interchange of all kinds between two brancl1eR 
of the same st1·eam, for example, than between the tracts 
of land which they sepa1 .. ate. Conseque11tly, one finds in a 
single body of water a far more c:omplete and independ­
ent equilibrium of organic life antl activity than in any 
equal b_ody of land. It fo1 .. ms a little world within itself­
a microcosm within ,vhich all tl1e elen1ental forces are at 
wor·k and tl1e play of life goes on i11 full, but on so small a 

• 

scale as to bring it easily witl1i11 the mental grasp. 
Nowhere ca11 one see more clearly illustrated what may 

be called the sensibility of st1ch an organic complex-ex­
pressed oy the fart that whatever affects any species be­
longing to it, must speAdily have its influence of some sort 
upon the wl1ole assemblage. He will thus be made to see 
the impossibility of studying any form successfully out of 
relation to the otl1er fo1 .. ms-the necessity for taking a 
comprehensi,re su1·vey of the whole as a condition to a sat-. 
isf actory understanding of any part. If one wishes to be-



I 

20 The Food of Fishes. 

come acq11ainted with the b1ack bass; for example, he will 
learn but little if he limits himself to that species. He 
must evidently study also the species upon which it de­
pe11ds for it s existe11c:e, and the vario11s conditions upon 
which these depend. H e must likewise study the species 
,vith whjc•h it comes in competition, and the entire systen1 
of conditions affecting their prosper it3r. Leaving out any 
of these, he is like one who under talres to malre out the 
construction of a watch, but overlooks one v\rheel ; and by 
the time he has studied all these sufficiently, he will find 
that he has 1·11n through the whole complicated mechan­
ism of tl1e aquatic life of the loc·alit3r, both animal ancl 
vegetable, of whicl1 his species forn1B l111t a sjnglr ele-
1nent.* 

In such a gc11eral s11rvey of the pla11ts a11<1 a11i111als <)ta 
1·egion, the st11dy of their food relations will be f ot1nd t o 
afford an admirable objective point. Doubtless, of all the 
features of the environment of an indi,ridual, none affect 
it at the sa.n1e time so povverfully, so ,1 a1·iol1sly and so in­
timately as tl1e elements of its food. Eve11 climate, sea­
son, soil ancl the inorganic circumstanres generally, influ­
ence an a.nimal through its food quite as mt1ch as by tbei1 .. 
(lirect action. It is through the food I'elation that animals 
touch each othe1· a11cl the surro11ncling wo1·l<l at the great ­
est n11mber of points, here they crowd upor1 each otlter 
tl1e most closely, at this point the strt1ggle for existence 
becomes sha1·pest and most dcaclly; and, finally, it is 
through the food I"elation almost entirely that anin1als 
a1--e brought in contact with tl1c mate1·ial inte1~ests of man. 
Both for the student of science a11(l f c)r tl1e econon1ist, 
tl1e1·ef ore, ,,re find this subject of pec11lia1· i11te1'cst ancl 
, 1a]l1e. It inr.J11cleR many of tl1e most in1porta.nt 1·rl:1.tions 

* I <·annot too ~lro:ng·Jy empl1rtflize the fact-freql1ently illustrateci, 1 
venture to hope, by the p apers of this series-tha,t a comprC'hen sivo s u r­
vey of Otlr e11tire natura! history is absolL1tcly essential to a g-ood ioorlrin.Q 
7c11.owlcdge of tl1ose pa rts of it which cl1iefly attrn.cl popt1lar attention, 
- that is, its edible fis hes, its injurious and beneficial insects~ a nd its 
para8itic plants. Such a survey, however, should not ~top with a s tudy 
r,f. the <.lea<l form s of Nature, ending in mere lists n.11cl description s. T o 
have an applicable value, it must treat the life of the region as o.n organic· 
t1nit, must study it in a.ction, ana (li r cct principal nttention to t h~ law~ 
()f iti:; ~.<'tivit)T, 

I 

• 



l 1lie Food of Fishes. 21 

of a spPcies, a11d 111ay prope1·ly be made the nucleus about 
\.v]1icl1 all tl1c facts of its natural history are gathered. 

In a pape1· on tl1e food o,.f Illinois fisl1es published in the 
second bulletin of tl1is Laborato1"y, t.he sub·ject vvas treat­
ed i11 a ge11e1·al and curso1 .. y wa3r, the amount of material 
11pon whicl1 tl1at l)aper was based being insl1fficient for 
exact or cletailed <lesc1--iption. The favor witl1 which that 
p1·elimina1•3r 11otice was r·eceived, ha.s made it 1>ossihle to 
u11de1·take ~l 11101·e se1~ious investig·ation; an<l tliis paper· 
oontains a11 accou11t of the food of tl1c Acanthopteri of 
the State wl1ich I IJelie,,e to be nea1·ly or· quite sufficient 
f<)1· tl ic Rtuc,1ent of science a11d fo1· the practical fish -c11l­
tu1·i~t. l t is still 11ecessa1"y only to study the food of 
specimens u11de1· a l1alf-incl1 le11gth, and to te~t the value 
of the ge11e1·al co11clusions l1e1·e r·eached, l1) " o<-lcasional 
examinations of fishes tal{en fro1n otl1er· ,vate1~s at othe1· 
seasonR of the yea1·. An1ong the results of this s tud}r, 
those 1·elati11g· to the food of the you11g are esp ecially 
vvortby of attention, and these have the1"efore l)een 
summed up separately. 

-The expla11ation of certai11 st1·uctural conditions about 
the mouth, throat a11d gills, has proceeded so f a1~ as to 
make it very likely that a number of definite ge11eral cor-
1·espondences bet,veen structu1"e and food ,vill be mad~ 
out, which will enable us to tell witl1 cor1siderable ac­
c·uracy and detail what tl1e food of an unknown fish must 
be, by a me1·e inspection of the fish itself; provided, of 
course, that we kno,\r ,vl1at food is acce~sil1]e to it in it~ 
habitat. It seems lil{ely to prove to be a ge11e1"al r ule tha t 
a fish makes scarcely mor·e tha11 a m.ecl1,a,riicctl srltlctio11 
from the articles of food access·ible to it, taki1Jp; 
almost indifferently ,vhateveI' edible tJ1ings tl1e wate1· 
contains which its habitual range and its p ect1liar alimen­
tary apparatus enal1le it to a.pprop1·iate, ,111cl eating of 
these in abol1t the ratio of their J"elative abu11dance and 
the ease witl1 which tl1ey can l)e ap111"0l)1·iatccl at any time 
and place. If this is so, kno,ving the st1·ucture of a fisl1 
and the contents of a body of water, we shall be able to 
tell, a priori, what the fish vvill eat if placed the1·ein. 

This is, in fact, tbe objective point of the present inves­
tigation-to arrive at a knowledge of tl1e co1·1·clations of 

• 



22 11he Food of Fishes. 

structure and food .habits sufficiently detailed and exact 
to make the tedious and difficult la·bor of examining the 
contents of stomachs unnecessary hereafter. Some gen-• 
e1·alizations of this sort are given in the following pages, 
and others relate to genera not included in this report. 

The method of this paper differs from that of the pre­
vious one ref erred to by the calculation of the ratios of 
the differ--ent kinds of food for each species or group of 
individuals. These ratios were obtained by averaging 
careful estimates of the relative amounts of the different 
food elements found in each stomach. 

It is proposed to follow a similar method hereafte1· 
. · clown through the remaining orders of the class. !1:ost of 

the mate1·ial l1as been collected fo1· this purpose, and 
much of it has been already studied. 

OT·der T E L E O C E P H A LI . 

Subo1--der ACANTHOPTERI. 

This subor(ler includes all Illinois fishes which l1ave tl1e 
a.nterior dorsal fin ( wher e the1·e are two) or· the first rays 
of the dorsal ( where there is but one) stiff, spinous, and 
sharp, and u11ited by an evident memb1·ane ; excepting 
only the re111a1·kable '' brook silver sides,'' ,,rl1icl1 is placed 
by Drs. Gill and Jordan in another· group. It embraces 
all our game fishes except those belo11ging .. to the pickerel 
family (Esocidce) at1d tbe salmon famil:r (~9al111.on,irlm). 
Its principal members are the darte1·s, the va1·iol1s spe­
cies of perch and bass, the 8l1nfis hes, and the sheepshead. 
Forty-six species of the order ]1ave bee11 collected jn the 
State, but 011ly thirty-fou1" of these ar~ con1mon eno11gl1 
to f orm feat11res of any in1portan ce in our fisl1 fauna. 

The n1ost n1.trne1·ous famil)r of the g·rot1p is tl1e Crnt ,ra,,·_ 
chidce (s1111fiRh es ); t11 e most important species cire tl1c two 
l{inds of black bass, the pike-pe1·cl1 or '' wall-eyccl Jlikc~ ', ,:i< 

* It is gen erally to b e d esir ed that the absurd names of ' 'Salmon" antl 
".Jack Salmon" for these species should b e suppressea. Th ey mi~ht os 
well be called suckers or catfish es or minnows, as far ns n.CCltracy ls con ­
cerned. Common n a mes are many tim es h ard er lo l<i ll than the ('a.t or 
the proverb, h owever; and it is probable tha t t1nnt1mbere<l g·cneration!=-1 
will continue to call the pike-perch "salmon " ; the st1nfls }1('~, "perch'': 
rt.nd the black b ass, "trout." 

• 



• 

23 

the common perch, the vvhite bass, and the cr0ppie or 
silver bass. 

The following account of the food of thi.s suborder is 
based upon the careful microsc·opic study of the contents 
of four hundred and twenty-five stomacl1s, 1--epresenting 
six families, twenty genera* and thirty-three species. 

These were all collected by myself or one of my assist­
ants (Mr. W. H . Garman), and labeled at the time with 
name of species, locality, and date. While the northern 
half of the State is most fully represented, several trips 
to southe1"n Illinois contributed to the material studied 
and it is believed that the resl1lts arrived at are substan­
tially true for our ,vhole area. 

Family ETHEOSTOMATIDAE. Tl1e Darters . 
..... W-r,hat the humming-birds are in our avif auna, the 

''darters'' are among our fresh-,,.rate1· fishes. Minute, 
agile, beautiful, delighting in the clear, swift waters of 
1·ocky streams, no group of fishes is more interestinQ; to 
the collector; and in the present state of their classifica­
tion, none will better repay his stl1dy. Notwithstanding' 
their trivial size, they do not seem to be dwarfed so much 
as concentrated fishes-eacl1 carrying in its little body all 
the activity, spirit, g1~ace, complexity of detail, and per­
£ ection of finish to be found in a -pe1·cl1 01· a '' wall-eyed 
pike.'' 

They are generally distributed, in suitable streams 
th1·oughout the State; but we l1ave found them much the 
most abundant in northern Illinois-in the upper Galena 
River, in Yellow Creek near Freeport, and in tributaries 
of the Kishvvaulree at Belvidere. 

A short and strong- minno,v-seine of ve1"y fine mesh is 
needed in collecting them. Rapid hauls, made almost on 
the run~ down stream, in swift and shallow water, will be 
found the most successful. Two or three species, of wider 
range, will be taken in ordinary situations, in collecting 
for· minnows generally: but the br·iQ;htest and most cha1·­
acteristic· forms can only be got by special effort. t 

• The classification of this paper is substantially that of Jordan's Ma.n­
ual or the Vertebrates of North America. etc., Ed. 2, 1878. 

t For a very entertaining and in~tructive account of these fishes, the 
reader is ref erred to papers in tl1e American Naturalist, by Messrs. Jordan 
and Copeland, Vol. X, pp. 3i5-341, and Vol. X1', pp. 86-88. 



• 

24 The Food of Ji''islies. • 

• 

I shall g·ive l1ere a desc1"iptio11 of the food of tl1e family, 
based upon a study of the contents of seventy stomachs 
I"epresenting fifteen species, collected in all parts of Illi ➔ 
nois, in several n1onths of f ou1-- successive years. These 
indicate mucl1 mo1·e than their number would imply, since 
from those collected at each time and place, as many were 
commonly studied as ,vere necessary to give a full idea of 
the food of t11e species tl1en and tl1e1·e. T11e clifferent in­
dividuals from the same date and locality usually agreed 
so closely in food, tl1at the study of fr~om tvvo to five gave 
all the facts obtai11able f1--0111 several times as many. The 
clata, here give11, tl1erefo1 .. e, r·e<1lly exl1ibit the food of the 
family at different seasons in twenty-nine localities with­
in the State. 

The genus Ple1~1·olepis is comparatively ra1~e i11 Illinois 
as there are few of the sandy streams in the State, which 
it inhabits. Seven individuals we1·e examined-four of 
P. pellucidus· and three of P. asprellus. The food of these 
specimens was I"emarkably uniform-the only elements 
found being· tl1e la1--vre of small Diptera and ephemerids. 
Eighty-one pe1· cer1t. ()f tl1e food of all consisted of the 
larvro of Cl1iro11omus*-a small, gnat-like i11sec·t-twclve 
per cent. of the la1·vm of otl1e1_· small Dipte1·a, a11d the re­
maining seven per cent. of ephemericl larvm (May-flies). 

T•welve speci111ens of tl1e g·enus Alvo1·rli1r.c; ,vere stt1diecl 
-seven ·of niacula,t zts and fi,,c of pli-o,1·r;cepl1 rtllt ·". Th(lst) 
represented five diffe1·ent localities ancl dates. This is n 
larger species than tl1e pr·eceding·, a11d to tl1is f clc1 t is prob­
ably due tl1e p1·edo1ninance ( se,renty-five pe1· rent.) in its 
food of tl1c la1·vre and pupm of May-flies '( Epl1emcI·idm). 
Th0se include<1 fou1'" 11e1· Cf)11t. of tl1(~ la1•vfr of Palin,qenirr 
biltineata, Say, 011e of tl1e ]a1·gest e11l1emeri<ls in ou1· 
streams. The r·emaining ]cinds were la1·vrn of dragon­
flies (Agrio11idm), fotlI' 1>e1· cent., larvro of Chironomus, 
seven per ce11t., C orixa. t1,,1riirla, Ul1l., tl1irte0n per ccn i., 
and Cyc·lops, 011e per cent. 

$ The larvoo of Chironomus are among the most important olc1nents o1' 
fish food In our waters, appearing in abundance in the stomachs of the 
young of a great variety of species. They have been too little atudio<1 
in this country to allow specific determination. 

• 

• 



• 

• The Food of Fishes . 

The genus Boleosoma, regarded by Dr. Jordan a.s tl1,l 
typical darter, wa,s represented by twelve specimens 
from eight localities-nine of macitla,tu1n, two of olmsted£ 
and one of camurum. * Tl1ese specin1ens show but slight 
food differences f ron1 other darters of simila1' size, the 
only notable variatio11 being the appearance of fifteen per 
cent. of case-wo1--ms. (larvm of Phryganeidm). Sixty-six 
per cent. of tl1e food vvas Chironomus la1·vm, seven pe1· 

• 

cent. larvre of othe1-- minute Diptera, and the remaining 
twelve per cent. vvas larvre of small ephemerids, and a 
few Cyclops. 

I studied the food of two SJ)eci111e11s of P c1 1cilic·litli.1J.~· 
variatus, four of P. spectabilis, and t,vo of P. aspri_qe1ii,) 
-making eight of the genus, representing· six localities. 
Fifty-eigl1t per· cent. of small larvm of Diptera (forty­
nine per cent. of Chi1--onomus), thirty-two per cent. of 
larvm and pupm of small epl1emerids, and t en pe1" cent. of 
case-worms made up the entire bill of fare. . 

• 

P erci1ia caprodes, the largest of the grou11, departs 
from all the fore going species by the prominence given to 
crustacean food-thirty per cent. of Entomostraca and 
three per cent. of the smallest of our A1nphipoda, Allot·­
chestes dentata, (Smith), Faxon. Most of the · Entomos­
traca were Cladocera, including D·aphnia, Eurycerct1s, 
and Daphnella. t . 

I-I ere occurred the only instance of molluscan f oocl in 
the group. One specimen had taken a few individuals of 
Ancylus rivitlaris, Say. Reduced ratios of Chironomus 
and ephemerid larvm, and a fe,v Cor·ixa tumida complete 
the list. • 

Of N a·riostoma. zonale, less cornmon tha11 tl1e others, but 
two individuals we1·e - examined, and these had ea ten 
nothing but larvre of small Diptera, including sixty-five 
pe1· cent. • of Chironomus. 

• Boleosoma maciilaturn, and B. olmstedi should undoubtedly be unite <l. 
Specimens in the laboratory collection present the extremes of both forms. 
together with numerous intermediate stages of each character used t u 
distinguish them. 

This whole group exhibits a .surprising variability, perhaps due to its 
comvaratively recent origin. 

t Daphnella was found in a Percina from the Calumet River, at Soutl1 
Chicago, but not in conditio11 to permit the determination of the species . 

• 



26 The Food of Fishes. 

Six specimens of Etlieostoma fiabellare var. lineolata, 
from four localities, had eaten sixty-one per cent. of Chi-
1·onomus larvre, twenty-seven per cent. larvre of small 
ephemerids, and twelve per cent. of Copepoda (Cyclops). 

Boleichthys elega1is, found only in tbe southern part of 
the State ( three specimens examined), had eaten only 
dipt.erous larvre ( thirty-seven per cent.) and ephemerid 
larvre ( sixty-three per cent.). This is a larger, heavier 
species than most of the others, and, therefore, like 
.l\.lvordius, prefers ephe1nerids to gnats. 

Last and least c·on1es M icroperca punctulata,, 1--epre­
sented by nine specimens from four localities in northern 
Illinois. This smallest of the darters shares witl1 Per­
cina, the largest, the peculiarity of a large ratio of crus­
tacean food, wl1ich made up sixty-foul" per cent. of the 
total. The principal kinds were Cyclops, Chydorus, young 
Gammariis f asc·iat1us, Say, and young Orang onyx gracilis, 
Smith. The 1"emaining· elements were Cl1ironomus larvre 
( tbirt,~-four pe1-- cent.) and a trace of epl1emerids ( two · 
per cent.). 

It will be seen that the family, taken as a whole, divides 
into two sections, disting11ished by tbe abundance or de­
ficiency of crustacean food. This is easily explai11ed by 
the fact that Per·cina and Microperca range much more 
f1--eelv than the other gene1"a, being frequentlv f 011nd 

amr ng weeds a.nd algm in comparatively slow water wit}1 
muddy bottom, while tl1e others are rather closely con­
fined t.o swift and rocky shallows. 

In discussing the food of the wl1ole group, taken as a 
u_nit, it may best be compared witl1 tl1e food of the young· 
of other perc1oids. It is thus seen to be remarkable f 01· 

the predominance of tbe larvre of Chironomus and small 
Ephemeridre.-the former of tl1ese com1,risjng,· fort~r_f 01-11· 

per cent. a11d the latter twenty-tl1ree per ce11t. of the 
whole food of the seventy specimens. In young black basR 
(Micropterits pa,llidu.s ), on the otl1e1· hand, the averages 
of nine specimens, ranging from five-eigl1ths inch to one 
and a half inches in length, ·were, in gene1·al terms as fol ­
lows: Cladocera forty-two per c·ent., Copopoda scvc11 
per cent., yot1ng fishes t"V\renty per cent., Corixa and yot1ng 



Tlie Food of 1!1,ishes. 27 

Notonecta twe11ty-nine per cent., and larval Chironomus 
only two per c·ent. The search for the cause of this differ­
ence leads naturally to an examination of the whole econ­
omy of these little fishes, and opens up the question of 
thei1· qrigin as a group. 

The close relation of tl1e Etheostomatidre to the Perci­
<lre requires us to believe that the two grol1ps have but re­
cently diverged, if, indeed, they are yet distinctly sep­
arate. 

We must inquire, therefore, into the causes which have 
operated upon a g·roup of percoids to limit their range to 
s11ch apparently unfavorable situations, to diminish their 
size, to develop unduly the paired fins and reduce the air-
.bladder, to remov,,e the scales of seve1--al species more or 
less completely from the head, breast, neck, and ventral 
1·egion, and to rest1"ict their food chiefly to the few forms 
mentioned above. 

No species can long n1aintain itself anywhere which 
cannot, in some way, find a sufficient supply of food, and 
also protect itself against its e11emies. In the contest with 
jts enemies it may acquire defensive structures or powers 
of escape sufficient £01· its protection, or a reproductive 
capacity which will compe11sate for large losses, or it may 
become adapted to some place of refuge wl1ere other fishes 
will not f ollo,v. What better refuge could a ha1·assed fish 
desire than tl1e l1iding-pl.aces among stones in the shal­
J ows of a str·eam, where the water dashes ceaslessly by 
with a swiftness few fish can stem, And if, at the same 
time, the refugee develops a swimming power which en­
ables it to dart like a flash ag·ainst the st1--ongest current, 
its safety would seem to be insured. But wl1at food could 
it find in such a place 1 Let us turn over the sto11es insucl1 
a stream, sweeping the roiled water at the same time witl1 
a. small cloth net, and we shall find larvre of Chironomus 
and small ephen1erids and other such prey, and little else 

• -food too minute and difficult of access to support a large 
fish, but answering· very well if our immigrant can kee1) 
(lo1un liis si.ze. Here the principles of natur·al selec·tion 
assert thei1 .. power. The limited supply of food ea1·ly ar­
r·ests the i~·rowtl1 of the young; while every fish which­
passes the allo~rable maximum is for·ced for food to brave 



28 The Food of Fishes. 

the dangers of the deepe1· waters, where the chances a1·e 
that it falls a prey. On the other hand, the smaller tl1e 
size of those vvhich escape this alternative, the less likel)r 

. will they be to attract the appetite of the small gar 01· 

other guerilla vvhich may occasionally 1"aid thei1· retreat, 
and the n1ore easily will they slip about 1111<le1· stones in 
search of their microscopic g·ame. ;,;, 

Like otl1er· ·fishes, the darters n1ust l1a,,<~ tl1ei1· per·iocls 
of repose, all tl1e 1nore u1'gent because of the constant 
struggle witl1 tl1e swift cur1·ent which thei1· habitat i1n­
poses. Shut out fr·o111 the deep, still pools ar1cl slow ed­
dies ,vhere tl1e lar·ge1· species lur"'k, tl1ey a1·e f or·ced to 
spend tl1eir leisure on 01· be11ea tl1 tl1e botto111 of the 
stream, resting on their extended pector·als and anal, or 
wholly buried in the sand. Possibly this fact is correlat­
ed with the absence or rudime11tary condition of the air·­
bladder; as it is a rule with many exceptions-but still, 
probably, a r·ule-that this or·gan is ,vanting' in ·fisl1es 
which live chiefly at the bottom. 

Doubtless the sea1"cl1 for food has mucl1 to do ,vith this 
selection of a habitat. I have found that the young· of 
nearly all species of our· fresh-v.rater fishes are competi­
tors for food, feeding almost e11tirely on Enton1ostraca 
a.nd the larvre of minute D1ipte1--a. t As a tree sendR out its 
roots in all directions in searcl1 of no111"isl1ment, HO earli 
of the large1-- clivisions of anin1a.ls extencls itf,; , , i1.1·i(lt18 

grol1ps mto every place whe1"e available food occu·1·s, earh 
group becoming adapted to the special ·feature:, of its 
situation. Give11 tl1is supply of c·ertai11 kinds of foo<l, 
nearly inaccessible to tl1e ordina1·y fish, it is to l)e expect­
ed that some fishes would become especially fitted to its 
utilization. Thus the Etheostornatidoo as a gro11p are ex­
plained, in a word, by the hypotl1esis of tl1e p1,.ogressiv(\ 
adaptation of the young of certai11 Percidro to a peculi::11· 
place of refuge and a peculiarl)r sitl1ated foo<l Sllf)ply. 

Perhaps we may, without violence, call t}1ese tl1e mow1-
taineers among fishes. Forced from tl1e populous and fer­
tile va.Tieys of the river beds and lalre bot1:oms, they bavf' 

• 

• In Boleosoma, which is normally scalf'd in front of the aorsal fin. Wl' 

oftPn fln<l the skin of this region bare in large specimens, nn•l sl1owing· 
evident signs of rubbing. 

t Several of the Catostomidre ( suclc<-rs) are an exception to thl.s ,.'tile. 
feeding when young chiefly on algm and Protozoa. 



11he Food of Fishes. 29 

taken refuge from their enemies in the rocky highlands 
where the free \\Taters play in ceaseless torrents, and 
there they have w1"ested from stubborn nature a meager 
Jiving. Although diminished in size by their continual 
strug·gle with the elements, they have developed an activ­
ity and hardihood, a vigor of life and glow of high color 
almost unknown among~ the easier· livers of the lower 
lands. 

The following table (see page 30) will facilitate a com­
parison of the records of the different genera. The per­
centages were obtained by estimating carefully the ratios 
of each element of the food of each individual, and aver­
aging these ratios for all the individuals of a species. 

Family PERCIDJE. The P erches. 
This family co11sists, in this State, of tl1ree species-tl1e 

common yellow IJerch and the two species of pike-11erch 
or· '' wall-eyed l)ike. '' I have examined the food of seven­
ty-five s1Jecimens of this family, so distributed in time 
and space as to give a satisfactory idea of the usual food. 

P ·ERCA AMERrc,ANA, Scbranl<. THE Co1,,,rMoN PERCH. R1NGEf) 

PERCH. 

This exceec1ingly well-k11own spec.ies is m~st abu11dant 
along the shores of Lal<e Michigan and in the small 
streams and lakes of the nortl1eastern 11art of the State, 
becoming less common to the south and west. In the Illi­
nois River· at Peo1·ia and Henry it occurs in limited nt1m­
l)ers, but in so11thern Illinois disappears so completely 
that even its name ( there g·e11erall3r pronouncecl 
'' pearch' ') is tr·ansf e1--1·ecl to a different family, the sun­
:fishes ( Centrarchidre). 

My knowledge of the food of this species is derivec1 
from the study of the contents of forty-nine stomachs, of 
which tl1irty ,vere from ad1-1lts and the remaining nine­
teen from fis11es ranging from 13/16 incl1 to four inches 
111 length. Ten localities anc:l as ma113T dates aro reprr­
sented by ·these specimens. Some were taken in the Illi­
nois River, others in Lake Michigan and its so1-1ther11 
tributaries, and still others in Fox R. at McH<~nry., and 
jn the lakes connected with that stream. One lot included 



-

The Food of Fishes. 

DETAILS OF THE FOOD OF THE E•rHEOSTO~fA'fIDiI~. 

• 
fl) 

~ ·---0 
l­
o 
> 

• ns 
8 
0 
fl) 

C 
QJ --0 

o::l 

.. 

·-

• 
('11 

6 
0 .... 
fl) 

0 
C 
('11 

z 

• U) 

~ 
..c ... 
..c: 
(.) 

(I) -0 
~ 

----------~---·---------------•--
Number of specimens.. . . . . . 7 12 12 8 I I 2 6 3 Q 

I. MOLLUSCA ••.....•.. • • • • . . . . . . . . 0 I •••• • • • • • ••• . .. .. 
Ancy/us ,-ivularis Say .... •••• . • • • . . . . 0 I • • • • • • • • • ••• • • • • 

II. !NSECTA .•••.•. 100 99 
1. Diptera . . . . . . . . . . . . . . . 93 07 

96 100 

73 58 
65 
43 
02 

100 
100 

88 100 

61 37 
36 
34 

Undetermined larvre. 12 01 
Chironomus larvre . . 81 06 

2. Henzzptera . . . . . . . . . . . . . . . . I 3 
Corixa . . . . . . . . . . .. . . . . . . . 13 

Undetermined ..... _ ...... . 
La r v re . . . . . . . . . . . ·. . . . . 07 
C. tu1nida Uhl... . . . . . . 06 

3. Neuroptera . . . . . . . . . . . 07 79 

E)>~e~er_i~~:::::::: .~:. J 

07 CX) 
66 49 
•••• • • • • 

.... . • • • • 

•••• • • • • 

• • • • •••• 

• • • • • • • • 

23 
08 

42 
32 

. . . . 14 

41 
05 
05 
03 
02 

• • • • 

35 
65 

• • • • 

• ••• 

• • • • 

• ••• 

•••• 

• • • • 

• • • • 

• • • • 

•••• 

• • • • 

• ••• 

I 7 . . . . 27 
0~ . . . . 27 

• • • • •••• • • • • 
Larv~ . . . . . . . . . . . . 07 63 

Palingenia . . . . . . . . . . 04 
Agrionidre (p,1pre) . . . . . . 04 .... 
Phryganeidre (larvre) . . . . . . . . 15 

Ill. CRUSTACEA ••..... 01 04 

08 
• • • • 

18 CX) • • • • 27 
• ••• • • • • • ••• • ••• 

• • • • • •• • • • • • • • • 

IO 08 .... • • • • 

1. A mphipoda . . . . . . . . . . . . .. . • • • • •••• 

Gammarus, yg.. . . . . . . .. . 
Crangony~ n • . • . . • . . .. . 

Allorchesus denlata Sm .. .. . 

•••• 
•••• 

•••• 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

33 
03 

• • • • 

• • • • 

. . . . 03 

. . . . l 2 
• • • • • • • • 

• • • • • • • • 

• • • • • • • • 

• ••• • • • • 

2. C!adocera ............. ... . • • • • • •• • ••• 24 
05 
o6 

• • • • • • • • 

U ndeterrnined.. . . . .. . . .. . •••• 
D b .. d a p 011 ~ . . . • . . • • . . . ••. 

Da pl:(nia. . . . . . . . . . . . .. . 
Sididce ......... ........ . 

•••• 

• • • • 
• • • • 

Dapilnella ............ . 
Lynccidre.... . . . . . . . . .. 

•••• 

•••• 

Chydorus ......... . .. . 
Eurycercus ...........• 

•••• 

•••• 

3. Ostracoda. . . . . . . . . . . . . . .. . 
Cyprididre ............. . 

U ndeterrnined ..... ... . 

.. . . . 
•••• 

•••• 

• ••• Cypris .............. . 
4. C opepoda . . . . . . . . . . . . . .. . . . o 1 

Cyclope . . . . . . . . . . . . . . . . 01 
Conlervoid Algre. . . . . . . . . . . . . . . . . ... 

• ••• 
• • • • 

• • • • 
• • • • 

• ••• 
• ••• 

• •••• 

• • • • 

• • • • 

07 
. . . 05 

05 
01 

• • • • 

• ••• 

• ••• • ••• 

• ••• • ••• 

•••• • • • • 

• • • • •••• 

• ••• • • • • 

• • • • • • • • 

• ••• • ••• • • • • • • • • • • 

• • • • . . . . 01 • • • • • ••• 
.. ... 0 I .•. • ••• 

. . . .. . . . . 01 
' 

• • • • . . . . 01 

• ••• . -.. • ••• 
44 . . . . 05 
oi . . . . 05 

•••• • • • • O! 

• ••• • • • • 

• ••• • ••• 

• • • • • ••• 

. . . l 2 
. • . • 12 

• • • • • • • 

JO 

27 
• • • • 

• ••• 

• • • • 

• • • • 
• • • • 

• • • • 

• • • • 

34 

• • • • 

• ••• 

• • • • 

• ••• 

02 
02 

•••• 

63 02 
• ••• • ••• 

• ••• • ••• 
••• > •••• 

. . . . 12 

• • • • 

• ••• 

• ••• 

o6 
o6 

• • • • 

. . . . 27 
• ••• • ••• 

• • • • • • • • 

• ••• • • • I 

• ••• 

• • • • • ••• 

. . . . 03 
• • • • 24 
•••• • • • • 

• • • • • •• ♦ 

. . . . ob 
• • • • 06 
• • • • • •• 
. . . . 19 
•• • • 19 
• • • • • ••• 

' • 

in these notes was bought in the Cl1icago marl{ct. They 
were evidently of the river form of tl10 species, a11cl judg­
ing from the contents of tl1ojr stomachs, wl1icl1 included 
a crustacean* not known to occur i11 Illjnois l)11t fo11nd 
abundantly in Michigan, I conclude that tl10)7 were fron1 
that state or from Wisconsin. 

- - - --~- - - -
"'NI ancasel1us te,iax, J-l:a,1·g-el'. 



• 

The Food of Fishes. 31 

Food of tlie Y oitng. 
Finding that the food of most fishes differs with age, I 

have grouped the young according to size, and averaged 
the food for eacl1 group separately-the first group con­
sisting usually of those under an iI1ch in length, the 
second of those from one to two, etc. 

Two perch under an inch in length had eaten nothing· 
but Entomostraca-about equal quantities of Cyclops 
and Daphnias. It was not until the specimens reached an 
inch and a half in length that insects of any considerable 
size appeared i11 the food. A single smaller fish had eaten 
a few minute larvre of Chironomus, but otherwise the 
food at this age consisted wholly of Entomostraca. 

About thirty-four per cent. of the food of nine speci­
mens ranging from 1~ to two inches in length consisted of 
insects, and sixty-six per cent. of crustaceans. The only 
insects recognized were the larvre and pupm of Cbirono­
mus ( eleven per cent.), small water-bugs-Corixa tu,mi­
da, Uhl., C. alterna.ta, Say, etc. ( twenty-three pe1-- cent.)­
and a trace of larvre of May-flies (Ephemeridre). The 
Crustacea vvere cl1iefly Cladocera and Copepoda.-thirty­
six per ~ent. and twenty-four per cent. respectively. Four 
of the nine had eaten small quantities of a small amphi­
pod c.rustacean, Allorchestes dentata, which is very abu11-
dant north, and has, in fact, about the same distribution 
in the State as the perch itself1. The Cladocera were 
chiefly Daphniidre ( twenty-seven per cent.), including· 
Da.phnia, pitlex, L., Simocephalu.s american1.ts, Birge, ancl 
Bosmina longirostris. Specimens of Chydorus and Pleu­
roxus made up the principal part of the nine per cent. of 
Lynceidre eaten. The Copepoda wer·e all Cyclops anc1 
Diaptomus. 

Four specimens two and a half i:Q.ches long·, all taken at 
Peoria in November, 1878, had eaten nothing but Hemip­
tera ( twelve per cent.) and N europtera ( eighty-eight per. 
cent.). The Hemiptera were all C orixa. alternata, and the 
Neuroptera were nearly all the extremely common larva 
of one of our most abundant May-flies (Palingenia. bilin­
eata, Say) . Larvre of small dragon-flies (Agrionini) 
made five per cent. of the food. The simplicity of the 



• 

32 The F ood of Fishes. 

food of these specimen s is probably due partly to the fact 
that they were all caught at the same time and place, and 
partly to the wintry weather when they wer e taken. 

Four specimens, from thr ee and a half to fo11r inches 
long, represe11ting two localit ies and dates, had eaten a 
greater va1·iety of articles, t l1e f oocl , in fact, now closely 
a.pproacbing· that of the adult . Forty-five per cent. of the 
food was insects-c11iefly larvre of May-flies- and fifty­
five per cent. Crustacea- ,chiefly Amphipoda and Cladoc­
era. Other· insect elements were larvre of Chironomus, 
six per cent., and four per cent. of Co1·ixas. The Cladoc­
era were all Daphnia, and the Amphipoda ,vere Allor­
chestes dentata. A single specime11 from Long L ., near 
Pelzin, Ill., hacl eaten an isopod cr·usta.cean (Asellus) . 
Cy1'.)rididre, anothe1· f~1rnily of minute crl1s taceans, formed 
eight pe1· cent. of the whole food of these specimens. 

Food of the Adult. 
The thirty 111at11re indi,.,.i<iuals ma3r best be treated in 

two groups, the first from streams ancl the second from 
I-1ake Micl1igan. 

Four of the first gI·oup ,vere bo11g·ht in the Chicago 
1narket, in March, 1880; six were tal{en from the uppe1· 
Fox, in May; f 011r were from Call1met R. at South Chi­
c~ago, taken in Aug11st, 1878, and fol1r we1·e caught in 
October of tl1at yea1·, from the Jll111ois nt Peoria. 

We notice, :fi1·st, tl1.e entir·e diRappetl1·ance of Entomos­
t1""aca, ,vhicl1 are thus seen to be food 1)1·oper to the young. 
We n ext ol)se1·ve the appeara.nce of Mollusca (ninetee11 
per cent.), whicl1 are evidently no i11signific·ant food r e­
source of the s11eci0s. Unio, Cyclas, S11ccinea, Phy.<,a het­
Prostropha, Say, ancl Va.lvcf.,ta tt~i(·r11·,i-;1ata, Say, are the 
mollusks recognjzecl. N otwitl1strlnclir1g· t l1e lacl{ of Ento­
mostraca, Crustacea ar·c the most impo1·tant resource of 
these rive1· specime11s, constituting· f 01·t)r-e igl1t per cent. 
of thej1• foocl. Crawfisl1es ( Camba1·11s) a11c1 0111· commo11 
little frcsh-wate1· s11rimp (Palrerr1,on(~tfs ex1ilipc',c;, St.) 
rompose te11 ))er cent. of tl1e wl1olc; t}1e p1·evio11sly no­
ticed Allorcl1estf\s amo11nts to fift(;Cll l )t~1· c1e11t.; ctn d sp 0-
ries of Asellt1s, n.r1cl M anca,<;;ellus tena,.x to twenty-tl1rec 
per cent. T he M anrare]li werP all from the s1><\cin1en~ 

• 



• 

• 1'lie Food of F'ishes. 33 

f1"om tl1e Cl1icago ma1"ket. Insects a1"e also a11 i1nportant 
item-amounting to twenty-four per c·ent., nea1"ly all l)e- · 
ing the larvre of Neuroptera-Mayflies (Ephemeridre), 
dragon-flies and case-flies ( Phryg·aneidre). A single spec­
jme11 from Peo1·ia Lake had eaten one small fish-a 
''darter'' of the genus Precilich tl1ys. 

The second group, t,velve specimens from Lal{e Mich­
igan, presents a curious and instructive contrast in food 
to the foregoing. Mollusks and insects wholly disappear, 
and Crustacea are limited to the commonest crawfish of 
the lakes ( Ca1nbariis virilis, Hagen), which forms four­
teen per cent. of the food. The remaining eighty-six per 
cent. consisted wholly of fishes, all minnows ( Cyprinidre) 
so far as recog·nizecl except one, and that was some unde­
termined percoi<l--probably itself a perch. 

It will thus be seen that the common perch has a food 
l1istory of three periods-the periods of infancy~ yo 11th, 
and mature age. In the first it lives wl1olly on Entomos­
traca and the minutest larvre of Diptera; in the second, 
commencing· when the fish is about an il1ch and a half in~· 
length, it takes up first the smalle1· and then tl1e larg·e1--· 
kinds of aquatic insects in gradually increasing ratio, the, 
cntomostracan food at the same time diminishing· in im­
portance; and in the third it appropriates, in addition, 
mollusks, crawfishes and fishes-in tl1e lake specimens 
depending almost wholly on the last two elen1e11ts. 

We l1ave here the fi1"st instance of a fact ,vhich we shall 
see again a.nd again illustrated-that the yo1111g, having 
at first an alimentary appar·atus too small and delicate to 
dispose of any insects but the minl1test larvre, live almost 
wholly on minute cr11staceans. 

It is proper to note that the lake and rive1" percl1 are by 
some good authorities rega1--ded as separate species-the 
latter being much more highly c·olo1"ed than the former. I 
have not found so strict a separation of the two forms as 
that described by Mr. E.W. Nelson, but have frequently 
taken both in the same haul of the seine in diffe1"ent parts 
of Calumet R. and in Lake George, Ind.-a body of water 
c·omm11nicating ,vitl1 l1ake Micl1igan hy an 011tlet three or 
four miles long;. Occasion~! pa]e speci111ens are also tak­
en far from the lakes, in the Fox and Illinois l"ivers. The 

.. 

• 



• 

• 

34 • 

(lifference i11 color is probably dt1e partly to the smaller 
amount of light to which those inhabiting the deeper wa­
ters of the lake are exposed, and partly to their pisciv­
orous habit combined with the comparatively few lurking· 
plac·es afforded them. There is some evidence that fish 
food bleaches a fish directly, and a good deal that it does 
so indirectly, by increasing the importance of an incon-

• 8p1cuous appearance. · 

ST1zosTETHru1vr CANADENSE, Smit11. GRA1.- PIKE-PERc:H. 

SAUGER. '' J ACIC-SALMON. J' 
J 

Fourteen specimens of this excellent fish were exam­
jned, all of ,vhicl1 were from the Illinois R., ten taken in 
October, 1878, 011e in June, 1877, and three in Novembe1~, 
]_877. It is evidently a very destr'l1ctive species. These 
specimens had eaten notl1ing· but fisl1es. In three cases 
tl1ese were u11recognizable, and in t,vo others I could only 
tell that the3r were Acantl1opteri. Fo111· of the remaining~ 
·'pike'' l1acl eat011 l1icl{ory-shad (Do1r·,tf."<J,1za ce11edian1i111i), 

two had eaten catfish ( Siluridre) of whicl1 one ,vas an 
A1niurt1s, . t,vo l1acl eaten sl1eepsheacl (H aploido1iotus 
,qrii1iniens), and one l1acl tal{en a blaclt l1aRs and some sun­
fish ( Cent1'arcl1iclre). Tl1e presence in tl1e stomach of one 
qf tl1ese fisl1es, of a catfisl1 of 111eclit1m Rizc, "11tl1 its poison­
ous pectoral a11cl clo1·sal spin es 11nb1·ol{en, was a Rt1·il{ ing 
j}lustration of tl1e g·ast1·ic ene1~gy of t}1is species. 

ST:r.zosTETHru1vr v1TI{E1J1vr., J\fitc]1 . Pr1(1~:-P1~I{("J H. ,iVAI.JTJ-1~\·1•:1 > 

PIKE. ''Salmon.'' 

~rhis is f a1" the fu1est of ol11· 1·ivc1· fif:ll1es-seconcl to 110 
J'1·csl1-water species except, possibly, so1ne of the Ralmon 
famjly. It occu1·s in the g·1"eat lal{es, and tl11·011gl1011t tl1c 
State gene1·ally in the larger streams. It is a much la1·g·e1· 
fish than tl1c 1J1·ececling, 11ot infreqt1ently reaching a 
wcjght of t,,-rc11ty po11nds. Certainly no fish of our wate1·s 
is l)ette1~ dese1·ving of attention than this. The only dr}tW­
t)ftc·k if> its jnr1·casr is i11 its ,ro1·acity; l1l1t, altl1011gh it dr­
' 'Ol1rs an immenRe nt1ml)er· of other fi shes, there is :no evi­
<lcnce that it is \\rantonly destructive or that it eats mor<" 
j11 proportio1t to its weight than the blacl{ bass. 



I 

• 

• 

Twelve of tl1is species we1~e exami11ecl, t,vo of ,vhich 
,vere under tl11~ee inches in length, and the others a.dult. 

Food of the Young. 
A specimen two incl1es long, taken in the Illinois R., at · 

Pekin, June 2, 1880, had ea.te11 only a minute :fish. One, . 
two and a half incl1es long, taken at the same place in 
June, 1878, l1ad also eaten a small fish and a few Ento~ 
mostraca ( Cypridiclre and Daphniidre). The appearance 
of these Entomost1·aca in the food of a fish of this size, 
makes it altogethe1" probable that Stizostethium, like 
Perea, wholly depends 011 these minute Cr11stacea, wl1en 
\rery young. 

Food of the Adi.tlt. 
The 1--emaining specimens, tal{en from three localities, 

had eaten nothing but fishes, one-half of them only the 
hickory-shacl 01" slrip-jacl{ (Dorysonia cepedianu.m). In one 
other specimen, tl1is sp•ecies was associatecl ,vit11 a mi11-
now ( Cyprinidre), ancl in still another ,vith a small sun­
fish with three anal spines ( Cent1"archidm). One of tl10 
r emaining stomachs containP-d only an u11recognizable 

• fish, and the otl1er two co11tai11ecl C1)711·i11iclm, inrl11rling· 
the creel{ chub, Seniotilus corpo1~azi.-, . 

• 

The two speci.es of this gen11s agree so closely in food 
that they may ,vell be disc11ss-ed toget11cr. Apart from 
their exclusively pisci,,orous l1abit, the most interesting 
fact sho,vn is the impo1·tance of the hickory-sha.d as food 
for this :fisl1. We sl1all find acc11mulati11g· G\'itlc11ce tl1at 
this shad, utterly useless for h11man food, is, notwitl1-
standing, one of tl1e 1nost valuable fishes in our streams. 
NevertJ1eless, not the slig·htest attention is paid to its 
p1·eservation, mucl1 less to its encol11·agement. The fisher­
men commonly 1"ega1·cl these fishes as a mere nuisance, 
a.nd leave them to die on tl1e bank by hundreds, rather 
than take the trot1ble to return them to the water. They 
are a very delicate species, and are easily killed by rough 
handling in the seine, but the majority of those captured 
might be saved with a little c·are. 

The abundance of these fishes as compared with some 
other species in the river might seem to indicate that they 

• 



• 

36 Tlie Food of Fislies. 

are commo11 enough as it is. Few realize, however, the 
number of fishes needed to feed a pike-perch to maturity. 
Two or three items from my notes will furnisl1 the basis 
for an intelligent estimate of this numl,er. 

From the stomach of a Stizostethiuni canadense caught 
in Peo1·ia Lake October 27, 1878, I took ten well-pre­
served specimens of Doryso1na,, each from three to four 
inches long; and from a Stizostet~iilni vitreum I took 
seven of the same species, none under four inches in 
length. As the Dorysoma is a very thin, high fish, with a 
serrate belly, these were as large _as a pike-perch can well 
swallovv; and we may safely suppose that not less ·than 
five of this species ,vould n1ake a full meal for the pike­
!Percl1. The species is a very active hunter, and it is not 
at all probable that one can live and thrive on less than 
three such meals a vveek. The specimens above mentioned 
were taken in cold autumn ,veatl1e1·, ,vl1en most other 
fishes were eati11g~ but little; l)l1t, since fishes generally 
.take relatively little food in ,vinte1--, we "\\7ill suppose that 
the pilre-perch eats, duri11g the yea1~, on an average, at 
this rate per weelr f 01,. forty ,veelrs, giving us a total pet· 
annum of six hundred Dorysomas dest1 .. oyed by one pike-

. !Jereb. We cannot reckon tl1e ave1 .. age life of a Stizo­
stetbium at less than tl1ree yea1·s, a11cl it is p1--obably nea1,.­
er five. The smallest esti1nate ,ve ca11 1"easonably make as 
to the food of eacl1 pike-percl1 wo11ld tl1erefo1--e be some­
vvhere betwee11 eigl1teen l11111c11·et1 a11t1 tl11·ce tl1011sa11<l 
fishes like Dorysoma. A l1und1·ed pike-pe1"cl1, such as 
should be talren each yea1" along a few miles of a rive 1, 

like the Illinois, would the ref ore 1--eq11i1"c one h11ndred and 
eighty thousand to th1 .. ec l111ndred tho1-1sand fishes for 
their food. Finally, vvhen ,,re talce into account that a 
number of other·· specjes also l')I"ey 11po11 Do1·ysoma., ancl 
that tl1e whole numbe1· destroyed in aJl ,vays n111st not ex­
ceed the mere surplus 1"eproduced-otl1e1·wise the species 
would be extinguishecl-wc ca11 form s01nc app1'oximato 

. i.dea of the multitudes in which tho foocl species ml1st 
abound if we would support any great numbe1' of proda­
ceous fishes. Dorysoma, bei11g a mud-eate1· and a vogotc1-
rian, tal{ing animal food 011ly dur·ing tho ento1110RtraPa11 

• 



Th,e "l!'ood of Fishes. 37 

period, can p1~obably be more readily maintained in large 
numbers in our muddy streams than any other fish. 

It is evident that the increase of edible fishes without a 
corresponding supply of food will be largely time and 
labor thrown away. Probably if protected from wanton 
and ignorant dest1"uction, the Do1 .. ysoma wot1ld abound 
sufficiently, as it is enormously prolific. 

The following table is similar to that given for the p·re­
ceding fa.mily. The mark -r is used to indicate the occur­
rence of an element in too small an an1ount to figure in 
the ratios. 

• 

' 



38 

• 

The Food of Flishes. 

TABLE OF THE Fooo OF THE PERCIDiE. 

<lJ 
C 
0 

• en 
Q.) 

..c u 
C 

0 .... 
<lJ 
s:: 
0 

PE RCA . 

• en 
Q.) 

...c:: 
u 
C 

V 
Cl) 
1-. 

..c .... 
0 .... 
0 
~ 

re 

• 
en 
<lJ 

..c u 
C ..... 
i,.., 

:::, 
0 -0 ... 
Q.) 

<lJ 
1-. 

..c 
re 

Number of specimens exami11ed.. . . . 2 9 4 4 

·-u 
<lJ 
0.. 
!Fl 

'­
OJ 
> -

• cn 
c:: 
<lJ 

8 

-- ---

.... 
::t 
E-< 
CzJ 
E-◄ 
er, 
0 
N ,..... 
f-4 
en 

18 12 26 
--------------------1--- -- ---- ----

• I. FISHES ......•.. . .. ... .. .. 
Undetermined .................. . 
Acanthopteri .................... . 

Undetermined ... ........... .. . 
Precilichthvs ........ ... ....... . 

• 
Centrarchidre ............... .. . . 

Undetermined ........... ... . 
Micropterus ................ . 

Hap loidono_t us . . . . . . . . .. . ... . . 
Dorysoma ...................... . 
Cyprinidre .............. . ....... . 

Undetermined ....... . .. . .... . . 
Semotilus .............. . ...... . 

Siluridre ................... . ... . 
Undetermined .............. . .. . 
Ami urus ........... ..... ..... . 

II. MOLLUSCA ............. . 
Physa heterostropl1 a . . . . . . ... . 
Succinea ...................... . 
Valvata 3-carinata . .. ... ....... . 
Cyclas . . . . . . . . . . . . . . . . . . . . . .. 
Uni o . . . . . . . . . . . .. . . . . . . . . . . . . .. 

Ill. INSECTA ...... .. ...... . 

I. 
Pup~ ................................. .... . .. . 
Dipte1·a (larv~c) .. . . . . . . . . . . . . . . . 

Undetermi11ed ............. ... . 
Chironomus .. . ............... . 

2. Hemzptera .. ................ . .. . 
Corixa .. ...................... . 

Undetermined .............. . 
C. alternata ........ . ........ . 
C. tumida .................. . 

3. Neuropte,·a (larv~) ...... . ...... . 
Epl1emerid~ ................. . 

Ut;1determined ..... . ........ . 
Palingeµia ... .... .......... . 

Agrionid..e ............ ... ..... • • 
Libellulidre . . ................. . 
Phryganei<:lre ................. . 

• • • • • • • • • • • • • • • • 

•••• • • • • • • • • • • • • 

• • • • • ••• •••• • • • • 

••• • • • • • ♦ • ♦ • • • • • 

• • • • • • • • • • • • • •• • 

•••• • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • 

• • • • • • • • • • • • • •• 

• • • • • • • • • • • • 

• • • • • • • • • • • • . . . .. 
• • • • • • • • • • • • 

• • • • • • • • • • • • • • • 

• • • • • • • • • ••• • •• • 

• • • • • • • • • • •• •••• 

• • • • • • • • • ••• • • • • 

• ♦ I • • • • • • ♦ •• • • • • 

• • • • • • • • • • ♦ • t 
• • • • ♦ • • • • • • • •••• 

• • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • 

• • • • • • •• • • • • • ••• 

• • • • 34 100 45 
• • • • • • • • • • • • • • • • 

• • • ♦ IO . . • . 06 
. . . . 0 I • ♦ •• •••• 

• • • • 

• • • • 

•••• 

09 
23 
23 
I I 

• • • • • ••• . 

. . . . 06 
12 04 

. . . . 04 
♦ •• • 04 

I 2 .• ,, . 
• • • • I 2 •••. • ••• 

. . . . 0 I 

. • . . 0 I 
88 35 
83 35 

· · · · · · · · · · · · 3 5 
• • • • . . . 83 • • • • 

• • • • . . . . 05 • • • ♦ 

• ♦ • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • 

o6 86 
. . . . 50 

I . . . . 0~ 
I . . . . 
I 06 

08 
• • • • 

I 
• • • • 

♦ • ♦ ♦ 

• • • • 

• • • • 

• • • 

•••• 

••• 

• • • ♦ 

• • • • 

• • • • 

19 
05 
04 
01 

05 
04 
24 
t 

01 

• • • • 
01 

• • • • 

,. .. . 
• •• 

• • • t 

• • • • 

• • • • 

♦ • • • 

• • • • 

. . . .. 
• • • • 

• • • • 

• • • • 

• • • • 

• • • 

• • • • 

• • ♦ • 

• • • • 

• ♦ • • 

• • • 

• • • • 

• • • • 

•••• 

• • • • 

• • • • 

• • • • 

• • • • • ••• 

23 ... . 
08 
03 
05 
04 
08 

• • • • 

•••• 

• • • 

•••• 

• • • • 

03 .... 

IOO 

23 
21 
08 
. . . ' 
05 
03 
02 

08 
41 
09 
05 
04 
08 
04 
04 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 
• • • • 

• • • • 

•••• 
• • • ♦ 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

. .. . . 
• • • • 

♦ ••• 

. . . .. 
• • • • 

. .. . . 

-



• 

TABLE OF THE FOOD OF P ERCIDJE-Contin ued. 

• 
\-, 
Q) • 

"O rn 
C: Q) 

..c: ::, u 
"O i:: 

C: ·-
~ 0 

~ • ..c:: ... u 
C: 0 ·- -
QJ QJ 

i::: i::: 
0 0 

Number of specimens exam ined . .. • • 2 9-

IV .. CRUSTACEA . . . . • • • • • • • • • • • • • 66 
1. Decapolia . .. .. . .. .. .. . . • • • • • •••• • • • • • • • • 

Cambarus .... . . . .... . • • • • • • • • • • • • • • • • • 

Palremonetes . .. . . ... . . • • • • • • • • • • • • • • • 

2. A mphipoda ..... .. . .. . . 
Un<letermined ....... . 

• • • • • • • • • • • • • 06 
• • • • • • • • • • • • • 0 2 

Allorchestes . .. . . . .. . . • • • • • • • • • • • • • 04 
3. l sopoda : . . . . . . . .. . . . . . . 

Asel lus ...... . . .. . . . . 
... . . • • • • • • • • • • • • • • 

. ., . . . . • • • • • • • • • • • 

Mancase llus . .... . .. . . • • • • • • • • • • • • • • . • • 

4. Entomostraca .. . . . . . . . . • • • . . ' . • • 100 6o 
Cladocera ... . . .. .... . 

Daphniidre . .. . . . .. . 
Undetermined . . . . 

. • • • • • • • • 55 36 
• • • • • • • • • 55 27 
• • • • • • • • • 55 13 

Simocephalus . . . . . . . . . . . . . . . . . t 
Daphnia . . . . . . . . . . . . . . . . . . . . . . 12 
Bosmina . . . . . . . . . . . . . . . . . . . . . . . 02 

PERCA. 

• 
• en en 

Q) Q) 

..c: ..c: • 
u u flJ 

i:: t C: ·-·- \-, 8 Q) ::, 
V 0 ·-a... u 

..c: - Q) - 0 0.. 
0 

... tn ... QJ \-, 

0 QJ Q.J 
a... > ~ .0 ·-~ ~ ~ 

- -
4 4 18 

• • • • 55 48 
. . . .. • • • • I O 

• • • • • • • • 04 
. . . .. • • • • 06 
• • • • 24 15 
• • • • .. ~ . • • • • 

• • • • 24 15 
• • • • 0 1 23 
• • • • 01 II 

• •• • • • •• 12 
• • • • 30 • • • • 

• • • • 2 2 • • • 

•••• 22 
I 

• • • • 

•• • • • • • • • • • • 

• • • • • •• • • • • • 

. . . . 2 2 • • • • 

• • • • • ••• • • • • 

• • • • • • • • • • • • 

• tn 
C: 
<1) 

8 ·-u 
(1) 

0.. 
en 
QJ 

~ 
<'a 

.....l 

12 

14 
14 
14 

• • • • 

• • • • 

• • • 

• • • • 

• • • • 

••• 

• • • • 

• • • • 

• •• • 

• • • • 
• • • • 

• • •• 

• • • • 
• • • • 

• • •• Lynceidre . . . . . . . . . . . . . . . . . . . . . . . . OCJ 
Undetermined . . . . . . . . . . . . . . . . 07 ••• • • • • • • • • • • •• 

Pl e u rox us . ..... .. , . . . . . . . . . . . . . t 
Chycto rus . . . . . . . . . . . . . . . . . . t 0 2 ..•. 

( :o[epoda.... . . . . . . . . . . . . . . . . . . 45 24 
yclops .... . ...... . ....... . . . 45 24 

Diaptomus . . . . . .. . . . . .. . . . . . .. . . # t 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 
I 

' 

• ••• 

• • • • 

• • • • • ••• 
I 

• • • • • • • • 
• 

♦ • • • • • • ♦ 

Ostracoda (Cypris). . .. . . . . . . . . . . . . . t 
V. V E GET ATION .. . .•. .• . . . . .... 

. . . . 08 • • • • 

• • • • • • • • . . . . 03 

• 

F amily LABRAC1ID..2-E. Tl1e Bass . 

• • • • 
• ••• 

• • • • 

• • • • 

•• • • 

• • • • 

39 

. 

• 
~ 
::> .... = ~ 
~ 
~ 
:n 
0 
N -f--4 

Cf) 

26 

t 
• • • • 

• • • • 

• • • • 

• • • • 

• •• • 

• • • • 

• •• • 
♦ . . .. 

• ••• 

t 
. . . . 
t 
t 

• • • • 

• • • • 

• • • • 

. .. .. 
• •• • 

• • •• 

• • • • 

• • • • 

• • • • 

. . .. . 

• • • • 

We have but two species of this family, t l1c wl1itc bass 
and the brassy bass (R occus cliry sops and 'JJf. 01·01ie inter-
1~1tptli) . As far as their food is concerned, these a r e evi­
dently equivalent species, agreeing closely i11 their gen­
eral relations, a11cl differing only in thei1-- clistril)11tion . 

• 



• 

40 11he Food of Fishes. 

Roccius CHRYSOPS, Raf. WHITE BAss. 
This species is of medium abundance throughout the 

northern half of the State-most common in Lake Mich­
igan. A Cllrious fact of its distribution is its rarity i11 
Fox River and the lakes connected with that stream. In­
deed, during several days' active collecting in this regio11 
we tlid not see a single specimen, neither could we hear 
of the occurrence of the species in those waters, althougl1 
we made careful inquiry for it amo11g ex1Jerienced fisl1e1"­
men. 

My notes on its food relate only to eleven specimens, of 
which three, taken at South Chicago, in August, we1"'e 
young, but of unknown size. Two of these had eaten only 
Chironomus larvre and the la1 .. vre of a remarkable ephem­
erid 1 not yet determined, and the stomach of the third 
contained only a minute :fisl1. The remaini11g eight indi­
vid·uals had depcndecl chiefly on the larvre of May-flies 
( sixty-nine 11e1-- cent.). The other important a1--ticles of 
their food we1"e twenty per cent. fishes (including one 
sun:fish-Cent1"archidre) and eight pe1" ce11t. isopod Crus­
tacea (Asellus). Several attempts to sec11re food fro1n 
Lake Michigan specimens we1"e 1111successfl1l, as, being­
taken in pound-nets, their stomacl1s we1·e a.l,,Tays cn1pty. 
Those studied were from various i11terio1· sitt1ations in 
t11e northe1"n third of the State. 

MoRONE INTERRUPTA, Gill. s~rRIP~D BASS. BRASSY BASS. 

This fish replaces the preceding· in tho so11the1·n half of 
the State, tl1e Illinois River forming· a 11eut1·al zone be­
t.ween the respective territo1"ies of the two si1ecies. 

The food of six specin1cns of this species was stl1died, 
~11 tal{rn from the Illinois River from JVIa)r to October. 

Fo111· of tl1ese were young~. The smallest, one and :1 

·f ol1rtl1 inc}1cs long, ta1(<'n at Peo1•j a, i11 J 11ne, ~I 878, l1arl 
eaten abotit eq11ally of s1nall DorJJsonia ceped1ianit1n a11c1 
Entomostraca-fo1·ty per cent. I_Jcptoclora and ten pe1· 
cent. Cyclops. One, an i11ch and a half i11 lcng·th, tal<en at 
tl1e same time and pla.ce, l1ad eaten onl)' Dorysorn~t, wit11 
a trace of Cyclops. Tho next, one an<l fi,,c-cigl1tl1s 
inches in longtr1, l1n.d eaten a Rmall l1n<let01"mi110<1 fi~h ancl 



• 

1'he Food of Fishes . 41_ 

a few Daphnias. The fourth, one and seven-eigl1ths 
inches long, caught at Peoria, in October, had eaten only 
larvre and pupre of Ohironomus. 

The two adult specimens were feeding chiefly upon the 
Jarvre of N europte1--a-especially May-flies. An Allor­
chestes dentata and a fe,v small grasshoppers also ap­
peared in the food. 

It ,vill be seen that this species apparently agrees 
closely with the preceding in its food. The large amount 
of crustacean food in the smallest specimen shows that 
we should probably find still smaller Lab1 .. acidre depend­
ing upon these as strictly as the Pereida>. 

Family OENTRARCHIDAE. The Sunfishes. 

This interesting g1"oup, kno,vn, in some of its members, 
to every one ,vho has eve1· see11 a doze11 fishes, is repre­
sented in Illinois by sixteen species, as the species of this 
family are now l1nderstood. The two black bass, included 
in this family f 01" technical reasons, a1"e, of col1rse, th0 
1nost important species. The rock bass, the croppie and 
the co.mm on sunfish (Lepiopomits pallidus), althoug·l1 not 
fishes of the ·fi1"st class, wo11ld be se1"io11sl)T missed if we 
were to lose then1; and boyhood in tl1e country would be 
quite another tl1ing if it were not for the '' pumpkin­
seed' ' in the mill-pond, whose barbaric splendor tl11·il]s 
the heart of the yo11thful fishe1"1nan as the more delicate 
beauties of tl1e t1"out or salmon do those of tougl1er fibre. 

I have studied the f oocl of thirteen species of this 
g·roup, as indicated by two hundred and thirty-seve11 
specimens, ,veil distributed in time and area. 

Decided diff ere11ces in f oocl made out in the various 
genera, have been found to coincide with differences in a 
few structures about the mouth in such a way that one 
may predict, from an exami11ation of tl1ese st1,.uctt1res, 
what the leading pect1lia1·ities of tl1e averag·e food of any 
genus will be. 

MrcROPTERUS PALLrous, Raf. LARGE-MOUTHED BLACK BAss. 

This famous species is too well known to reql1ire ex­
tended comment. The ordina1--y fishermen rarely distin-



42 The Food of Fishes. • 

guish it from the following; and, indeed, sportsrnen do 
not al,vays recognize the difference. 

I have examined the food of thirty-one specimens of 
this species, fourteen of which were ad11lts, and the re­
mainder young·, of diff e1"ent ag·es. 

Food of the Yol,t1ig. 

The first group, consisting of five specimens u11der one 
inch in leng·th ( ranging from ~ to 1 in.), rep1~esents three 
localities-Crystal Lake, in J\ticHenry county, tl1e Illinois 
River at Pekin, Tazewell county, and tl1e same stream at 
Starved Rock, in LaSalle cou11ty. They vvere tal{en in 
.June, July and August of three differe11t yea1--s. It is evi­
dent, the ref ore, that the com1non f ea·tures of their f oocl 
cannot vv~ll be attrib11ted to a11y other tl1an t.hei.r similit1· 

• size. 
The enti1"e food of these fishes co11sisted of small Crus-. 

tacea-all Entomostraca except se,Te11 per cent., eaten b}'" 

a single fish, ,vl1ich c·onsistecl of tl1e very young of some 
undetermined a111phipod-p1·obably Allo1·cl1estes. Eighty­
seven per cent. of the food ,vas Cladocera, p1"'inc_ipally 
B osmina longi1,·ost1·is, Mi.ill. Si11ioce plialu s a111 e1·-icr n,i10, 
Birge, was also an important ele1ne11t; and t1'aces appea1' 
of Chydorus, Pleuroxus and Eitt·ycei·cits l amellatus. 
Abol1t six pe1~ cent. of Cyclops l1ad been eaten. 

In tl1e food of the next grot1p-six specimens, from 1-} 
to 1-½ inches lo11g-n1i11t1te fisl1es and insects appear. Tho 
fishes (twenty-nine per cent.) were not large enot1gh to 
determine. The insects (fo1~ty-six per cent.) we1·e mostly 
young wate1'-bug~s (Corixa), tl1e p1"incipal pa1't of whirl1 
,vere about l1alf gr·own. The adt1lts were all C.orixt1 
tu-mida, Uhl. The Entomostraca drop to twenty-five per 
cent., a1'out equally Cladocera and Cyclops. A1)1ong tl1P 
for·mer ,vere many specirnens of Si1-JiocPpli<1l1,,._. a,11.r:,J"·ir:rr­
nus, and a fevv of the 1·are ancl cu1"iOllS Leptc)<l<) t',L rricr1 -
tioned in a previous paper.* The specirnen in wl1ich this 
was found was talren at Peoria, in Jt1ne, 1878. All of this 
group were ·taken from the Illinois River, but at different 
places and dates. Some, taken at the same place and 
-- - - --------- -

• See Bull. No, 2, Ill. State Lab. Nat. Hist .. p. 88. 

• 



• 

- Tlie F'ood of Fishes. 

• 

t • > 
-t-•) 

time as othe1·s of tl1e preceding group, .. differed fro111 
them in the smalle1"' nt1mbe1-- of Entomostraca eaten, ancl 
the larger nt1mbe1· of insects.-diff erences evidently onl}r 
to be explained as clue to the different sizes of the fishes. 

The next t,vo specin1ens, between two and three inches 
long, l1ad eaten only insects, chiefly C orixa. tumida. 

Fo11r specimens, ranging~ from th1>ee to tl11·ee anc1 ,1 

half inches in leng·th, all taken from a lake i11 the Illinois 
River bottom, in October, 1879, had eaten nothing but in­
sects- almost wl1olly Corixas ancl tl1e larvre of May-flies 
(Ep,hemeridre) . Tl1e Corixas were C. altp1·11atrc , Sa'}r, clllll 

C. tu'fliida, Uhl. . 
Food of tlie .L4-ditlt. 

Turning to the food of the fourteen ad11lts, ,ve note tl1e 
total disappearance of Entomostraca, the merely acci­
clental occurence of insects, the appeara11ce of crawfishcs 
( Cambar1.ts i1n1nitnis), which amount to seven per cent. of 
the whole food, and tl1e g1"eat lJl'eclomiriance of :fisl1t1

:--: 

( eighty-six per cent.). These were of sufficient variet_, .. 
to show that no g·roup is safe from the appetite of tl1P 
bass unless it be the gar. 

Perch, minno,,rs, catfish ancl hicko1~y-sl1acl were 1--eco~;-
11izable. The la,st ,vere mucl1 tl1e 1nost abun(la11t, orcu1·1·i 11,~· 

in eight of tho specimens, and constitt1ting fifty-eight pe1-­
cent. of the food of the whole 11U111ber. They rangerl 
from three to six in each stomach,· a.nd ,;ve1"e from th1·ee 
to four inches long'. It should be noted, however, tl1at 
these were all eaten by fishes taken at tl1e same }Jlace ancl 
time. A la1"ge mouse was found i11 the sto111acl1 of on(; 
bass from the Illinois River. 

We may generalize these c1ata by saying tl1at this black 
bass lives, at first, wl1olly on Entomostr·aca ; that it com­
mences to take the smallest aquatic insects ,vl1en abot1t 
an inch in lengil1, and that n1inute fishes appear in its 
diet almost as early. From this forward, the Entomos­
traca diminisl1 in importance, and the insects a11d fishes 
bec·ome larger and more abundant in the food. The 
adults eat voraciously of a great va1·iety of fishes­
especially 1he hickory-shad (Do1·ysoma )-a.nd. fe(id l1po11 
crawfishes also to some extent. 



• 

The Food of Fishes. 

M1cROPTERus . SALMOIDEs, Lac. SMALL-MOUTlIED BLACK 
BASS. ,\)~ 

This species, called also tiger bass, river bass, etc., is 
the black bass par excellence. It ranges usually in deeper 
and clearer water than the preceding; but both are often 
taken together. 

I have made full notes of tl1e f oocl of twenty-seven spec­
imens-three adult and the others yo1111g. I had none of 
this species under an inch in length; but, judging from 
the g~neral resemblanc-e of the food of this and the pre­
ceding bass at later ages, I do not doubt that this will also 
be found to feed at first on Entomostraca, although insect 
food is possibly mo1"e important to it from the beginning. 

Seven individuals, from one to two inches in length, 
we1"e all taken in July from rocky 1"ipples in the Fox 
R,iver, at Dayton, Ill., a few miles Rbove the mouth of the 
stream. These had eaten only five pe1" cent. of Entomos­
traca-the whole remainder of the food consisti11g of in­
sects, of which Co1"ixa titmida, young· and adult, and 
larvre of May-flies and da1·ning-needles (Ag·rionidre) were 
the most important kinds. E1 ou1· pe1" cent. of the larvre of 
Ohironomus are worthy of notice. The scarcity of Ento-
1nostraca in the food of fisl1es as small as these is prob­
ably due to the situation in which these specimens oc­
curred, as few Entomost1·aca are to be f Ol1nd in swift 
water. The same fact ,vill account for tl1e p1·esence of 
Ohironomus larvre-found abundantly t1nde1· stones in 
1·apid streams. 

The next te11 specimens, between two and th1·ee inches 
long, were talcen in July, partly at the same place as the 
preceding, a11d partly from the Illi11ois l{ive1·, a few miles 
below the mouth of the Fox. Tl1ese differecl from the 
smaller specimens chiefly in the appear·ance of fishes in 
the food ( five per cent.) and in tl1e abse11ce of Neu r·op­
te1"a. Probably tl1e last of these cliffe1·e11c·es, at lca_st, was 
accidental. A fevv lar·vre of aquatic Ooleoptera (l[ydro­
philid:::e and Dytiscidro) wcr·e noticed. Corixas, includi11g 
C. titmida, Uhl, and C. S'i,qnata,, Fi c b., ,x, ::1.n1ountcd t<) 
eighty-two per cent. of tl1e food. 

In those rang·ino- from th1"ee to f 01-11" inches in lengtl1 
( seven individuals), the fisl1cs eate11 1·ise to f our·tecn pe1~ 

f.i Determined by Mr. Uhler. 

\ 



• 

Tlie Food of Fishes. 45 

cent., but the insects drop away to seven per cent., and 
the Crustacea rise to seventy-nine. Here, .however, dif­
ference of locality interferes to prevent any satisfacto1"y 
comparison with other ages-as these specimens were all 
taken in August, from Calumet River, at South Chicago. 
This slow stream, clogged with Algre and a great variety 
of other aquatic plants in midsumme1", also swarms with 
C'1·11stacca-e8pecially the little Allorcliestes den tat a. This 
species made sixty-three per cent. of the food of these 
specimens ; and an undetermined species of Asellus, four­
teen per cent. A few Gammar1.ts f asciatits were also 
found. The insects were Corixa and larvre of Ag1 .. ionidre. 

I t will be seen that, excepting the gradual increase of 
the number of fishes eaten, these data show no especial 
difference in the young of different ages. Smaller speci­
mens and a large1~ number from a g·reater variety of situ­
ations, would be necessary to exhibit this difference. 

The food of the young as a whole, apparently, does not 
differ essentia.lly from that of the large-mouthed species, 
except in the probal)ly greater importance of the insect 
element-especially Corixas, which in these twenty-four 
specimens amounted to fifty per cent. of the food-ancl 
the inferior importance of fishes. 

This peculiarity is expressed in a slig·htly different 
manner in the food of the adult. The th1 .. ee specimens ex­
amined bad eaten only fishes (N otil,r1.ts fiavi,s ancl 
Percina ca,prodes) a.nd cra,vfishes ( Cambarits propin­
quits )-thi1"ty-eig·l1t per cent. of the former and sixty­
two per cent. of the latter . 

Tl1is is the first of several instances in which the ratio 
<>f fishes in the food of allied species and genera. was 
found to cor1·eRpond to the size of the mo 11th, being larg­
est in those witl1 the largest or·al opening.* 

$' The frequency wjth wbjch these two speci~s of blacl{ bass are co11-
founded makes it d esirable that a single reliable character should b e 
selected by which they ca11 be invariably distinguished, whatever the 
age of the specimen. This character is afforded by the size of the scales, 
the small-mouthed species having the smaller scales. In this species 
t h er e are eleven longitudinal rows of scales between the dorsal fin ancl 
the row of perforated scales r unning a long the middle of the side. callecl 
the la t eral line. I n the lar ge-mouthed species. t here are never more than 
nine su ch rows. The young are easily d isting uish ed by the longitudinal 
black s t r ipe a lon g the s tde of t h e large-mouthed bass, wh ich is wanting 
in the young of the other sp ecies. 

• 
• 



• 

• 

• 

4(i 1'he Food of Fishes. 
rr ABLE OF THE FOOD OF MICROPTERU S. 

I M. PALLIDUS. 

• ..c: 
u 
C ·-
OJ 
C 
0 
~ 
<l) 

'O 
i:: 

::> 

0 -
...c:: u 
C ·-· 
<l) 

c:: 
0 

• 
tn 
<l) 

..c: u 
c:: ·-

0 -

• en 
<l) 

.Cl 
u 
C 

0 ... 

----- ------·----·- - - - -1--
Number of specimens. . . . . . 5 6 2 

l. FISHES . ... ..... . . . ' . . 29 . . .• . 
A can thopteri ..... . .... . ... . • • • • • • • • • • • • 

Percina ... . ..... .. .... . • • • • • • • • • • • • 

Pe rca ... . .... . .. . ..... . • • • • • • • • • • • • 

Dorysoma ... .. . . . ... . .... . 
Cyprinidre . . . . .... . . .. .... . ,.... 

Lam poston1a .... . .... . 
• • • • • • • • • • • • 

• • • • • • • • • • • • 

Sil uridre ... . .. . ... . .. . .... . • • • • • • • • • • • • 

Noturus flavus ....... . . • • • ♦ • • • • • • • • 

II. INSECTS ....... . . . . . . 

Undetermined larvre . . ... . • • • • 

1. Dzptera (larvc.e) . ........ . 
Culicidre .... . ....... . .. . 

. . . . 02 

• • • • • • • • • • • • 

• • • ♦ 

Chironomus ........... . . . . . 02 . . . . 
M uscid ce. . . . ......... . • • • • • • • • • • • 

2. Culeoptera (larYre) .. .. .. . 
Dytiscidre . ............ . 
Hydrop11ilidce . . ....... . 

• • • • • • • • • • • • 

• • • • • • • • • • • • 

• • • • • • • • • • • • 

3. H eniip tera ... . ..... , ... . 
Terres trial . .... . ..... . . 

. . . . 4 4 50 

. . . . . . . . . . . . 

. . . . . ' . . . . . . 

4 14 

. . . . 86 

. . . . I 5 
• • • • • • • • 

. . . . 08 
• • • • 

• • • ♦ 

• • • • 

• • • • 

58 
06 
06 
07 

• • • • • • • • 

100 t 
• • • • • • • • 

• • • • • • • • 

• • • • • • • • 

. . . . 1 · . . . 

• • • • • • • • 

• • • • • • • • 

. . . . . . . . 
57 t t .... 

• • • • 

M . SALMOIDES. 
---·-----

0 ..... 
..c: u 

c:: 

• Ul 
<l) 

..c: u 
c:: 
<l) 
Q) ... 

..c: -
0 ..... 

Q) 0 
c:: ' ~ 
0 ~ 

7 I O 

• 
VJ 
<l) 

..c: u 
c:: ·-
1-
:::s 
0 -0 -
<l) 
Q.J 
'-..c: 
~ 

7 

• 
U) --:, 

'O 
~ 

3 

. . . . 05 14 38 
• • • • • • • • • • • • • • • • 

• • • • • • • • . . . . 13 
• • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • 

• • • • 05 . . .. • • • • 

• • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • 

• • • • • • • • • • • . 2 5 
07 ... . 

• • • • • • • • • • • • • • • • 

04 05 .... 
• • • • 01 • • • • 

04 .... • • • • • • • • 

. . . . 

♦ ♦ • I 

• • • • 

51 

04 . . .. . . . . 
02 • • • • • • • • 

02 .. . . • • • • 

• • • • • • • • t 
82 03 . ... 

• • • • • • • • • • • • • • • • 

. . . .. . . . . . . . . . . . . Zaitha ........... . ... . t 
Corixa .... . ..... . .......... 42 50 57 .... 51 82 03 . .. . 
Notonecta . . . . .... . ... . • • • • 

4. _l\1ezi ,-opte1·a (larvre) ..... . . . . . 
E pl1emerid£C .. . ... . .. . . 
Ag rionid ~ ... . . . . . ... . 

III. CitUSTACEA . ... . 

. . . . 

. . . . 
100 

1. Decapoda ......... . .... . • • • • 

Cambarus, . . .. . ... . ... . • • • • 

z. A 111/Jhipoda . . . . . . . . . . . 07 
Gammarus ......... . .. . . . . . 
P._llo rcl1estes ..... . . . . . . . . . . 

3. Jsopoda (Asellus) ... . .... . . . . . 
4. E nto1;1ost1·actz . . .... , . . . . q3 

Cladocera...... . . . . . . . . 87 
Dapbniidre . . . . . . . . . . 26 

Si mocc 1)l1al us . . . . . . I 8 
Bosmi11a.... . . . . . . . 6(> 

I.,cptodora .......... . 
Cupe pod a (Cyclops) . . . . 06 

IV . V l•: GE1'ATION .. . . . . . 
Endogen<JUS . .. .. . . . ...... . . . . . 
A I g ,e . . . .. . . . . . . . . . . . . . . . . . . 

]\,f1SCEIJLANEOUS .. . .. 
. . . . 
. . . . 

----- --- - -

C:! .... • • • • • • • • 

• • • • · · · · 4 3 t 
• • • • • • • • 43 . . . . 
. . . . . . . . . . . . 
2 5 ... . 

. . . . . . . . 
• • • • • • • • t I t o , 

. . . . • • • • ., • • • • 

t 04 .. . . 
t .. . . • • • • 

T I • • •• 

05 oi 
• • • • • • • • 

. . . . . . . . 

04 ... . 
79 6z 

• • • . tJ2 

• • • • 62 
• • • • • • • • • • • • • • • • • • • • • • • • 

. . . . . . . . . . . . . . . . . . . . • • • • 

• • • • • • • • • • • • • • • • • • • • . . . . . . . 

······· · ········ I ······· 1-1 ···· . 
2 5 .... 
14 . .. . . 

. . . . . . . . 
t .... 

0 5 .... 
05 04 .... 

• • • • . . . . 
. . . . 

I 2 ... . t 05 oi . . . . • • • • 

06 ... . • • • • • • • • . . . . . . . . . . . . . . . . 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
02 .... 
l I . . . . 

• • • • • • • • 

• • • • . . . . 
• • • • • • • • 

• • • • . . . . 

• • • • . . . . 
. . . . . . ' . 
. . . . . . . . 
• • • • • • • • 

• • • ♦ t 
. . . . 07 

• • • • • • • • • • • • 

t t . . . • • • • 

. . . . 02 ... · I 02 

• • • • I t . . . . I . . . . 

• • • • • • • • 

• • • • • • • 

. . . . .. ... 

. . . .. . . . . 
-----· -- ---



The Food of Jt-,,ishes . 47 

.. i\.MBLOPLITES RUPESTRrs, Raf. Roc1c BAss. 

This favorite and widely distributed species does not 
differ f1"om the other fishes 1nentioned in respect to the 
food of the young. Tl1e smallest specimen examined, five­
eighths of an inch long·, contained only a few Cladocera 
(Pleurox11s). Another, three-f ourtl1s of an inch long·, bad 
eaten Daphnids ( seventy-five per cent.), Cyclops ( te11 pe1· 
cent.), and la1"vre of Chi1--onomus. A tl1i1"d, seven-eighths 
of an inch long, contained only min11te fragments of a f e,v 
Jarvre of N europtera. These specimens were all tal{en 
from Fox Rive1-- in July, 1879. The 1"emai11ing· you11g of 
the year v\rere living· chiefly on Co1~ixa ( eigl1ty-three per 
cent.), as were also the young of the year p1--eceding 
(ninety pe1-- cent.) , so far as co11ld be judged from t11c 
f ood of two speci111ens, from three to four inc.11es i11 

length. Son10 lancl insects, ~pl1emerids, ,,rater-beotles1 

and a f e,v Allo1--chestes we1"e also found in the food. 
Four adult speci1nens, take11 at Otta,va on the 8tl1 of 

July, had eaten some mint1te fishes (fifte·en pe1· cent.), a 
few water-lJeetlcs, incll1cling· T ,·01Jiste1~1i1ts li11ibatit•~'>, o,rer 
forty pe1-- cent. of N e111"optera la1 .. vre, a11d abot1t tl1i1"ty pe1· 
cent. of small crav,,fishes. The N el11--opte1"a incll1ded 
Baetis and otl1e1-- ep1te1ne1·ifls ( twe11t,~ 11:)1• c1 c11t.), ..Li\.g1·i c11 -
idre and la1"ge Libelll1liclre, and fiftee11 pe1" cent. of case­
flies (Phr·yganeidre) . Pond-weecl (Potamogeton) founrl_ 
jn two sto1nachs, l1ad p1"obabl3.,. been tal{en accidentall~r. 

CHlENOBRrTTUS GULOSUS , C. &, V. \VIDE-l\.f01TTHED SuNFISI-I. 

This fine SJ)eries i s a111011g tl1e co1nn10112st of the fam11~, 
in the lalres ancl l)ondR of souther11 Illinois, ,vhere it j R 

commonly lrnow11 as the '' goggle-eye.'' 
The no1·thc1·n limit of its 1·ange, so far as kno,:vn, is the 

Illinois Ri,1cr , ralle3r. 111 n t1mbe1" a11d habitat it replaces 
in the sout11 the E11po11iotis aitreits of the n orth ; but t 11is 
equivalence i s 011ly apparent as the t,\TO species diffe1" 
widely in food. F1"om its size a11d al)u11clance, it is 110 i11-
8jgnifiea.nt foofl 1"e80U1"ce. 

Food of tlie Young. 
My smallest specimens were from lakes in the Mississip- • 



• 

48 Tlie Food of Fislies. 

pi bottorr.1., near _ Bird's Point, Missou1"i. Two of these, 
one inch long and u11der·, take11 in Septernber 1879, had 
oaten 011ly B 0s1nina longirostris and Cyclops. Insect 
food first appears in specimens one and one-half inches 
long. Eight specin1ens, between one and three inches 
long, six of which were taken from a lake in the Illinois 
bottoms, near Peltin, in October, 1879, and two from a 
lake in l(entucky, nea1-- Cairo, Illinois, had eaten about 
forty per cent. Entomostraca, thirty per cent. N europ­
tera larvre, and thirty per cent. Corixas and Dipte1·a 
larvre. Dapli1iia pulex, Simoceplialus aniericanus, Bos-
1,nina lo1igirostis, Chydo1·us, Pleu1"oxus a11.d Cyclops, wer·e 
among the Entomostraca. Corixa alternata was found 
among the Hemiptera. Most of the Diptera (i. e., fifteen 
per cent.) ,v-ere larval Chironomus . 

• 

Food of the Adult. 

Six adults from rivers, streams and lakes in central 
and southern Illinois, show the usual change in foocl, 
carried farther than in the preceding species. Entomos­
traca disappear-except a fe,v Ol1ydo1·11s i11 a singls spec­
imen-and fishes become the principal reliance, amount­
ing to forty-seven per cent. of the food. Corixas, larvro of 
Paling e11,.ia bilineata, and some terrestrial Coleoptl3ra­
A nomala binotata-which made half the food of one 
specimen, are the remaining items. 

The especially pisci,7 orous habit of this species is 
probably related to the size of its mouth, which is mucl1 
the larg·est among the su11fishes p·roper. A similar rcla ­
ti<>ll has already been noticed between the two bl~1rl\ l)a R.~ . 

• 



• 

• 

1'lie F'ood of Fishes. 49 
• 

T ~i\BLE OF FOOL) OF A1vrnLOPLITf£S .A.ND CR}ENOBRYTTUS. 

-

-----·- - ------·--
:-'1 umbe r of specin1ens examined 

I. FIS H RS ...... . .......... . 
ll. INSttCTS ...... . ....... . 

Undetermined larv~ ... .. .... . 
Cater I) i 11 a rs . . . . . . . . . . . . . . . . . . . 
1. TJzptera (larvcE) .... . ....... . 

Ch ironomus ............ . . . 
2. Coleoptera . . ... . .... . ..... . 

Terrestrial .. ........ . .... . 
Aquatic ........ . .. . ...... . 

Dytiscid~ . .. ....... ... . 
HydrophilidcE ...... --. ... . 

3. f-IemijJtera. . . . . . . ........ . 
Corixa.... . . . . . . . ..... . 
Hygrot r-echL1s (young ) .... . 

4. Ne11rojJte,·a (larvcE) ........ . 
E phcmerid re . ....... . .... . 

Palingenia ........... . . . 
Baetis .. ... ............. . 

1\grionid~ ............... . 
Llbellulidce ...... . .... . .. . 
Phrygan eid~ ..... . ...... . 

I I 1 .' ARACHNIDA (H }'drachna) 
IV. CRUSTACEA .. . ... . ..... . 

l)eca i1oda (Cambaru~) ...... .. . 

A MBLOPLITES. 

·-------

• ...c: 
u 
C: 

(1) 

~ 
0 
'-c 
(1) 

"'O 
C: 
~ 

0 ..... 
..c 
u 
C: 

• en 
Q.) 

..c u 
s:: 
'-c 
::, 
0 .... 
0 -
<l) 
<l) 
1-. 

..0 
~ 

3 3 2 
- -- ----·--
• • • • • • • • 

39 99 
. . . . I 6 
. . . . 
05 
05 

17 
03 
03 

. . . . I 5 
97 

• • • • 

52 
01 

• • • • • • • • 

. . . . 06 
• • • • • • • • 

• • • • . . . . 02 

• • • • • • • • 0 I .... 

• • • • • • • • 01 
. . . . . . . . 0 I 

03 
01 

. . . . • • • • . . . . 02 

9 5 · · · · 
' . . . 90 • • • • 

. . . . . . . . 05 • • • • 

34 · · · · . . . . 42 
. . . . . . . . • • • • 21 

• • • • • • • • • • • • • • • • 

• • • • . . . . 

. . . . • • • • 

• • • • 

• • • • 

. . . . . . . . 

. . . . 0 I 

. . . . 0 I 

. . . . 

. . . . 

. . . . 

05 
15 
t 

6 I . . . . 03 31 
31 • • • • . . . . . . . . 

A m11l1ipoda.. ... . . . . . . . . . . . . . . . ... • • • • 03 ... . 
E~ 6 ntomostraca . . . . . . . . . . . . . . . . . I 0 I .... • • • • 

Cladocera . . . . . . . . . . . . . . . . . . 58 
I)aphnia ......... . ..... . 
I3osmi na ............ . . . 

• • • • 

. . . . 

• • • • 

. . . . 
• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

P leu roxus .......... .... . 
Cl1ydorL1s .... .......... . 

33 · · · · • • • • • • • • 

• • • • 

C(1 pe pod a .... . ......... . 
V. VEGETATfON ... . ....... . 

03 
. ' . . 

Pot a n1oge ton . ....... . .... . ... . • • • • 

. . . . • • • • 
• 

0 I .... 

. . . . 
• • • • 

. . . . . . . . 02 

• • • • 02 

CH..ENOBRYTTUS. 

• 
'-c 
Q.) 

"O 
C: 
::, 

"'O 
C: 
~ 

..0 u 
Q 

<l) 

s:: 
0 

2 

0 ..... 
...c: u 
s:: 
CJ 
Q 
0 

4 

• • • • • • • • 

· · · · 5 7 

• VJ 
V 

.,Q 
u 
C: 

V 
Q.) 
I-

.a .... 
0 ..... 

4 6 

. . . . 47 
64 53 

• • • • • • • • • • • • • • • • 

. . . . 32 
• • • • 26 
• • • • • • • • 

• • • • • • • • 

04 .... 
04 •••• 

. . . . 10 

. . . . I 0 
. . . . . . . . . . . . . . .. . 
• • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • 

• • • • . . . . 20 18 
18 • • • • . . . . 20 

• • • • • • • • • • • • • • • • 

. . . . 2 5 
' 

• • • • 03 
f I • • I I ♦ I 

40 25 
12 25 

. . . . 25 
. . . . . . . . . . . . . . . .. 
. . . . IO 28 . .. . 
• • • • • • • • • • • • • • • • 

. . . . . . . . . . . . ,, . . --

. . . . . . . . . . . . . . . .. 
100 43 34 t 
♦ ♦ ♦ • o t I ♦ ♦ I • ♦ ♦ • ♦ • 

• • • • • • • • • • • • • • • • 

100 43 
70 24 

• • • • • • • • 

70 .... 

34 t 
34 t 
21 .... 

• • • • • ••• 

• • • • 

• • • • 

t .... 
t • • • • 

• • • • 

t 
I 9 .... • • • • 

• • • • • • • • 02 .. . . 

• • • • • • • • • • • • • • • • 
A 1 g_~ . . . . . . . . . . . . . . . . . . . . . .. . . __ :-....':?:::...=::==================================================-• • • • • • • • • • • • • • • • • • • • • • • • 02 . · ... 

AP01\10Trs CYANELLus, Raf. BLUE-SPOTTED SuNFISH. 

This species, distributed th1·oug·l1011t tl1e State, is espe-­
cially abundant in central Illinois, ,vhere it is the com--
1non fish of the pon.ds and smalle1· str eams--' ' the st1n-

• 



50 

fisl1 '' of t]1 c count1·y scl1oolboy and tl1e picnic pa1 .. ty. It 
is tl1e constant companion of tl1e ''bull-head'' (Amiurus) 
ancl '' sl1i11e1··'' (Notemigonus) in tl1e small stagna11t 
ponds of tl1e p 1·ai1·ie regions, and of the '' chub n1innow '' 
( Semotill1~) i11 11111ddy c1"eeks. It ,vas found ab11ndant 
,,Tjth Ce11t1·a1·chus, Apl1r edoder11s and A nii11rus cat1is, i11 
tl1c r·a.})idlJr c11 .. 3r~ng 1nl1cl-l1oles;x, only a few feet acr oss, left 
by the 1·et1--eating' o,,erfiow of the Mississippi bot toms, i11 
U11io11 co11nt,r . ., 

• 

Tl1e s111allest of 11i11etee11 specimens stt1died, ,,ras one 
i11ch i11 le11gtl1- tal{en in J 11ly, in a p1'airie pond 11ear N 01"-

1n al. Ni11et3T-fi,re per ce11t. of i t s food ,,ras Cyclops ancl 
t l11'CC }J€!1' cent. Daph11ids. Tl1e trifling r emaincle1· co11-
sistecl of a Co1"ixa j11st ]1a tchcd, a11d a Cl1i1"on0In11s la rvre. 

Nine s1)eci111e11s, 1--a11g,i11g f l"Om one to t,\7 0 and a f 011~rth 
i11ches in le11g'tl1, Vftl"}T so little in food t]1at it is 11ot wortl1 
·\,r l1ile to t1·ea t tl1e111 sepa1--a tely. These ,,Te1·e tal{e11 f1--on1 
,Ta 1·io11s po11cls, st1·eams and lakes in ce11t1"al I llinois. 
TJ1ei1· fooc1 ,,7 c1 S dist1 .. ibl1ted ql1ite g·e11e1"all}T tl11--ough the 
,Ta1--1 011s c>1·(l01"s of i11~ects and cr11staceans accessil1le to 
tl1en1, 8ll()\\·i11g tl10 j11cliffe1'e11t appetite of tl1is :fisl1 ,111cl 
tl1e gc11e1·al effecti,Te11ess of it s collecting· appa1·atus. 

T Ja 1·vre c)f Cl1j 1·ono11111s, D·:1tiscidre, Sta p l1Jrlinidm_, Co1--­
ixa8, E pl1e111e1·icl lar,ra:, Decapocla, I sopoda, Cladocer a, 
C)T1)r·ic1s a11cl Co11epoc1a ,,,.e1·e ::1ll f Ol111cl i11 consic1e1 .. ablP 
ql1a11tities i11 tl1 e f oo(l of t l1ese s1Jeci111e11s. 1-\.s 11s11al, tl1e 
1nost i1111)(J1·tant j11sects ,,rere Co1"ixas and May-flies- six­
tce11 })e1· c·e11t. of tl1 2 f 01·11101· a11cl t,,.,.e11t3T-11inc ]) e 1· re11t. of 
t.110 l::1tte1·. .1-\ l1011t eigl1t yJe1· ce11t. of tl1e food was Cla­
<-l () ('(1 1·:-1 ( D a J) l 111 j cl, ~ l l ll occp 11a 1118, Pl ell 1·0 :x11 s, r11~T(10 l ' l l R) . 

Fon rl n f t li (' A cl 1 t 1 t . 

rr' llfJ (ligl1t <lcl11 lt s, f'l' ()ll) 11()1·tl1e1·11 a11(1 R()11t11e1·11 llli1l () iR, 
(lj ffr1·ecl f1·0111 tl1c ~ro1111g· i11 tl1e cli sap11ca1,anc,(:) of E11-

'~.t\11 th(' s 1Jec irn e 11s t nlccn fr o111 ll1esc hole!-- , so 111u(l<l~· t ha t ll1c ,\·n lt' I' 
,1va~ ~J1110Rt opacrt1e, ,v0 r e of }l 1Jcc1.1lin rly blc~1t' l1 ecl np1>t--ar :.111 C' C'- 111 ,111~· tir 

t h en1 nl,nos t c o l o 1·1 <':'ls--.t f n <'l nf i11tc·rcst r Pln tivc to tl"1n ln:vv~ 0f ,,01oratin11 
a 111011g· fi~}1(' S . 

• 



Tlie l!1oocl of· Fislies. 
• 

51 

t.on1ost1·aca 1·1·0111 tl1e food, the la1~ge1" size of the insects 
take11, and the a1)pea1 .. ance of fisl1es and craw:fishes. 

Among· the insects were a la1--g'e Hyd1--opbilus unknovvn 
to me, l1ut 11early as la1 .. ge as H. t1·iangitlaris, the larva of 
Coryclalus cor1iit.tirs, of Libellula and of some Ephem­
('1·icl. Tl1e fishes composed about tl1irty-six pe1'" cent. of 
tl1e f 0<1(1. Tl1e only 1"ecognizable specime11s ,,re1"e a small 
(~y})rinoicl a11d a 3,ou11g· lJ11ffalo-fish (I clitliyobits buba.lus) . 
Crawfishes a11d the 1 .. i,1 er sl1rimp (Palremonetes) hacl 
l)ee11 eate11 113, t,vo of tl1e specimens . 

... I --1EPIOPOl\IlTS PALLIDUS, 11it. COl\11\fON su~FISH. 

This abl111dant, ha1·cl3.,. a11cl ,ro1·acio11s s1)ecies, is· f Ol111rl 
tJ1ro11gl1011t the State, a11d 111a}1 l)e 1"ega1--ded as the typical 
s11nfisl1. It is most ple11tif11l i11 tl1e la1--g·e1; 1·i,"e1·s in cen­
t.1·al Illinois, being' 1"rplacerl i11 po11cls b~r -L4 po11iotis cyan~ 
ellus. 

. -Co11siste11tly ,,,itl1 i ts witlc 1·ang·e ancl , ra1--iec1 hal)itat, it 
is a, ge11eral f eec1e1· fo1" a Rl1nfis]1-pcc11lia1· only in tl1e 
fact of its strictl).,. 11011-1)1·eclaceo11s c11a1·acte1'. Of forty­
five s1)ecimens e:xa1ni11ecl, 0111~,. 011e 11acl eatc11 a fiRh, ancl 
that 011e 011ly a single s111all c1a1,te1'. 

U 1icliff'ere,1itict tecl C' e Jl t 1·c11·clz, iclct P.-I i11 trod 11ce l1ere tl1e 
f oocl of six specin1e11s of tl1is fan1il}T ,vhich were too small 
£01· clrter1J1inatio11. Tl1e3r we1·e too cleep £01· Micropterus, 
ancl as tl1e~,. bacl 1111 t tl11·ee a11al spines, col1ld not have 
been Aml1loplites 01· Pomox),.S. Tl1ey ,,rere probably L'ep­
iopo 11i 1,1 .s· JJCtl licl 7t.s. ..~\_ll ,,re1"0 talren f l"OID the Illi11ois River 
-a pa 1·t o-f tlJ e111 11ear J_;a Salle, i11 J 11ly, 1879-the others 
f1·om Peo1·ia., i11 J 11ne, 1878. 

T11 e sn1allest ( se\"'e11-sixtee1itl1 s of a11 incl1 long) hacl 
eate11 onl~,. Daphniidre. The next i11 size ( 011e-l1alf inch) 
contai11ecl C3rclo1)s (11i11et) ... -eig]1t 1)e1· cent.) ancl Chydor11s. 
N ea1·l},. the ,,rl1ole of tl1e f oocl of tl1e 1·emai11i11g· four was 
Dapb11iiclre (11i11ety-fo111" 1)e1· ce11t.), incl11ding Daphnia 
J?itlP.1.' . 

F oocl of tli e Y oittzg. 

~1:y sn1allest specime11s, fi,re i11 nl1mbe1", ranging ·fro111 
three-fo111·tl1s of a11 j11c11 to one i11cl1 , we1~e tal<:en in All-

-



52 . Tlie Food of Fishes. 

g·11st, SeptemlJe1· and October, a t Pel{in, P eoria, and Macl<­
i11avv C1--eek, Woodford county. Neither locality nor date 
seems to have 1nade any marked difference in their food, 
the p1"incipal elements of ,vhicl1 vvere Entomostraca and 
Chironomus la1 .. vre-fifty-seven per cent. and thirt3r-seve11 
pe1" cent. respectively. 

A few water-spiders (IIydrachnidre) and undeterminecl 
Amphipoda were the other items. The Entomostraca 
,vere all Cyclops ( t \\·e11 ty pe1· cent.) ancl Olaclocera (S inio­
cephalus vetuliis a11d a11ie1·icarnits, B osmina lon,r;irost1-,js 
and Ple,itroxits dentatus). 

Nine specime11s, between two and three inches long·, 
vvere caught at the san1e times and places as the preced­
ing, except tl1at one speci1ne11 fron1 Macki11a,v CI·eek ,vas 
taken in J u11e, a11d 011e take11 i11 Septembe1· was f 1·0111 

Clear Lake, Kentucky. The g1·eater size of these speci­
mens vvas indicated by the appea1"ance of a few N europ­
tera la1--vre in the f ood-,eigl1t per cent. In other essential 
1"espects, the food was like that of the fore going group. 
011e specimen had eaten larg·ely of v\rater-mites and an­
other of Cyp1"ids (fifty pe1" cent.), and these elements 
have therefo1"e grea t er p1·0111i11ence in the a, .. e1"nges. Chi­
l"onomus la1•,rre 

1
a11cl En1.,omost1·aca now s11m 11p eig·hty­

one pe1-- cent. 
In the third g1"ot1p of the 3roung·, consisti11g of seve11 

fishes, betvveen t,vo ancl tl11·ee inc11es long·, the C}1i1'ono-
111u s larvre 1"emain abol1t a s befo1"e ( thi1·ty pe1-- cent.), 
Corixa s appear ( t,venty-fi,lc pe1· cent.) a11d N europte1~a 
larvre 1·ise to f ot1rtecn per cent. Ent_omostraca now fall 
away to a trifle, a11cl la1"go1" p e1 .. ce11tages of Ampl1ipoda 
appear. Si11gle fishes l1acl eate11 tbe la1"vre of a Gy1·i11id. 
beetle, })01·tio11s o-f the Polyzoa11 Pecti1iatella 11ia!11iifica, i , 

L eidy, ancl an ca1·thwor·1n- the latte1~ p1·obal)]y nibblecl 
f1~om some fishc1·man 's 11001c. 

* This a nima l f orms the la rge, tra n slu cent masses fot1 11<.1 i11 111i(l s t1r111l 'l f' t' 

jn the s low wat er along tl1e m a r g ins of the Illinois River an tl C> lsewl1er P 
throu g hout t l1e s t a t e, u s ually collectc cl a bout a s ti clc or a s t e111 of a watc1·­
weed. "fhe)' v a ry from the size of a walnut to tl1at of l1n.1f ~t bushel. 
Tl1e f r ag·m e nts wer e easily r ecog ni zecl t,y tl1e pcc1,1liar f or111 .111<.l }trtnn.ltir, 
of t h e \Vinte r egg s (s tatobla s t. s ), \vhich are cliscoi<lal u11d borclc>recl witll :t 

r ow of s lcn<.ler c1ouble hoolcs, shaP<'fl someth in g· 1il{e an a11cl1or. • 



The Food of Fishes. 53 

These specimens were all from the Illinois River, i11 
June, July, October and November. 

Food of the Adult. 

The twenty-four adults exa1nined we1"e from va1·ious 
parts of the State nortl1 of the center; and, as the food 
has been found to diff e1" so vvidely according to the local 
situation, I have t1"eated the111 in tb1--ee g1--oups-the first 
including those taken in the clear, inland, northern lakes ; 
the second those from Calumet River, at Soutl1 Cl1icago, 
and the shallow, muddy lal{es of that vicinity, and the 
third tl1ose from tl1e Illi11ois Rive1" fr·om Ottawa t.o 
Peoria. 

The s1)ecime11s f 1"01n the no1--ther11 lal{es ,vere talren in 
May and June. Sixty-t,,ro per cent. of the food consisted 
of N e11roptera-eigl1t pe1" cent. being a black caddis-fly 
( Sia.lis itifii,mata) and the remainder tl1e larvre of la1--ge 
dragon-flies ( Libellulidre), Ag·rions ( eleven per cent.) 
and Baetis ( t,vo per ce11t.). Allor·cliestes de1itata was tl1e 
next most impo1·tant element ( t,;venty-seven per• cent.). 
A numbe1-- of te1--restrial i11sects besides Sialis appearerl 
in t11e food. These incll1cled a Harpalid beetle, an Ap7io­
rli11,s fiJ1 ieta1·ius, a11d some g1--assl1oppe1·s ( Tettigiclm, etc.). 

Tl1e seco11d group of f ou1", f1--om Calt1met Rive1", anc1 
from Lake Gco1"ge, Indiana, was peculiar in the number 
of tet1"adecapod Crustacea a11d case-wo1"ms taken, and 
especially in the a111ount of vegetation eaten. 

The Crustacea were Allo1 .. cl1estes ( tl1irty-two per cent.) 
a11d Asellus ( tv\renty per ce11t.). Tl1e ,regetation was pres­
ent in sucl1 quantities as to 111ake it eviclent tl1at it had 
been taken as food. It an1011nted to abo11t a fourth of the 
conte11ts of these sto111achs. Tl1e sto111ach of one fish was 

• 

paclred with a piece of tl1e stem of a pla11t ( apparently a 
Scirpns) a tl1ird of a11 i11cl1 i11 diameter ancl six inches 
long. Tl1r·ee others c·ontained smalle1 .. amo1111ts of con­
£ ervoid Algro. 

The fifteen specimens 1"emaining we1"e take11 f1,.om ·the 
Illinois in May, J 11ljr, Au·gust, Octobe1" and November. 
Their food was especiall:\r 11oticeable for tl1e p1 .. esence of 

I 



54 Tlie F oocl of F islies. 

mollusks ( sixteen per· ce11t.) , f 01· the 11l11111Je1· a11(l \"ariety 
of land insects ( fifteen 1}e1-- ce11t .) , a11c1 f 01· t11e large 
a1nount of ,reg·etatio11 it containecl ( thi1"t3r-011c 1)e1· cent.) . 
A single s111all fisl1-tl1e 011l j.,. 011e taken 1)}T these f ort3:---
five speci111e11s-"'\;,,ras also 11oticecl. 

The moll11sks incl11ded Pla1101"lJis, Pl11rsa, ..L'1.J11nicola and 
·vivipara. Amo11g· the i11sects ,,,.e1"e ants, cate1·pillars, 
flies, Anisodactyl1,ls cliscoirl eits a11c1 otl1e1· Ha1·1Jalids, 
A phodiits -i1iqiti1icttits, wi1·e-v,;'orms, 111inu te c111 .. c11lios, 
Cryptoce2,lictlits 4-11ictc2tlc,t1ts, Dictb1·oticct 12-g11ttata, Col­
orado potato beetles, flea-beetles, 1)la11t-b11gs (Pe11tato111-
idre), c11.cket8 (Nemobi11s), locl1sts, l{atyc1ic1s (P l1 {1 1z ~-
1·opter;·a cit'i·vicctitcl a), g1--asshoppe1"S a11cl case--flie s. 

The vegetable food, as fa1· as dete1·111i11ecl, co11sistecl of 
. 

Ceratopl1ylll1m, J..T ais ft exilis a11d co11fer,,,oicl ..._'\.lgm. Frag·-
rnents of Pol)"ZOa ,,-e1·e 11oticecl. C optoto 11z zts i ,zte,· ,·o.ga­
tus, G3T1·inicl lal"\vffi, ~~ Tr·o1Ji,c;te1·Jll{ S li11ibcttllS a11cl othel" 
Hydrophilidre, la1 .. ,7al a11cl adult, a la1•g'e Nepa, la1·vre of 
Palingenia lJ ili1,ieata a11cl otl1er :IYia},.-flies, of Ag·1 .. io11s ancl 
dragon-flies ,,,ere an1011g· tl1e aq11atic i11sects talre11 . 

• 
The Cr11stacea v\re1 .. o li11ritecl to s111c1ll c1·aw:fisl1es ( t,vo 

per cent.), a t1·ace of Allo1·c}10stes, a11cl a f e,,- ..._\ selli ( f ot11· 
per cent.). 

On co1npa1·i11g· specin1e11s £1·0111 1101·tl1e1·11 Illi11oi8 wit]1 
those take11 f1·om tl1e Illi11ois Ri,rc1· i11 the SclD1e mo11tl1, I 
find that tl1e1--e a1·e no c·on11no11 -soaso11al f oocl r l1t1.1·acter·s, 
a11d that t]1e cliffe1"e11ccB of food a1·e tl1e1 .. ef 01--e <.ll1e to dif­
f erence of locality anc1 11ot to cliffe1·e11ce of ti111e 1-.ep1·e­
sented by the g1·011ps. Co11ce1·11i11g the e11ti1·c 11111nl)c1· of 
adults, we ca11 the1 .. efo1·e sa}r t l1 rtt t.l1c'i1· ,f '<)o<l 1·::111g·0~ 

through tl1e ,,,.hole list of tl1e s111alle1· Jnollt1slcs, tc1·1·est1·ial 
and aquatic i11sects, a11cl s111allc1· c1·t1stacea11s ( al)o,rc E11-
tomostraca) accessil)le in tl1ei1· localities, ::111< l t11a t tll('~? 
feed largely 011 aquatic veg·ctatio11. 1\ st1·il{i11g 11eg·,1ti \ '"C 

feature is the aln1ost total abse11ce of fishes it1 tl1c foo(l­
a fact whicl1 co1·1,.espo11(l s ,,1 itl1 tl1e 1·elt1,ti,:rcl.''" Hll1,1ll Rt7'C 

of the mouth. 

* Several of these little-known larvre ,ver c fot1ncl i11 tl1 c 8tomacl,~ of 
this species,-some of th~.m in. sujlable conclitio11 for cl <>sc-ri1>lio11 . 



1'lie Food of Frislies. 

APOl\lOTIS. 

• 
b.O 
C 
0 

..c:: 
u 
s:: 
<l) 

C 
0 

• 

• rn 
V 

..c:: 
u 
C 

l,... 

;:, 
0 ...... 
0 -
V 
c::: 

0 

-u· 
C 
C1:l 

..c:: 
u 
C 

0 -..c:: u 
C .... 
OJ 
C 

0 

LEPIOPOMUS . 

• en 
OJ 

..c 
u 
C 

0 .... 

• en 
V 
~ 

C1:l -
C 
I­
Q) 

..c ...., 
l,... 

0 z 

.... 
OJ 

6 
::l 

ro 
u 

• 
l,... 
Q.; 

> ·-1-., 

en ·-0 
c:: ·­-

55 

• cn ..., -::, 
"'C 

t<:S -
------------- 1--· ---- _ _ , __ , __ , ____ , ___ , --

Number of specimens .. 
l. FISH ES . ........ . . 

I 

• • • • 

Undetermined . .. .. . . . . • • • • 

Et heostoma tidre ...... . . . . . 
Cyprinidre ........... . 
Ichthyobus ........... . . . . . 

I I. MOLLUSKS • . ..... • • • • 

I. GasterojJoda . ...... . • • • • 

Undetermined ...... . • • • • 

Planorbis .......... . • • • • 

Ph ysa . . . . . . . . . . . . . . . • • • • 

Vivi para ....... , ... . 
Amnicola .......... . 

• • • • 

• • • • 

2. A cejJhala. . . . . . . ... . • • • • 

IO 8 
. . . . 36 
• • • • 

• • • 

. . . .. 
• • • • 

• • • • 

IO 

• • • • 

13 
13 

• • • • 

• • • • • • • 

• • • • • • • • . . . . . 
• • • • 

. . . . ...... 
• • • • • • • • 

• • • • • • • • 

. . . . • • • • 

79 111. lNSECTA. . . . . . . . 02 
Undetermined...... . .. . . . . 12 
Terrestrial . . . . . . . . . . . . . . . . 07 
Aquatic . . . . . . . . . . . . . . . 02 60 

42 
01 

• • • • 

41 
I. Dzpte,·£1(Chironomus) 01 09 .... 
2. C oleojJtera . . . . . . . . . . . . . . 02 

TJndetermined ...... ~ • • • • • • • • 

05 
• • • • 

Dytiscidre ... . .... . . , . . . . 02 • • • • 

Undetermined .... . . . . . 02 • • • • 

La r v re . . . . . . . . . .. . . . .. . • • • • • • • • 

Coptotom us .. .... . • • • • • • • • • • • • 

Gyri11idre (larva:) . .... . 
H yd rophilid a= ........ . 

Undetermined ...... . 

• • • • 

• • • t 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

. . . . 05 
Tropisternus ...... . . 

3. Henzzpte,·a. . ... . . . . . 01 

• • • • • • • • 

16 
•••• 

03 
Undetermined .. . ... . • • • • • • • • . . .. . 
Cori xa . . . . . . . . . . . . . . 01 16 
Nepa ...... . ...... . ... : . • • • • • • • • 

Ranatra .... . ........... . • • • • • • • 

4. Ne2,1ropte,·a . .. . . ... . • • . . 33 
Larv~ (undetern1ined) ... . . . 
E phemerid~ (la rv ~ ). , , , . . . . 29 

Baetis.. ... . . . . . . . . . . . . . .. 

• • • • 

• • • • 

33 
• • • • 

• • • • 

Palingen ia .. . .. . ....... . 
Agrionidre (larv~) ........ . 
L ibell u lid~ (larv~).. . . . . . . 04 

. • • . 0 I 
06 • • • • 

02 

5 9 7 5 4 I 5 
I O • • • ♦ • • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • • • • • • • • 

. . . . . . . ~ . . . . . . . . . . . . . . 
• . . . . . . . . . . . . . . . . . . . . 16 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

...... 
37 

• • • • 

• • • • 

37 
37 

• • • • 

♦ • • • • • • • • • • ' 

• • • • • • • • ♦ • • 

• • • • • • • • • • • • 

♦ o • o I ♦ ♦ • o t, ♦ o 

• • • • • • • • • • • • 

• • • • • • • • • • • 

• • • • • • • • • • • • 

34 72 
. . . . 02 
. . . . . . . " 
34 _ 70 
26 30 

01 • • • • 
• 

• • • • • • • • 

• • • • 

05 
b5 

• • • • 

O I 

• • • • 

• • • • • • • • • • • • • • • • 

, 

♦ • • • IO 

. . . . 04 

. . . . 
• • • • 

t 
• • • • 

• • • 

23 

t 
05 
c7 
t 
t 

43 
• • • • • • • • 

01 

22 

t 
01 

t 

15 
28 
0 1 

09 
04 

. . . . 02 

• • • • • • • • • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • . • . . 0 I 

• • • • • • • • • • • • • t • • 0 1 

• • • • • . . 01 . . . . 0 I O I 
02, 
01 
01 

04 

• • • • • • • • • • • • 0{ • • • • 

• • • • • • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • • • •• 

t . . . . 2 5 02 0 1 

t • • • • • • • • • • ♦ • • • • • • • 

. • . . 2 5 
• • • • • • • • • • • 

. . . . . . . . . ., . . 

. . . . 08 I 4 

01 
01 

. . . . 04 
• • • • • • • • 

• . . . O I 
62 20 

• • • • 

14 
. . . . 0 I • • • • • • • • • • • • • • • • 

• • • • 

• • • 

• • • • 

• • • • 

• • • • 

07 . . . . 02 . . . . 0 5 
• • • • • • • 

• • • • 14 
♦ ♦ ♦ I • • • • 

02 .... • • • • 

• • • • 
l I 

41 

. . . . 04 
• • • • t 
. . . . 02 

-

24 
01 

• • • • 

• • • • 

• • • • 

IO 
I O 

• • • • 

• • • • 

• • • • 

. . . . 
t 

. . . . 
• 

45 
• • • • 

12 

33 
or 
06 

• • • • 

♦ • • • 

• • • • 

• • • • 

. . . . 

• • • • 

• • • • 

. . . .. 

02 

• • • • 

• • • • 

. . . . 

24 
• • • • 

. . . . 
02 

ro 
02 

• 

• 

• 



' 

• 

• 

• 

56 TJie F ood of F ishes. 

TABLE OF F OOD OF APOMOTI S AND L El,IOPOl\lIUS-Cont inued . 

• 

umber of • specimens .. N 
s ialidce . • • • • •••• • •• •• • 

Sialis •••• • • • • • • • • • • • -Corydalus (larvre). • 

p 

s 
H 

hryganeidce ..... : .. . . 
IV. ARACHNIDA ... • . 

piders . ....... . ... . .. 
ydracl1nidce . .. .. . ... 
V. CRUSTACEA ••.... 

D • 
eca pocta ............ . 
Undetermined ... . . . . 
Cambarus •. . .. • • • • • • 

Palcemonetes. • • • • • • • 

A mphipoda ..... • • • • • • 

Undetermined. • • • • • • 

Al lorchestes. • • • • • • • • 

sopoda (Asel lus) . . .. I 
E 

. . 
ntomostraca • • • • • • • • • 

Cladocera. . . .. . • • • • • • 

Daphniidce ........ 
Lynceidce ......... 

Ostracoda ....... . ... 
Cope pod a. • • • • ..... • • 

VI. VERMES • • • • • • • • 

ndetermined. • • • • • • • • u 
p olyzoa • • • • . • • • • • • • • • • 

L umbricus • i • • • • • • • • • • 

VII. VEGE1'ATION ... 
h~nogamous ..... • • • • 

• • • . . " . • • • • 

p 
A l~a:! . . . . . . 

APO MOTIS. 

I . 

• 
• rn 

Q) 

..c:J 
• u 

bD i::: 
C: ..... 
0 1-. - :::, ,.... 0 -V • 
i::: 0 en ..... .... ..... -Q) (1) ::, 
C: s::: -0 

0 0 <t! 
. 

I I O 8 
• • • • •••• 04 
•••• • • • • . . . . 
• • • • ••• • 04 
• • • • • • • • •••• 

• • • • • • • • • • • • 

• • • • • ••• • • • • 

• • • • • • • • • • • • 

98 21 20 

• ••• 01 20 
• • • • OI • • • • 

• • • • • • • • 08 
• • • • • • • • 12 
•••• • • • • • • • • 

•••• • • • • • • • • 

• • • • • • • • • • • • 

• • • • 04 • • • • 

98 16 • • • • 

• ••• 08 • • • • 

03 07 • • • • 

• • • • OT • • • • 

• • • • 03 •••• 

95 05 • • • • 

• • •• • • • • • • • • 

• • • • • • • • • • • • 

• • • • . . . . • ••• . 
• • • • • • • • • • • • 

• • • • • • • • 02 

• • • • • • • • 02 
" . . . • • • • • • • • 

I LE P IOPOMUS . 
• 

. 
rn 
(l.) 

~ 
• • ro 

1-. r.n -Q) Q) 

"O ..c:: 'd 
s::: • u C: 0 C: • ro :::, 

~ 
Cl) ·- V 

'd 1-. ...., 
Q) ~ Q) 

c::: 0 (l.,) ~ > ro ...., .... - ·-..c 1-. 
..c ..Cl C: ~ ...., 
u u I-< V 0 Q) s::: s::: 6 ...., ,.... ·- ..... 

+J .... 
Q) (1) 0 .... .., 

~ 0 -s::: C: rel 
0 0 ~ z u 

5 9 7 5 4 
• • • • • • • • • • • • 08 • • • • 

• • • • • • • • • • • • 08 • • •• 

• • • • • • • • • • • • • • • • • ••• 
. . . " • • • • • ••• • • • • 20 
04 II 01 01 It It I It 

• • • • • • • • ' . . . 01 - t 
04 I I 0 1 • • • • • ••• 

59 55 06 27 52 
• • • • • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • • • • • 

• • • • • • • • • • • • • • • • •••• 

02 • • • • 05 27 32 
02 • • • • • • • • • • • • • • • • 

• • • • • • • • 05 27 32 
• • • • • • • • • • • • • • • • 20 

57 55 01 • • • • t 
37 14 • • • • • • • • t 
33 12 • • • • • • •• • • • • 

04 02 OI • • • • t 
• • • • 06 • • • • • • • • t 
20 35 t • • • • • • • • 

• • • • • • • • 20 • • • • • • • • 

• • • • . . . . t • • • • • • • • 

• • • • . . . . I I . . . . • • • • 

• • •• • • • • O<) • • • • • • • • 

• • • • • • • • OI 02 25 
• • • • • •• OI 02 21 
• • • • • • • . . . . . . . . 04 

XEN OTIS l\'fE<JALOTIS) Raf. I-ioNG-EARED SuN 1?1s1r . 

I 

• ,_ • 

V 
UJ ... 

> -. :::, ·-.... '"Cl 
rn rel ·-0 -ro s::: ... .... 

0 -- ~ -
15 24 
07 o6 
07 06 

• • • • • • • • 

• • • • 03 
• • • • • • • • 

• • • • • • • • 

t • • • • 

06 18 
02 01 

•••• • • • • 

02 • • • • 

• • • • • • • • 

• • • • II 
• • • • • • • • 

t • • • • 

04 06 
• • • • • • • • 

• • • • • • • • 

• • • • • • • • 

• • • • ♦ ♦ • I 

t • • • • 

• • •• • • • • 

03 02 
. .. . . • • • • 

03 02 

• • • • • • • • 

31 24 
19 16 
12 08 

'l' l1is litt.l<~ SJ)ecie8 is 11ot ,1t all con1111011 i11 tl1e SLcit '-\, 
b1-1t ltaR l)ee11 tc1lce11 by llS £1,.0111 t l10 111idclle col11·se <>f F<)X 
R., f1·01n t1·ibt1ta1·ies of t]1e I lli11ois R., ancl f1·ort1 l)()n<ls i11 

Unio11 col111ty ancl s011tl1e1·11 I llinois. 
Unfo1·tl1n::1.tcly, tho tl11·ee Rpeci111e11s oxa111i11o(l }tad not 

la.t e]y tal<e11 f'oocl, ancl 011]y a vo1·3r i111pc1·f ort 11()ti o11 of' 
tl1cir 11~l1al alimc-}11t c1a11 l)<l g·i,·~11 . (: c>1·ixc1, }iJJ>l1(\111c\1·i<I 



• 

• 

57 

la1'vre, Cl1i1·onom11s la1·vre, tl1e tube of a case-v,1 01·n1, a few 
fish-scaJes a11d a11 jndete1"111inable aqt1atic l)eetle were 
the only olJjects found. 

X ENOTIS PELTASTES) C·ope. * 
This beal1tif11l little fisl1, l1itl1e1·to take11 i11 tl1is State 

<)nly in ve1·3r small 11umbe1· from Fox R., ,,1as found quite 
a l)undant i11 tl1e ''slip'' at S011tl1 Chicago, in J u11e, 1880. 
Tl1e t.l11·ee 01)e11ed l1ad ra ten 111ore larvre of Cl1iro1101n11s 
tl1an a11ytl1i11g else ( sixty pe1" cent.) . Next ca1ne sixtee11 
lJer cent. of 111oll11sks, tl1e11 Allor·chestes a11cl Asellus, Co­
rixa., Gy1--inid la1·vre a11c1 a few te1·1:est1"ial la 1·vre ( Chr)rso-
1nelidre). Tl1e la1·ge 11e1·rentag·e of Cl1i1"011011111s ,vas p1·ob­
ab]y o,vi11g to tl1e sit11atio11-a foul a11c1 11111(1c1y little ba3r, 
se1·,1i11g· as a ]1a1·bo1· f 01· fi~l1i11 g· boats. 

-
E uPoJ.\iroTrs A UREus,, vV al1l. P ul\1PI(I N -SEED. BREAM. 

This s1)ecics s,,ra1·111s in t.l1e lrtl(es anc1 1)011ds of 1101·tl1-
easter·n Il1i11ois, b11t is 111l1ch less abl111cla11t in the Illi11ois 
R,., ancl in tl1e sol1tl1e1·11 pa1·t of t}1e State is al1nost u11-
l{nown. Tl1e ca11sc of tl1is ] i1nitatio11 of its ra11ge is ap­
parently cli111atic, as tl1e1·e is certai11ly 11othi11g in its 
f ooc], no1·, appa1·e11tly, i11 a113T of its l1abits, to exclude it 
from ol11-- sol1tl1e1·11 ,,7ate1·s. Inc1eecl, I clo not sec that its 
11lace is take11 l)y a11y othe1· fi.s11 to the s011t]1,,ra1--d. No 
otl1e1·, l1nless E upo11iotic) palliclits,, resembles it in food, 
and this i. · too inf1·eque11t to 1·e1Jlace it. My kno,,Tledg·e of 
its f oocl is l)asec1 11po11 tl1e stl1cly of twe11ty-fi,re specimens 
1"anging· f1·01n 011e c111d 011e-half i11cl1cs l1p,,1a1·d, taken 
from tl1e Illinois, Fox clncl Calu1net 1·ive1·s, ancl fron1 
Long·, C1·ystal ancl Nipisinlc lakes ci11cl Lal{e Geo1"ge, i11 
centr·al a11cl 1101·tl1e1"11 Illinois and Indiana. Tl1e 1nonths 
of May, J 11ne, July, A11g11st a11d Octobc1· a1·e 1·ep1--ese11tecl 
lJy these specin1ens. 

Foocl of tlie Young. 
Tl1e ni11e s111alle1· speci111e11s, f1"om one ancl 011e-half to 

two incl1es lo11g, show at 011ce tvvo prominent peculiar~ities 
of the foocl. The la1 .. ,rre of Cl1i1~011omus compose fifty-one 

--- --
'~ Jt is c:onsiclerecl c10\1btft1l, 1;):\· ))1·. J orcla11, if tl1is Rpec- ies :1n<1 t11e p1·e ­

ee<ling a1·c rlistinct. 



• 

58 l 1Jie Food of Fislies. 

pe1" cent. of the fooc1, and E11tomost1·aca of t]1e 01 .. .._Je1· 
Ostracoda ( Cyp1"ids), twent3r-six. As lJoth tl1ese 13,r·e 
found most abu11dantly in 11111dd)r bottoms,. it is ·e,riclent 
that the fish is, at least at first, a bottom feede1·. rr1·aces 
of n1ollusks appea1· ·thl1s ea1·l3r, · as ,,Tell as a f e,\,. Epl1e111-
erid larvre ( :fi,re 1)e1~ cent.). Tl1e 1·e111ai11cle1" of tl1 c f oocl 
was insects ' egg·s and Dapl111icls-cl1iefl}r ).'Ji11l(JCPJJl1c1l111.-::; 

americaniis-( twel,re pe1· ce11t.). Cl1·5:"clort1s ,,~as f c1l111cl i11 
:five specimens, l)llt i11 too small c111antit}T to :fig·l11·e i11 the 
a.ve1~ages. 

Five specime11s ,,~e1·e st11lliecl bet,,ee11 t,,To a11c1 tl11·cr., 
inches long·. lJ.1 tl1ese tl1e sc11ne foocl cha1 .. acte1 .. s co11ti11110~ 
modified some,,Tl1at by the i11t1·ocll1c.tio11 of la1·ge1· ol)jects. 
Tl1e Cl1ironoml1s la1·,1re sta11cl at fo1·t3r-fol11· pe1· cc11t .. a11cl 
the Cyprids at ejghteen 1)e1· ce11t. Fot11--tee11 pe1~ cie11t. ot 
Allo1·chestes a11cl ole,re11 p e1" ce11t. of N e111·optc1·c1 ]a1·,yre 
are the only i1111Jortant elen1ents 1·e111ai11i11g·. T,,To 11e1· 
cent. of young U11ios we1~0 11oticecl. N ea1·l}T l1c1lf of tl1c 
food of t,,vo la1~g,e1,. speci111e11s, l)et,,Toe11 t·\y·o a11cl tl11·ee 
inches long, consisted of 111oll11slrs-cl1iefl.)r Pl1)T~~1 . J\_ f e"\\­
Chironomi and abol1t eqt1al (111a11tities of E1)l1e111e1·icl 
larvm and Allo1~c11estes ,,Te1·e ::111 t.he 1·e1nai11i11p; f 001.l. 

Entomostraca tlJe1--efo1"e (list111pPa1· at this l )C)i11t. 

Foocl of tlie Arl11lt. 

Forty-six per· co11t. of tl10 foocl of tl10 11i11c £l(l11lts t'{)ll­

sisted of Mollusca, incl t1cli11g Pla1101·l)is, ..1.\ 11111 i C'() lcl ,l11c l 
17 alvata t ,1•ica1~i1iata

1 
a11cl six pe1· (1e11t. c>·f 1111cl et<l1·111i11c<l 

bivalves. 
The insect foo(l " ras t,,c11t,)T 1)c1· cc1·1t. of tl1 L1 ,,~lit..>tl\. 

Crustacea t,ve11ty-t,,r<) 1)c1· cc11t., a11cl , .. cg·otc1tic>11 t\\' t'l\-(\ 

per cent. Half of the last was Cl1a1·a, c:111cl tl1e 1·c,111rti11tlc1· 
cl1iefly M3r1·io1)h)rllllll1 ancl A lg~. rr11e C1·11st,lC()cl ,,-(' re~ ,\11 
Allorchestes ancl A sell 11s. Tl10 insects i11cl11cl<.' <l rt t 1·,1<'l' <) f' 
Chironomt1s larvre a11cl a ·f e,,,. "\\1 ate1·-l,cetles ( H )~(11 ·(>J)l1 i l i­
rlm), and t11e ust1al Ne111·011toJ·a la1·,1,t', a1no11 ,~· ,,~l1ic·l1 <·tt:-;L1

-

flies of tl1e g·er1us J_.1optoccr1ls "\\"01·c 11oticccl. 
Not a trace of :fisl1es ,vas fou11cl in tl1c sto111r1,ci]1~ <>f t.J1 t•~c 1 

specimens; ancl this ftlct, tog·etl1e1· ,~Titl1 tl1e l,11·g·<' l)Cl'<•c•11 t­
age of mollt1sca11 food, const it11tc.,cl t l1c l0a<li 11g· :1 l i111 c1lt,t1·~ 
peculiarities of tl10 P.1,cci0s. 

• 



• 

- 59 

The fi1·st of tl1esc is doubtless 1 .. elated to tl1e s111all 111011tl1 
-tl10 seco11cl to the stout, blunt pl1ar}rngeal teeth . :1 
cl1a1"acte1-- l1sed i11 defining the g'e11us. In all tl1e prececl­
i11g species t l1e pl1a1"y11gea1s· a1·e set ,vitl1 n101~e sle11de1·, 
lJointed teeth. 

EuPOMOTJS PALLIDus., -'--1\.g. PALE SUNFISH. 

Having· but fe,v speciinens of tl1is 1·atl1e1· 1111co111mo11 
species, I have exa111i11ed the f oocl of b11t one-enougl1 to 
i11dicate tl1at it p1·obal)l}~ ag1·ees closely ,,:ritl1 t l1e preced-
• • 
1 r1g· species. 

TL is fisl1, tal{e11 i11 Clea1" Lake, IC)T., l1acl ec1te11 la1·g,el~"' 
of small Mollusca--}~oung U nionidffi~ Pla1101·1)1 s, A11111ic­
ola, etc. These amot1nted to seventy-fi, ... e pe1· ce11t. of the: 
food . 1fl1e 1·emai11ir1g elements we1·e Ol1irono11111s la1·, ... ~, 
seve1·al small wate1·-beetles, (Hycl1~opo1~it s liyb,·iclits., 
c-r1ie:miaotits 12-pitn-c·tatits., ancl Haliplits., 'SIJ,), aJl 'llll­

l<no,vn aq11atic pt1pa and a little po11d-,,Teed. 

CEN'l'RARCHus IBIDEus., Lac. 
r.rhis li t ·tle species is f 011nd in co11sicle1"a ble 11 l1111lJe1·s i11 

l)Onds and strea1ns i11 the s011tl1ern hill-col1ntr~T of Illi-
11ois. M3 ... s1Jecimens, all take11 i11 J 11l)T, a1--c f1·om lJ011cls 
and streams i11 tl1e Mississippi 1)ottoms i11 Union a11d · 
Jackson c.ou11ties, a11cl from Cacl1e R. ar1cl its t 1·ib11ta1·ies 
in J ol1nso11 county. 

~.,ive of tl1e 3ro1111g, fro111 tl11·ee-f ot11·tl1s of a11 jn cl1 to an 
incl1 i11 le11gtl1, l1ad ea te11 seven t3r-011e pe1" ce11t. of Ento-
1nostraca and t,,renty-one pe1· cent. of lar·,Tm of Cl1irono-
111us, a11d, for tl1e 1·est, a.l1011t e(Jl1al c1t1a11tit ics of E1)l1-
cmerid lar,rre and )roung· Allo1"c]1estes, witl1 a tI·2 .. ce of 
,vate1" mites (Hyd1·acl1nidffi). 

Thirty-eigl1t per cent. of the foc)cl ,,,.as O)rc.lops ; Cyp1·ids 
amounted to twenty-011e per ce11t.; and t,,relve per· cent. 
of Simocephal11s completed the 1"atio of E11ton1ost1·aca. 
The smallest specimen, three-fou1"tl1s of a11 inch long', 
had eaten sixty p e1" cent. Simocephalus a11d forty pe1 .. 
cent. Cyclops. 

About a fifth of the food of 011e specimen, a11 i11ch a11c1 
an eighth in le11g'tl1, consisted of minute yo11ng Co1"ixas, 
the 1 .. omai11de1· being; abo11t eqt1ally Cyclops a11<l Cyprirls . 



60 The Food of F,ishes. 

• 

' 

TABLE OF FOOD OF EUPOMOTIS AND C'ENTRARCHUS. 

• 
0 
~ .... 

.c u 
s:: 
V 
C: 
0 

EUPOMOTIS . 

• en 
V 
.c 
u 
C --
(1) 

V 
1-
.c .... 
0 .... 

• en 
V 
.c u 
C 

0 .... 
(1) 
(l.) 
I-

.cl 
r4 

• 
• 
• 
• 
• 
• 
• 
• 

• 
• 
• • 

en --

CEN­
TRARCHUS . 

• 
0 
~ ..... 
0 .... 
.c 
u 
C 

• r.n .. .. 

- - - --------------------1-- -- __ , __ --· 

Number of specimens examined. . . . . . 9 5 
04 

2 9 
45 46 

. . . . 07 

5 I 2 

I. MOLLUSCA . . . . . . . . . . . . . . . . . . . OI • • • • • • • • • • • • 

U 11determined ........ . ........ ..... . . • • • • • • • • ♦ • • • • • • • 

Gasteropoda. . . . . . . . . . . . . . . . . . . . . . OI 
Amnicola . .. .... . ... . .. ..... . . .. . . 

02 

• • • • • • • • 

33 
. . .. . 04 
45 . . . . 

. . . . 
• • • • 

• • • • 

• • • • 

• • • • 

V 
.. 
l\11para . . . . . . . . . . . . . . .... . ... . 

Planorbis ... . ........ .. . .. .. . .. . . • • • • • • • • 

I I • • • • 

. . . . 0 I 
• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

Ph ysa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 . . . . . . . . . . . . . .. . 
A cep ltala . ..... : ........ . .... 4 • • • • • • • • • 02 . . . . 06 . . . . . . . . . .. . 

I I. lNSECTA..... . . . . . . .... . . . 60 61 30 20 24 20 91 
Undetermi11ed · ..... . ........ .. ....... 03 03 . .. . · .. . ......... 07 
1. Diptera (larvre) . . . . . . . . . . . . . . . . . . 52 45 05 01 21 . . . . o6 

Chironomus . . . . . . . . . . . . . . . . . . . . . . . 5 I 44 05 01 :21 . . . . 06 
2. Coleoptera . . . . . . . . . . . . . . . . . . . . . . . . ... . . 02 . . . . 02 ..... . ..... . 

l-Iydropbilidce .. . . . . . . . . . . . . . . . . . . . . . . 02 . . . . 02 ........... . 
3. l-ft:'1n1j.Jtera . .... ...... .. o • • • • • • • • • • • • •• • I . . . . . . . . . . . . . . . . 20 23 

4 
E pbemeridce.. . .. . . . . . . . . . . . . . . . . . 05 05 I 25 03 ! OJ . . . . 55 

, ) 1 · • I ta 1ngen1a . .. .. ... .... . . . ... . . . ...... .. . .. 1 •••• 03 ..... . ...... . 
Agrionidce.. ... . . . . . . . . . . . . . . . . . . . . . . . . o6 . , . .... · I ... ....... . . 
Lib e i l u l id ce. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . c8 . . . . . . . . . . . . . 
Pl1 ryganeidre . . . . . . . . . . . . ......... 1. . . . . . . . . . . . c,2 ..... .... .. . 

I 11. ARACHNIDA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OI ....... . 
I-I yd rachn id~. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . o I . . . . . .. . 

IV. CRUSTACEA . . . . . . . . . . . . . . . . 39 35 25 ::.:2 75 8,'.) · ·. · 
Amphipoda (Allorchestes).......... . . . . . 14 25 13 04 ...... . 
1-sor)oda (Asellus). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 09 ........... . 
Entomostraca....... . . . . . . . . . . . . . . . . . 39 21 . . . . . . . . 71 80 . .. . 

Ci a d oc er a. . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 03 . .. ·. . . . . . I 2 . . . . . . .. 
Si mocephal us . . . .. .. .......... .. . 

Ostracoda .... . ..... .. ... .. . . . ... . . 
Co11epoda .... .. ... . . . . . .. ........ . 

V. VEGETATION . .. .. . ... ... .. . . . 

12 01 . . . . . . . . I2 ...... . . 

26 I 8 · . . . . . . . . 2 I 3 5 .. - -
. . . . . . . . . . . . . . . 38 · 4 5 O<J 
.... t .. . . 1:" ............ . 

}ltyriophyllun1 ...... . . .. .... . . . ... .. . 
Chara .. . .... . ... .... . .......... . . . . . 

• • • • • • • • . . . . 04 
06 

• • • • • • • • • • • • 

• • • • • • • • • • • • . . . . . . . . • • • • 

A}g:e ... .... .............. ... ........ ... ... . . • • • • • • • • • • • • • • • • t . . . . 02 -- - ·- _ _. _______ _ - . - --- ·-- -

• 

()11ly tvvo s11ecime11s \\701,.e · cxan1i11ed ,,1 ]1 ic.~11 <i.c,ttl(i l)e 
classed as aclults-one th1--ee a11d a fot11·tl1 i11cl1cs 1011g, tl1c 
other smaller. Tl1esc indicate tl1at tl1e food of 1'11ll-g1·ow11 
inrlividuals cliffeT·s f1"om t]1at of tl1c ) ' 011ng c1 l1iefly in tl1c 

• 



• 

• 

Tlie Food of Fishes. 61 

addition of co11siderable quantities of te1"rest1"ial and 
aquatic insects . 

The gill-rakers of this species are nur11e1"ol1s, long and 
slender-a fact reflected in tl1e food. Fifteen per cent. 
of the contents of the stomach of the la1"gest specime11 
consisted of Cyclops and :five pe1" cent. of Chironomt1s 
lar,rre. Consistently with the small mouth and pointed 
11l1aryng~eal teeth, 110 traces of fisl1es 01" 111ollusks ,\ier·e 
found in the food. 

PoMoxYs .NIGRO·MACULATus, Lac. BLACI<. CRoPPIE. LAT(E 

CROPPIE. SILVER BASS. B UTTER BASS. 

PoMOXYS ANNULARis, Raf. WHITE CRoPPIE. Trl\a:BER 

0ROPPIE. SILVER BASS. 

Tl1ese two species, often not disti11guisl1ed even l1y ex­
perienced fishermen, agree so closely in food that I have 
not thought it wo1"th while to treat them separately. In 
the Illinois and Mississippi 1"ive1·s they are much the most 
valt1able and impo1"tant of the f a111ily, excepting" the black 
l,ass. Tl1ey are nowl1ere else so ab11nc1ant in the State, al­
thoug·h occur1 .. ing in the la1"ger rivers generally and in 
the Great Lakes. The first species is commonest to the 
north, a11d tl1e seco11d southwa1"c1, so f a1" as my obse1--vatio11 
g·oes. In the Illinois tl1ey are about equally abu11dant .. 
These fishes are eve1--ywhe1"e great favorites, and ranlc 
among· tl1e most impo1·tant a11d p1"omising of ot1r smalle1· 
species. They a1--e I"al"ely found in creeks 01" small ponds, 
lJut seem to req11i1"e deepe1" water for thei1" maintenance. 

The gill-ralrers of this species a1--e numei"o11s, long, and 
finely toothed, constitut.i11g· the most efficient straining' 

• 
apparatus to be fol1nd a1nong the Sl1nfishes. The pha1"yn-
geal teeth a1--e sha1--p, and the mouth is rathe1-. vvide ancl 
considerably enla1·g·ed by the leng~t11ening· of the lo,,ie1· ja:\,~. 

Consiste11tly witl1 the hypothesis concerning· the mean­
ing of the gill-rakers wb.icl1 I l1ad already forn1ed from a 
study of the preceding species, before I came to this, I 
found that the young continued to feed almost exclusivel3r 
t1pon Entomostraca m11ch longe1" than the othe1~ st1n­
fishes. Six specimens between three and fou.r inches long, 



• 

62 1 1lie Food of Fislies. 

l1ad eaten little else tha11 Entomost1--ac·a and the larvre of 
1ni11ute Dipte1·a ( Chi1"onomus Corethra). Even full­
g·1·ovvn speci1nens were fou11d eating Cladocera mo1·e free­
ly than a113r otl1e1" food. As might be inferred f1 .. om the 
pha1"yng·eals, not a trace of molluscan food ,vas found in 
tl1e forty-tv\70 specimens exan1ined, ,,rhile fishes fo1"med 
ni11e pe1· cent. of tl1e food of tl1e twenty-se,.,en adults. 
Most of these "\\7 e1"e eaten late in tl~e season, ,vl1en E11to­
most1·aca a11cl i11sect la1"vre became less ab11ndant. 

Foocl of tJie Y oii·>ig. · 
The sn1allest specimen, tl1ree-f 0111--tl1s of a11 incl1 long, 

l1acl eate11 abo11t equal q11antities of Cyclops and Simo­
cepl1al11s, witl1 011l3r a fe,\T Ple111"0:x11s besicle. Th1"ee, a11 
i11cl1 long· a11d 1111de1--, l1acl confinecl tl1eir f oocl enti1 .. ely to 
Entomostraca a11cl Cl1i1"onom11s la1"\"'fC·-tl1e latte1-- form­
i11g· about a fou1"tl1 of' tl1e ,,.,hole. A thi1·d of tl1e Entomos­
t1 .. aca ,,.,e1·e C)rclo1)s, t]1e 1·en1ai11de1· cl1iefly Si1nocephal11s. 

Six speciJ11e11s between one and tl11·ee inches 1011g, dif­
f e1"ed esJ)eciall>r in t11e i11t1"od11ction of abo11t ejg·l1teen pe1· 
cent. of Co1·ixas a11c1 tl11·ee pe1· ce11t. of s111all Ephe111erid 
la1"vre. Cl1iI·o11on111s la1--,rro we1·e recl1-1cecl to seven pe1· 
ce11t. The Entomost1·aca ,,rere abol1t eql1ally cli,ricled be­
t,\ree11 Cyclops a11cl Oladocera. 011e specime11 taken i11 
J11ly, 1·879, f1"'om tl1e canftl 11ea1-- Otta,,Ta, l1a<l tal{e11 a large 
nl1mbe1~ of Dapl111ella. 

Six s1Jeci1ne11s betwee11 tl11·ee a11<l fol11"' i11cl1e. · long were 
examinec1. Eigl1ty-tl11·eo pe1-- cent. of tl1ei1" food ,,ras En­
tomost1·a<·a, n l)o11t tl11·er-f ou1·tl1s of tl1is a111ol111t being~ 0),.­
c]ops, ancl tl10 1·emainde1· 11ea1--l3r a-11 Si111ocophal11s. 
Twel ,re 1Je1" ce11 t. of la r·vro of Cl1i 1·ono11111 s and Co1·etl1ra, 
t111·ee pe1· ro11t. Co1·ixas anc1 t,,ro pe1· c0J1t. la1·,r~ of small 
E1Jl1e111e1--icls ,,Te1·0 tl1e jnsert clc1nents. Cl1ydo1"11s, Ple11-
1·ox11s a11cl Cy1,1· iR ,,,.01·0 p1"es0n t i11 sn1 all n11m be1"s. 

Tl1ese fifteen )ro1111g·, ag·1·eei11g· so close}Jr in food, i1--1·c- · 
. . 

s1Jective of si~c, ,,,ere neve1·tl1<\lcss f1·om a var·iety of sit11-
ations ancl clato8. All we1·e f1·on1 the Illinois River, its 
lal{es a11cl t1·il)11ta1·ies, f1·0111 Otta,,ra to Pcl<in, b11t ra11gcrl 
i 11 time f 1·om ,J lln e to Octo l)e1· of t l I I' ()(l <l i ('f e1 .. e11 t yetlJ .. R. 

Sjx ,,re1·c P. ni_{Jro11z ct,C?l la tit ,c:;, seven v\7 <?1'<: P. ri111i1tla,1· i.~ , 
ancl two ,,,.c1·c 11 ot i clenti fled sperifirall)r. 

• 



• 

li'oocl of tlie Acl1tflts . 
. i111 exan1i11ation of tl1e notes on tl1e t,,renty-se,7en 

<-lcll1lts s110,,rs 111ate1·ial cliffe1"ences of f oocl at different 
1Jart~ of tbe >;-ea1·. As all l1l1t 011e ,,~ere talten f1"om the 
J]]i11oi. R i,.re1·, I l1a \.,.O not the 111ea11s of noti11g· tl1e co1"1·e­
s11011<.1e11ce of f oocl \\~itl1 localit>~-

Fi,re Bpccin1e11s tc1l{e11 at Peo1·ic1, i11 Ma1·cl1, ,\'ere fot1nd 
f eecli11g· 1110s t f 1·eel5.,. l1po11 Cladoce1"a, ,v l1icl1 composed 
fift)r-fi,7e 1)e1· <")ent. of tl1ei1· foocl. These were chiefly of 
tl1e two ~pecieR Si,Jzoce1Jllctl'lt ., 1;c>f11llt.s a11c1 i'3 . c1,111e1,.ica1>i1f..<,. 

'l,J1ese little Ento111ost1·ar,1 ,,·c1·c tal~e11 at that time i11 
~uc}1 c111antit).,. as ,Tisibly to cliste11cl tl1e stomacl1 when see11 
£1·01n tl1e ol1tsicle, ancl tl1e i1111r1ense nl1mbe1" of tl1ei1· eg·g·s 
£(ave a 1"ecldisl1 colo1" to the co11tents of the alimentar,r 
-· . 
cnna.1. The la1·vre o E N el11·opte1"a, l)oth '' cla1"11ing-needles '' 
a11<1 l\Ia:r-flies (Pali11genia), we1"e also eate11 in co11sider­
~1 l)l e lll1llll)e1·s (tlJi1·t::-11i11e pe1" ce11t.) . .... l_ s111all fl3rl)opis, 
n little c1a1·te1· ( B rJl r, r;.<. <J 111 r, ,,, r, c 11 l rl t ct) a11c1 ::111 l1111 .. ecog-
11 i zable :fis]1 we1·e f 01111<l i11 t]1cse sto111aclJs~ 111al{i11g abo11t 
~ix J)<1 1· re11t. of t]1c f c) o<l. 011J~T t1·i,T.ial 1111n1l)e1·s of Ent<)-

. 111ost1·aca appca1· aftc1" tl1is ti111e. 
Ni11e speci1ne11s, ta]\e11 i11 ... \.p1·il, lil{e,,Tisc-. at Peo1"ia, 

,,-e1·e fr0cli11g· c]1icfi).,. 111)011 Xc111·01)t()1 .. a la1·,Ttl: ( rig}1t,)r-s i .'\: 
11P1· rc11t.), c~peci(1l]~- 11JJ011 t]1at al1110Rt i11, ... all1ablP elc-
111cnt of fiRl1 fooc1, tl1e la1·, ... <P or Prtli11,qP11ir1 l;i1i12-Patrt (six­
t~ ... -six 11c_:i1· rc11f.). .,.\. fe,,~ l,11·,Tm of G~ ... 1·i11i<lrc a11cl 1)>rtis­
<'ic1ce " .,.e1·e 11otccl ( tl11·ee 1')e1· ce11t.), c111c1 a f e,,- Oo1·ixas also. 
"" \ r:(1 JJl 11ict ,1·1f,c:; .fclscirtfzf.r:; a11cl a little Cc1·atopl1),.ll11111, etc .. 
,, ... E)1·e J1otir.e(l; anc1 also t11e flo,,-e1· of an cln1 a11cl tl1e 
f e;-1 t l1e1· of a lJi1·cl. . 

J-\_ si11p;1e 8peci111c11 f1·0111 Pista1{ee I-'al{e, i11 lVIcIIen1"y 
c·ol111t),., tal{en i11 iia)r, ga,.,.e e,-ricle11ce of a simila1· 1·elifl11ce 
1111011 N e111·01)te1"011s la1",.,.ffi ( eigl1t}r -fi,re per cent.). Here, 
11owe,~e1·, i11 tl1e abse11ce of Pali11genia, Ag·rio11s and tl1c 
] cl 1·g·e1· cl l"ag·o11-flies ,\re1·e 1·eso1"ted to. A little \Tf geta tio11 
11 ac1 lJeen taken ,,,i tl1 t11 ese ( 0 e1·ctf op 71,yll 1t11i cl e 111 e1·s111n anrl 
l~PJ>tJ?(t fJ·is1rlca te11 pe1· re11t.). 111·ol1abl.\~ 11>'" c1cc·i<le11t. a~ 
t]1is lal{e ,,-ras full of aq11:-1tic pla11ts, a11cl it wo11ld ha1"dl>'" 
l1a \·cl l)ec11 poRsil)le fl)1· a fis]1 to catcl1 l i,Ti11~; foocl f1"01n tl10 
,~·c1 te1· ,,i t]1ol1t g·etting- n101·e 01· less , ,.eg·etation at tl1c 
sa111c t i111e. .1\ si11g·lc fT>T111011011te1·-tl1c 0111>,. la11cl insert 



64 T Jie F ood of Fishes. 

found eaten by tl1is species-was t aken from tl1is sto111-
a.,cl1. A specime11 taken in J t111e at P eo1--ia had .~ate11 abot1t 
equally of minute unrecognizecl fisl1-fr y and Palinge11ia 
larvro. One caught at Ottawa, in J uly, had eaten onl)­
insects-Co1--ixa twent3r-five pe1" ce11t., Paling·e11ia la1•,rce 
seventy-fi,re per cent. 

TABLE OF FOOD OF POl\10XYS . 

• 
1-, 

V 
-0 . 

S:: V 
::, ~ 

-0 -5 
C 0 
C'd -

..c ..c: 
u u 
C I:: ·- ·-
V V 
C C 
0 0 

• en 
<lJ 

..c: 
u 
C 

s.. 
::, 
0 ...... 
0 -<lJ 
V 
1-, 

..c: 
~ 

.... 
1-, 

0 
<1) 

~ 
~ -........ 

u 
1-, 

C'd 

~ 

• 
ro • 

C'd 
i-.. 
0 
V 
~ 

~ 

V 
C 
::, 

........ 

• 
C'd 
~ 
C'd ..... -0 

-::, 
........ 

·-1-, 

0 
<1) 

~ 

-1-, 

<lJ 
..0 
0 ..... 
u 
0 

-1-, 
QJ 

..0 
E 
V 
> 
0 z 

-::; 

-
----------------------- --1----

~! 1: 0J1~~:c~ ~~-
0
.
5
.': : : : . ~ .. ~ ... ~. J .. ~. . . ~ . 5~ .. ~ . 3t 2~ ~~ 

Aca11tl1opteri... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Jo 08 03 
Boleoson1a. . . . . . . . . . . . . . . . . . . 01 . . . . . . . . . . . . . . . . . . . . .... . 

Cy CI O id. . . . . . . . . . . . . . . . . . . . . . . . 04 . . . . ~ . . . . . . . . . . . I I . . . . . . . 
Cyprinidce . . . . . . . . . . . . . . . . . 04 . . . . . . . . . . . . . . . . J I . . . . 03 

Hybopsis........ . --· ·:· ..... 04 ... . . . . . . . . ... . . . . . . . . 01 

11. INSECTS .. -...... 28 28 17 39 90 90 50 IOO 61 72 73 
1. Hyme12ojJte ra.. . . . . . . . . . . . . . . . . . . . . . . 05 . . . . . . . . . . . . . . . . . . .... 
2. DijJtera (larvce) .... 28 07 12 ........ 

1

.... . . . . . . . . 01 02 Of 
Cc)rethra..... . . . . . . . . . t 03 . . . . . . . . . . . . . . . . . . . . 01 . .... ... ... . 

Chironorrius . .. . . . .. 28 07 cg . . . . t t . . . . . . . . . . . . 02 . .... . 
3. Coleoptera (larvre) . . . . . . . . . . . . . . 03 t . . . . . . . . . . . . 03 01 

Gyrinldre. . . . . . . . . . . . . . . . . . . . . . . 02 ..... , . . . . . . . . . . 03 I ••• • 

Dytiscidre . . . . . . . . . . . . . . . . . . . . . . . 01 . .. . ...... .. .......... . . 

4. He11ziptera . . ... · .... . 18 03 .... 01 ........ 25 ... . .. . 01 

Cori x a . . . . . . . . . . ; . l 8 03 . . . . o I t . . . . 2 5 . . . . . . . . o i 
5. Neuroptera (larv·re) . . 03 02 39 86 85 50 75 60 67 68 

E pherneridre. . .. . . . . . 03 02 15 72 . . . . . . . . . . . . 44 . . . . 54 
Palingenia ... . . . ...... . .... 15 66 .... 50 75 44 67 5'.! 

Agrionidre.. . . . . . . . . . . . . . . . . . 24 14 55 . . . . . . . . . . . . . . . . 1 2 
Libellulidce. . . . . . . . . . . . . . . . . . . . . . . . . . 30 . . . . . . . . . . . . . . . . <-' r 
Sialidre (Corydalis) ... . ..... • . . · . . .. . ........ : . . . . . . 16 .. .-. ·or 
III. CRUSTACEA ... 7"- 72 . 83 57 IO . . . . . . . . . . . . . . . . . . . . 12 

Gammarus... . . . . . . . . . . . . . . . . . . . . . t ..................... . 
Entomostraca ........ 72 72 83 55 10 . . . . . . . . . . . . . . . . . . . . I J 

Clactocera . .... . . .. 49 33 17 55 10 .............. . ..... 12 
Daphniidce ...... 46 18 17 55 t ................ .... 11 
Lynceidce ... . ... 03 01 t .............................. . . 
Sididce . . . . . . . . . . . . 14 ................................... . 

Ostracoda . . . . . . . . . . . . . . 01 t t ............ ....... , ... . 
Copepoda . . ....... 23 39 65 . . . . t . . . . t ... • . • • • • • • • • • · • 
IV. VEGE1'ATION . . . . . . . . . . . . t t I O t t · · · · · · · · · · • · 

:::::::=============-===========================--=====---=-=:========= 
• 

}f'ivc croppies from Peoria, in Octobe1·, 1878, and fi.\·e 
i'rom I-Ien1·y, thirty miles above, i11 No,,e111l)c1·, 1877, i11di ­
cate th3.t the at1t11n1nal foorl of t l1e Rpecie8 js :1g·rti11 c1i ffC'l' -



• 

• 

Tlie Food of Fishes. G5 

c11t. Tl1ese l1ad eaten, 1·espectively, tl1i1"ty-11ine 11e1· cent. 
a,nd t,ve11t}r-eigl1t pe1" cent. of small fisbes-pa1"tly 0)"­

prinidre ancl pa1·tly l1ndetern1ined Acanthopte1--i. The rc­
mainde1" of tl1ei1-- foocl was co1nposed chiefly of Paling·e11ia 
larvre. 011e October specin1en had eaten two lar,rre of tl1e 
large ''l1elg'1•amite' ', 001,.ydalits co1'"nutits. Alt]1ol1p;l1 tl1e8e 
fishes ,,Te1·e taken cli1"ectly from the seine, a11(l ope11ecl 
11pon tl1e spot, tl1e food in thei1" stomachs did 11ot a,:erage, 
111ore tha11 a fou1"tl1 of the quantity i11 those take11 in earl>"" 
Rp1·ing. The ,,reather dl11 .. ing~ both these mo11tl1s .. \\Tas 1111◄ 

comfo1"tabl)r cold, with falling snow, a11cl tl1e food of 
these speci111ens p1"obably gives a C<)l"rect l1int of tl1e v\7in­
ter food of the species. 

Fourtee11 of tl1e abo,Te we1"e P o112oxys tiig1·011ict,citlati1.s 
. and t,velve P. rtnnitla1·is-011e 11ot l1a,ri11g· l)ee11 dete1"◄ 

mined. 
Sit·111,1riar·y of tlie Fct11iily. 

Fo1" tbe pu1"pose of a comparati,Te 1·ecapit11lation of tl1e 
above clata respec.ti11g tl1e food of tl1e Sl1nfishes,. I l1ave 
l)l"epared tl1ree concle11sed tables, s11 o,,Ti11g, upo11 the sa111e 
page, the foocl of tbe differe11t g·enc1"a in parallel columns. 
The first table exl1il)its tl1e foocl of tl1e yot1ngest speci-
111ens, the second, of those of inter111ediate size, and tbG 
tl1ird, of those "Tl1icl1 111a3r prope1·l3~ be 1"ega1"ded as ma­
ture. 

By an i11spectio11 of tl1e first table, it ,,Till lJe seen tl1at 
tl1e thi1"ty specimens, one inch long a11cl l1nder, 1"ep1"esent-
j ng eight genera, which aJ)pear thereon, l1a,re eate11 little 
else than Enton1ostraca and larvre of Cl1i1"onomus-these · 
t,vo elements amol1nting to ninety-three pe1" cent. of the 
·f' ()Od. The only exception to this rule ( that of tl1e 1--ocl{ 
1lass) is appa1 .. e11t rathe1" than real. The la1·ge percentage 
of N europte1·ot1s larvre appearing under tl1e na1ne of that 
species is a tec11nical ratio, inserted only fo1"' the sake of 
consistency, l>eing based upon the fact that one of tl1e 
~.pecimens examinecl contained no food except a fevv 
traces of so1ne indetern1inable minute larvm of ·tl1at -
01 der. The mino1" differences in the f ood of the generic 
g-.•oups are doubtless d11e to diffe1"ences of locality1 anc1 
tr:e l ike. That Ost1"acoda, fo1-- exan1ple, were found onl)--



• 

66 Tlie Food of Fishes. 

in tl1e stomachs of Centrarcl1us, is accounted £01-- by tl1e 
fact that the youngest specimens of this genus were 
taken- £1--om small m11d-holes, favorable to tl1e occurrence 
of Entomostraca of that order. The uniformity of foocl 
at this tin1e i1nplies that tl1e selective apparatus of tl1ese 
fishes, whatever its co11struction, has not yet gro"T11 be­
yond t.}1e size of these 111in11te animal for111s. 

From the second table of one l1l1nclrec1 and six speci-
1nens we learn that with a ge11eral cl1ang·e of food f1·0111 
Entomostraca and Chironomus to larg·e1" Crl1stacea ancl 
insects, tl1ere appear certain cliff e1~e11ces-notably tl1e 
continl1ance of Entomost1--aca as the n1ost impo1"ta11t ele-
111ent in Pomo~ys, and tl1e occurre11ce of molll1sks m E11-
pon1otis a11d of fishes in Micropterus. It is impo1·tant to 
r·ecall, at this point, that Pomoxys has the largest, :fi11est . 
and 1nost numerous gill-rakers of the grol1p-tbe best 
st ·,·a-i·11i1ig apparatus, in s1101--t-that E11po111otis l1as sto11t, 
blu11t pl1aryngeal teetl1, a11d that the black l)ass l1a,re 
relati,rely tl1e vvidest mouths of all. It is a.l so to l)e 11otecl 
tl1at the lar·ge-111011tl1ed-bass con1n1e11cecl to take fiRl1 ,vl1en 
an i11cl1 and a quar·te1" long·, ancl the s1nall-1no11tl1ecl spe­
cies 11ot 1111til it 1·eachec1 a length of t,vo and a l1alf inches. 

It will also be obser,recl tl1at E11tomost1·aca are least 
a .b1111dant u1 tl1e food of the small-mol1tl1ed black bass anc1 
tl1 e 1·oclc bass-species found 11s11all>r i11 swift a11(l sl1allo,,r 
wate1·, ,,rl1en of tl1is size. Tl1e i111po1~ta11ce of ,,:rate1~-l)11gs 
( 001--ixa) to tl1e first th1"ee species of tliis table is evident. 

F1"01n the table of adult foocl ,,re fi11cl tl1at these co1n­
mencing pec11lia1·ities. of the p1·ececling_ tab]e beco111e l1er·0 
n.101"e pron1i11e11t. Jl_ll the Enton1ost1·ara of tl1is tal)lc, ex­
cept i11sigi1ifica11t t1"aces, no,,T appea1· i11 t11e food of Po­
moxys; t]1e moll11scan f ooc1 of E11110111oti s is 11ea1·ly five 
ti111es tl1at of any othe1· g·enus; and t}1e ratios of fish foor..1, 
ru11ni11g· f1--om eig·l1ty-six })er cent. clown to nothi11g, vvhe11 
ar1·angecl i11 a se1·ies, a1"e seen to correspo11cl, vvitl1 curio11i; 
,exactness, to a se1"ies of tl1e species t]1emsclves a1"1·,111g·e<i 
acco1--ding to t]1e 1"ela,ti.vc sizes of their 1no11ths. ,. -·r ,vas clisa l)pointed in being· 11na·blc to fi11d an)r f oocl 
characteristics corres1,ondi11g to s11cl1 mino1· diff e1·e11ce~ 
in the le11gtl1 of t,l1e gill-1·a]{ers of t11e ante1·io1· a1·cl1 aR a1)-



TJie Food of Fislies . 67 
• 

11ear i11 Lepiopo1nus, Apomotis, etc., on tl1e one hand, and 
Xenotis a11d Eupo1notis 011 the othe1". If s11cl1 peculiarities 
,exist, they ca11 p1·obably be deter111ined only by taking at 
one time and place a nU111be1" of s1Jecimens of unlike char­
.acte1" i11 tl1is 1Ja1"tic11la1". 

\\Thile I believe tl1at the g·eneralizations made above 
,,rill holcl g·ood, at least f 01" :fisl1es of similar form and in­
ternal str·11ct11re an1011g t11e Acanthopte1--i, I do not wish to 
l)e 1111clerstood as extending them at prQsent beyond this 
orcle1·. Do11btless, while the cha1"acters mentioned must 
rtssist g'1"eatly in dete1--mining· tl1e food of a species a 
p,·io,'i) they a1·e 11ot by a11y mea11s sufficient for this pur­
pose ,vl1e11 tal{en by themsel,res. Tl1e disc11ssion of other 
f eat11res, exte1"11al a11cl i11te1--nal, l1ea1"ing 11pon this subject 
n111st 1Je l)Ostponecl to a late1" 1)e1"iocl of the i11vestigation. 

TABLE OF FooD OF YOG:\"G CE.NTRAI{CI--IlD:E. (One inch and itnder.) 

• 1'l 
• ~ 

en ,:, 
::, ·-

"'O 0 
·- E -- -~ ('ti • 

0.. en • ,:, en . :, • • V 
tn en If) ... rn (f) C: :, • :, :::, il) ... en :::, ·->, • .... .... - 11') E ·- .0 6 ·- .... ... • V il) - ·- 0 u en ...., ... 0.. ..0 - 0 >, .... 
0.. 0.. 0 0.. s ... V 0 0 ('ti >< 0 0 C: 8 0 .... .... • - 0 0 V -.... ... ..0 ·- ... ('l:l u ~ 0 0.. 0.. C 6 "'O • u E ... . ·- ·- .c 0.. V ::, V 0 C 0 
~ ~ <t: u <t: ..J ~ u ~ ~ ~ 

- - - - - - - - - -
Number of specimens .............. 5 • • 3 2 I 5 • • 5 3 6 30 

I. INSECTS ...... .... ..... • • 39 02 37 24 28 17 • • • • • • • • . . . . . . • • • • • • 

I. Diptera (larv~) 05 01 37 , 21 28 13 • • • • • • • • • • • • • • • • • • • • • • • . . . . • • . . ... . 
Chironomus . ..... ........... ..... • • • • • • cs • • • • 01 37 • • 21 28 • • • • 13 
Henziptera. 

. 
2. • • • • • • ♦ • • • • • • • • • • • • • • • • • • • • • • • I t I 01 • • • • • • • • . . .. . • • 

Corixa (you11g ) ...... ..... . ..... .. 
. 

♦ o I I • • • • . . ' . 01 • • • • • • • • • • • • • • 

3. Neuroptera (larvre) .............. . . . • • 34 • • • • • • • • . . 03 • • 1 ♦ t I 04 
II. ARACHNIDA (Hydrachna) ..... • • • • . . • • • • • • • • 04 • • 01 • • • • • • 01 
Ill. CRUSTACEA .. .. ............. 

• 61 98 75 82 100 • • 100 59 • • 72 100 
Tetradeca pod a.. . . . . . . . . . .... .. ... 07 • • • • I I I ♦ • • 02 • • 04 • • • • • • 02 
Entomostraca ...................... 93 • • 61 100 98 57 • • 71 72 100 80 

Cladocera • • • • • • • • • • • • • • • • • • • • • • • 87 • • 58 70 03 37 . . 12 49 88 53 
Ost racoda ....... .. .............. • • • • • • • • • • • • • • • • • • 21 • • t O-t 
Copepoda . . . . . . . . . . . . . . .. . . . . . . . . 06 .. 03 30 95 20 . . 38 23 22 ' 23 

-

• 



• 

68 

TABLE OJ!' Foon OF Yo1JNG CEN'r1t,\RC1r10.,E. (One to four inclies.) 

• 
VJ 
:::, 

"O ·­--~ 
0.. 
VJ 
:::, 

'"' Q) -0.. 
0 
'-u 

rn 
Q) 

"O ·-0 
E -~ 
VJ 

VJ 
::, 
a... 
Q) -0.. 
0 
a­
u 

24 

-0.. 
0 -.0 
E 
~ 

5 

• 

"' ::, -->- - . 
a- -~ .0 ..... 
O 0 
~ E 
~ 0 
~ 0.. u ~ 

8 IO Number of specimens........ 12 
.I. FISHES... . . . . . . • • . • • . . . 15 06 .... • • • • • • • • 

l 1. MOLLUSCA .. . . .. . . ... . • • • • 

III. lN~ECTA ......... ~ ... _72 
1. Diptera (larv~) . . . . . . . . . . . 01 

Chironomus. . . . . . . . . . . . . . . 01 

67 
03 
01 

2. Cvleoptera ...... .... .... . . . . . 02 
Terrestrial .... .' .......... . • • • • • • • • 

Aquati_c ... _. ....... ·/ .......... 02 
3. Hemzptera (aquatic)..... . . 50 50 

Cori xa. . . . . . . . . . . . . . . . . . 49 50 
4- Neuroptera. . . . . . . . . . . . . . . I 4 I 2 

Ephen1erid~. . . . . . . . . . . . . . 14 08 

• • • • 

98 
02 
02 
01 · 

• • • • 

• • • • 

61 
18 
15 

• • • • 

. ... . . 
0 I . ... 
78 
76 

IO 
IO 

· · · · 33 
08 

• • • • 

78 
CX) 
07 
CX) 
07 
02 
16 
16 

Odonata .... . .. .. ........ . • • • • 04 . . . . 19 

33· 
29 
04 

l V. AR-ACHNIDA .. ........ . . ' . . • • • • 

V.CRUSTACEA ............ 13 26 
• • • • t • • • Dec a pad a ........... _ ...... . 

Tetradecapoda....... . . . . . . . . . . . . 23 
En to most ~aca. . . . . . . . . . . . . . . 13 03 

Cl.adocera. . . . . . . . . . . . . . . . . 07 03 
Ostracoda ............... . • • • • • • • ♦ 

Copepoda.. . . . . . . . . . . . . . . . 06 
VI. POLYZOA ............ . . . . . 

t 
. . . . 

vrr. LUMBRICUS ... .. .. . . . • • • • • • • • 

V-111. VEGETATION . ..... ;. . . . . 0 I 

• • • • • • • • • • • • 

02 22 
• • • • . . . . 0 l 
0 I .... 
or 

• • • • • • • 

01 

• • • • • • • • 

. . ... • • • • 

. . . . 0 I 

04 
17 
09 
03 
05 

• • • • 

• • • • 

• • • • 

• 

• rn 
:::, 
8 
0 
0.. 
0 ·-0.. 
Q) 

....:l 

• 
00 .... -0 s 
0 
0.. 
::, 
~ 

• 
VJ 
;;,-,. 
>< 
C 
6 
0 
~ 

I 6 16 3 12 
0 ♦ 0 ♦ I ♦ • ♦ ♦ ♦ ♦ ♦ o O ♦ .. 

• • • • 

51 
28 
28 
t 

08 .... 
56 67 
44 04 
43 °4 
0 I .... 

22 
09 
08 

• • • • 

♦ ♦ o ♦ ♦ 0 ♦ I • • • • • • • • 

t · oi . . . . . . . .... 

I I . . . . 23 
I I . . . . 2 3 
I I 10 37 
05 08 37 
06 02 .... 
07 .... 
32 36 

• • • • 

• • • • 

33 
" .. . . 

♦ • • • 08 .... 
33 

I I 
I I 
02 
02 
. . ... 
• • • • 

• • • • 

• • • t 

78 32 
08 

28 
08 . . . . 2 5 

03 20 I 2 OI 
20 . . . . 21 52 
05 
04 
01 

• • • • 

• • • • 

• • • • 

• • • • • • • • 

• • • • • • • • 

• • • • • • t • 

TABLE OF Foon OF ADULT CENTRARCHIDJE . 

• • en en • 
::, QJ en 

:::, • en "O • • rn "O rn - rn rn 
~ ·-· ::, .... :::, • ::, 4) - VJ a- :::: a- 0 ..... >- • 8 ·- ..0 ' 

~8 U) • 
4) ~ ·- a.. - (J) - ·- 0 • 0 u -o.. 0.. .0 ..... rn a- ~ 
0. o..-

0 0 0 p.. ·- E ~ ),: 0~ _. 
0 a- rn - ~ 8 0 0 0 ... 0 a- .0 ~ ·- C 0.. - 6 u u 0 0.. C 8 .,... ·- ..0 0.. V V ::, Q) 0 
~ :E < u ~ ~ :>< ~ u ;lo. 

• 

-
Number of specimens ... 14 

3~ 
4 6 8 24 6 9 2 27 

l. FISHES .. ..... ·. · . ... 86 15 46 36 or 07 • • • • •••• 15 
Acanthopteri ........... 

I~ • • • • • • • • • • • • • • • • 01 • • • • • • • • • • • 03 
Dorysoma ............. ' 

~ • • • • • • •• • • • • • • • • • • • • • • • • • • • • • • • • • • • 

Cyprinidre ............. • • • • • • • • I2 • • • • • • • • • • • • • • • • 03 • • • • 

Siluridre ............... 07 • • • • •••• • • • • • • • • • • • • • • • • . . . "-• • • • • • • • 

I I. MOLLUSCA • • • • • • • • • • • • • • • • • • • • JO 08 46 •••• • • • • • • • • • •• 
Gasteropoda • • • • • • •• • • • • • • • • 10 04 ~ • • • • • • • • • • • • • • • • • • • • • 

Acephala . . . . . . . . . . . . .. . • • • • • • • • • • • • • • • • t 04 . . . ' • • • • • • • 

' 



• 

• 

Tlri e Food of Fishes . 69 

TABLE OF Fooo 01,' ADULT C1~NTrtARCHID.E-Continued . 

. ,.,, 
::, 

"'O ·- ·- • 
flJ 
:, 

• VJ ·-..... 
0 
E 
0 
c.. 

<( 

• ,.,, 
:, 

8 
0 • 

VJ 
0. '·-
0 ·-0.. 
Q) 

.....l 

-0 
C 
V 

~ 

-0 ,... 
C 
0 
0.. 
:, 

w 

• 
Vl 
:, 

..c: 
(,) ... 
~ ... -i:: 
Q) 

u 

• Vl 
>, 

>< 
0 
E 
0 

A.. 
----------- - - - -1--1-- ---------
Number of specimens.. . 14 

I I I. INSECT A. . . . . . . . . t 
I. HymenojJtera (ants) .. ... . 
2. Diptera (larv~) ..... .... . 

Chironomus.... . . . . . . . .. . 
3. C oleojJtera. . . . . . . . . . . . .. . 

Terrestrial .... .. . .... . ... . 
Aq·uatic . . . . . . . . . . . . . . . .. . 

4. H emijJtera (Corixa).. t 
5. 01·/hojJtera ... . ..... .. .. . 
6 . NeurojJtera. . . . . . . . . . t 

Ephemeridce ............ . 
Palingenia . . . . . . . . . . .. . 

Odonata . . . . . . . . . . . . . . .. . 
Sialidc:e .... . ........... . . 
Phryganeidce .. . ......... . 
IV. ARACHNIDA . ... . ... . 

3 4 
. . . . 52 
. . . .. • • • • 

. . . . 06 

6 
54 

• • • • 

• • • • • • • • • • • 

8 
42 

• • • • 

24 
45 

• • • • 
. . • . 0 I 

• • • • • • • • 

6 
82 

I ♦ • • 

9 2 
20 91 

07 • • • • 

27 
73 

• • • • 

o6 Ol 
06 • • • • 

. . . . 03 IO 05 

37 01 

37 01 
13 06 02 . • . . 0 I 

• • • • . . . . IO 
. . . . 03 • • • • 

• • • • . . . . I 8 
• • • • • • • • 

. . . . 4 2 

• • • • 21 

• • • • • • • • 

• • • • 06 
• • • • • • • • 

. . . . I 5 
• • • • 

• • • • 

25 
25 
25 

• • • • 

• • • • 

• • • • 

• • • • 06 04 • • • • 

05 • • • • 

03 02 

• • • • 02 

33 24 
27 03 
0 1 02 

0 2 12 
04 06 

. . . . 02 
1 7 .... 

. . . . I I I • 

16 17 
. . . . 04 
• • • • 

• • • • 

• • • • 

03 
08 

• • • • 

• • • • • • • • 

I I • I 01 
23 01 

• • • • • • • • 

68 55 
55 52 

. . . . 5 2 

• • • • 

• • • • 

13 
01 

• • • • 03 08 01 .... • • • • 
• 

• • • • I • • • • • • • • • • . . . . • • • • 

V. CRUSTACEA . . . . . 07 62 
t 

31 
31 

t 20 18 03 22 09 12 
·Dec a pod a . . . . . . . . . . . . . . 07 62 
Tetradecapoda ............ . 
Entomostraca . . . . . . . . . . . .. 

Cladocera, . . .. : . ........ . 
Ostracqda. . . . . . . . . . . . . . . . 

• • • • 

• • • • 

• • • • 

•••• 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

t .... 
t 

• • • • 

2 0 01 

17 

t 
t 

• • • • 

• • • • • • • • • • • • • • • • • • • • 

••• • • ••• • • • • · . . 02 
. . . . 02 . . . . 02 24 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

• • • • 

. . . . • • • • • • • • 

2 2 . .. . • • • • 

. . . . 09 I 2 
. • . . I 2 • • • • 

. . . . • • • • 

. . . . ()(:;) t 
• • • • • • • • • • • • 

. . . . ] 2 • • • • t 

Cope po'da. . . . . . . . . . . . . ; .. 
VI . POLYZOA •.••.••••.•.. 
VII. VEGETATION .. • . t 
.,:Wiscellaneous . . . . . . . . 07 • • • • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

HAPLOIDONOT1J S GR.UNNIENS, Raf. SHEEPSHE_.\D. GRU N TING 

PERCH. 

Tl1is species i s abt111cla11t i11 Lal{e Micl1ig·an and tl1e 
la1--ge1-- 1--i,,er s, occt11--ring in the s111aller st1·eams ra1--ely, at 
l)eriods of exceptionally l1igh ,,Tate1". It is sometin1os 
eate11, l)11t i s 1--ega1·clecl u sl1ally as l111:fit f 01· f oocl. 

But six of tl1e twe11ty-five specime11s stl1clied were 
)rou11g, a11d tl1c sn1allest of tl1ese, £1·0111 tl1e Ol1io R., in 
Septen1be1--, was ar1 inch and a11 eig'l1tl1 i11 lengtl1. Seventy­
five pe1· cent. of its foocl ,vas la1•,rfe of Chironon1l1s and 

· twe11ty-five l)er cent. la1"vffi o·f Palinge1iia bili1ieata. Be­
s jdes tl1e usual indications tl1at tl1e food of the veryyou11g 
is made up of n1inute animals, we see here evidence tl1at 
thi 8 species seeks its foocl £1--0111 the fi1--st 11po1L the botto1n. 

• 

• 



70 Tlie Food of Fishes. 
• 

In a specime.11 t,vo incl1es lo11g·, the Cl1i1--onoml1s la1--vre fell 
to fifteen per cent., ,vhile tl1e Palingenia larvre 1·ose to 
eigl1ty per cent., and othe1" Ephemer·ids ancl Cyclops 
n1ade up the remainde1" of tl1e food. 

Four specimens, also f1"om the Ol1io, at Cai1·0, f1·om 
two to four incl1es long·, ,,re1·e fou11cl to ha,re 1"ece11 tl}r f ecl 
upon Epheme1·id la1•vTce ancl lar,rre of aquatic 1Jeetles, 
Gyrinidre and J-Iydropl1ilicl~e, in abol1t eql1al c1l1a11tities. 
Only five l)er ce11t. of tl1ei1" f oocl ,,ras Cl1i1·ono1n11~. 

Sixteen indi,riduals of 111edium size ,,1 e1·e talzen fro111 
the Illinois a11d Ohio 1·ive1·s, i11 Ap1 .. il, J l1ne, Se1Jteml)e1" 
and Octo be1" of f Olll" c1iff e1"ent yea1·s. There was 11othing 
i11 the conte11ts of these stornacl1s to indicate a11, ... cliff e1---

• 

e11ce in food 1·esl1lting· fro111 tl1ese c1iffe1"e11ces of elate ancl 
si.tuation. Tl1e f ooc1, on tl1e cont1·a1•}r, " 1as 1·e111a 1·kably 
simple and lU1ifo1·1n, co11sisting· cbiefl)r of tl1e la 1•,:re of 
Neuroptera (eigl1ty-fol11· per· cent.), of ,,rl1icl1 PaliJl ,(Jer1ict, 
bilineata f 01·111ecl altog·etl1e1· tl1e 1110s t i1111)01·ta11t IJc11·t 
( seventy-six pe1.. cent. )-tl1e 1·en1rtil1i11g· eig·l1t 11e1· ce11t. 
being drago11-flies. A si11gle small suclre1-- ( Catostc>111iclm), 
a fe,,r mollt1sks ( Plano1·l)is, young· U11ios a11c1 tl1i11-sl1Pllecl 
Anodontas), a11d s01ne Aselli co1n1)lete tl1e b1--ief clietc11·)r 
of tl1is g1"ol1p. 

It is not until ,ve exa111ine the food of f11ll-g·1·o"r11 ~1)eci­
n1ens that vve ,vholly app1,.eciate tl1e 11tili ty of tl1e e1101"­
mo11s c~rusl1ing· pha1"3,ngeal ja,,rs ,,ritl1 tl1ei1· }),1,?e111e11t 
teeth, fol1nd in this specjes. The onti1--e foocl of tl1e tl11·ee 
large specimens exami11ccl, talre11 at Peo1·ia, i11 .1\.1)1·il a11cl 
October, pro,,.c(l to co11sist of 1nolll1Sl{s 0111}7 , i11<·l11di11g· 
forty-six per cent. of the tl1icl{ ancl · l1eav3T "Tate1· s11,1il, 
lif ela1itho decisa, vvhose sl1ell p1--obably no otl1er fisl1 i11 

our rive1--s coulcl breal{. Cyclas, Anoclonta a11cl 111<.leter·111-
inable Gaste1.·opoda composecl tl1e 1·e111ai11de1· of ·t]1c f oo<l . 

• 

• 


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