17 
TABLE 9.—Stomach contents of Etheostoma squamiceps from Big and Ferguson creeks, by size class of darter. 
igures in parentheses are numbers of stomachs examined. 
2 ee 
Percent of Stomachs in Which Food Organism Occurred 
ined. A large variety of food organisms was found 
ables 8 and 9). The predominant components of 
> diet of the Big Creek population were chironomid 
vae, mayfly naiads, copepods, amphipods, isopods, 
racods, and cladocerans, and of the F erguson Creek 
pulation were chironomids, caddisflies, mayflies, 
Phipods, and isopods. 
Little seasonal variation in the diet was found 
able 8). The use of cladocera, ostracods, and 
ina by juvenile E. squamiceps accounts for their 
sence in the diet during summer and early autumn 
1 their absence in the rest of the year. The large 
bulations of small crayfishes in spring correlates 
h their appearance in stomachs of May- and 
ril-collected darters. The most commonly eaten 
anisms, chironomids, were eaten in the largest 
Big Creek Ferguson Creek 
ood Organism 
< 21 21-30 31-40 41-50 51-60 > 60 < 21 21-30 31-40 41-50 51-60 > 60 
mm mm mm mm mm mm mm mm mm mm mm mm 
(10) Le) (43) (57) (16) (6) (7) (10) (17) (14) (14) (5) 
ematoda 2.4 
ligochaeta 2.4 4.7 1.8 
astropoda 2.4 se) 8.8 12.5 mall 20.0 
rachnida 
Araneae ep a sige 20.0 (hil 
Acarina 10.0 4.8 2.3 10.0 
rustacea 
Cladocera 30.0 22.0 4.7 1.8 a 42.9 
Ostracoda 50.0 ikgiail 2.3 3.5 12.5 28.6 
Copepoda 30.0 43.9 20.9 7.0 12.5 71.4 
Isopoda 
Asellidae AC les 9.8 8.8 37.5 16.7 14.3 sie 17.6 14.3 14.3 20.0 
Amphipoda 10.0 1083 20.9 17.5 37.5 50.0 14.3 10.0 23.5 35.7 
Decapoda 
Astacidae 1.8 12.5 16.7 
secta 
Plecoptera ae ale Wises 1.8 Als oe ae ats aa ae Ural 
Ephemeroptera 30.0 29.3 27.9 45.6 31.3 16.7 28.6 10.0 ila lefss 28.6 28.6 
Odonata 
Zygoptera 2.4 ait Pi an ae se Fite oi 
Trichoptera 12.2 2.3 5.3 6.3 10.0 58.8 14.3 42.9 
Coleoptera 
Dytiscidae es 1.8 ae 
Hydrophilidae Ae 2.3 a 6.3 
Psephenidae go 2.3 1.8 6.3 Ss 
Elmidae 4.8 1.8 14.3 
Diptera 
Tipulidae ae Se Tell 
Simulidae ae a oe se ‘a ei see 20.0 11.8 Rag a6 ee 
Chironomidae 70.0 56.1 (2.1 36.8 43.8 50.0 100.0 90.0 82.4 64.3 50.0 40.0 
Ceratopogonidae we Si 4.7 Ao 
Others 10.0 7.3 4.7 3.5 
scellaneous 2.4 4.7 16.7 5.9 Leal 7.1 
numbers in the months immediately preceding spawn- 
ing, presumably reflecting an increase in consump- 
tion associated with spawning preparedness. 
The smallest darters examined fed predominantly 
on copepods, cladocera, ostracods, and chironomids; 
the largest darters fed mainly on amphipods, isopods, 
and chironomids in Big Creek, and on amphipods, 
chironomids, and caddisflies in Ferguson Creek 
(Table 9). 
Aquarium-held E. squamiceps searched for food 
by moving over the gravel bottom in short, jerky 
movements. When a benthic organism was located, 
the darter approached closely, directed his snout 
toward it, and then quickly sucked it into his mouth. 
Nest-guarding males fed as readily as other indi- 
viduals. Fry were successfully raised on brine shrimp. 
