48 UNIVERSITY OF WISCONSIN STUDIES 



Ten small individuals were examined, August 12, 16. Length 

 42-52; average 46. Food: fish 9; chironomid larvae 7.2; mayfly 

 nymphs 9; bug nymphs 1.5; chironomid pupae 14.5; insects 1.5; 

 Daphnia 51.4; Ceriodaphnia 1.5; Diaptomus 3.3; ostracods .1. 



Notropis hudsonius (De Witt Clinton), shiner 



Twelve shiners were studied, August 12-19. Length: 33-53; 

 average 41. Food: chironomid larvae 22.1; chironomid pupae 

 2.1; insects 17.3; midges 1.3; entomostracans 3.8; Daphnia 38.3; 

 mite .4; oligochaetes 11.7; filamentous algae .4; mud (chirono- 

 mid larval tubes?) 1.7. 



Perca flavescens (Mitchill), yellow perch 



Nineteen perch were examined, August 10-21. Length: 98- 

 195; average 138. Food: fish 5.3; chironomid larvae 15.8; may- 

 fly nymphs 2.8; Sialis nymphs 1.1; caddis fly larvae .7; beetle 

 larvae .1; crayfishes 5.6; Hyalella 19.9; Daphnia 25,3; Eury- 

 cercus .2; Leptodora 8; Diaptomus .3; ostracods .1; snails 2.7; 

 plants .6; Arcella-like seeds -f; bottom 11.1. One individual 

 contained no food. 



Salvelinus fontinalis (Mitchill), brook trout 



A specimen, 315 mm. long, caught August 24, had eaten 

 nothing but chironomid pupae. 



Stizostedion mtreum (Mitchill), wall-eyed pike 



Ten pike were examined; August 13-24. Length: 208-300. 

 Average 274. Food: fish 75; perch 25. Two individuals con- 

 tained no food. 



DISCUSSION or FOODS OF FISHES IN ALL LAKES 



The observations on the foods eaten by the fishes in Lake Win- 

 gra are not extensive enough to be compared with those from 

 other lakes and the following discussion therefore relates to five 

 Wisconsin lakes. The foods are summarized in Tables IX to 

 XII. 



The following list gives the classes of foods and the lakes in 

 which the foods were found to be eaten by fishes. The lakes are 

 arranged according to the volume of the total that each item 



