FISHES OF THREE WISCONSIN LAKES 39 



Five small specimens were examined, July 9. Length: 46- 

 51; average 49. Food: fish 70; chironomid pupae 4; Hyalella 2; 

 Daphnia 11; Leptodora 13. 



Scaphirhnchus platorhynchus (Rafinesque), hackleback 

 Twelve specimens were examined, June 23, 30. Length: 

 565-680; average 627. Food: chironomid larvae 17.5; Corethra 

 larvae 2.7; caddis fly larvae +; Sialis nymphs 8.9; mayfly 

 nymphs .3; chironomid pupae .5; Corethra pupae 2.9; Corixa 

 + ; Hyalella .7; Daphnia 23.7; Leptodora 38.1; Cyclops .2; 

 snail .7; Sphaeridae .2; young clams 1.2; gordiacean (from insect 

 larva?) + ; Ceratophyllum -f-J Chara +; stick .2; filamentous 

 algae .1; sand 1.1; bottom debris 1.7. 



Schilbeodes gyrinus (Mitchill), tadpole cat 

 Five specimens were caught with a dip net, June 23 July 1. 

 Length: 16-67; average 44. Food: chironomid larvae 30; may- 

 fly nymphs 27.5; mites 2; Hyalella 39.5; ostracods .5; filamen- 

 tous algae .5. One individual contained no food. 



Stizostedion canadense griseum (De Kay), sauger 

 Ten saugers were examined, June 22 to 24. Length: 113- 

 275; average 206. Food: fish 65; small pike 10; chironomid 

 larvae 2.5; Hyalella 1; Daphnia .5; Leptodora 1; Cyclops 1.5; 

 ostracods 2; mud 2.5; bottom debris (partly chironomid tubes) 

 4; unknown 10. 



Stizostedion mtreum (Mitchill), wall-eyed pike 

 Eleven adults, taken in a commercial seine, were examined, 



June 25 to July 10. Length: 330-415; average 386. Food: 



fish 79; Sialis nymphs 21. 



Five small pike caught alongshore in a minnow seine July 



25 furnished the following data: Length 48-53; average 52. 



Food: fish 30; chironomid pupae 13; Daphnia 52; Leptodora .4; 



Cyclops 3; unknown 2. 



FOOD OF THE FISHES IN LAKE MICHIGAN 

 Ambloplites rupestris (Rafinesque), rock bass 

 Six specimens were examined, July 23 to August 6. Length: 

 132-200; average 156. Food: minnows 17.5; mayfly nymphs 

 21.7; crayfishes 60.8. 



