FISHES OF GREEN LAKE, WIS. 265 



Leucichthys birgei Wagner. Cisco. 



August Ij. — Depth, 41.5 m.; number examined, 10; lengths, 148 to 288, average, 199. Food: 

 Chironomid larvae, 0.3; Mysis, 5; Pontoporeia, 76.6; copepods, 1.6; ostracods, 5; SphEeridae, 11. i; Amni- 

 cola, 0.6; Planorbis, 0.2; brown, spindle-shaped seeds, 0.8; plants, 0.5; bottom ooze, 1.6; calcium car- 

 bonate crj'stals, o.i; imknown, i.i. 



August 14. — Depth, 71.5 m.; number examined, 8; lengths, 207 to 246, average, 225. Food: Chirono- 

 mid larvae, 3. 2; Mysis, 13.3; Pontoporeia, 24.2; Canthocamptus, ^.^; ostracods, 12.5; oligoch^tes, 21.7; 

 Sphaeriidae, 0.8; brown seeds, 0.2; dandelion seed, 0.2; bottom ooze, 12.6. 



August ig. — Depth, 70.5 m.; number examined, 12; lengths, 154 to 296, average, 228. Food: 

 Chironomid larvae, 0.2; Silais nymph, 0.4; Pontoporeia, 73; oligochaetes, +; Sphaeriidae, 14.8; Valvata, 

 0.1; Linnaea, 0.2; Amnicola, 0.3; Planorbis, 0.6; brown seeds, o.i ; plants, 0.4; bottom ooze, 9.8. 



Sumynary. — Number examined, 30; lengths, 148 to 296, average, 218. Food: Insect larvae, i.i; 

 Mysis, 4.7; amphipodis, 61.2; copepods, 1.3; ostracods, 3; Sphaeriidae, 9.9; snails, 0.8; seeds, 0.4; plants, 

 0.3; bottom ooze, 8.2 ; calcium carbonate crystals, + ; unknown, 0.3. 



The Cisco feeds largely on crustaceans and molluscs in summer. Eighty -eight per cent of its food 

 is made of bottom ooze and the organisms associated with the bottom. Perhaps the ciscoes tiUTi more to 

 plankton at other seasons. If so, their feeding habits differ markedly from the perch, which is the deep- 

 water fish in Lake Mendota, for it feeds largely from the bottom at all seasons (Pearse & Achtenberg, 



1920). 



Micropterus dolomieu Lac6pfede. Smallmouth black bass. 



August 75. — Number examined, 6; lengths, 46 to 57, average, 51.5. Food: Chironomid larvae, 6; 

 Orthocladius, 30.1; mayfly nymphs, 0.6; chironomid pupse, 4; insects, 0.8; Acroperus, -f ; Eur^-cercus, 

 0.1; Ceriodaphnia, 57.8; plant remains, 0.3; filamentous algae, -f; sand, 0.3. 



August 16. — Depth, 14.5 m.; number examined, i; length, 392. Food: Perch, 50; grasshopper, 50. 



August 18. — Number examined, 2 ; lengths, 52, 56. Food: Chironomid larvaac, 35; mayfly nymphs, 

 7.5; beetle larvae, 5; chironomid pupae, 30; Hyalella, 225. 



August 21. — Number examined, i; length, 55. Food: Chironomid larvte, 35; Eurycercus, i; 

 Ceriodaphnia, 64. 



August 2j. — Depth, 10 m.; number examined, i; length, 395. Food: Fish remains, 100. 



Summary. — Number examined , 11; lengths, 46 to 395, average, 114. Food: Fish, 13.6; insect larvae, 

 31.8; insect pupae, 7.6; insect adults, 5; amphipods, 4.1; cladocerans, 37.6; plants, 0.2; sand, 2. 



Micropterus sahnoides (Lac^p^de). Largemouth black bass. 



August 18. — Number examined, 3; lengths, 49, 58, 61. Food: Fish, 5; chironomid larvae, 3.3; 

 damselfly nymphs, 13. 3; mayfly nymphs, 6.7; chironomid pupae, 157; Corixa, 8.4; Chydorus, 0.3; amphi- 

 pod, 2.7; Hyalella, 4; ostracods, 0.3; Eurycercus, 0.3; Ceriodaphnia, 39; sand, i. 



.August ig. — Number examined, i; length, 52. Food: Chironomid larvae, 15; chironomid pupae, 

 40; Eurycercus, 10; Ceriodaphnia, 30; sand, 5. 



August20. — Number examined , i;length,63. Food: Chironomid larvae, 25; chironomid pupae, 75. 



August 21. — Number examined, 3; lengths, 63; 63, 64. Food: Chironomid larvae, 6.7; mayfly 

 nymphs, 5; chironomid pupae, 9.3; fly, ji-y, Hyalella, 13. 3; Ceriodaphnia, 61.3; sand, i. 



August 22.— Number examined, 8; lengths, 55 to 283, average, 97. Food: Chironomid larvae, 9; 

 mayfly nymphs, 6.3; chironomid pupae, 13.5; midges, 14; fly, 0.3; cra;)-fish, 8.1; Hyalella, 28.5; ostracods, 

 0.1; Chydorus, 0.1; Eurycercus, 0.8; Ceriodaphnia, 7.2; plants, 10.6; sand, 1.5. 



Summary. — Number examined, 16; lengths, 49 to 283, average, 78. Food: Fish, i; insect larvae, 

 16. 1 ; insect pupae, 18.6; adult insects, 8; crayfish, 4; amphipods, 18; cladocerans, 24.8; ostracods, 0.1; 

 plants, 5.2; sand, 1.4. 



Only one of the fishes examined was over 88 mm. in length. This one had eaten chironomid pupae, 

 15, and plants, 85. The most important foods for all bass examined are insects and their immature 

 stages (42.7), cladocerans, and amphipods. 



