FISHES OF GREEN LAKE, WIS. 265 



Leucichthys birgei Wagner. Cisco. 



August 13. — Depth, 41.5 m.; number examined, 10; lengths, 148 to 288, average, 199. Food: 

 Chironomid larvae, 0.3; Mysis, 5; Pontuporeia, 76.6; copcpods, 1.6; ostracods, 5; Sphjerida, 11. i; Amni- 

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

 bonate cr>-stals, o.i; unknown, i.i. 



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

 mid larvae, ^-i; Mysis, 13.3; Pontoporeia, 24.2; Canthocamptus, 3.3; ostracods, 12.5; oligochaetes, 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 larvs, 0.2; Silais nymph, 0.4; Pontoporeia, 73; oligochaetes, -|-; Sphacriidae, 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. 



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

 Mysis, 4.7; amphipodis, 61.2; copcpods, 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 turn 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). 



Microptenis dolomieu Lac^p^de. 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 pupae, 4; insects, 0.8; Acroperus, -f ; Eurj'cercus, 

 0.1; Ceriadaphnia, 57.8; plant remains, 0.3; filamentous alga, +; sand, 0.3. 



August 16. — Depth, 14.5 m. ; number examined, 1; 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 larvae, 35; Eurjcercus, i; 

 Ceriodaphnia, 64. 



August 23. — 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. 



Microptenis salmoides (Lacepfede). Largemouth black bass. 



.\ugusl iS. — Number examined, 3: lengths, 49, 58, 61. Food: Fish, 5; chironomid larvae, 3.3; 

 damselfly nymphs, 13.3; mayfly nymphs, 6.7; chironomid pupae, 15.7; Corixa, 8.4; Chydorus, 0.3: amphi- 

 pod, 2.7; Hyalella, 4; ostracods, 0.3; Emy'cercus, 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. 



August 20. — Number examined, i; length, 63. Food: Chironomid larvae, 2 5 ; chironomid pupae, 75. 



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

 nymphs, 5; chironomid pupae, 9.3; fly, ^.-i,; 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; crayfish, 8.1; Hyalella, 28.5; ostracods, 

 0.1; Chydorus, 0.1; Emycercus, 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. 



