298 Lake Maxinkuckee, Physical and Biological Survey 



parasites were attempting to fasten themselves to the gills of the 

 little fish, they evidently met their just deserts and were swallowed. 



The stomachs of the larger bluegills contained many Chirono- 

 mus larvae. Of 50 obtained near the middle of August the stom- 

 ach of every one was gorged with the tender tips of Potamogeton, 

 Heteranthera, Naias, and other water plants. But most of the 

 vegetable matter was so chewed and digested as to be incapable of 

 identification. 



Ergasilus centrarchidarnm was obtained from the gill-filaments 

 and Achtheres ambloplitis from the gill-arches of a few fish, but 

 neither parasite was at all common. 



To the sportsman, acquainted with the carnivorous habits of 

 most game fishes, this vegetable diet of the bluegill comes as a 

 surprise, but of course the fish eats many animals also. In the 

 summer they eat Potamogeton, Ceratophyllum, Naias, some 

 Chironomus larvae, and a few Sphaeriums. In the fall they eat 

 large branches of the brown bryozoan of the lake, Plumatella poly- 

 morpha, Rivularia, and bits of Chara. 



These bluegills are particularly infested with leeches, some 

 being found on nearly every fish, and often eight or 10 huddled 

 together on the roof of the mouth of one fish. Trematodes also 

 occur on the gills and cestodes and Acanthocephali in the stomach 

 and intestine. 



20. Sunfish ; Bream. Eupomotis gibbosus. 



Only six specimens of this fish were examined, the food of which 

 consisted of insect larvae, mollusks, and small crawfish. One ex- 

 ample had two tapeworms in its stomach, but there were no ex- 

 ternal parasites on the gills or the outside of the body. 



21. Small-mouthed Black Bass. Microptenis dolomieii. 

 Twenty-five specimens of this fish showed almost nothing beside 



crawfish and minnows ; what there was of other material was so 

 digested that it could not be identified. 



Every bass had at least some specimens of Ergasilus centrarchi- 

 daru7n on its gill-filaments, and about half of them (11) had also 

 Achtheres amblojHitis on the gill-arches. There were usually but 

 two or three of the latter on a single fish, but from one bass weigh- 

 ing one and a half pounds there were taken 37 specimens, includ- 

 ing both sexes and every stage of development from a copepodid 

 larva just attached up to the mature adult. 



Cestodes were also found on the gills and in the stomach, and 

 Acanthocephali in the stomach and intestines. A single leech was 

 taken from the pectoral fin of one of the smaller specimens. 



