258 FISHES OF ILLINOIS 



atines; lower pharyngeals narrow and weak, the teeth slender and sharp; 

 operculum more or less prolonged backward in adults, always rather wide 

 and bluntly rounded posteriorly, usually rather conspicuously striate 

 longitudinally, the membranous margin very narrow or wholly wanting, 

 its color when present very little if any lighter than the black of the 

 osseous portion of the flap ; gill-rakers rather long and slender, but firm 

 "the longest almost $ diameter of eye. Dorsal X, 10 to 12, usually X, 1 1 

 spines long, the longest 1.3 to 2.4 in head, usually about 2 in adults 

 anal III, 10 or 12; pectorals long, pointed behind, about equal to head or 

 a little less, .9 to 1 in head, usually about 1 in adults; ventrals reaching 

 anal. Scales 6, 38-48, 13 or 14; those on cheek in 5 rows. 



This is the principal sunfish of our larger rivers, and the one ap- 

 pearing most frequently in the large nets of the regular river fisher- 

 men. It occurs throughout the state, but is generally limited to the 

 larger streams and their principal tributaries, except that it is com- 

 mon in the northeastern glacial lakes. It has also been taken by 

 us in the Michigan drainage. Judging from our 214 collections, 

 it is primarily a pond species, its frequency ratio in the ponds and 

 lakes being 1.6. In flowing streams it is commonest in the larger 

 rivers, and least common in creeks. 



Along the Atlantic coast it is found from New Jersey to the 

 Florida peninsula ; in the Great Lakes, from Ontario westward, rang- 

 ing thence to the south and west through the Ohio and the lower 

 Missouri basins to New Orleans and Texas. 



It is said by Jordan and Evermann to be perhaps the best known 

 and certainly the most important of all our true sunfishes, decidedly 

 a lake species everywhere, but more abundant in the smaller lakes. 

 It is the largest of our sunfishes, reaching a length of twelve to 

 twenty -four inches and a weight of nearly a pound, the maximum 

 weight being about a pound and a half. 



In the food of twenty-six specimens we have found a trace of 

 fishes — a single darter eaten by one — a moderate percentage of uni- 

 valve mollusks, a large ratio of insects (45 per cent.), and many of 

 the medium-sized Crustacea. The insect food is derived in great 

 measure from larger aquatic larva? than most of our sunfishes feed 

 upon. The stomachs of some of our specimens were found to con- 

 tain as much as 24 per cent, of aquatic vegetation — too large a quan- 

 tity to have been swallowed accidentally with the animals eaten. 

 Its food differs in detail, however, according to the situation in 

 which it is found. 



The bluegill moves in schools, and may be caught with almost 

 any kind of bait or tackle. Its flesh is firm and flaky, and it is not 

 excelled as a pan-fish by any of our species, .unless it be the yellow 



