The Relation of Shellfish to Fish in Oneicla Lake 19 



indicates that of 225 species inhabiting the fresh waters of 

 the states of Illinois and Xew York, 4(5, or about one-fifth, 

 are eaters of shellfish to a greater or less degree. The average 

 amount of molluscan footl eaten by these 4G fish is about 

 one-fourth, or 24 per cent. 



Among those fish that eat a large percentage of shellfish 

 food may be mentioned such common species as the Sheeps- 

 head, which eats 100 per cent, the Lake Sturgeon and 

 Spotted Sucker, which consume upwards of 90 per cent, the 

 Common Red-horse which is credited with G2 per cent, and 

 the Pumpkinseed Sunfish which eats about half mollusks. 

 or 51 per cent. The Common Sucker eats 30 per cent while 

 the valuable Whitefish consumes 26 per cent. The Bullhead, 

 a common bottom feeder, is credited with but 20 per cent. 

 Many of the fish mentioned are provided with especially 

 modified mouths containing, in some species, crushing appa- 

 ratus of more or less perfection, which appear as if they had 

 been modified by nature to include a diet of shellfish. 



Some fish confine their diet to a few kinds of shellfish but 

 the majority of mollusk-eaters devour any shellfish available 

 that is of the right size. The large number of different 

 species or kinds of shellfish eaten by a single species of fish 

 is, however, interesting. Thus, the Pumpkinseed is known 

 to eat 18 different kinds of shellfish, the Whitefish, 17 kinds, 

 the Yellow Perch and the common Red-horse, each eight 

 kinds, and the common Bullhead, 11 kinds. Upwards of 

 50 different kinds of shellfish are now known to be eaten by 

 fish and this number w y ill probably be greatly increased with 

 further study (Fig. 8). 



FOOD FISHES FEEDING rroisr SHELLFISH 



There are about twenty-five food fishes inhabiting the 

 waters of Xew York State that feed upon shellfish. These 

 include a majority of this class of fish and indicate the value 

 and importance of the shellfish as a source of food supply. 

 If we divide these fish into four classes, in the order of their 

 importance economically, we see at once the significance of 



