41 



the first stage of their food and feeding habits. More than 

 half these young belonged to a single species — the common 

 lake whitefish — but the remainder were well distributed. 



I have arranged the matter under the following general 

 heads : (i) a general account of the food of the most impor- 

 tant species and families of our native adult fishes ; (2) a brief 

 account of the food of the young ; and (3) a summary state- 

 ment of the food, so made as to exhibit (a) the kinds and rela- 

 tive importance of the principal competitions among fishes, and 

 {b) the relative value to the principal species of fishes of the 

 major elements of their food. 



First, then, I will attempt to give you very briefly, and in 

 the most general way, the facts relating to the food of the most 

 important fishes, those which I think most likely to interest you 

 as fish-culturists, taking the species in their zoological order 

 rather than in the order of their economic importance. 



FOOD OF ADULTS. 



The abundant white perch or sheepshead of the larger rivers 

 and lakes, now commonly marketed, I find feeding, when full 

 grown, almost exclusively upon the bivalve moUusks known in 

 the West as clams, whose heavy shells this fish is enabled to 

 crush and grind by a special apparatus in the throat. The shells 

 are swallowed with the bodies and pass, in part at least, through 

 the intestine. Half-grown specimens feed in much larger ratio 

 upon aquatic insects, especially the larvae of May flies, but 

 take likewise the smaller moUusks with spiral shells, commonly 

 known as water snails, the food in my examples being about 

 equally divided between these two elements. The youngest 

 specimens feed, like the young of fishes in general, upon the 

 smallest of the Crustacea. 



The common perch or " ring perch," excessively abundant 

 throughout the northern part of the country, varies in food 

 according to the waters it inhabits, those in the great lakes 

 feeding almost wholly upon small fishes (especially of the min- 

 now family), and upon crayfishes — five or six times as many of 

 the former as of the latter. River specimens, however, eat few 

 fishes, but find nearly half their food among the Crustacea, 



