Fish Culture in Inland Waters 311 



taken annually and placed in the hatcheries, and of these usually 

 from eighty to ninety per cent are hatched and placed in the waters 

 of the Great Lakes, 165,000,000 in Lake Erie alone in 1888. 



" This is very nearly all that is known about these young white- 

 fish. About their food habits we know only that in captivity they 

 eat certain species of Crustacea. Whether in their natural habitat 

 they eat other animals in addition to these Crustacea or in preference 

 to them we do not know. It is uncertain at what age they begin 

 to take food, or how much they require. We do not know their 

 natural enemies. We do not know w'h ether they thrive best in run- 

 ning water or in standing waiter ; in shallow water or in deep water ; 

 whether at the surface or near the bottom. What changes of 

 habitat or of food habits the fish undergo as they grow older is a 

 still deeper mystery. 



" Our problem is to place young whitefish in the Great Lakes 

 under such conditions that as large a number as possible of them 

 shall grow into adult fish. It is clear that of one of the elements in 

 this problem, namely, the whitefish, we know but little." 



Forty years ago Professor Forbes ('83) found that young 

 artificially hatched fish in captivity would eat certain forms of 

 minute crustaceans, but since that time scarcely anything has been 

 learned of the food of young whitefish under natural conditions, 

 although some advance has been made in the knowledge of the food 

 of the adult fish. 



Hankinson ('14, '16) records the food of little whitefish, 3 to 3.5 

 inches in length, which were found in a lot of small " herring " of 

 similar size on a shoal of Lake Superior. He said that he was unable 

 to find in the literature a record of whitefish beyond the fry stage 

 as small as those taken at Vermilion. The young whitefish were 

 found to be eating entomostracans freely, and this appeared to be 

 the chief food of those collected. Midge larvae (Chironomus) were 

 found to be taken by them in important numbers. 



2. Round Whitefish; FrostHsh. Bean ('16) says that the round 

 whitefish is found in the lakes of the Adirondack region and that 

 its food habits are similar to those of the common whitefish. " The 

 fry are ready for distribution in March and April, and are usually 

 planted by the Commission in the waters from which the eggs were 

 collected." No definite instructions are given for planting the fry, 

 and there appears to be no specific information concerning the food 

 of the fry. Very little information concerning the habits of the 

 species is available. In certain waters, as in Maine, this species 

 ascends tributary streams of lakes to spawn. How long the young 

 remain in the streams after they are hatched does not appear to be 

 known. Basing the recommendation, however, upon the fact that 

 the fry's first existence is in the stream, other things being favorable, 

 it is best to plant fry of frostfish in tributary streams. 



Hankinson ('16) states that this species was found common on 

 the deeper part of the shoal near Vermilion (Northern Michigan). 

 Those taken were of edible size, a little over a foot long. Two 



