FRESH WATER CRUSTACEA AS FOOD FOR YOUNG FISHES ' 



By William Converse Kendall 



Scientific Assistant, U. 8. Bureau of Fisheries 



Washington, D. C. 



Some years ago a number of species of small crustaceans were 

 recommended as natural food for artificially-raised young fishes, 

 particularly salmon and trout. The claim was made that the ease 

 with wWch certain species of these little animals could be kept and 

 bred made them particularly valuable for fish-cultural purposes; 

 and it was also suggested that natural streams and ponds deficient 

 in food could be stocked with this kind of food, since some species 

 were so common and of such wide distribution that a supply was, 

 as a rule, conveniently available. The principal advocates of the 

 growing of crustaceans were European fish-culturists. In this coun- 

 try the idea had its supporters, although there were others who had 

 no faith in it. The latter took the ground that while the culture of 

 crustaceans as food for young fishes was practicable in European 

 establishments, where small numbers of fish are raised, it would 

 be impossible to maintain a sufficient supply for such food require- 

 ments in this country, where the business is conducted on a much 

 larger scale. 



In general the method of procedure was to stock adjacent ponds 

 with crustaceans and the necessary water plants. In some instances 

 young fish were admitted to one inclosure while another was de- 

 veloping. When the first pond was depleted the fish were admitted 

 to the second, and the first allowed to be repopulated. In other cases 

 the procedure was simply rationing out the crustaceans to the fish in 

 their own ponds, either by dipping or admitting through troughs 

 or pipes. The crustaceans to which particular attention was given 

 were Daphnia and shrimp (Amphipoda). It should be noted, how- 

 ever, that the method of raising them did not usually admit of pure 

 cultures of any one form, so that the stated results are affected by 

 a certain element of error. 



It is not the purpose of the present paper to discuss the relative 



^ The subject matter of this paper is more fully covered by the author's contribution 

 under the same title and issued as Bureau of Fisheries Document No. 914, or appendix : 

 of the report of U. S. Commissioner of Fisheries for 1922. It discusses the distribution, 

 habits, and life histories of the most common forms of fresh water crustaceans, such as 

 the fairy shrimps, water fleas, copepods, ostracods, isopods, amphipods, Mysis, prawns, 

 and crayfishes. The document also treats of the possibilities of successful crustacean 

 culture. 



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