CRUSTACEA AS FOOD FOR YOUXG FTSH, 25 



VALUE OF CRUSTACEANS AS FISH FOOD. 



Mr. Eaveret-Wattell (1887) said of the fish raised at Gremaz that 

 from their well-developed stomach and their finely rounded forms 

 it could be seen that the fish had not only never suffered hunger but 

 that they had always had abundant food of excellent quality. This 

 crustacean food, he said, was exceeding'ly suitable for young fish on 

 account of the large quantity of phosphate of lime which it contains, 

 and this circumstance explained the rapid growth and exceptionally 

 fine and vigorous condition of the young trout raised at Gremaz. 



Mr. Mason (1887), after stating that the organisms thus raised 

 and fed to the fishes at Gremaz far surpassed in value, as food for 

 fish, anything that had been devised by man, enthusiastically con- 

 tinued : 



Thus the simple inexpensive process goes on from year to year, the fish 

 always healthy and vigorous, and larger at 2 years old than those artificially 

 fed are at 3 years. Yearlings bred in this way are strong and capalile of 

 making their way in any open stream or pond supplied with food and suitable 

 for their existence. One thousand of such yearlings have been found more 

 effective in stocking a depleted trout stream than 50,000 young fry turned in, 

 as has been so often done heretofore. 



Muntadas (1887) said that ever since his first season he had fed 

 nothing but small shrimp to his young trout, " which grew amazingly 

 fast." 



Seal (1892) said that young trout in aquaria would always take 

 Crustacea in preference to dead food, and that it was natural that 

 they should. 



Prof. Lintner, to whom Cheney (1892) had shipped Caledonia 

 shrimp, had expressed the opinion that in time every order for 5,000 

 brook trout would be accompanied with an order for 100,000 shrimp. 

 In the discussion of Cheney's paper (1892), Mr. Gilbert said that in 

 his brook in Massachusetts the water cress and other aquatic plants 

 were literally alive with fresh-water shrimp and that he did nothing 

 to increase them. His trout fed on them all of the time, and in one 

 place he had 20,000 yearlings. 



Mather (1900) expresses his belief that Gammarus is greatly oA'-er- 

 rated as trout food. The stomachs of 247 trout from Wilmurt Lake, 

 Herkimer County, N. Y., were examined by him and were estimated 

 to contain but 5 per cent Gammarus. The same ration was found to 

 obtain in 138 stomachs of trout taken from Meacham Lake, in the 

 northern Adironclacks. He further stated that a trout of a pound 

 weight seldom eats them. 



Dr. Jousett de Bellesme (1895) said that in their efforts to produce 

 an abundant supply of annual food for fishes certain specialists be- 

 lieved that the problem was solved by an unlimited supply of crusta- 

 ceans. This was stated to be the system of Lugrin (at Gremaz), but 

 that it had been demonstrated at the Trocadero Aquarium that feed- 

 ing by means of Daphnia is simply a dangerous illusion, as these 

 little animals possess very small value as food, and fish which are 

 subjected to this regime do not grow. 



Embody (1911) says that it is common knowledge that the eastern 

 brook trout {Salvelinus fontinaUs) feeds upon amphipods, and espe- 

 cially upon the so-called Caledonia shrimp {G. Jimna'us). Three 

 young trout approximately 100 mm. long (3.93 inches) captured in 



