AQUATIC PLANTS IN POND CULTURE. 



By John W. Titcomb, 

 Chief of Division of Fish Culture, Bureau of Fisheries. 



POND CULTURE AND ITS APPLICATION. 



Among the freshwater fishes most desirable for food purposes 

 and for sport-fishing tliere are certain species, such as the basses, 

 crappies, sunfishes, and catfishes, wliich are not susceptible to 

 manipulation for the taking and impregnation of their eggs, but 

 must be allowed to mate and select nests, on Avhich the spawn is de- 

 posited, fertilized, and hatched in the natural way. For the cultiva- 

 tion of these species, therefore, it is necessary to provide surround- 

 ings fulfilling their requirements, and at the same time permitting 

 control of the fish, wdiich purpose is accomplished by the maintenance 

 of natural or artificial ponds. These ponds are stocked with the maxi- 

 mum number of adult fish, and the young hatch in numbers abnormal 

 for the volume of water in which they are contained, there to be reared 

 for a few weeks or months and then distributed to other waters as 

 desired. The jDond itself affords sustenance to the young, and there- 

 fore the pond is the direct object of attention in order to produce the 

 maximum number of fish. Fish culture under these conditions is 

 consequently intensive pond culture, and in the United States the 

 term " pond culture " distinguishes this branch of fish culture from 

 the propagation of all fishes whose eggs can be expelled and fertilized 

 artificially or which are incubated in hatching houses by the use of 

 special apparatus and equipment. The species to which it is applied 

 are chiefly the black basses, crappies, sunfishes, and catfishes. 



The propagation of the Salmonidse, notably the fronts, approaches 

 pond culture in the fact that several species are often reared in ponds, 

 whereas the other fishes hatched in special equipment are usually 

 distributed as fry as soon as the yolk sac is absorbed. But although 

 the cultivation of the trouts in this country may require ponds in 

 which to rear the young, the different service the ponds perform and 

 the different management required places American trout-rearing 



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