AQUATIC PLANTS IN POND CULTURE. 
By JoHN W. TIFCOMB, 
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 there are certain species, such as the basses, 
crappies, sunfishes, and catfishes, which are not susceptible to 
manipulation for the taking and impregnation of their eggs, but 
must be allowed to mate and select nests, on which 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, which purpose is accomplished by the maintenance 
of natural or artificial ponds. These ponds arestocked 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 pond 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 Salmonide, notably the trouts, 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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