224 American Fisheries Society 



transferred, close watch is kept of weather conditions and 

 temperatures every moment until the hatching season is 

 over. Only enough water is introduced into the breed- 

 ing ponds to keep them at normal level, as this is better 

 than having too large a flow. If the temperature starts 

 downward, the water is shut off immediately. 



If the fish culturist has studied different varieties of 

 fish during the breeding season, he will probably recall 

 that some streams in his vicinity failed to produce any fry 

 during certain seasons. If he will study this matter 

 closely he will find that proper conditions did not prevail. 

 There may have been a few warm days and the fish came 

 on the spawning ground and actually laid their eggs. 

 Later on there was a cold spell, one or two cold nights 

 when the temperature of the water dropped, thus caus- 

 ing the fish to desert their nests and practically the whole 

 season's output was a total loss. The farther north the 

 fish culturist is located, the more trouble he has with 

 temperature conditions; but there is nothing to hinder 

 him, if he keeps in close touch with the situation, in bringing 

 about almost whatever he desires in this respect. 



REARING YOUNG BASS IN PONDS 



When the young bass are about to rise from the nest, 

 they are screened, if for no other reason than to determine 

 how many should be left in a certain pond to be reared to 

 fingerlings. If there are too many, the surplus is trans- 

 ferred to other ponds or planted in public waters. Too 

 many fry in one pond will result in their destroying the 

 food supply, and then they would naturally all starve. 

 The practical fish culturist after looking over his ponds 

 carefully and estimating the amount of food therein, 

 should be able to determine about how many thousand 

 fry ought to be released. Scattering finely ground clam 

 meal around the borders of the ponds increases the nat- 



