MANUAL OF FISH-CULTURE. 175 



fed almost every hour in the day, though but little food is given at 

 one time and that well scattered through the trough. The attendant 

 should be about the trough constantly to accustom them to his pres- 

 ence, care being taken not to alarm them. Instead of* being frightened 

 and darting to the dark corners of the trough at his approach, they 

 soon learn to come to meet him, not a few at a time, but all together. 



For several days their food will have to consist of such minute ani- 

 mals as can be conveniently collected from the ponds with a dip net of 

 cbeese-cloth. After four or five days they will accept prepared food, 

 as fish of some kind, ground to a fine paste. In general, bass fry under 

 l^ or li inches in length are too small to take artificial food, and some 

 die before they can be accustomed to take it. 



The number of young bass to be put into a pond depends upon its 

 size and its capacity to produce food. If the nursery has been prepared 

 in advance with aquatic plants some Crustacea will be found there, and 

 the deficiency is supplied by the introduction of snails, Gammarus, 

 Gorixa, etc. The use of beef liver as food is not advised. To a nursery in 

 fair condition from 3,000 to 5,000 young bass may be allotted. The death 

 of a part of these must be expected, and if even a fair percentage are 

 to survive they must have more food than the pond can grow. Should 

 a large part of them survive the first few weeks they can be distributed 

 into other nurseries. 



At Neosho crayfish have been used for food with good results, not 

 that they have any value over other forms of aquatic life, but because 

 they are abundant, cost nothing, and are acceptable to the fish. Young 

 bass can easily be fed on any kind of fish, and all that is necessary is 

 to reduce the fish to a paste by passing it through a meat-cutting 

 machine. Carp may be cultivated for the purpose. At the Forest 

 ponds of the Missouri Fish Commission little branch chub are caught 

 and placed in the pond several weeks before the bass spawn. As the 

 chub spawn and hatch out before the bass, when the young bass are 

 transferred to the nursery they find a lot of young chub ready to be 

 eaten. An objection is that the old chubs destroy the young bass, 

 though this could be obviated by hatching the chub artificially (as can 

 be easily done) and turning only the young chub into the pond. How- 

 ever, the propensity to cannibalism in the bass should not be fostered, 

 and it is better not to feed bass, old or young, on any kind of live fish. 

 They are thus trained, while under domestication, to forego their natural 

 inclination for fish diet. 



Sometimes, even with abundance of natural food, the young prey upon 

 each, other, and they should then be thinned out by transferring a part 

 to nursery-ponds, or the entire lot remo*^ed to troughs or vats in the 

 hope of inducing them to take the prepared or natural food. As the 

 summer advances the strongest fish may be observed to grow rapidly, 

 and at the first evidence of unusual growth the fish must be sorted out 

 and those of a certain size placed in separate ponds. The successful 



