A METHOD OF CULTIVATING RAINBOW TROUT AND 

 OTHER SALMONOIDS. 



By CHARLES L. PAIGE. 



CLAIMS OF THE METHOD. 



The experiments here described were conducted on Boulder Creek, in the 

 Shasta Mountains, in Shasta County, Cal., in water to which the rainbow trout 

 is native, under most favorable conditions for studying the fish and its habits. 

 The experiments were made independently, with a view to determining a method 

 for propagating trout without stripping the fish and resorting to the process of 

 hatching the eggs artificially. 



The claims established by the results of these experiments are: 



1. That the rainbow trout (Salmo irideus, and probably nearly all the 

 genus Salmo) will readily deposit their spawn in runs or races properly arranged; 

 that after spawning the fish may be excluded from the runs or races, to prevent 

 egg eating and cannibalism ; that the water can be regulated under control while 

 the eggs are in process of incubation where naturally deposited by the parent 

 fish; that a high percentage of the eggs will produce hardy fry without other 

 care than the proper regulation of the flow of water in the race and the exclusion 

 of such fish or animals as prey upon the eggs, embryos, or young fish. 



2. That when the fry appear, as they swim from the nests of the spawning 

 beds of the race, they may be readily diverted into nursery pools connected 

 with the race without any handling whatever, and that they may be there cared 

 for and fed, if necessary, more advantageously than they can be in troughs or 

 crowded colonies. 



3. That pools made ready and filled with water for some months before the 

 fry hatch will accumulate natural food for the fry, and where they are con- 

 nected with an open race of running water this food supply is continued by the 

 natural succession of aquatic and insectiverous food that is denied to fry hatched 

 and held under artificial methods. 



4. That the fry, having more water area, more varied and natural con- 

 ditions in the flow of water — such as swift water, shallows, and depths — are not 

 forced to constant struggles ; that in an adequate race with side pools they have 

 natural foraging area and may follow their instinct of independent exploration 

 and solitary habits. 



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