48 



DEPARTMENT OF FISH AND GAA4E 



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Pellet blower for blowing fish food pellefs into raceway ponc/s provides better distribution of food and reduces time required in feeding. 



— Fish and Game Photo by Hal Wolf 



Trout Brood Stock Improved 



Efforts were continued to improve California's trout 

 hatchery brood stock, with much of the emphasis 

 placed on adjusting spawning periods to fit more 

 closely \\ith hatchery production schedules. 



Selective breeding and the introduction of new 

 strains have extended the spawing period. Because of 

 the small volume of water required, trout egg incu- 

 bators have proved highly successful. It is possible to 

 heat or cool water to obtain specific temperatures 

 which control the rate of egg development. 



The combination of altered spawning periods and 

 controlled water temperatures during egg incubation 

 and hatching resulted in lengthening the period of time 

 that trout eggs and fry are available to the hatcheries. 

 This improved timing permits better scheduling of 



hatchery production and assures the desired number 

 of trout of the correct size for planting when required. 



Disease Investigations 



Inland Fisheries Branch disease specialists were kept 

 busy assisting the state hatcheries with disease and 

 nutrition problems, as well as inspecting loads of live 

 fish imported from other states and at California's 

 commercial hatcheries. It is extremely important that 

 all planted trout, whether state or commercially 

 reared, be free from any disease that can be trans- 

 mitted to wild fish. 



During the biennium, 180 shipments of live trout 

 entered California from other western states. This 

 number of shipments represents approximately 1,800,- 

 000 live trout. In almost all cases the fish being im- 

 ported were in good condition. Only one shipment 



Trout ftngerlings in hatcfyery troughs being fed dry food granules v/iih a modified valve funnel. 



— Fish and Game Photo by Joe Wales 



