HEPATOMAS IN RAINBOW TROUT: DESCRIPTIVE AND EXPERIMENTAL EPIDEMIOLOGY.

Four ingredients of a dry diet, Santa Monica, and a special food supplement, were tested for their effects on the occurrence of hepatomas in Salmo gairdnerii. When cottonseed meal was omitted from the diet, no hepatomas developed in the experimental fish. When the same diet with its usual cottonseed meal component was fed, 48 percent of the fish developed hepatomas.