THE EFFECT OF TEMPERATURE ON PRODUCTION OF GONADS BY THE SEA-URCHIN STRONGYLOCENTROTUS-FRANCISCANUS FED NATURAL AND PREPARED DIETS

Strongylocentrotus franciscaltus (248 +/- 76 g wet body weight, mean a nd standard deviation) were maintained in the laboratory at 12.9 and 1 6.1 C and fed either Nereocystis luetkeana or a prepared feed for 4 mo (July through October), The size and histological condition of the go nads of an initial sample, the experimental animals, and a sample from the commercial fishery were evaluated, The gonad index of experimenta l S. franciscanus increased from an initial 3.4% +/- 1.4 to 19.2% +/- 3.3 (mean and standard deviation) for the four treatments, The feeding rate was greater for individuals fed N. luetkeana and for both foods at the higher temperature. Gonad production was not significantly diff erent among the experimental treatments, indicating the prepared feed was nutritionally superior to the algal diet and an increase in catabo lism at the higher temperature balanced the increase in food intake, H istological preparations determined the urchin gonads developed from a n initial spent condition to the premature stage for both experimental and fishery samples, indicating neither food or temperature affected gametogenesis.