SURVIVAL AND GROWTH OF LARVAE OF THE EUROPEAN OYSTER (<i>OSTREA EDULIS</i>L.) AT DIFFERENT TEMPERATURES

Abstract

1. The temperature range for satisfactory growth of O. edulis larvae (70% or more of optimum) was from 17.5° to 30° C. 2. The temperature range for satisfactory survival (70% or more of optimum) was from 12.5° to 27.5° C. Even at 10° and 30° C survival was poor, perhaps, because the unfavorable temperatures weakened the larvae, making them more susceptible to bacterial toxins and diseases. 3. In these experiments approximate setting times were as follows: 17.5° C—26 days, 20° C—14 days, and at 25°, 27.5°, and 30° C beginning of setting varied from the 8th to the 12th days. 4. More spat were obtained at 20° to 22.5° C than at higher temperatures. 5. It is suggested that larvae be reared to setting size at temperatures from 25° to 27.5° C, then kept at 20° to 22.5° C during setting to obtain fastest growth of larvae and highest percentage setting. 6. Spat kept at 10° C showed virtually no growth; at temperatures from 12.5° to 27.5° C growth of spat increased with each increase in temperature.