Precocious Gonad Development in Oysters Induced in Midwinter by High Temperature

Abstract

Oysters (Ostrea virginica) were brought in from near-freezing temps. and exposed to gradually rising temps. which finally attained 20[degree], 25[degree] or 30[degree] C. After 20 days exposure to 20[degree] C, several oysters developed eggs and a few developed active sperm. This development was more advanced at 30 days. Oysters exposed 1 month to 25[degree] or 30[degree] C developed gonads comparing favorably with development under natural summer conditions. Their isolated eggs placed in sea water were fertilized and normal larvae developed and survived several days.