Seasonal gonadal changes of adult oviparous oysters in Tomales Bay

• Main Author: Berg, Carl John
• Format: Text
• Language: unknown
• Published: Scholarly Commons 1968
• Subjects: Oysters California Tomales Bay; Gonads; Animal Sciences; Biology; Life Sciences; Crassostrea gigas
• Online Access: https://scholarlycommons.pacific.edu/uop_etds/1656; https://scholarlycommons.pacific.edu/cgi/viewcontent.cgi?article=2655&context=uop_etds

Two species of oviparous oysters, Crassostrea virginica (Gmelin, 1790), the Eastern oyster, and Crassostrea gigas (Thunbert, 1793), the Japanese oyster, were introduced into Tomales Bay, California, for commercial purposes. Because these oysters do not propagate in Tomales Bay, new shipments of adult oysters or oyster spat must be periodically sent from the east coast of the United States or from Japan. It is the purpose of this study to compare the seasonal gonadal changes which occur in the two species of adult oysters in Tomales Bay with one another, and to compare them with the seasonal gonadal changes which occur in the same species of oysters in other regions. The differences in gonadal changes will be related to variances in environmental conditions and to specific or racial characteristics. The introduction of oysters into a new environment is valuable for both commercial and scientific reasons. Although it has long been known that C. virginica and C. gigas do not propagate in Tomales Bay, no one has ever done a detailed study of their reproductive cycle or the seasonal histological changes in their gonads. This study, therefore, extends the knowledge concerning an oyster's reaction and adaptation to its new environment.