Variation of Shell-closing Strength among Several Families in Pearl Oyster, Pinctada fucata martensii

Abstract

The variation of shell-closing strength among several pearl oyster families was investigated to determine the involvement of heredity. It became clear that shell-closing strength was significantly different between families throughout the experimental period. The mortality in the family of weak shell-closers was higher than the family of strong shell-closers. This result indicated a strong possibility that genetic factors were involved in the determination of shell-closing strength. It suggested that the shell-closing strength is useful as an indicator in the selective breeding to develop a family with high survival.