Colour and thickness of nacre in four generations of Indian pearl oyster, Pinctada fucata (Gould) produced in the hatchery

Abstract

In the case of the Japanese pearl oyster, Pinctada fucata martensii, the frequency of shells with white nacre has increased to 80% in the third generation from 20% in the base population by selective breeding. In this study an increase in the percentage of thickness in pinkish-yellow (19.55), yellow (9.33) and white nacre (1.84) respectively was observed in the fourth, third and second generations respectively when compared with the first generations respectively when compared with the first generation. According to Wada (1986) the yellow coloured pearls produced from the oysters of second generation were heavier than the white ones. In the present study, the maximum thickness of nacre of yellow and pinkish-yellow colours was observed in the oysters produced in almost all generations. Based on this study it is suggested that the quality of pearls and nacre thickness of shells could be improved through selective breeding.