Effects of Stocking Density on Hatching, Growth, Survival and Metamorphosis at Larval Stages of Pearl Oyster Pinctada maxima

LIANG Feilong; WANG Qingui; DENG Yuewen; XIE Shaohe

Abstract：In order to determine the appropriate stocking density of egg and larvae of pearl oyster Pinctada maxima at different developmental stages during hatchery production,four experiments were carried out to investigate the effects of stocking density on early performances of pearl oyster Pinctada maxima.In Exp Ⅰ,the effects of fertilized egg density on hatching rate and growth of D-shaped larvae were investigated.The densities were set at 10,20,30 and 40 eggs/mL.In Exp Ⅱ,the effects of D-shaped larvae density on growth and survival rate were investigated.The densities were set at 1.0,2.0,3.0 and 4.0 larvae/mL.In Exp Ⅲ,the effects of umbone larvae density on growth and survival rate were investigated.The densities were set at 1.0,1.5,2.0 and 2.5 larvae/mL.In Exp Ⅳ,the effects of eye-spotted larvae density on growth and metamorphosis rate were investigated.The densities were set at 0.4,0.8,1.2 and 1.6 larvae/mL.The results showed that effects of densities of fertilized egg on hatching rate (P＜0.05) were significant.However,the effects of densities of fertilized egg on growth of D-shaped larvae were not significant (P＞0.05).The effects of stocking density on growth and survival rate of D-shaped and umbone larvae were significant (P＜0.05).Growth and survival rate of D-shaped and umbone larvae decreased with increasing density.The effects of stocking density on growth and metamorphosis rate of eye-spotted larvae were significant (P＜0.05).The present results suggest that the optimal densities of fertilized egg,D-shaped,early umbone and eye-spotted larvae should be 10-30 eggs/mL,1.0-3.0,1.0-1.5 and 0.4-0.8 larvae/mL,respectively,in the hatchery production of pearl oyster Pinctada maxima.