Effects of age on growth, survival and pearl production and traits in pearl oyster Pinctada martensii

Abstract

The present experiment reported the effects of age on growth,survival and pearl production traits of pearl oyster Pinctada martensii.The donor and host oysters were sampled each from the selected line by a two successive selection for superior growth in the base population.Pearl production traits included retention rate,pearl thickness,high quality pearl rate and pearl yield.Four groups were designed in the present experiment: A group,2-year-old individuals with nuclei-operation;B group,2-year-old individuals without nuclei-operation;C group,1.5-year-old individuals with nuclei-operation;D group,1.5-year-old individuals without nuclei-operation.Growth traits of the four groups were evaluated based on the total weight measurement data at days 15,30,60,180,270 and 450 after nucleus-inserting operation.Survival rate were evaluated among the four groups at each sampling time and retention rate,pearl thickness,high quality pearl rate and pearl yield between groups A and C were also compared at days 270 and 450.It was found that there were significant differences in body weight and survival among the four groups at days 15,30,60,180,270 and 450 after nuclei operation(P 0.05).Survival rate of groups C and D were significantly higher than those of groups A and B at each sampling time(P 0.05).The growth rates of body weight in groups C and D were significantly higher than those in groups A and B at day 450(P 0.05).At day 270 after nucleus-inserting operation,retention rate,pearl thickness and pearl yield of group C were significantly higher than those in group A(P 0.05),while the difference in high quality rate between groups A and C was insignificant(P 0.05).At day 450 after nucleus-inserting operation,retention rate,pearl thickness,high quality pearl rate and pearl yield of group C were significantly higher than those in group A(P 0.05).The present results suggest a new culture method for improving pearl quality by sampling young oyster as host oyster.