Abstract
The rearing of entire stages of the pen shell Atrina pectinata larvae was conducted and 1,484 juveniles were obtained. The survival rate of larvae at the settlement was approximately 0.04%. The settlement and metamorphosis to juveniles was observed from 35 to 42 days post-hatch and the average larval shell length at settlement was 514.1±25.9μm. When crushed mature ova prepared from pacific oyster, pen shell and abalone were added into the diet, growth and survival rate of larvae during transition from D-shaped to umbo larval stage were significantly higher in the experimental group as compared to the control group, which were fed only algae. The use of crushed mature ova as a supplement of the conventional algal feed seemed to reduce mortality that occur during the transition from D-shaped to umbo-stage larvae and resulted in increased settlement. Juveniles grew rapidly and the average shell length reached 26.0±5.5 mm at 72 days post-hatch in indoor rearing. Continued indoor rearing resulted in a stagnant growth and mortality, and survival rate was 55% at 118days post-hatch. By contrast, survival rate was 100% and average shell length reached 64.3±5.3 mm at 133 days post-hatch when juveniles were reared in a sand-filled container suspended at sea from 83 days post-hatch.
