FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

This study conducted an experiment on artificial propagation of Venus clams, Tapes literatus and cultivation of juvenile clams. In addition to the observation of embryonic development, the effects of abrupt salinity changes (0, 5, 10, 15, 20, 25, 30, 35, 40, 45 psu) on survival rates of juveniles were also examined. At water temperature of 28℃ and salinity of 32 psu, fertilized eggs of T. literatus developed into 2-cell stage 1.5 hours after fertilization, 4-cell stage after 4 hours, 8-cell stage after 6 hours, 16-cell stage after 8.5 hours, 32-cell stage after 10.5 hours, Morula stage after 12 hours, Blastula stage after 14 hours, Trochophore stage after 17 hours, Veliger stage (D-shaped larvae) after 31 hours, Pediveliger stage after 9 days, and settled juveniles after 14 days. The survival rate of juveniles cultured in 33 psu water was 0% after 72 hours after being transferred to salinity of 10 psu. The survival rates after 72 hours were 76.6% at salinity of 15 psu, 100% at salinity of 20-30 psu, 96.6% at salinity of 35 psu, 93.3% at salinity of 40 psu, and 80% at salinity of 45 psu.