Triploid induction by hyperosmotic shock in the Yesso scallop, Patinopecten yessoensis

The triploid technology is a new frontier in shellfish aquaculture and has shown encouraging results in numerous shellfish species. We induced triploid larvae in the Yesso scallop, Patinopecten yessoensis, using hyperosmotic shock for the first time in this study. Different induction parameters, including salinity strength, treatment starting point, and the duration, were tested. The highest triploid ratio of D-shaped larvae (72.12%) was obtained by 60 ppt salinity treatment for 20 min at the first appearance of zygote showing polar body II (PB2). A significantly faster growth rate was observed during the swimming larvae stage despite a decrease in the hatching and survival ratios. The triploid ratio decreased to 46.67%, and approximately 1.76 million triploid juveniles were harvested after 90 days of cultivation. The treatment parameters can be further optimized to improve the yield of Yesso scallop triploids.