Genetic diversity of a Phascolosoma esculenta population following stock enhancement in Yueqing Bay, East China Sea

Responsible stock enhancement should aim to restore a population while ensuring uninterrupted genetic characteristics of the species. In this study, five pairs of screened microsatellite primers were used to analyze genetic diversity in a wild population (YS, before release), released population (FL), and recaptured population (HB, after release) of Phascolosoma esculenta to assess the impact of stock enhancement in Yueqing Bay. Microsatellite analysis revealed that the average numbers of alleles (Na) for the YS, FL, and HB of P. esculenta were 4.40, 5.40, and 5.40, respectively. The average effective numbers of alleles (Ne) were 2.11, 2.07, and 2.24, respectively. The average observed heterozygosity (Ho) was 0.312, 0.340, and 0.305, respectively, while the average expected heterozygosity (He) was 0.489, 0.465, and 0.496, respectively. The average polymorphic information content (PIC) was 0.425, 0.409, and 0.434, respectively. Analysis of Molecular Variance (AMOVA) revealed that most of the genetic variation was within populations. The genetic differentiation index (FST) values between the three populations were all less than 0.05. The three populations of P. esculenta all had moderate genetic diversity and there was minimal genetic differentiation between the populations, suggesting that the released P. esculenta were suitable for stock enhancement and that the current stock enhancement practices in Yueqing Bay have had no negative impact on the genetic diversity of P. esculenta.