Genetic population structure of the pen shell Atrina pectinata along the coastlines of China revealed by microsatellites

An ecologically and economically important species in East Asia, the natural resources of pen shell Atrina pectinate have suffered severe population declines due to habitat destruction, pollution, and overfishing. Assessing genetic diversity and population structure is the basis for establishing conservation programs for A. pectinate. Our data indicated that high genetic diversity was found in all six populations, with mean allelic richness (Ar) ranging from 8.255 to 9.734, mean observed heterozygosity (Ho) from 0.574 to 0.680, and mean expected heterozygosity (He) from 0.620 to 0.691. The five A. pectinate populations were divided into two clusters. This clustering result was partly consistent with their geographical origin; the RZ population did not cluster with the northern populations (DL, CD), suggesting that there is no genetic divergence and geographical differentiation between the North China Sea (CD, DL, and RZ) and the Southeast China Sea (HK and ST). Our results show no significant genetic differentiation between samples from the North China Sea and the Southeast China Sea. High dispersal potential of larvae by passive drift with ocean currents may explain the lack of genetic differentiation between samples. The results suggest a weak level of genetic structure in A. pectinate with a long planktonic larval stage.