In aquaculture, good germplasm resources are nearly decisive for its development. The hard clam ( Mercenaria mercenaria ), a significant marine aquaculture bivalve in China, has flourished quickly since being introduced from North America in 1997. However, for numerous reasons, it has suffered from germplasm deterioration and uncertain origins. To address these issues, seven microsatellite DNA loci (SSRs) and mtCOI were employ...