Population structuring and historical demography of a common clam worm Perinereris aibuhitensis near the coasts of Shandong Peninsula

► We investigate the phylogeography of Perinereris aibuhitensis using mtDNA COI sequence. ► The haplotype diversity and nucleotide diversity were low. ► The common haplotypes showed obvious associations with sampling sites. ► Significant genetic differentiations were found among the populations. ► The populations likely experienced recent bottleneck or selection.