Population genetic diversity of mud crab (Scylla paramamosain) in Hainan Island of China based on mitochondrial DNA

In this paper, we analyzed population genetic diversity of Scylla paramamosain in Hainan Island of China based on COI gene sequence. Totally 92 individuals were collected from six localities: Haikou, Wenchang, Wanning, Sanya, Dongfang and Danzhou. A 761 bp fragment was sequenced, defining 32 different haplotypes. H4 was the most frequent haplotype, existing in all six localities, while the majority of haplotypes were rare ones, existing in only one or two individuals. Haplotype diversity (h) and nucleotide diversity (π) ranged from 0.625 to 0.914 and from 0.001 to 0.003, with an average of 0.841 and 0.002, respectively. Genetic distance ranged from 0.001 to 0.003 within localities and from 0.002 to 0.003 between localities. The AMOVA analysis indicated a low level of genetic differentiation among six localities (F_ST = 0.0176, P > 0.05). Neutrality tests and mismatch analysis implied a potential population expansion event for this crab species.