Background Amphioctopus aegina
is an important fishery resource distributed in the coastal waters of China. However, the genetic variation and population genetic structure of it have never been investigated, to date.
Methods
In the present study, the genetic diversity and population genetic structure among the four A. aegina populations across its full distributional range in China were assessed based on the mitochondrial cytochrome oxidase1 (COI) sequences.
Results
The results revealed a remarkably low genetic diversity (Hd: 0.2842–0.6670; pi: 0.0007–0.0015) in A. aegina populations. The neighbour-joining (NJ) phylogenetic tree and the haplotype networks constructed, as well as the results of molecular variance (AMOVA) analyses, indicated a shallow phylogeographic structure among the four populations. However, pairwise genetic differentiation coefficient (ΦST) statistics and genetic distance analyses revealed significant (p < 0.01) genetic differentiation among Qinzhou and the rest three populations of Zhanjiang, Huizhou, and Dongshan. The demographic history analyses indicated a population expansion in A. aegina, and the role of Leizhou peninsula isolation in shaping the population differentiation.
Conclusion
These results would largely enhance our understanding of the genetic structure and promote the scientific management of A. aegina fishery resources in coastal waters of China.