LAUSR

Simple Summary This study investigated the genetic diversity and connectivity of 15 Ocypode ceratophthalmus populations in the East and South China Seas based on two genetic markers. The results showed that O. ceratophthalmus had a high genetic diversity among all collected populations, and an insignificant population structure was observed by a hierarchical analysis of molecular variance and fixation index. Additionally, Migrate-n revealed high historical gene flow and migration rates among populations. The results of this study could inform the construction and management of marine protected areas in the East and South China Seas. Abstract The East and South China Seas are rich in marine resources, but they are also under great pressure from climate change and human activities. Maintaining diversity and connectivity between communities is thought to be effective in mitigating these pressures. To assess the diversity and connectivity among the populations of Ocypode ceratophthalmus in the East and South China Seas, 15 populations from or near 15 marine protected areas in the two seas were studied using COI and D-Loop as genetic markers. The results showed that O. ceratophthalmus populations had high diversity, and the results of a hierarchical analysis of molecular variance and fixation index found that there were no significant genetic structures among these populations. High historical gene flow and high migration rates were further observed among populations by Migrate-n. Furthermore, the COI sequences further showed the asymmetric migration rate with a higher migration rate from south to north than from north to south. This information could provide recommendations for the management of marine protected areas in the East and South China Seas.