The distribution pattern and biodiversity conservation of freshwater crabs in hainan island

Abstract

Aims: The biodiversity of tropical islands is a popular topic in global biodiversity conservation research. Hainan Island is the largest tropical island in China. Freshwater crabs are a keystone species for freshwater ecosystems in Hainan Island. The aims of this study were thus to identify the distribution pattern and assess the threat status of freshwater crabs in Hainan Island. Methods: In this study, we used field surveys and conducted a literature review to investigate the species diversity and conservation status for freshwater crabs in Hainan. Results: Our results indicate that the diversity hotspots for freshwater crab species on Hainan Island are located in the south-central mountainous area (especially Bawangling, Yinggeling, Mihouling, Wuzhi Mountain, Diaoluo Mountain and Jianfengling). Freshwater crab diversity is higher in the central and southern mountains and lower in the plains. According to the IUCN Red List Categories and Criteria, 16.7% of freshwater crab species on Hainan Island are y threatened. Diversity conservation effectiveness analyses demonstrate that the Hainan Tropical Rainforest National Park system as leading part of Hainan’s protected area system is better than the previous system (which was several fragmented nature reserves) for covering the potential distribution areas of freshwater crabs. Overall, conservation status for freshwater crabs in Hainan Island is favorable, but some species are threatened. Conclusion: The establishment of the national park system is expected to provide unprecedented opportunities for the conservation of freshwater crab species diversity in Hainan Island. Monitoring freshwater biological diversity based on the distribution pattern of species diversity will promote the long-term protection and sustainable development for freshwater ecosystems on Hainan Island.