Species composition and distribution of brachyuran crabs in Duyen Hai town, Tra Vinh province

Abstract

Brachyuran crabs are the most diverse group of crustaceans. They are found in most marine habitats such as coral reefs, sandy beaches, rocky beaches, mangroves, and seagrass meadows. In this study, we investigated the species composition of brachyuran crabs at 10 sampling locations belonging to three habitats (mangrove forest, artificial dykes, sandy beaches) at Duyen Hai town on August (rainy season) and December (dry season) in 2017. We found that there were 22 species belonging to 10 genera of six families present in the research area. The Ocypodidae family is the most abundant, with 45.5% of the species, following by the Grapsidae (22.7%), Sesarmidae (13.6%), Portunidae (9.1%), Matutidae (4.5%), and Xanthidae (4.5%). The densities of brachyuran crabs ranged from 2.0±1.1 (inds/m²) to 17.2±4.3 (inds/m²). The mangrove forest habitat showed a greater diversity of species than the sandy beach and artificial dyke habitat. The rainy season supported greater diversity than the dry season.