A Study on Distribution of Brachyuran Crabs Inhabiting the Intertidal Coral Reef and Mangroove Ecosystem of Andaman Islands

Abstract

Abstract The present study documents the systematics, taxonomy, distribution, and ecological characteristics of brachyuran crabs inhabiting the intertidal, coral reef and mangrove ecosystems of the Andaman Islands. A total of 28 species belonging to 10 families were recorded during the survey. Among the collected specimens, the family Xanthidae was the most prevalent, represented by 11 species, followed by Portunidae with three species, Carpiliidae with two, and the remaining families represented by a single species each.. The results revealed habitat type significantly influenced crab distribution, with rocky intertidal zones supporting higher species richness than sandy habitats due to the greater availability of shelter and food resources. Environmental factors such as salinity, tidal fluctuations, substrate characteristics, and anthropogenic disturbances were found to play important roles in determining species abundance and distribution patterns. Several species exhibited notable ecological adaptations, including camouflage, burrowing behaviour and specific habitat preferences, which enhance their survival in the dynamic intertidal environment. The study also identified species of ecological and economic significance, while some species were considered less important for consumption due to their small size or toxicity. Overall, this study provides baseline information on the taxonomy, systematics, ecology, and distribution of intertidal brachyuran crabs in the Andaman Islands and highlights the importance of conserving intertidal and coral reef habitats to maintain biodiversity and ecosystem stability.