Diversity of freshwater crabs (Crustacea: Decapoda: Brachyura) in the Subansiri River basin of Arunachal Pradesh and Assam, northeast India

Abstract

Crabs are significant invertebrates in the Subansiri River basin, one of the major sub-basins of the Brahmaputra valley in northeast India. They have immense ecological and economic value and provide an alternative source of income for the local inhabitants. Following thirteen sites in the Subansiri River basin were surveyed to determine the availability and diversity of crab species in this region: Hatinala, Kalma river, Dikrong river, Senki river, Poma river, Harmuti, Ranganadi river dam site, Diju stream, Lower Subansiri river, Downstream Ranganadi, Pani gaon wetlands, Bosa gaon beel, and Bhelamora beel. Crab samples were collected using a random sampling method and identified using standard taxonomic keys. Seven species from two families were identified and distinguished by their morphology and habitat preferences: Sartoriana spinigera, Sartoriana trilobata, Maydelliathelphusa lugubris, Maydelliathelphusa harpax, Liotelphusa laevis (Gecarcinucidae) Lobothelphusa woodmasoni, and Acanthopotamon horai (Potamidae). These crabs are thought to be endemic to the Eastern Himalayan region due to their limited dispersibility. This is the first study aimed at contributing to the documentation and conservation of freshwater crabs in North East India. Additionally, the economic relevance of freshwater crabs is highlighted.