Ichthyofaunal diversity from Sonkosh river, Assam, India

The ichthyological field survey was undertaken from April 2012 to March 2013 in the river Sonkosh of Kokrajhar district, B.T.C., Assam. The river is an important tributary of the mighty river Brahmaputra in the northern bank. It portrayed 83 species of fishes belonging to 10 major orders and 26 families. Of these the Cyprinidae family with 31 species dominating the fish diversity in the river and followed by Anguillidae (1), Balitoridae (2), Cobitidae (4), Amblyceptidae (2), Bagridae (5), Siluridae (2), Schilbeidae (3), Sisoridae (5), Oliridae (2), Chacidae (1), Belonidae (1), Mastacembelidae (3), Nandidae (2), Badidae (2), Chaudhuriidae (1), Chandidae (2), Osphronemidae (1), Anabantidae (1), Belontidae (1), Channidae (6), Gobiidae (1), Aplochelidae (1), Mugilidae (1) and Tetradontidae (1). The collection contains overlapping species of true hill stream, semi torrential and migratory forms.