Freshwater molluscs

Abstract

21 species of freshwater molluscs under 16 genera and 9 families are reported as occurring in Nagaland. Bivalves are rather poorly represented by 4 species, under 3 genera and 2 families. Out of these 21 species, 11 are restricted to the north-east region of India and also Myanmar. Rest of the species have all-India range of distribution. Three species, Angulyagra, microchaetophora from Dimapur, Trapezoideus dhanushori from Dhanushori stream and Sphaerium austeni from 'Naga hills' were described from Nagaland. T. dhanushori has subsequently been synomymised with T. exolescens exolescens (Gould). Only 5 species, Lymnaea ovalior, Segmentina calatha, Ferrissia viola, Trapezoideus dhanushori (= T. exolescens exolescens) and Sphaerium austeni were recorded from Nagaland in earlier literature and the rests are all recorded for the first time.