Polymorphic variation in edible freshwater snail species Filopalundina bengalensis (Lamarck, 1822) in Nepal

Abstract

Freshwater snail Filopaludina bengalensis (Lamarck, 1822) from 17 different parts of Nepal particularly from terai region including some middle hill districts were analyzed by clustering for the shell morphological variability. This study demonstrates the likelihood of the snail population variations in the shell shape, size, colour bands and operculum structure. In this study, the range of shells was from 7.94 mm to 43 mm with the maximum size 43 mm from Budhi Khola, Itahari. However, the maximum size of operculum was found 20.38 mm from Dhongrahuwa lake, Kailali. All analyzed samples were grouped in four clusters with some exceptions. Most of the samples from East, West and Central Nepal formed separate clusters; however, large numbers of samples from all sites were grouped into fourth cluster. This analysis indicated that Filopaludina bengalensis is a species complex with the typical bengalensis falls in the largest cluster and their might be more than one species in other clusters. But further analysis with more morphological and anatomical data along with molecular information is required for the conformation of species complex status.