Diversity, distribution and abundance of freshwater snails in Eleyele dam, Ibadan, south-west Nigeria

Abstract

Freshwater molluscs help in the assessment of the ecological status of water bodies and also play significant roles in the public and veterinary health. Hence, scientific studies pertaining to their diversity, distribution and abundance become essential. In Eleyele dam, freshwater snails were sampled and physicochemical parameters of the water body were analysed fortnightly using standard methods from May to October 2013. Plant species distribution and abundance, bottom sediment types were also identified. A total of 2230 freshwater snails were collected. The snail species, total number and relative abundance were: Melanoides tuberculata 450 (20.18%), Potadoma liberiensis 301 (13.49%), Biomphalaria pfeifferi 37 (1.66%), Indoplanorbis exutus 456 (20.45%), Bulinus globosus 18 (0.81%), Gabbiella africana 53 (2.38%), Lymnaea natalensis 386 (17.31%), and Physa marmorata 529 (23.72%). 4 out of these 8 species are of medical importance. The study revealed that the density of freshwater snails varied monthly and spatially and that the diversity and distribution of the malacofauna of Eleyele dam were mostly influenced by the presence of plants Eichhornia crassipes and Nymhaea lotus, water depth, alkalinity, total dissolved solids, total hardness, and conductivity. The presence of a high number of snail species of medical importance indicates that the people participating in various activities on the dam are predisposed to infections harboured by these organisms.

Keywords:

• Abundance
• bottom sediments
• distribution
• ecological factors
• Eleyele dam
• freshwater snails

Acknowledgment

Special thanks to the entire staff of Nigeria Institute of Oceanography and Marine Research for making their laboratory accessible to me for my laboratory work and also to the entire staff of the Department of Zoology, University of Ibadan, Ibadan.