A comprehensive study on correlation of gastropod diversity with some hydroenvironmental parameters of selected waterbodies of lower Damodar basin, West Bengal, India

Abstract

Gastropods, an important group of mollusc, inhabitants of sediment-rich bottom zone have evidentiary role in freshwater ecosystem. Their community structure has been influenced by the water and soil quality parameters. Under the scenario of intensive agricultural practice and fast urbanization waterbodies particularly the ponds of lower Damodar basin in Howrah district, West Bengal, India are badly affected by growing pollution load. In current study, three lentic waterbodies i.e Shiberjala pond, Nayachak Wetland and Dhasa Waterbody were chosen to assess the gastropod diversity. Selected physico-chemical parameters including Temperature, Dissolved Oxygen, pH, Free Carbon di oxide, Nitrate and Phosphate of all three waterbodies were determined also. Dhasa Waterbody containing 7 species, exhibited highest species richness. The density and species richness showed spatial variation among study sites. Bellamya bengalensis was the dominant species found at all study sites. Melanoides tuberculata in spite of their absence in Shiberjala pond, appeared to be the second most dominant species. Brotia sp and Bithynia sp was the least abundant species. Gastropod species richness showed significant negative correlation with DO level(r=-0.705, P<0.05).Nitrate level was significantly positively correlated(r=0.474, P<0.05) with gastropod species richness and density. Phosphate level (r=0.33) also positively correlated with gastropod richness.