Comparing diversity of freshwater macroinvertebrate community along habitat gradients within a riverine system in North Bengal, India

Abstract

The main aim of the study was to estimate macroinvertebrate species diversity and overall beta-diversity with respect to interrelationship of environmental gradients-substrate types in some river streams of Jalpaiguri and Darjeeling district, West Bengal. Macroinvertebrates were collected by D-shaped net sampling-hand picking method and field measurements were recorded for one year from November 2013 to October 2014. A total of 1,500 individuals belonging to 39 families distributed in nine different study sites. The results indicated the tendency of species densities towards higher habitat substrates, air temperature and water temperature. Site Teesta, which was found to have highest beta diversity at the level of beta-dissimilarity matrix (0.8-0.89) and Whittaker beta-diversity (27.5), which was significantly negatively correlated with species density (r=-0.936), air temperature (r=-0.773) and water temperature (r=-0.878) and significantly positively correlated with sand (r=0.726) from rest of study sites. Thus habitat characteristics control macroinvertebrate species abundance and diversity.