Zooplankton diversity of three floodplain lakes of the Dibru-Saikhowa Biosphere reserve, upper Assam, northeast India

Abstract

Limnological survey (October 2013–September 2015) of Maghuri, Khamti Guali and No.11 floodplain lakes (beels) of the Dibru-Saikhowa Biosphere Reserve (DSBR), upper Assam, northeast India (NEI) revealed 210 (184±4) species of zooplankton, belonging 78 genera and 32 families, with several species of global and regional distribution interest. The biodiverse zooplankton assemblage and interesting taxa are hypothesized to habitat diversity and environmental heterogeneity of these wetlands located in the Assam-gateway’- an important biogeographic corridor of India. The monthly richness and community similarities depicted heterogeneity of zooplankton composition of the individual beels. Low abundance is attributed to soft–moderately hard waters with low ionic concentrations. Zooplankton richness and abundance followed no definite pattern of monthly or annual variations; Rotifera > Cladocera influenced overall diversity in the three beels. High species diversity affirmed habitat heterogeneity, while high evenness and low dominance without quantitative importance of any species affirmed ‘generalist nature’ of zooplankton of the different beels. Our results indicated limited influence of individual abiotic factors but CCA registered moderately high cumulative importance of seventeen abiotic factors on zooplankton assemblages of DSBR beels.