Richness, abundance and ecology of zooplankton in a tropical floodplain lake of majuli river island, Assam, (N. E. India)
Mrinal Kumar Hatimuria, Nogen Noroh
Plankton samples collected (September, 2010–August, 2012) from Chela beel of Majuli River Island of Assam, N.E. India, revealed a total of 95 zooplankton species with diverse nature of Rotifera (59 species). This floodplain lake exhibited fairly rich species diversity and indicated a monthly richness between 36 – 56 (44±7) species and 36 – 59 (46±7) species during the first and second year respectively, with nearly identical ranges of community similarities during both the years. Cladocera and Rhizopoda formed the sub-dominant qualitative groups in the sampled floodplain lake. Zooplankton abundance ranged between 123–242 (184 ± 27 n/l) during the study period; it formed the sub-dominant quantitative component of net plankton in the sampled beel both during the first year (36.9±5.0%) as well as during the second year (38.1±3.7%). Rotifera > Rhizopoda mainly influenced zooplankton density variations in the sampled floodplain lake. Richness and abundance of zooplankton registered both insignificant annual as well as monthly variations in the sampling site. Zooplankton communities of the sampled floodplain lake are characterized by higher species diversity, higher equitability and lower dominance. Richness of zooplankton of Chela beel registered a significant negative correlation with rainfall and a significant positive correlation with magnesium while their abundance is significantly inversely correlated with water temperature. The canonical correspondence analysis (CCA) of zooplankton with 17 abiotic parameters recorded 84.4% cumulative variance of zooplankton assemblages.
Mrinal Kumar Hatimuria, Nogen Noroh. Richness, abundance and ecology of zooplankton in a tropical floodplain lake of majuli river island, Assam, (N. E. India). International Journal of Ecology and Environmental Sciences, Volume 3, Issue 1, 2021, Pages 114-121