Seasonal variation in functional composition and diversity of cladoceran zooplankton of a lotic eutrophic habitat from India

This study explores the seasonal variation in functional composition, diversity and redundancy of Cladocera from an Indian lotic eutrophic habitat using two-year sampling data. Two seasonal clusters distinguishable by faunal and functional diversity patterns were obtained. Cluster A comprised of four functional groups while the ctenopod filter feeders were absent in cluster B. Cluster A had more number of species, higher functional divergence and lower redundancy than cluster B. Relatively, higher divergence values observed during the cluster A time period could be associated with set of functionally varied species occurring throughout the season. Decline in redundancy values seen within cluster A might be explained by the loss of littoral and benthic species in the peak of summer due to disappearance of submerged macrophytes and an increased nutrient load. Peculiar occurrence of Moina species in the most polluted months needs further investigation as a potential local pollution indicator.