Effect of heavy metal toxicity on zooplankton community in fresh water ecosystem of southern Rajasthan, India

Zooplanktons are very sensitive fauna of aquatic or fresh water ecosystems; there richness and high diversity indicate healthy and unpolluted aquatic ecosystems, whiles lower abundance & richness indicate polluted water and contaminated with various types of pollutant including heavy metals toxicity. During study total nine species of zooplanktons were selected for assessing heavy metal toxicity (Zn, Cd, Pb) in different lack and rivers of southern Rajasthan. These following species namely (Brachionus, Monostyla, and Filinia belonging to Rotifers, Diaptomus, and Cyclops belonging to Copepoda, Daphnia, Ceriodaphnia and Moina belonging to Cladocera and Cypris belonging to Ostracoda were selected for assessing heavy metals toxicity in various lake. Present study observed Cadmium was the most toxic to Diaptomus, Cyclops, Cypris, Daphnia, Moina, Brachionus, Monostyla and Filinia. Zinc was found more toxic to Ceriodaphnia as compared to cadmium and lead. In general, following trend of metal toxicity was observed in relation to freshwater zooplankters: - Cadmium > Lead > Zinc.