Rotiferan Community Structure in a Tannery Effluent Stabilisation Pond in East Calcutta Wetland Ecosystem

摘要

Nine rotifer species were observed to thrive in a fishpond fed by tannery effluents. Several Brachionids were observed to be highly tolerant to different adverse physico-chemical conditions. like very high TDS (1080-2360 mg l~(-1)), TSS(319.0 mg l~(-1)), BOD (202.5 MG l~(-1)), COD (11401 mg l~(-1)), chloride content (550-1200 mg l~(-1)) besides several metals like Cr (0.05 mg l~(-1)), Pb (1.0 mg l~(-1)), Zn(0.02 mg l~(-1)), Mn (1.0 mg l~(-1)), Cu (0.2 mg l~(-1)), Mg (0.14 mg l~(-1)) and Fe (3.5 mg l~(-1)), Further, significant negative correlation between water temperature and illoricate forms on one hand and positive correlation between water temperature and loricate rotifers was noted. Asplanchna intermedia and A brightwelli were the two hardy. predatory, illoricate species observed in the fishpond. Corelations between the populations of different rotiferan species and physico-chemical factors were noted. Different indices for the rotifer community structure were calculated. Stressful physico-chemical conditions apparently regulated the population size as well as species diversity.