ACUTE TOXICITY OF OIL EEFLUENT AND ITS METABOLISM IN DIGESTIVE GLAND TISSUES OF FRESHWATER MUSSEL, LAMELLIDENS MARGINALISBALAMURUGAN S. AND SUBRAMANIAN P.Abstract Acute toxicity test using the freshwater mussel, Lamellidens marginalis were conducted on oil effluent. Tentative preliminary test were conducted to fix the minimum concentration of the oil effluent. The test revealed that 96-hr LC50 total hydrocarbons was (upper level) 11.88 ppt and (lower level) 8.55 ppt. Based on this test, two sub-lethal concentrations 1/4th and 1/10th of LC50 were prepared and exposed to mussels. Hydrocarbon showed gradual increasing trends from Ist day (8.47±0.43 μg g-l) and maximum attained at 30th day (43.7±0.67 μg g-l) in both concentrations. More than 5 fold higher accumulation level of hydrocarbons were observed on 30th day, when compared to first day. Positive and significant regression coefficient (P<0.05) were observed. Approximately 90% of accumulated hydrocarbons were eliminated in 22nd days during depuration study. Significantly decreased (P<0.05) and negative regression coefficient observed in depuration study. Evidence indicates that concentration of hydrocarbon, duration of exposure; may influence patterns of accumulation and release of hydrocarbons in mussel. |