A. STALIN, M. SAIYAD MUSTHAFA AND B. AMANULLAH
Abstract
In the present study the freshwater mussel Lamellidens marginalis was exposed to sub-lethal concentration (5 ppm) of an organophosphorus insecticide, chlorpyrifos for 30 days. Mussel gill cells are attractive models in ecotoxicological studies because gills are the first uptake site for many toxicants in the aquatic environment; gill cells are thus often affected by exposure to pollutants. The gills of the mussels were dissected out and processed for light microscopy studies. Chlorpyrifos exposed mussels were found to result in several alterations in the histoarchitecture of gills. The alterations included: the bulging of primary filament gill tips, curling of secondary filament, fusion of gill lamellae, hyperplasia, necrotic and clavateglobate lamellae of the gills. The results suggest that the gills of mussels exposed to chorpyrifos were structurally altered. Such alterations could affect vital physiological functions, such as respiration, nutrient uptake and ionic regulation of the gills, which turn could ultimately affect the growth and survival of Lamellidens marginalis.