D. Selvaraj

ABSTRACT

The textile effluent has been proved to impart adverse effects on the aquatic environment and its fauna. The aim of the present study was to determine the lethal concentration of a textile industry effluent to the freshwater fish Poecilia reticulata by toxicity bioassay method. The LC50 values of the effluent for 6, 12, 24, 48, 72 and 96 hours were found to be 73.081, 67.030, 60.398, 55.521, 49.211 and 39. 726% respectively. The fishes exhibited abnormal behaviors including erratic swimming, hyper-excitation, rapid opercular movement and thick mucus covering which indicated the toxicity of the effluent. The effluent induced histopathological changes also. The primary gill bar was enlarged and secondary gill bar was detached. Liver showed cytoplasmic vacuolation and clustering of nuclei whereas in the intestine disintegration of intestinal villi and infiltration of haemocytes into the lumen was seen.