Behavioral and morphological changes in a freshwater fish, Labeo rohita exposed to tannery industry effluent

Acute toxicity of the tannery industrial effluent was determined for 96h period against Labeo rohita. The LC50 value of effluent was calculated by Finney method (1971). Three sublethal concentrations 3.53%, 1.76% and 0.88% were selected on basis of (1/2, 1/4, 1/8) of LC50 value. Various behavioral and morphological changes were observed in the three sublethal concentrations for 96h. Behavioral changes include erratic swimming, gulping of air, opercular movement, loss of equilibrium, restlessness and sluggishness. Morphological changes like loosening of scales, sinking of eyeball, redness of eye, profuse mucous secretion, bleeding from gills and haemorrhages were recorded. Concentration 3.53% proved to be highly toxic whereas 1.76% and 0.88% concentrations cannot be ignored because they also induced changes in behaviour and morphology of fishes. Con- trol fishes were also continuously monitored and compared with the changes caused by effluent in each concentration.