Pathologic Studies, Induced By Some stress Factors On Some Fresh Water Fish With Special Refererence To Immune System

A total of 680 apparently healthy Clarias lazera were used to determine the effect of lethal concentration dose (LCso/72 hr.) and the long term exposure of lead acetate, carbosulfan and ammonium chloride on the health status and immune response of experimexperiment for clinical signs, mortality and postmortem lesions,specimens were collected for clinicopathology, histopathological andelectron microscopical examinations after 1 S\ 2nd, 3rd day, 1 week, 2weeks, 1 month and 2 months of exposure to these contaminants. The acute lethal concentration dose (LCso/72 hr.) for lead acetate, carbosulfan and ammonium chloride were 152 mgjL, 5.2mg/L and 6800 mg/L respectively.Long term exposure: Clinically, Clarias lazera exposed to different pollutants showed unbalanced fish movements gasping, darkening of the skin and lossreflex action with 15, 10 and 3.33% mortality for the groups exposedto lead acetate, carbosulfan and ammonium chloride, respectively.Grossly, congestion of liver, kidney and spleen was evident in Clarias lazera exposed to different pollutants. Numerous hemorrhagic areas were observed on the body surface in catfish exposed to ammonium chloride.