Abstract
Pollution of marine ecosystem by various xenobiotic chemicals including pesticides is of great concern, because of their high toxicity and persistence in the environment. In the present study acute toxicity of organophosphates (Malathion, Chlorpyrifos) pesticides on the marine fish (Oreochromis mossambicus) was investigated. Acute toxicity of the pesticides on marine organism was estimated by determination of the 24 hour LC50. The toxicity tests were performed separately for each pesticide. Data generated from the acute toxicity tests were evaluated using the probit analysis statistical method. The LC50 values obtained at 24 hour show that the fish were sensitive to all the two pesticides tested. The rate of mortality (%) was directly proportional to the concentration of pesticides. In the present study, we noted that Malathion was more toxic than chlorpyrifos. The result of the study suggested that organophosphates pesticides were highly toxic to fish juveniles.
