Histopathological, Hematological and Genotoxic Study on Channa punctata (Bloch 1793) Treated with a Sub-Lethal Dose of Organophosphate Pesticide Malathion

Application of pesticides could represent a contaminant source for the aquatic environment and thus affect aquatic fauna. Fish are often used as indicators of pesticide water contamination. Therefore, the present study deals with the effect of Malathion, an organophosphate insecticide, on the histological, hematological (total leukocyte count), and genotoxic study on a freshwater teleost Channa punctata. In the present study, the effect of a sub-lethal concentration of 1.3 ml/L of Malathion (1/5th of LC50) for 24, 48, 72, and 96 hrs on hematological changes (total leukocyte count), Histopathological changes in gill, liver and kidney and genotoxic effect through micronucleus test of C. punctata was studied. The WBC count increased during the study’s exposure period. Structural variations like epithelial lifting, fusion and curling of secondary lamellae, hyperplasia in secondary lamellae, and aneurysms were observed in fish gills; distended sinusoids, necrosis and vacuolation in the fish liver were observed. Moreover, necrosis, vacuole formation, degeneration of tubular epithelial cells, degeneration of interstitium, and necrosis in hematopoietic tissue were observed in the kidney of C. punctata. The mean frequency of micronuclei induction increased with the exposure time, which was the highest in 96 hrs of treatment.