The present investigation was carried out to the effect of dimethoate on histopathological changes in intestine of freshwater fish, Garra mullya. Fishes was exposed to sub lethal concentration of dimethoate (0.0238ppm of 96hrs.) for 7, 14, 21 days. Apart from its role in preparing and absorbing nutrients, the intestine is the first line of defense against chemical insult through oral route. Fishes exposed to dimethoate were characterized by findings revealed that the intraperitoneal administration of pesticides produced various histopathological changes which include mitotic inhibition, dead mitotic figures, loss of villi, vacuolated and pyknotic nuclei in crypts and presence of notches in villi. Vacuolation are also observed in the mucosal part of the tissue. Several breaking of villi and mucosal cell membrane. Cell necrosis is observed. In chronic treatment of dimethoate exposure may pose serious threat to fish health and affect their population.
