Toxicological alteration of Dimethoate (rogor) insecticide against freshwater fish Colisa fasciatus and Mystus mystus

Like other organophosphates, dimethoate is an acetylcholinesterase inhibitor which disables cholinesterase, enzyme essential for central nervous system function. Dimethoate insecticide can be used both indoor and outdoor purposes to eliminate a number of insect pests under different condition. Dimethoate, one the most extensively studied pesticides, may induce many significant changes in fishes. The aim present study determine toxicological action on freshwater teleost has shown strong piscicidal activity fish Colisa fasciatus Mystus mystus all exposure periods (24 or 96h) time as well dose dependent manner. LC50 values decreases from 0.084 ppm (24h) 0.059 (96h) winter season (water temp.19⁰) 0.028 0.010 summer temp. 23⁰). 0.039 0.022 against mystuus 0.040 0.015 season. pesticide also fatal non- targeted organisms like where it hampers its health through impairment metabolism, occasionally leading death fish.