STUDIES ON TOXICITY EVALUATION OF DIMETHOATE ON THE FRESHWATER FISH RASBORA DANICONUS WITH SPECIAL REFERENCE TO THE GILL HISTOPATHOLOGY

Abstract

: The acute toxicity bioassay of dimethoate was carried out by the probit analysis method. The 24, 48, 72 and 96 h LC50 values were obtained as 11.63, 10.08, 10.54 and 9.136 ppm respectively. In the present investigation the effect of dimethoate on the gill of Rasbora daniconius at 96 hours LC50 marked histopathological changes found like degeneration of epithelium of secondary gill lamellae, vacuolation, fusion, shortening of secondary gill lamellae, thickness and fusion of primary and secondary gill lamellae