• Version
• Download 5
• File Size 254.46 KB
• File Count 1
• Create Date 17 June 2023
• Last Updated 17 June 2023

Study of effects of an organophosphorus pesticide, malathion (50% EC) on the freshwater fish, Cirrhinus Cirrhosus(Mrigal)

Dr. S . R . Shaikh

Abstract

Malathion is a wide spectrum aliphatic organophosphorus pesticide commonly used for agricultural purposes. In the present study, an attempt was made to study the acute toxic effects of malathion in the adult freshwater fish,Mrigal. The median lethal concentration or LC50-96 h was determined by exposing the fish to six different concentrations of malathion i.e., 0.25, 0.50, 0.75, 1.00, 1.25, 1.50 μg/ L concentrations for 96 h along with the control group, without toxicant. The weight of the animals was recorded before and after exposing to the pesticide, which showed no significant changes after the treatment period. Behavioural modifications of the fish such as frequent surfacing and air engulfing, irregular erratic swimming, aggressiveness, rapid opercular lifting along with slight haemorrhage and mucous deposition throughout the body were noticed. The study proved that an increase in the malathion concentration for 96 h caused increase in the rate of mortality in which 50% mortality occurred at 0.5 μg/ L concentration, which was taken as the median lethal concentration or LC50-96 h. The data obtained was subjected to Probit analysis at 95% confidence limit also proved 0.5 μg/ L concentration as 96 h-LC50 value of malathion in the fish, Mrigal.

Keywords: Malathion, mortality, behaviour, Mrigal.