Toxicity study of pesticide to fish in simulated paddy field

Abstract

Endosulfans are being used to determine acute toxicity of pesticide towards fishes at different concentrations at normal water condition and in simulated paddy field condition. This paper also investigates the effect of initial pesticide concentration on fish’s behavioural changes. The acute toxicity of endosulfan in puyu (Anabas testudineus sp) with 13.3625 cm +/- 0.9 cm length and 45.625 g +/ - 9.0 g weigh was evaluated in aquariaum tank under static conditions within 96 hours exposure period. Before acute toxicity test, acclimatization period within 7 days was carried out to make sure fish samples can adapt the change of surrounding environment and the quality of water being checked daily. Three concentrations of endosulfan used were 20, 35, 50 μg/L. The concentration of endosulfan killed 50% or LC50 of the fish was 39.72 μg/L in normal water condition but LC50 can be used in simulated paddy field due to percentage of mortality did not exceed 50%. None of the unexposed control fish died, and almost all tanks shown death of fishes after 12 hours of exposure to endosulfan. Mortality of fishes was significantly increased with the increased amount of concentration for the same volume of water. Changes of behaviour were recorded after being exposed to edonsulfan. The behavioural changes were observed based on condition of fish, swimming behaviour, the aggressive behaviour, and colour changes.