Determination of Acute Toxicity of Metasystox among Freshwater Fish, Nemacheilus botia from Kedrai Dam in Maharashtra, India

This chapter primarily focuses on the acute toxicity of Metasystox on the freshwater fish, Nemacheilus botia from Kedrai dam in Maharashtra, India. The indiscriminate use of these pesticides to improve agricultural production and yield may have impacts on non-target organism, especially aquatic life and environment. On the freshwater fish Nemacheilus botia, the acute toxicity of the organophosphate pesticide Metasystox has been investigated. For many years, the fish have been used to assess the level of water contamination. To determine the median fatal doses of Metasystox (Oxydemeton-methyl) over 24, 48, 72, and 96 hours, static bioassays were conducted on freshwater fish, N. botia. The LC50 values were 10.3, 9.131, 7.884, and 7.018 ppm after 24, 48, 72 and 96 hours respectively. The results show that the LC50 values decreased with increase in exposure period. Fish mortality due to pesticide exposure mainly depends upon its sensitivity to the toxicants, its concentration and duration of exposure. The evaluation of LC50 concentration of pollutants is an important step before carrying out further studies on physiological changes in animals. In the present study the N. botia exposed to metasystox, the acute toxicity level was expressed in terms of LC50 values.