Toxicity Assessment of Diazinon (Sabion 60 EC) on Some Local Fish Species of Dinajpur

Four different fish species such as Climbing perch (Anabas testudineus), Spotted snakehead (Channa punctatus), Stinging catfish (Heteropneustes fossilis) and Tangra (Batasio tengana) were exposed to various concentrations of Diazinon (Sabion 60 EC) to investigate the toxic level of Diazinon and mortality rate of fish species. The various concentrations in which the fish species were exposed as 100, 200, 300 and 400 ppb including a control. The median lethal concentration (LC50) values of Diazinon (Sabion 60 EC) on Climbing perch, Spotted snakehead, Stinging catfish and Tangra were 167.45, 182.90, 217.59 and 190.29 ppb respectively for 96 hours of exposure. Remarkable behavioral abnormalities were found during the exposure. The study was also undertaken to investigate and to compare the percentages of protein and fat content of the fish species before and after application of pesticide. Some water quality parameters such as temperature, pH, dissolved oxygen, total dissolved solids and electrical conductivity were also measured during the experiments. In this experiment the pH value was in the range of 6.87-7.92 and temperature was in range of 26 to 29 ? in presence of pesticide. Fish species showed various physiological and behavioural alterations as rapid opercular movement, erratic swimming, gulping, mucus secretion in response to various concentrations of pesticide. These alterations were more in higher concentrations. The protein and fat percentages of the fish species were reduced after exposure of pesticide during this experiment.