Determination of Lethal Concentration (LC 50) of Channa Striata

The present study was conducted to assess the acute toxicity of Channa striata by static bioassays. Channa striata is a native fresh water carnivorous air breathing fish species. The average length and weight of fish used in the present investigation were 18-20 cm and 40-45g, respectively. The fishes were fed daily with minced fish and chicken liver. Only healthy and active animals of more or less similar size were randomly selected for the experiment. The physico-chemical parameters such as pH, Temperature, Dissolved Oxygen of test water were measured daily. The ten fishes were exposed to Organophosphate pesticide Chlorpyrifos with different concentrations of 1.5, 2.5, 3.5, 4.5 and 5.5. mg/l All the exposed fishes were daily observed and dead fishes were removed immediately. The mortality was recorded on daily base. The LC50 value at 96 hr was found to be 4.521 ppm to C. striata. The data obtained were statistically evaluated by using Finneys probit analysis method. It was found that there was positive relationship between the mortality and concentration level.