Determination of 96-hr LC50 value of cadmium for a fish, Labeo rohita

This paper emphasizes on the determination of 96hr LC50 value of Cadmium sulphate for the fish, Labeo rohita. The test was performed according to the standard methods in APHA and the value was calculated by probit analysis. The fish specimens were acclimatized in the laboratory conditions for 25 days. The stock solution of Cadmium sulphate was prepared and the fish were treated with various concentrations for 96 hours. The results showed that the median lethal concentration (LC50) of Lead Nitrate for the fish, Labeo rohita is 24 mg/l. The susceptibility of Labeo rohita to the lethal effect of Cadmium sulphate was dependent on duration as well as on concentration. The mortality of the fishes is directly proportional to the concentration.