Toxicity study of selenium in the fresh water cat fish Heteropneustes fossilis (Bloch) and the role of Eichhornia crassipes in its control

Experiments were carried out to study the effect of water plant. Eichhornia to control the selenium residues in a fresh water cat fish. Heteropneustes fossilis (Bloch) Hundred percent mortality was observed at a concentration of 42 ppm selenium. The LC₅₀ value was found to be 26.4 ppm. At a concentration of 6 ppm and below, the fishes survived without any stress. So 6 ppm and belowis considered to be the sub-lethal or around sub-lethal concentration. The rate ofoxygen consumption decresed by 66.67% in control fishes, raised without plant, while experimental fishes, raised with aquatic plant showed a drop of 58.99%. The protein content in the muscle tissue of experimental fishes was minimized by 18.29%. The heavy metal selenium accumulation in the muscle tissue of the control fishes was more significant (65.23%) than that of the experimental ones. The loss of energy was also found to be higher (1.35% higher) in the control fishes than that of the experimental fishes raised along with Eichhornia.