Acute toxicity of malachite green and its effects on certain blood parameters of a catfish, Heteropneustes fossilis

Abstract An attempt has been made to collect upto date information of the toxicity of a dye malachite green on H. fossilis which are frequently used in fish farming. Exposure to malachite green to a concentration of 0.20 mg/l ( 1 5 th of 96 h LC 50 ) for 96 h caused significant depletion of serum calcium and protein levels. Short-term (10–20 days) exposures to sub-acute 0.10 mg/l ( 1 10 th of 96 h LC 50 ) and sub-lethal 0.05 mg/l ( 1 20 th of 96 h LC 50 ) levels of the dye also affect significant decrease in the serum calcium and protein levels; however, long-term (30–60 days) exposure did not show any changes in comparison to control fish. The total cholesterol level of blood is increased significantly at all the concentrations of malachite green in respect to all the time intervals.