Evaluation of Acute Toxicity of Copper to Four Fresh Water Fish Species.

The acute toxicity of copper (Cu) to the four fish species viz. Labeo rohita, Cirrhina mrigala, Catla catla and Ctenopharyngodon idella of 90-, 120- and 150-days age groups was evaluated in the wet laboratory under static bioassay at constant water pH, temperature and hardness. Although all fish species exhibited variable sensitivity to different Cu concentrations, 90-day C. idella showed significantly (P<0.05) higher sensitivity to Cu with the mean 96-h LC50 and lethal concentrations of 5.17 and 9.39 mg L-1, respectively, while 150-day L. rohita were least sensitive with mean concentrations of 33.41 and 45.57 mg L-1, respectively. No-significant difference was found between 150-day C. mrigala and C. catla for 96-h LC50. Amongst three age groups, 90-day fish of all four species showed highest sensitivity against Cu, while 150-day fish were least sensitive. Therefore, tolerance limits of all the four fish species against Cu increased with increase in fish age. [ABSTRACT FROM AUTHOR]