Toxicity of Copper and Nickel to Freshwater Prawn Macrobarchium lanchesteri

Adult Macrobrachium lanchesteri were exposed for a four-day period in the laboratory condition to a range of copper (Cu) and nickel (Ni) concentrations. The mortality was assessed and median lethal times (LT50) and concentrations (LC50) were calculated. At the end of four-day period, the survived prawns were used to determine bioconcentration of the metals. LT50 and LC50 increased with decrease in mean exposure concentrations and times respectively for the two metals (Cu and Ni). LC50s for 24, 48 and 96 hours for Cu were 261.6, 171.6 and mu g/L and for Ni 30786.3, 28534.7 and 8056.6 mu g/L respectively. Copper and Ni bioconcentration in M. lanchesteri increases with increase in concentration exposure and Cu was more toxic than Ni to M. lanchesteri.