Individual and combined effects of copper and lead on the fresh water crab Sesarma Boulengeri from Shatt al-Arab, Basrah Iraq

الملخص EN

The acute toxicity by single or combined of Copper and Lead on the fresh water crab Sesarma boulengeri (Calman, 1920) was evaluated by static bioassays, calculating the values of LT50 (median lethal time) and LC50 (median lethal concentration), after exposure to concentrations (50, 100, 150, 175 and 200) μg l-1.Each bioassay tested up to 96 hours, the survival time was decreased with increasing concentrations of Copper and Lead in the laboratory circumstances.

Copper was more toxic to S.

boulengeri than Lead, when tested individually.

When tested in combination, the toxicity increased, and the expected mortalities were not similar to those observed mortalities, the effect of paired metals is synergistic and the two metals acted interactively.

Toxicities of mixtures of Copper and Lead were assessed using the toxic-unit concept.