Soumeya Belabed and Noureddine Soltani
Pollution by heavy metals is a serious problem due to their toxicity and ability to accumulate in the biota. The present study was undertaken to investigate the acute toxicity of cadmium, a heavy metal widely detected in the aquatic environment due to natural effects and anthropogenic activities. Thus, we evaluate the toxicity of this metal on acetylcholinesterase (AChE) and glutathione S-transferase (GST) activities in the marine bivalve Donax trunculus L. (Mollusca, Bivalvia). Cadmium was added in the rearing water at a concentration corresponding to 96- h LC50 prealably determined. The activities of GST and AChE were determined in the mantle at different exposure times (0, 24, 48, 72 and 96h). The results show a significant decrease (p< 0.001) in AChE activity and a significant increase (p< 0.05) in GST activity as compared with controls. In a second series of experiment, exposed animals were thereafter transferred to clean water up to 4 days to assess the recovery pattern. The data obtained suggested that D. trunculus was able to overcome relatively rapidly the stress induced by cadmium.
