AChE inhibition in Carcinus aestuarii as biomarker of exposure to neurotoxic compounds.

The use of biomarkers in monitoring aquatic environments is nowadays a common practice, fish and bivalves being mostly chosen as target-species. Since it is often difficult to estimate the possible adverse effects due to contamination on selected ecosystems, a multi-species strategy should be adopted. In this context, we applied the biomarker approach to the Mediterranean crab Carcinus aestuarii, which could provide different and/or additional information with respect to fish and bivalves. In this work we evaluated the possible use of acetylcholinesterase (AChE) activity, measured in different crab tissues (gills and hemolymph), as biomarker of exposure to neurotoxic compounds. Crabs were exposed for 96 h to various sublethal concentrations of Chlorpyrifos (CP). A significant inhibition of AChE activity was shown from 5 mg CP/L in the hemolymph and at 15 mg CP/L in gills. These preliminary results suggest that measurement of AChE activity is a useful biomarker of exposure to neurotoxic compounds in C. aestuarii.