Efficiency in heavy metal purge in crustaceans during the ecdysis

An abundant population of Ucides cordatus swamp crabs is present at Lameirão Ecological Station (Brazil), a tropical ecosystem man-made with discharges of domestic, industrial and agricultural pollutants. Concentrations of heavy metals in water, sediment and muscle tissues, gills, hepatopancreas and exoskeleton present in crustaceans were analyzed. The results showed variations in the concentrations of all metals according to precipitation, tide and physicochemical factors. This fact possibly influenced the results of bioconcentration (BFC > 1), indicating a tendency of bioaccumulation according to environmental conditions. We also found a high accumulation of metals in female specimens. However, regardless of gender, we found a reduction in metal concentrations in all tissues analyzed during the period of ecdysis. In this study, we highlight the ecological role of U. cordatus in mangrove ecosystems and its importance in transferring pollutants to the upper trophic levels of the mangrove community, and even to man.