Alterations of reproductive parameters in the crab Carcinus maenas after exposure to metals

The objective of this study was to investigate the effects of acute exposure to copper, chromium and mixtures of these metals on reproductive parameters of female Carcinus mamas. The parameters studied were ovarian esterase, acid and alkaline phosphatase activity, ovarian protein content, gonadosomatic index (GSI) and hepatosomatic index (HSI). Metals induced significant decreases on ovarian alkaline phosphatase activity, esterase activity and protein content. Ovarian acid phosphatase activity significantly increased in crabs exposed to chromium, while only a slightly increase was found in females exposed to copper and to mixtures of these metals. Furthermore, a dose-dependent reduction of both GSI and HSI were observed in crabs exposed to metals. These observations suggest that copper and chromium may interfere with the ovarian cycle in Carcinus maenas and, therefore, with the reproduction of this species. In general, the mixture had more pronounced effects than individual metals. This subject requires further investigation because in polluted estuaries, crabs may be simultaneously exposed to several metals.