A COMPARATIVE-STUDY OF SUPEROXIDE-DISMUTASE ACTIVITY IN MARINE BENTHIC INVERTEBRATES WITH RESPECT TO ENVIRONMENTAL SULFIDE EXPOSURE

Exposure to environmental sulfide has been related to formation of rea ctive oxygen species (ROS) in vertebrate and invertebrate tissues. The present paper compares activity levels of the oxygen radical quencher superoxide dismutase (SOD) in benthic polychaetes and bivalves of dif fering sulphide tolerance. Total SOD activity showed no correlation to biotope related sulphide exposure of different species. Sulfide-insen sitive MnSOD is present in tissues and body fluids of some sulphide ad apted species. Total SOD activity was generally higher in haemoglobin containing animals, than in species lacking respiratory pigments. The sulphide-resistant MnSOD was the dominating enzymatic form in respirat ory fluids of haemoglobin containing species, whereas sulphide-sensiti ve CuZnSOD dominated in the body tissues. Bivalves without respiratory pigments had mostly SOD deficient haemolymph. The results indicate, t hat release of reactive oxygen species in tissues and body fluids of i nvertebrates could be connected to the presence of haemoglobin, rather than to sulphide oxidation.