Sulphide detoxification in the bivalve,Arctica Islandica(L.) from two different habitats

Abstract

Abstract The metabolic end products of sulphide detoxification were studied in Arctica islándicafrom Laholm Bay and from Kockholmen, Sweden. In summer, Laholm Bay becomes hypoxic with significant concentrations of sulphide in the bottom water whereas Kockholmen shows little sign of hypoxia or of sulphide accumulation. There were considerable differences in the concentrations of some of the thiol compounds in the haemo-lymph and in the tissues of A. islandicafrom the two sites but, because of the large variation between individuals, most of these differences were not significant. Exposure of A. islandicato sulphide in the laboratory resulted in significant increases in the concentrations of sulphide and thiosulphate in the tissues of animals from both sites. The concentrations of glutathione in the tissues of freshly collected A. islandicafrom Kockholmen were much lower than in those from Laholm Bay, but increased significantly following exposure to sulphide to reach concentrations similar to those found in the Laholm Bay animals. In contrast, the concentrations of L-cysteine in the haemolymph and the heart tissue of the A. islandicafrom Kockholmen were significantly higher than those found in the A. islandicafrom Laholm Bay. The concentration of L-cysteine in the haemolymph of the A. islandicafrom Kockholmen increased significantly during exposure to sulphide. Possible mechanisms of sulphide detoxification in this species are discussed.