PHYSIOLOGY OF SULFIDE DETOXIFICATION IN THE ISOPOD SADURIA (MESIDOTEA) ENTOMON

The physiology of sulfide detoxification in the isopod Saduria (Mesidotea) entomon (L.) was studied in vitro as well as in vivo using a sulfide oxidation assay and high-performance liquid chromatography. S. entomon is unable to prevent hydrogen sulfide from entering its body. Hydrogen sulfide is transported by the blood to the hepatopancreas, where it is detoxified in the fluid portion by an O2-dependent oxidation to S2O32- and SO32- (S0 or SO42- formation could not be demonstrated). An O2-independent binding of sulfide, probably by iron, also occurs in the hepatopancreas. In addition, H2S iS oxidized to S2O32- in the muscle. This oxidation is suggested to be localized in the mitochondrial fraction of the muscle. Glutathione does not play an important role in the detoxification. This study supports the hypothesis that hydrogen sulfide is an important factor in the distribution of marine invertebrates in soft sediments.