When oxygen is available, the species is able to detoxify penetrating sulphide mainly by oxidizing it to non-toxic thiosulphate. Sulphide influx rate can be quantified by calculation of the diffusion coefficient for total sulphide. The amount of accumulated sulphide in the tissues is strongly dependent on individual size. This is confirmed by experiments as well as by field studies. After specific sulphide incubations, only low internal sulphide concentrations are found in large clams, whereas small clams accumulate much more sulphide in the tissues.
Field studies show a distinct reduction in numbers of small clams in high sulphidic areas.
We conclude that efficient sulphide detoxification seems possible only if the body size exceeds a certain minimal value.