Effects of cadmium exposure on metal-containing amoebocytes of the oyster Ostrea edulis

Oysters, Ostrea edulis, were exposed to cadmium (0.1 mg l^-1) for up to 110 d (in 1982) under laboratory conditions in order to determine the effect of Cd exposure on blood amoebocytes. The results demonstrate that Cd-accumulation does not alter the total Cu and Zn concentrations in gill tissue. There was a decrease in the numbers of metal-containing amoebocytes, and electron microprobe analysis showed that this was largely due to a reduction in numbers of the mixed Cu/Zn-containing cells rather than in Cu-or Zn-containing cells. It is postulated that this response, which may involve the release of metals from amoebocytes into gill tissue, is a generalised stress response of this oyster. No evidence was found for the presence of a specific Cd-containing blood cell or Cd-binding protein in blood cells.