Damage to cultivated Japanese pearl oysters by oxidative stress that was related to "mass mortality".

Increased blood-DNA breakage was observed in diseased pearl oysters. They showed significant formation of 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA), whereas the oysters that had a low mortality rate from the disease had high activity of superoxide dismutase (SOD) and low amounts of 8-OHdG and MDA. These results suggest that radical damage had occurred only in the diseased pearl oysters with the cytolysis of their haemocytes, which was related to the mass mortality of the Japanese pearl oysters.