Oxidative Stress and Response of the Antioxidant Complex of Pacific Oyster Tissues Magallana gigas (Thunberg, 1793) to Shell Damage by the Boring Sponge Pione vastifica (Hancock, 1849)

The present study investigates the effects of damage by the boring sponge Pione vastifica (Hancock, 1849) to the shell of the commercially important bivalve mollusk, the Pacific oyster (Magallana gigas (Thunberg, 1793)). The activity of glutathione peroxidase (GP), glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT) and the level of oxidatively modified lipids, which are products reacting with thiobarbituric acid (reactive substances) (TBARS), were determined in the hepatopancreas and in the mantle of oysters. The results demonstrated that the intensity of lipid peroxidation was significantly higher in affected than in healthy oysters. In the mantle of affected oysters, catalase activity increases and glutathione peroxidase activity decreases, while in the hepatopancreas there is a decrease in superoxide dismutase and glutathione peroxidase activity. These results indicate a higher level of oxidative load in the mantle of affected oysters compared to the hepatopancreas.