Nickel bioaccumulation and the antioxidant response in Pacific abalone Haliotis discus hannai, Ino 1953 exposed to waterborne nickel during thermal stress

Pacific abalone, Haliotis discus hannai (mean length 2.92 +/- 0.5 cm, and mean weight 2.63 +/- 0.4 g) were exposed to different concentrations of waterborne nickel (0, 100, 200, and 400 mu g/L) at 18, 22, and 26 degrees C for 2 weeks. The exposure concentration of Ni induced a significant Ni accumulation in specific tissues of H. discus hannai depending on water temperature. The order of nickel accumulation in tissues was hepatopancreas > gill approximate to digestive gland > muscle. Regarding antioxidant response indicators, the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) in the hepatopancreas and gill tissues of H. discus hannai was significantly increased by the waterborne nickel exposure depending on water temperature. These results suggest that waterborne nickel exposure can induce a considerable nickel accumulation in specific tissues and stimulation of enzymatic antioxidant systems in Pacific abalone, H. discus hannai Ino, 1953 depending on water temperature.