Oxidative stress, neurotoxicity, and non-specific immune responses in juvenile red sea bream, Pagrus major, exposed to different waterborne selenium concentrations

•The antioxidant enzymes of Pagrus major were considerably increase by Se exposure.•The AChE activity was significantly inhibited by Se exposure.•The significant changes were observed in non-specific immune parameters. Juvenile Pagrus major (mean length 15.8±1.6cm, and mean weight 90.4±4.7g) were exposed for 4weeks with waterborne selenium concentration (0, 50, 100, 200, and 400μgL−1). In oxidative stress indicators, liver and gill superoxide dismutase (SOD) activity and glutathione S-transferase (GST) activity were markedly elevated after 4weeks exposure. Similarly, glutathione (GSH) level in liver and gill was also increased in response to the highest Se exposure after 4weeks exposure. In neurotoxicity, AChE activity was inhibited in brain and muscle tissues by waterborne Se exposure. In the non-specific immune responses, lysozyme activity of plasma and kidney was significantly increased by waterborne Se exposure. Peroxidase activity and anti-protease activity were decreased at high Se concentration. The results suggest that waterborne Se exposure can induce significant oxidative stress, inhibition of AChE activity, and immunological alterations.