Effects of waterborne selenium on toxic and physiological stress response in goldfish, Carassius auratus

Selenium (Se) is an essential element, known to bioaccumulate to toxic levels in aquatic environments. Here, we tested the toxic and physiological stress response of goldfish, Carassius auratus exposed to different concentrations of Se for 120 h. At the end of the experiment, the toxic stress indicators [metallothionein (MT), aminotransferase/aspartate (AspAT and AlaAT), and gill Na+/K+-ATPase] and other stressrelated parameters [corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and glucocorticoid receptors (GRs) mRNA and activity and/or plasma ACTH, cortisol, glucose, hydrogen peroxide (H2O2), and muscle lipid peroxidation (LPO)] were significantly higher in specimens exposed to 3 and 4 mg/L of Se than in those exposed to lower concentrations (0 and 2 mg/L). These results indicated that 3 and 4 mg/L Se concentration can induce an acute toxic and physiological stress response in aquarium conditions.