Abstract: Using deicing salt was one of the primary measures to remove the snow and ice in cold regions in winter, and its negative effect on ecosystem and environment has been gradually attracted attention. In order to detect the toxicity of deicing salt to aquatic organisms, the effects of deicing salt on superoxide dismutase (SOD) and catalase (CAT) activity in gills and muscle tissues of Ctenopharyngodon idellu (C.idellu) were investigated, with experimental methods of a pyrogallol autoxidation and a UV absorption spectrum. The exposure experiments of deicing salt on the C. idellus were carried out under five concentration treatments (4.10 g·L^-1, 5.13 g·L^-1, 6.41 g·L^-1, 8.01 g·L^-1 and 10.01 g·L^-1), and the control treatment was set without deicing salt (0 g·L^-1). The results show that the 96 h LC50 value of deicing salt for C. idellus is 14.19 g·L^-1 and the safe concentration is 4.03 g·L^-1. According to the 96 h LC50 value, the SOD activity in gills and muscle tissues of C. idellus is inhibited significantly under the concentrations of 5.13, 6.41, 8.01 g·L^-1 and 10.01 g·L^-1 (P<0.05 or P<0.01) compared with the control treatment. The CAT activity in gills and muscle tissues of C. idellus is inhibited significantly (P<0.05 or P<0.01) after 7 days comparing with the control treatment, and the CAT activity in gills of C. idellus is higher than that in the muscle tissues.

Key words: Deicing salt, Ctenopharyngodon idellus (C.idellu), Gills, Muscle, Superoxide dismutase (SOD), Catalase (CAT)