title: Combined effects of cadmium and salinity on juvenile Takifugu obscurus: cadmium moderates salinity tolerance; salinity decreases the toxicity of cadmium.
abstract: Obscure puffer Takifugu obscurus, a species of anadromous fish, experiences several salinity changes in its lifetime. Cadmium (Cd) is a toxic heavy metal that can potentially induce oxidative stress in fish. The present study aimed to detect the combined effects of Cd (0, 5, 10, 20 and 50 mg L(-1)) and salinity (0, 15 and 30 ppt) on juvenile T. obscurus. Results showed the juveniles could survive well under different salinities; however, with Cd exposure, the survival rates significantly decreased at 0 and 30 ppt. At 15 ppt, tolerance to Cd increased. Cd exposure clearly induced oxidative stress, and the responses among different tissues were qualitatively similar. Salinity acted as a protective factor which could reduce the reactive oxygen species and malondialdehyde levels. In addition, salinity could enhance the antioxidant defense system, including superoxide dismutase, catalase and glutathione. Na(+)/K(+)-ATPase activity significantly decreased under Cd exposure in gill, kidney and intestine. These findings indicated that Cd could moderate the adaptability of juvenile T. obscurus to high salinity and low salinity played a protective role upon Cd exposure. Thus, the role of salinity should be considered when evaluating the effect of heavy metals on anadromous and estuarine fishes.
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
authors.forename: Xuexia
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Lake and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
authors.forename: Yafen
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D004781:Environmental Exposure / Q000009:adverse effects; D005880:Gills / Q000502:physiology*; D005978:Glutathione / Q000378:metabolism; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D054712:Salinity; D055049:Salt Tolerance; D013482:Superoxide Dismutase / Q000378:metabolism; D023741:Takifugu / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D002104:Cadmium; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione