Author/Authors :
Zahedi، Saeed نويسنده Young Researchers and Elite Club, Torbat-e Heydarieh Branch, Islamic Azad University, Torbat-e Heydarieh, Iran. , , Akbarzadeh، Arash نويسنده 1Department of Fisheries, Faculty of Marine and Atmospheric Sciences, University of Hormozgan, Bandar Abbas, Iran , , Rafati، Maryam نويسنده Department of Natural Resources, Savadkooh Branch, Islamic Azad University, Savadkooh, Iran. , , Banaee، Mahdi نويسنده Department of Aquaculture, Natural Resource and Environmental Faculty, Behbahan Khatam Alanbia University of Technology, Iran. , , Sepehri moghadam، Heshmat نويسنده Department of Agriculture, Payam Noor University, Mashhad, Iran , , Raeici، Hadi نويسنده 1Department of Fisheries, Faculty of Marine and Atmospheric Sciences, University of Hormozgan, Bandar Abbas, Iran ,
Abstract :
In Caspian Sea basin, sturgeons spend the larval and juvenile stages in freshwaters of rivers and then, they migrate to
brackish waters of the sea where they grow and mature. With regard to the elevation of the metal concentrations in
coastal waters and sediments of the Caspian Sea and its adjacent rivers, it is likely that juvenile sturgeon are exposed to
sub-lethal levels of metals during seawater entry process. We compared the biochemical responses of juvenile European
sturgeon, (Beluga, Huso huso) exposed to a sub-lethal level of copper (Cu, 20 ?g/L) and cadmium (Cd, 300 ?g/L) in
freshwater (FW, 0 ppt) and brackish water (BW, 11 ppt) for seven days. The results showed that the levels of plasma
glucose increased significantly in BW and in all metal exposed groups. Also, plasma cortisol concentrations showed
significant increases when juveniles were exposed to BW, Cu(FW/BW) and Cd(BW). The activity of liver superoxide
dismutase (SOD) decreased significantly in BW compared with FW. Moreover, Cu and Cd exposure enhanced the activity
of SOD in BW, while SOD did not show any changes in FW. The levels of tissue and plasma proteins as well as plasma
triiodothyronine (T3), thyroxine (T4) and liver Catalase (CAT) activity remained constant when animals were exposed to
Cu/Cd in both FW and BW environments. Our data indicate that exposure of juvenile beluga to BW stimulated the
general biochemical responses of stress such as cortisol and glucose, while sub-lethal exposure to Cu and Cd caused
oxidative stress in BW environment but not in FW.
