The effects of exposure to sub-lethal copper and cadmium concentrations on biochemical factors of one year old Persian sturgeon, Acipenser persicus

The aim of this study was to determine the 96h LC50 of copper and cadmium, and also, to evaluate the effects of their sub-lethal dose on stress factors in Persian sturgeon, Acipenser persicus. Obtained results from Probit analysis showed 96h LC50 values of 0.502 and 14.78mg/l for copper and cadmium, respectively. Also, in single sub-lethal exposures, 72 juveniles (130±19g) were exposed to 0.026 and 0.68mg/l of copper and cadmium in semistatic conditions, and some stress-related biochemical factors were assessed in 1, 7 and 14 days. According to the obtained results, plasma glucose and cortisol were increased (P<0.05) in experimental fishes compared to the controls only in the first day of sampling. There were no significant (P>0.05) differences in plasma and liver protein contents between experimental groups and controls with the exception of copper treatment at the first day of sampling when plasma protein contents showed significant increases, but decreased significantly (P<0.05) in the subsequent sampling stages. In addition, with copper treatment, significant decreases were observed in plasma triglyceride concentrations as time passed by compared to day 1 (P<0.05). Results showed that copper is more toxic than cadmium for this species and also, 96h LC50 of copper and cadmium are stressful for Persian sturgeon.