Effect of 2-phenoxyethanol on the stress responses, hematological parameters and hepatic enzymes in Siberian sturgeon (Acipenser baerii)

The present study examined the effects of various concentrations (0.1-1.1 ml L-1) of 2-phenoxyethanol, an anesthetic agent, on the stress responses, the hematological parameters and the hepatic enzymes in Siberian sturgeon (Acipenser baerii; Brandt JF, 1869).  The results showed that placing Siberian fish in low concentrations of the drug causes deep anesthesia over a longer period in compared with higher concentration, but the time required for fish recovery significantly decreases. Furthermore, plasma cortisol levels significantly increased (P< 0.05) and decreased (P< 0.05) at low (0.1- 0.5 ml L-1) and high (0.9 and 1.1 mg L-1) concentrations of 2-phenoxyethanol in compared to the control group, respectively. Different concentrations of 2-phenoxyethanol had no effect on the levels of WBC (P> 0.05), but the levels of RBC, hemoglobin and hematocrit significantly increased in the concentrations of 0.1 and 0.3 ml L-1 of the drug (P <0.05). It was seen no changes in the ions levels of blood plasma as well as MCV, MCH and MCHC in compared with the control group in the different concentrations of 2-phenoxyethanol (P> 0.05). ALP and AST levels in high concentrations (0.9 and 1.1 ml L-1) of anesthetic agents had not significantly different with the control group, but their values significantly increased at low concentrations of the drug (0.1 and 0.3 ml L-1; P <0.05). In conclusion, these findings show that 2- phenoxyethanol at doses of 0.9 and 1.1ml L-1 is suitable for the anesthetization of Siberian sturgeon because these concentrations have the least effects on the physiological system of fish.