Determination of the Effective Anesthetic Dose of MS-222 and 2-Phenoxy Ethanol and Comparing Their Effects on Some Blood Biochemical Indicators in Barbus grypus

Given the inevitable side effects of anesthetics in aquaculture, blood and biochemical assessments are among the appropriate ways of identifying their side effects. This study was aimed at comparing the effects of the density and the duration of two anesthetics, known as 2-fenoxyethanol and MS-222, on the blood stress indicators (Glucose & Cortisol) of Barbus grypus. To do this, 100 Barbus grypus weighing 50±5 g were selected and considered as three groups: one for anesthesia with 2-fenoxyethanol with concentrations of 200, 300 and 400 µl/l, one for anesthesia MS222 with concentrations of 40, 50 and 80 mg/l and one as the control group. For each of the anesthetics, the anesthesia times were recorded after the fishes reaching the 4 th and 5 th stages of anesthesia, then blood sampling was done in effective dose in 3minutes-6hours-12hours and 24 hours intervals. According to the results, the effective dose of anesthesia for 2-fenoxy ethanol was 300 µl/l and for MS222 was 50 mg/l. The results showed that MS-222 and 2-fenoxy ethanol caused the increase in the blood glucose through increase in cortisol since the early minutes after the fish’s anesthesia and theses increasing effects would remain in the fish’s blood for 24 hours after its anesthesia. The comparison of the effects of these anesthetics on the stress indicators showed that both of them caused the rise of the stress indicators, but the increasing effect of 2-fenoxy ethanol was higher, and there was a direct correlation between glucose and cortisol. So both of the anesthetics caused the stress induction on the studied species.