Abstract:To determine the appropriate anesthetic method and dose for perch, hydrostatic anesthesia effects of two common fish anesthetics (MS-222 and eugenol) on perch under different concentrations was compared. An experiment of 24-hour anesthesia transport was carry out under the optimal anesthetic concentrations of MS-222 and eugenol. The changes of serum biochemical indexes, water quality pH, ammonia nitrogen and residual concentration of anesthetics were measured after 0.5, 4, 8, 16 and 24 h of anesthesia. The results showed that the anesthetic time was shortened and the recovery time was prolonged with the increase of anesthetics concentration. The concentrations of eugenol and MS-222 are suitable for long-distance transportation of perch at 18-20 mg/L and 50-60 mg/L respectively. The survival rate during the transportation and after 24 h of recovery for the anesthesia group were both 100%, there were significantly higher than those for the non-anesthetic transportation group (p<0.05). The serum cortisol (COR) in eugenol group and MS-222 group decreased from 336.83 pg/mL to 291.41 pg/mL and increased from 286.11 to 367.05 pg/mL (p<0.05) with the prolongation of anesthesia time, and the serum COR in eugenol group was significantly lower than that in control group. The glucose decreased from 14.36, 7.48 mg/dL to 7.36, 3.11 mg/dL (p<0.05), respectively. The concentrations of lactate dehydrogenase (LDH), alkaline phosphatase (AKP), glutamic oxaloacetic transaminase (GOT), urea nitrogen (BUN) in eugenol group were significantly lower than those in MS-222 group (p<0.05). Residual test results showed that the maximum eugenol content was 5.14 mg/kg at 0.5 h of anesthesia and the residual amount of eugenol was 0.45 mg/kg at 1 day of resuscitation in clear water. In MS-222 group, the maximum content was 36.24 mg/kg after 8 h of anesthesia, and it was almost eliminated after 4 days of resuscitation. The results showed that eugenol had low dosage, fast metabolism and fewer side effects in inducing oxidative stress and tissue damage.
