The efficacy of clove powder Eugenia caryophyllata as an anesthetic for snow trout Schizothorax zarudnyi broods and measurement of blood biochemical and immunity parameters

Clove (Eugenia caryophyllata) powder is used as a fish anesthetic because it is a natural and inexpensive product with low toxicity risks. The goal of the present study was to determine the appropriate concentration of clove powder for anesthetizing of snow trout, Schizothorax zarudnyi broods to be used in artificial reproduction. We applied three different clove powder concentrations (200, 250 and 300 mg/L) with 7 replicates for each concentration on female (1240.1 ± 291.3 g) and male (407.14 ± 55.8 g) broods. In addition to the time required for anesthesia and reduction, serum biochemistry parameters including glucose, total protein, IgM, C3 and C4 were monitored before and after anesthesia. Results showed that time elapsed for anesthesia and recovery of female broods at 250 mg/L was 160.14 ± 9.78 and 145 ± 12.1 seconds, respectively, which was less than 200 (319 ± 20.2 sec. for anesthesia and 108.63 ± 12.15 sec. for recovery) and 300 (117 ± 7.86 sec. for anesthesia and 271 ± 22.24 sec. for recovery) mg/L concentrations. Also, this time for male broods at 300 mg/L (86 ± 3.73 sec. for anesthesia and 64.71 ± 11.25 sec. for recovery) was less than the 200 (155.71 ± 7.81 sec. for anesthesia and 56.43 ± 7.73 sec. for recovery) and 250 (116.86 ± 12.57 sec. for anesthesia and 70.71 ± 14.44 sec. for recovery) mg/L concentrations. The anesthesia did not change blood glucose, total protein, and C4 levels, but IgM concentration was decreased at 300 mg/L in both female and male fish (p < 0.05) and C3 concentration was increased at 300 mg/L in the male brood (p < 0.05). We conclude that 250 mg/L of clove oil is the most efficient dose that requires fish euthanization for artificial reproduction.