The Anesthetic Effects of Clove Oil and 2-Phenoxyethanol on Rainbow Trout (Oncorhynchus mykiss) at Different Concentrations and Temperatures

In this study, anesthetic effects of five different concentrations of 2-phenoxyethanol (0.2, 0.3, 0.4, 0.5 and 0.6 ml/L) and clove oil (0.50, 0.75, 1.00, 1.25 and 1.50 ml/L) on rainbow trout (Oncorhynchus mykiss) were studied at temperatures 7, 13 and 18ºC. For this purpose, 900 fish (39.08 ± 1.13 g and 15.48 ± 0.21 cm) were used in the experiment. Induction time of 2-phenoxyethanol and clove oil varied between 1.05 and 3.36 min at all concentrations, except for 0.2 ml/L (for 2-phenoxyethanol only) and at every temperature application. Full recovery time occurred between 2.44 and 7.14 min for 2-phenoxyethanol and 3.23 – 6.11 min for clove oil. It was found that full recovery times significantly increased with increase in 2-phenoxyethanol concentrations (r2=0.81). The same increasing trend was observed in clove oil, but the increase was not strong compared to 2-phenoxyethanol (r2=0.21). On the other hand, full induction times of 2-Phenoxyethanol and clove oil significantly declined with the increase in concentrations (r2=0.74 r2=0.84 for 2-phenoxyethanol and clove oil, respectively). Based on the ideal induction (less than 3 min) and recovery (less than 5 min) time criteria, it can be suggested that the most appropriate concentrations for rainbow trout were 0.3, 0.4 and 0.5 ml/L for 2-phenoxyethanol and 0.50, 0.75 and 1.00 ml/L for clove oil.