Evaluation of anesthetic potential of rosewood (Aniba rosaeodora) oil as a new anesthetic agent for goldfish (Carassius auratus)

The aim of this research was to investigate the efficacy of rosewood (Aniba rosaeodora) essential oil (EO) as a new herbal anesthetic compared with camphor (Cinnamomum camphora) EO and commonly used chemical agent 2-phenoxyethanol (2-PE) on goldfish (Carassius auratus). The anesthetic efficacies of these herbal EOs and 2-PE were evaluated in goldfish with mean body weight of 7.36 ± 0.77 g. Fish were exposed to each anesthetic concentrations and the lowest effective concentrations (LECs) were established according to deep anesthesia (AD < 3 min) and full recovery (RF < 5 min) times. RD and CP showed anesthetic characteristics and induced AD. The LECs for each anesthetic were established at 250 μl L−1 for RD (AD; RF → 171 ± 2.28 s; 297 ± 7.69 s), 250 μl L−1 for CP (AD; RF → 129 ± 4.18 s; 291 ± 2.81 s) and 700 μl L−1 for 2-PE (AD; RF → 177 ± 2.35 s; 214 ± 4.93 s). At concentrations of 50, 100, 150, 200 μl L−1 for RD, 50, 100, 150 μl L−1 for CP and 400, 500 μl L−1 for 2-PE failed to induce AD in goldfish. There were significantly differences found among RD, CP and 2-PE concentrations in terms of induction and recovery times (p < 0.05). The fastest AD and RF were obtained by 300 μl L−1 CP (120 ± 1.94 s) and 600 μl L−1 2-PE (190 ± 4.34 s), respectively. Fish exposed to 300 μl L−1 RD and 800 μl L−1 2-PE took slightly longer to achieve AD than 300 μl L−1 CP. Induction and recovery times for EOs and 2-PE were significantly dependent on concentrations. Negative relationships was recorded between AD and RF for all anesthetics. No mortality or adverse effects occurred and fish stayed calm during trials. Results showed that RD was found to be an effective anesthetic as well as CP for goldfish and can be used at least 3-fold lower concentrations than 2-PE. In conclusion, rosewood (Aniba rosaeodora) EO, as a new potential anesthetic for fish, proved to be an effective natural agent resulting in rapid induction and recovery.