Anesthetic efficacy of clove oil and 2-phenoxyethanol on doctor fish, Garra rufa (Heckel, 1843)

This study aimed to determine the anesthetic efficacy of clove oil and 2-phenoxyethanol on doctor fish (Garra rufa) at two different water temperatures. Experimental fish (1.2 ± 0.2 g mean weight) were subjected to 25, 50, 75 and 100 μL L-1 clove oil and 100, 200, 300, 400 and 500 μL L-1 2-phenoxyethanol concentrations at water temperature of 15 and 25 °C, and the induction and recovery times were investigated. Results showed that induction and recovery times in doctor fish were significantly affected by clove oil and 2-phenoxyethanol concentrations as well as water temperature. The interaction of anesthetic concentration and water temperature on all induction stage time was significant in clove oil. Between the anesthetic concentration and temperature interaction was significant for recovery times in both anesthetic agents. The induction time decreased significantly with increasing concentration of both anesthetic agents at water temperature of 15 and 25 °C. The lowest effective concentrations that produced induction within 3 min and recovery within 5 min were 50-75 μL L-1 of clove oil and 300 μL L-1 of 2-phenoxyethanol in both 15 and 25 °C respectively. The results also indicated that clove oil was effective at 4-fold lower concentrationsthan 2-phenoxyethanol, but the recovery time was longer than 2-phenoxyethanol. These results suggest that clove oil and 2-phenoxyethanol were effective anesthetics and could be used as anesthetic agents in doctor fish.