Potential anesthetic properties of bay leaf (Laurus nobilis) essential oil compared with 2-phenoxyethanol on blue dolphin cichlid, cyrtocara moorii

The efficacy of Bay leaf (Laurus nobilis) essential oil (LnEO) as a herbal anesthetic agent was evaluated with 2-Phenoxyethanol (2-PE) in Blue Dolphin Cichlid, Cyrtocara moorii. Fish were exposed to different anesthetic concentrations and the lowest effective concentrations (LECs) were determined according to deep anesthesia (AD<3 min) and full recovery (RF<5 min) times. LnEO showed anesthetic properties, and all applied concentrations of both agents induced AD in C. moorii. The LECs of LnEO and 2-PE for C. moorii were determined as 800 µl L-1 (AD; RF → 183 ± 6.3 s; 191 ± 2.6 s) and 600 µl L-1 (AD; RF → 171 ± 3.2 s; 239 ± 4.9 s), respectively. Significant differences were found between anesthetic agents in terms of deep anesthesia and full recovery times for the same concentrations (p<0.05). Induction and recovery times decreased with increasing in LnEO concentrations. On the other hand, anesthesia times were decreased with increasing of 2-PE concentrations, while recovery times increased. Induction and recovery times for LnEO were significantly dependent on concentrations and positive relationships were recorded between AD and RF, whereas the relationship was negative in 2-PE. Bay leaf essential oil has not been used as an anesthetic agent in fish until now. Our results showed that LnEO was an effective anesthetic agent with some minor side effects on C. moorii.