Anesthetic and sedative efficacy of peppermint (Mentha piperita) and lavender (Lavandula angustifolia) essential oils in blue dolphin cichlid (Cyrtocara moorii)

The use of different essential oils (Eos), which are considered as a good alternative to synthetic materials, is increasing day by day in fish species. Nevertheless, studies on the anesthetic effect of peppermint Eo (Mentha piperita; MPEo) and lavender Eo (Lavandula angustifolia; LAEo) are scarce. In the present study, the effective concentrations of three anesthetic materials (MPEo, LAEo, and MS-222) were previously determined in the concentrations range of 100–400 ppm in Cyrtocara moorii juveniles (4.92 ± 1.03 g and 7.13 ± 1.22 cm) with the criteria of appropriate induction time (AIt) and ready recovery time (RRt) (Trial 1). Afterwards, four different groups were established at three different sedative concentrations (10, 20, and 30 ppm and a control group without anesthetic additive) for transporting (Trial 2). The study concluded that MPEo and LAEo can be used as anesthetic and sedative agents in tropical fish species safely. The use of 100 µL L–1 (183.5 s AIt and 227.8 s RRt) and 300 µL L–1 (109.2 s AIt and 420.0 s RRt) MPEo and LAEo, respectively, was sufficient for deep anesthesia, whereas concentrations in the range of 10 to 30 µL L–1 are recommended for fish transport.