Lavender and bay oils used to anaesthetise trout
Scientists in Turkey have demonstrated that essential oils from plants can be used as natural and safe anaesthetics for rainbow trout (Oncorhynchus mykiss).
Researchers from Isparta University of Applied Sciences and Burdur Mehmet Akif Ersoy University used oils from lavender (Lavandula angustofolia) and bay laurel (Laurus nobilis).
They exposed fish of approximately 10 grams to different concentrations of essential oils (5, 10, 20, 50, 70, 100, 150, 200, 300, 400, 500 and 600 mg per decilitre (L¯¹)) and evaluated the times of induction and recovery of the anaesthetic effect.
In addition, histopathological effects of the essential oils in fish tissues were determined after deep anaesthesia.
Recovery times
Lavender essential oil at 200 mg L¯¹, dose and bay laurel essential oil at 400 mg L¯¹ dose showed ideal anaesthetic effects on rainbow trout.
At these concentrations, the times to induction of deep anaesthesia were 258 seconds for lavender and 189.5 seconds for bay laurel. Recovery times at these concentrations were 41 seconds for lavender and 129.5 seconds for laurel.
In addition, no histopathological findings were observed in the gills, liver and kidney.
“Consequently, this study demonstrated that lavender and bay essential oils can be used as effective anaesthetics in rainbow trout,” the researchers concluded.
Review the abstract of the study here.
