ANESTHETIC EFFICACY OF CLOVE OIL AND 2-PHENOXYETHANOL ON DOCTOR FISH, <i>Garra rufa</i> (HECKEL, 1843)

Abstract

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 concentrations than 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.

Effective concentration of herbal anaesthetics Origanum vulgare L. oil and its effects on stress parameters in Nile tilapia (Oreochromis niloticus)

“…Any chemical agent or herbal content might anaesthetize fish but the important part of anaesthesia research studies is the question how this anaesthetic agent affects welfare of fish after recovery. There are many studies to investigate some good herbal anaesthetic candidates but many of them focused on finding the best application concentration of essential oils; therefore, many of these studies unfortunately did not show the stress and welfare effects of the recommended concentration of these herb extracts on fish (Aydın et al., 2019 ; Baldisserotto et al., 2018 ; Charoendat et al., 2009 ; Ribeiro et al., 2015 ). On the other hand, although some other researchers (Hohlenwerger et al., 2016 ; Ventura et al., 2019 ; Yousefi et al., 2022 ) analysed stress parameters at one‐ or two‐time point after recovery to understand the efficiency of essential oils on fish welfare, which is not enough to see clearly how the stress mechanism continues for 24 h or longer period, there should be more frequent time point to check the physiology after recovery in order to understand the effect of anaesthetics on stress (Pottinger, 2008 ; Sadoul & Geffroy, 2019 ).…”

Essential oils as anaesthetics and sedatives in native Brazilian fish, with a special emphasis on Colossoma macropomum : A review

“…In addition, biological factors, such as age, gender, body weight, growth rate and physiological state, and environmental factors, such as water quality, water temperature and oxygenation, can also influence the times for induction and recovery from an anaesthetic (Aydın et al, 2019;Santos et al, 2015;Sneddon, 2012). The investigation of the lipid content in a given species or experimental group and the lipid solubility of the drug, as well as the relationship of body volume and the surface area of the gills, are also fundamental for…”

“…Anaesthetics used in fish are classified according to their synthetic or natural origin. As for synthetic anaesthetics, the most used in fish are tricaine methanosulphonate (MS‐222), benzocaine, 2‐phenoxyethanol, quinaldine and propofol (Aydın et al, 2019; Bolasina et al, 2017; Purbosari et al, 2019; Souza, Baldissera, et al, 2019; Uehara et al, 2019). However, due to factors such as environmental impact, residues in fish that can be transmitted to humans, and their high cost of acquisition, synthetic anaesthetics have been avoided in favour of natural anaesthetics, since they have biodegradable properties, do not accumulate in fish tissues as a residue and are less likely to produce multi‐drug resistant pathogens (Aydın & Barbas, 2020; Dawood et al, 2021; Purbosari et al, 2019; Reverter et al, 2014).…”

“…In general, the response to the anaesthetic agent is quite variable between fish species as well as within the same species, and these responses may be the result of differences in the pharmacokinetics and pharmacodynamics of different anaesthetics (Zahl et al, 2012). In addition, biological factors, such as age, gender, body weight, growth rate and physiological state, and environmental factors, such as water quality, water temperature and oxygenation, can also influence the times for induction and recovery from an anaesthetic (Aydın et al, 2019; Santos et al, 2015; Sneddon, 2012). The investigation of the lipid content in a given species or experimental group and the lipid solubility of the drug, as well as the relationship of body volume and the surface area of the gills, are also fundamental for understanding the pharmacokinetics of the anaesthetic tested (Zahl et al, 2012).…”