Anaesthesia of Atlantic halibut (Hippoglossus hippoglossus) Effect of pre‐anaesthetic sedation,and importance of body weight and water temperature |
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Authors: | Inger Hilde Zahl Anders Kiessling Ole Bent Samuelsen Magne Kjerulf Hansen |
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Institution: | 1. Institute of Marine Research, Bergen, Norway;2. Department of Biology, University of Bergen, Bergen, Norway;3. Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Aas, Norway;4. Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Ume?, Sweden;5. Animalia Meat and Poultry Research Centre, Oslo, Norway |
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Abstract: | The efficacy of the anaesthetic agents benzocaine, metacaine (MS‐222), metomidate, 2‐phenoxyethanol, quinaldine and isoeugenol was studied in Atlantic halibut (Hippoglossus hippoglossus). Fish with an average body weight of 33 g were anaesthetized at 8 °C and fish with an average body weight of 1243 g were anaesthetized at 8 and 15 °C. Agents were tested individually and as combination anaesthesia comprising pre‐anaesthetic sedation, followed by anaesthesia. Induction and recovery times varied in relation to the body weight and water temperature. Large fish had longer induction times and shorter recovery times, and displayed reduced responsiveness to handling compared with small fish. A higher temperature resulted in shorter induction times, longer recovery times and increased responsiveness to handling. Lower dosages were used for all agents in combination anaesthesia. In small fish, this had no effect on the induction times but resulted in shorter recovery times and reduced responsiveness to handling. In large fish, combination anaesthesia resulted in shorter induction times whereas no uniform trend in recovery times and no differences in responsiveness to handling were observed. Neither individual agents nor combinations blocked all reflex reactions to external stimulation in all fish of any treatment group. MS‐222 and benzocaine, used separately or in combination anaesthesia, were the most effective agents in reducing reflex reactions. |
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Keywords: | Atlantic halibut anaesthesia pre‐anaesthetic sedation MS‐222 benzocaine metomidate 2‐phenoxyethanol isoeugenol quinaldine |
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