Clove Oil Anesthesia Does Not Inhibit the Stress-Induced Increases in Plasma Cortisol and Glucose in Rainbow Trout.
J.D. Morgan* and E.P. Groot, Faculty of Science and Technology, Malaspina University-College, Nanaimo, BC V9R 5S5
Clove oil has recently become a popular fish anesthetic due to its low cost and apparent safety to both fish and humans. Effective anesthetic dosages have been determined for several fish species, however the physiological stress effects of clove oil are not well understood. Laboratory trials were conducted that investigated the modulation of the plasma cortisol and glucose stress response by several concentrations (20 â€"œ 200 mg/L) of clove oil. Rainbow trout were anesthetized prior to a 1 min dipnet stress and sampled at 15 and 60 min after the stressor was applied. For comparison, similar trials were conducted with doses of MS-222 (100 mg/L) and metomidate (5 mg/L) that are known to suppress the stress-induced increase in plasma cortisol and glucose. Prior anesthesia with clove oil did not significantly block the cortisol and glucose stress response, and there appeared to be a dose-related increase in these variables. By contrast, prior anesthesia with MS-222 and metomidate did significantly reduce the stress response. The different response observed with clove oil may be related to its mode of action, as it may anesthetize the fish without inhibiting the H-P-I axis. The results also suggest that clove oil would probably not be effective as a sedative in reducing physiological disturbances that may occur during aquaculture procedures such as handling and transport.
Clove oil as an anaesthetic for adult sockeye salmon:
Anderson WG, McKinley RS, Colavecchia M (1997) The use of clove oil as an anesthetic for rainbow trout and its effects on swimming performance. North American Journal of Fisheries Management. 17(2):301-307
NAL Call No. SH219.N66
The only anesthetic registered in North America for use in fisheries science is 3-aminobenzoic acid ethyl ester methanesulfate (tricaine or MS-222). Although MS-222 is a very effective anesthesia for several fish species, its application in the field is limited because U.S. Food and Drug Administration guidelines demand a 21-d withdrawal period after exposure to MS-222 before fish can be released and enter the food chain. As a consequence, carbon dioxide (CO2) has been used as a substitute anesthetic; however, induction and recovery times with CO2 are long, and anesthesia is shallow in comparison with MS-222. We compared the efficacy of MS-222 to that of clove oil, a naturally occurring substance, for use as an anesthetic for juvenile and adult rainbow trout Oncorhynchus mykiss. Clove oil was as effective as MS-222 in inducing anesthesia in both age-groups. Furthermore, exposure to either clove oil or MS-222 at the concentrations tested was not detrimental to critical swimming speed of juvenile or adult rainbow trout. We propose that clove oil be considered as an alternative to MS-222 for use as a fish anesthetic.
Descriptors: swimming, anaesthetics, anesthetics, Oncorhynchus mykiss, Eugenia aromatica, clove oil, rainbow trout
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Effects of clove oil anaesthesia on common carp (Cyprinus carpio L.)