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United States Department of Agriculture

Agricultural Research Service

Research Project: Genetics, Physiology, and Health Research to Improve Catfish Production

Location: Warmwater Aquaculture Research Unit

Title: Efficacy of metomidate and tricaine methanesulfonate to modulate the short-term cortisol stress response in channel catfish Ictalurus punctatus

Authors
item Mertell, M -
item Booth, Natha
item Peterson, Brian
item Stephens, W -
item Goudie, C -
item Simco, B -

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 23, 2013
Publication Date: N/A

Interpretive Summary: The ability of the anesthetics metomidate and tricaine methanesulfonate (MS-222) to reduce the cortisol stress response of channel catfish (Ictalurus punctatus) was evaluated during a 10 min confinement stress. Channel catfish (11.9 g) were transferred from holding tanks to confinement buckets and their plasma cortisol levels were compared every minute for 10 min to levels in fish confined but sedated with 12.5 ppm metomidate or 100 ppm MS-222. Cortisol levels of channel catfish anesthetized in metomidate remained at baseline levels throughout the 10 min exposure. Cortisol concentrations in fish anesthetized in MS-222 and non-anesthetized fish were approximately seven and twenty-two fold higher, respectively, than their baseline levels. However, the response of fish anesthetized in MS-222 did not significantly differ from baseline levels until 6 min of confinement. While both anesthetics effectively reduced the cortisol stress response, these results suggest that MS-222 is a sufficient anesthetic to use during the first 5 min of sedation and that metomidate should be used for longer periods of sedation.

Technical Abstract: The ability of the anesthetics metomidate and tricaine methanesulfonate to mitigate the cortisol stress response of channel catfish Ictalurus punctatus was evaluated during a 10 min confinement stress. Channel catfish (11.9 ± 0.5 g; mean ± SE) were transferred from holding tanks to confinement buckets containing 2 L of aerated water and their plasma cortisol levels were compared every minute for 10 minutes to levels in fish confined but sedated with 12.5 ppm metomidate or 100 ppm MS-222. Cortisol levels of channel catfish anesthetized in metomidate remained at baseline levels throughout the 10 min exposure (P > 0.05). Cortisol concentrations in fish anesthetized in MS-222 and non-anesthetized fish were approximately seven and twenty-two fold higher (P < 0.05), respectively, than their baseline levels. However, the response of fish anesthetized in MS-222 did not significantly differ from baseline levels until 6 min (P = 0.02) of confinement. While both anesthetics effectively mitigated the cortisol stress response, these results suggest that MS-222 is a sufficient anesthetic to use during the first 5 min of sedation and that metomidate should be used for longer periods of sedation.

Last Modified: 7/22/2014
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