Abstract
Invasive surgical procedures on sturgeon (family Acipenseridae) are sometimes conducted without anesthesia. We examined plasma cortisol concentrations in Atlantic Sturgeon Acipenser oxyrinchus exposed to the anesthetic MS-222 (tricaine methanesulfonate), electronarcosis, or no anesthetic 1 and 24 h after a small incision mimicking an invasive procedure (tag implantation or laparoscopy). We also determined the feasibility of using electronarcosis in the field and the effect of salinity on electronarcosis. One hour after surgery under electronarcosis or MS-222 anesthesia, cortisol concentrations did not differ significantly from those in untreated controls but all three were significantly lower than the no-anesthetic group. There were no significant changes between 1- and 24-h blood cortisol concentrations. We recommend electronarcosis as a method to minimize stress in fish studies involving surgical procedures because it avoids the use of toxic chemicals and because induction and recovery are virtually instantaneous.
Received March 7, 2013; accepted June 28, 2013
ACKNOWLEDGMENTS
We thank all the members of the Maryland Department of Natural Resources Fisheries Division for supplying fish for this study. We also thank Mark Matsche (Maryland Department of Natural Resources Cooperative Oxford Laboratory); Albert Spells, Cyrus Brame, Michael Odom, and Ed Darlington (U.S. Fish and Wildlife Service); Chuck Frederickson and Jameson Brunkow (James River Association); Boyd Kynard (University of Massachusetts, Amherst); Thomas Huff, Anne Wright, and Leonard Smock (Virginia Commonwealth University); and Jason Kahn and Malcolm Mohead (National Oceanic and Atmospheric Association) for assistance with this project. We thank three anonymous reviewers for their editing of this paper. This is Virginia Commonwealth University Rice Center Contribution Number 36, and Contribution Number 3316 of the Virginia Institute of Marine Science, College of William and Mary.