Table of Contents
ISRN Zoology
Volume 2013, Article ID 635704, 9 pages
Research Article

The Response of Gray Treefrogs to Anesthesia by Tricaine Methanesulfonate (TMS or MS-222)

1Department of Biological Sciences, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA
2Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN 55108, USA

Received 30 June 2013; Accepted 1 October 2013

Academic Editors: B. Crother and T. Miyata

Copyright © 2013 Mary Paduano et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The design of anesthetic protocols for frogs is commonly hindered by lack of information. Results from fishes and rodents do not always apply to frogs, and the literature in anurans is concentrated on a few species. We report on the response of treefrogs (Hyla chrysoscelis and H. versicolor) to tricaine methanesulfonate. Body mass did not differ significantly between the species or between sexes. In the first exposure of a frog to TMS, variation in induction time was best explained by species (H. chrysoscelis resisted longer) and body mass (larger animals resisted longer). Multiple exposures revealed a strong effect of individual variation on induction time and a significant increase of induction time with number of previous anesthesia events within the same day. Recovery time was mostly explained by individual variation, but it increased with total time in anesthetic and decreased with induction time. It also increased with number of days since the last series of anesthesias and decreased with number of previous uses of the anesthetic bath. This is one of the first studies of anesthesia in hylids and also one of the first assessments of the factors that influence the variability of the response to anesthesia within a species.