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

Abstract

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.

Dietary niacin requirement of juvenile blunt snout breamMegalobrama amblycephalabased on a dose-response study

“…The remaining fish were anesthetized in diluted MS‐222 (tricaine methanesulfonate; Sigma) at a concentration of 100 mg/L. The solution was neutralized with NaOH before use because MS‐222 has been shown to be safer and more effective for aquatic animals at a neutral pH (Paduano, Colafrancesco, Wong, Caldwell, & Gridi‐Papp, ). Six fish/tanks were randomly sacrificed for an analysis of biometric parameters.…”

The right thalamus may play an important role in anesthesia-awakening regulation in frogs

“…On the other hand, previous studies in fishes and amphibians have found that larger subjects need longer MS-222 induction times and exhibit shorter recovery times ( Cecala & Price, 2007 ; Paduano et al, 2013 ; Zahl et al, 2009 ; Zahl et al, 2011 ). In the present study, the body mass of females on average was twice that of males, suggesting that the observed sex differences may have resulted from body mass differences.…”

The directional testes asymmetry increases with temperature in seven plateau brown frog (Rana kukunoris) populations

“…A plastic bucket was prepared with the TMS (Tricaine methane sulfonate, CAS: 886-86-2, Purity: > 97.0%, Sigma-Aldrich) at 2g/L in 5000 mL fresh water aerated for at least 48 h for dechlorination and oxygenation (Paduano et al, 2013). Then, every five frogs were put into this plastic bucket containing the 5000 mL anesthetic bath.…”