No Effects of Two Anesthetic Agents on Circulating Leukocyte Counts or Resistance to Trematode Infections in Larval Amphibians

Abstract

Abstract Pharmacological anesthetics are used frequently in aquatic animal husbandry and research. Although several studies have investigated the effects of these anesthetic agents on immune responses in fish, none have assessed such effects in amphibians. To address this disparity, we exposed Osteopilus septentrionalis tadpoles to 0.005% benzocaine, 0.1% tricaine methanesulfonate (MS-222), or artificial spring water, and quantified circulating white blood cells and susceptibility to infection by larval trematodes. Exposure to neither MS-222 nor benzocaine elevated circulating white blood cells relative to water-exposed tadpoles. Furthermore, anesthetic treatment did not affect resistance to larval trematode infection. These results indicate that the anesthetics tested here probably do not affect tadpole immune function and should aid researchers in determining anesthetic usage.