Of the nearly 30,000 species of fish,1 teleosts constitute approximately 96%, so most anesthesia studies involve these and, to a lesser extent, elasmobranchs (sharks, rays, and skates) and other fi sh. But given the anatomic, physiologic,
and behavioral variation among fi sh, extrapolation of the limited published data to all species is potentially harmful. Development of anesthetic regimens for unfamiliar species-drug combinations will benefi t from an understanding
both of fi sh natural history and of the taxonomic relationship between the species of concern and more studied species.