Pharyngeal teeth from a Freshwater drum (Aplodinotus grunniens). Pharyngeal "throat" teeth are located on the last gill arch at the posterior region of a fish's head. They are visible only upon lifting off the gill cover (operculum) and exposing the gills beneath. The arrangement and number of these teeth are specific for certain families and species of fish. Shown here are those of the freshwater drum or "sheepshead."