pharyngeal teeth

noun

Opposing patches of teeth which occur on the upper and lower elements of the gill arches. May be placed in a dorsal and ventral pair, as in most teleost fishes, or in laterally opposing pairs, one set on each side, as in Cyprinidae and Catostomidae. The upper pharyngeal teeth are located on a dentigerous plate on the fourth pharyngobranchials and the lower pharyngeal teeth on the dentigerous plate on the fifth ceratobranchials. The pharyngeal teeth of minnows and suckers are processes on the dentigerous plate of the fifth ceratobranchials and are thus homologous to the lower pharyngeal teeth of other fishes; these oppose a prominent horny pad which rests on a projection from the basioccipital. The pharyngeal teeth vary from sharp and piercing to nodular or molariform; they may be modified into a grooved grinding apparatus (or pharyngeal mill), such as seen in the parrotfishes.