20., see text Naso is a genus of marine ray-finned fishes belonging to the family, Acanthuridae, the unicornfishes, surgeonfishes and tangs.

The fishes in this genus are known commonly as unicornfishes because of the "rostral protuberance", a hornlike extension of the forehead present in some species.

[2] Naso is the only genus in the monogeneric subfamily Nasinae, proposed by Henry Weed Fowler and Barton Appler Bean in 1929[9] within the family Acanthuridae.

[11] Naso unicornfishes are found in the Indo-Pacific region from the eastern coast of Africa to the Galápagos Islands.

[12] Naso unicornfishes have a pointed snout and a rhomboidal or oval shaped body, with some species possessing a long protuberance on the forehead, typically present in both males and females.

The caudal peduncle is slender and there are 1 or 2 anteriorly directed sharp, blade-shaped spines mounted on bony plates on each side.

[14] Naso unicornfishes differ from other acanthurids in that they eat zooplankton rather than grazing on algae or detritus and that they tend to live at greater ranges of depth.