Uncommon in the Solitary Islands Marine Park. Distributed throughout the Indo-Pacific region: Red Sea and East Africa to the Hawaiian, Marquesas and Tuamoto islands, north to southern Japan, south to Lord Howe and Rapa islands. In Australia recorded from around Geraldton and north through to the North West Shelf of Western Australia, the Coral Sea and Great Barrier Reef in Queensland south to southern New South Wales and including Lord Howe Island.
Frequents shallow reef flats, lagoons and seaward reefs with strong surge. Juveniles often found in shallow coastal bays. Depth to 30 m.
Pale olive colour with two blue spines on tail base. In adults the horn does not project past mouth. Sub adult top picture, juvenile below. Feed on coarse leafy algae like Sargassum. Grows to 70 cms.
R. Stuart-Smith, G. Edgar, A. Green, I. Shaw, Tropical Marine Fishes of Australia. Reed New Holland Publishers, 2015. p.435.
Atlas of Living Australia website at https://bie.ala.org.au/search?q=naso+unicornis. Accessed 08/06/18.
FishBase. Froese, R. and D. Pauly. Editors. 2018. World Wide Web electronic publication. https://fishbase.ca/summary/naso-unicornis.html. Accessed 08/06/18.