Description:

Dorsal spines: 6; Dorsal rays: 27-29; Anal spines: 2; Anal rays: 27-30.

Adults light bluish grey (can be metallic blue perhaps in case of breeding colours) to olivaceous brown, usually paler anteriorly and on throat. Short, dark grey, irregular 
vertical lines on body ending as rows of spots ventrally. Head with small dark spots or a reticular pattern of lines; a broad-based tapering horn, with oblique dark lines, 
in front of the eye projecting as much as a head length in front of the mouth. Edges of lips pale blue, opercular membrane white, adjacent body often blue.  Caudal fin 
truncate to slightly rounded, mainly whitish. 2 peduncular plates on each side with only moderate keel development.  

Maturity: Lm unknown. Range unknown. Max Length: 60cm FL.

Occurs on coral reefs and over rocky substrata, inhabiting mid-waters on steep outer lagoon and seaward reef drop-offs (depth 2-122m, usually 4-46m). Juveniles in sheltered
habitats usually 2-20m depth. Juveniles and subadults graze on benthic algae; adults feed primarily on zooplankton. Usually occurs in small groups but forms large schools 
in oceanic locations or on reefs subject to strong currents. 
 

This species is not protected or subject to fishery regulations. It is caught in the fish trap fishery, but is an uncommon component of the catch.
 

In water photo courtesy Eleanor Brighton and Chris Mason-Parker (c) 2022 Blue Safari Seychelles/Marine Conservation Society, Seychelles. Photograph taken at Alphonse group 2022.

Choat, J.H. et al. (2012). Naso brevirostris. The IUCN Red List 2012: e.T177990A1513480. http://dx.doi.org/10.2305/IUCN.UK.2012.RLTS.T177990A1513480.en. (16/10/18).
EOL (2018). Naso brevirostris Spotted unicornfish http://eol.org/pages/213852/details (16/10/18).
Froese, R. & D. Pauly. Eds. (2018). FishBase. www.fishbase.org, https://www.fishbase.de/summary/Naso-brevirostris (16/10/18)
Randall, J.E. (2001). Surgeonfishes of Hawaii and the World. ISBN: 1-56647-561-9
 

Nevill, J.E.G. (2019). Naso brevirostris, Spotted unicornfish. Seychelles Seatizens. www.seatizens.sc. https://seatizens.sc/species/naso-brevirostris-cuvier-1829/  (edited 16/06/22).