Bluespine Unicornfish, Naso unicornis Click to enlarge image
A Bluespine Unicornfish at a depth of 12 m, Harrier Reef, Great Barrier Reef north of Port Douglas, Queensland, 22 Nov 1998. Image: Erik Schlögl
© Erik Schlögl

Fast Facts

  • Classification
    Species
    unicornis
    Genus
    Naso
    Family
    Acanthuridae
    Order
    Perciformes
    Class
    Actinopterygii
    Subphylum
    Vertebrata
    Phylum
    Chordata
    Kingdom
    Animalia
  • Size Range
    The species grows to 70 cm in length.

Introduction

The Bluespine Unicornfish is usually greenish-grey and has a bony horn projecting from the head in front of the eyes. It is found in tropical reef waters.



Identification

The Bluespine Unicornfish has a bony horn projecting from the head in front of the eyes. There are two blue plates bearing knife-like spines on either side of the caudal peduncle. The tail is emaringate (glossary) in young fish but becomes truncate with filamentous lobes in larger individuals.

The Bluespine Unicornfish is usually greenish-grey. The dorsal and anal fins are yellowish with thin blue lines.

Distribution

The species is found in tropical reef waters of the Indo-Pacific. In Australia it is recorded from south-western to north-western Western Australia and the northern Great Barrier Reef to northern New South Wales.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.



References

  1. Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Western Australian Museum. Pp. 292.
  2. Allen, G.R. & R. Swainston. 1988. The Marine Fishes of North-Western Australia. A Field Guide for Anglers and Divers. Western Australian Museum. Pp. 201.
  3. Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. New Holland. Pp. 433.
  4. Randall, J.E., Allen, G.R. & R.C. Steene. 1997. Fishes of the Great Barrier Reef and Coral Sea. Crawford House Press. Pp. 557.