Bluespine Unicornfish

The bluespine unicornfish (or Naso unicornis) inhabits tropical coral reefs, reef slopes, and outer reef drop-offs, where it occupies both shallow coastal waters and deeper reef zones. Its range is extensive across the Indo-Pacific, stretching from the east coast of Africa and the Red Sea through Southeast Asia to Australia, Japan, and the islands of the central Pacific.

It has a streamlined, laterally compressed body and grey-blue to olive colouration, with distinctive blue caudal spines near the tail. Mature individuals develop a characteristic horn-like projection on the forehead, giving the species its common name and making it easily recognisable among reef fishes.

The bluespine unicornfish typically reaches 45cm to 60cm in length and weighs 3kg to 5.5kg. Males and females are similar in size and appearance, but males have longer horns, fin spines and fin filaments than females.