Fin's Fish Guide
The Bluespine unicorn (Naso unicornis) is a saltwater fish of the family Acanthuridae that grows up to 70 cm.
Description
The bluespine unicornfish is a large surgeonfish of the family Acanthuridae from the Indo-Pacific. The species grows to about 70 cm and has an olive-grey body and a conspicuous, forward-projecting bony horn on the forehead, to which the name refers. It inhabits channels, moats, lagoon and seaward reefs with strong current. As a herbivore it grazes mainly coarse leafy seaweed. Unlike true surgeonfishes it bears on each side of the tail base two pairs of fixed, sharp, blue bony plates (keel spines) that can give deep cuts; never grab the fish by the tail. The bluespine unicornfish is a local food fish.
Frequently asked questions
How do you recognise the Bluespine unicorn?
The Bluespine unicorn has a flattened, disc-shaped body, is mainly green and shows a plain pattern. Forward-projecting bony horn on the forehead and two pairs of sharp blue keeled spines on the caudal peduncle. Note: in tropical areas this species can cause ciguatera poisoning when eaten; large specimens of coral reef predators can accumulate the toxin. Eat with care or avoid in risk areas.
Where does the Bluespine unicorn live?
The Bluespine unicorn lives in the sea (marine waters) and is mostly found around stony or rocky ground. Indo-Pacific; channels, lagoon and seaward reefs with strong currents.
How big does the Bluespine unicorn get?
The Bluespine unicorn grows to a maximum of about 70 cm. On average the species is around 50 cm.
Is the Bluespine unicorn dangerous to humans?
The Bluespine unicorn is venomous — handle spines with care and seek medical help after a sting if needed. On each side of the tail base are sharp, scalpel-like bony plates that can give deep cuts; never grab the fish by the tail. Clean the wound thoroughly and seek medical care for a deep or infected wound.
Is the Bluespine unicorn edible?
Yes, the Bluespine unicorn is commonly eaten.
More photos
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All data
Identification
Appearance
Habitat & distribution
Behaviour & biology
For anglers
Safety
Status & sources
Same genus Naso
More from the family Acanthuridae
Want the complete picture on the Bluespine unicorn?
Point your camera at the fish and Fin names the species in seconds. Free, and the Bluespine unicorn is one of 12,519 species in the app.