Whitemargin Unicornfish

The Whitemargin Unicornfish is a large and elegant member of the Naso genus, named for the distinctive white margins visible on its tail and fins. Adults display a blue-gray to olive body with a long, prominent forehead horn that develops as the fish matures — a hallmark feature of many unicornfish species. With an adult size reaching 24 inches, this is a substantial and commanding reef fish.

In the wild, Whitemargin Unicornfish inhabit outer reef slopes, channels, and areas with strong currents throughout the Indo-Pacific. They are active swimmers that often form schools, feeding primarily on brown macroalgae and occasionally on zooplankton. Their powerful caudal fin and streamlined body make them well-adapted for life in current-swept environments.

In captivity, this species requires a very large aquarium of at least 300 gallons to accommodate its adult size and active swimming habits. It is a hardy species once acclimated, readily accepting dried nori and prepared foods. Like all large tangs, maintaining excellent water quality and providing a nutritious, algae-rich diet are essential for long-term health and preventing HLLE.