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Marine Animal Encyclopedia

Bignose Unicornfish Naso vlamingii

Unicornfish are so called because many have a hornlike projection on their forehead. However, the bignose unicornfish just has a rounded bulbous snout. At the base of the tail are two pairs of fixed, bony plates that stick out sideways like sharp knives, and the fish can inflict a serious wound on a potential predator. These blades are characteristic of surgeonfish (Acanthuridae), the family to which unicornfish belong.

Usually dark with blue streaks, the bignose unicornfish can pale instantly to a silvery gray. This often happens when the fish is being cleaned by a cleaner wrasse. The bignose unicornfish favors steep reef slopes where it can feed on zooplankton in the open water.

Bignose Unicornfishzoom image
  • Order Perciformes
  • Length Up to 24 in (60 cm)
  • Weight Not recorded
  • Depth 3–165 ft (1–50 m)
  • Distribution Tropical waters of Indian Ocean and southwestern Pacific
Bignose Unicornfish habitat mapzoom image