Banded Unicornfish

About

The banded unicornfish (Naso annulatus) is one of the larger members of the unicornfish clan, and that size is the first thing any prospective keeper needs to reckon with. Adults develop the characteristic rostral horn projecting from the forehead, and the tail base sports the paired keeled plates typical of the Naso genus. The species ranges across a huge sweep of the Indo-Pacific, from East Africa and the Mascarene Islands out through Polynesia to Hawaii, with populations documented as far north as southern Japan and as far south as Lord Howe Island. Juveniles hang around shallow, clear lagoon reefs close to the surface, but mature fish shift dramatically toward deeper water, typically appearing along outer reef drop-offs at 25 meters or more, often moving in small schools. They feed primarily on large zooplankton during daylight hours and retreat into reef structure at night, with benthic algae rounding out the diet. In the aquarium this species is peaceful toward tankmates of compatible temperament, though like most large surgeonfish it can hold its own if pushed. The immediate challenge for most hobbyists is the sheer tank footprint this fish demands. This is genuinely a species for public aquariums or exceptionally large private systems, not a typical home setup.