Clown Surgeonfish

About

The blue banded surgeonfish (Acanthurus lineatus) is widely regarded as the most aggressive tang species you are likely to encounter in the saltwater hobby, and that reputation is well earned. Across its broad Indo-Pacific range, from East Africa and the Mascarene Islands out to Hawaii and the Marquesas, this fish dominates the surge zones of exposed seaward reefs. Males stake out well-defined feeding territories and maintain harems of females, patrolling almost constantly throughout the day. In the aquarium that territorial drive does not switch off, and this species will bully, harass, and potentially injure tankmates if conditions do not give it enough room to establish its own space. The bold pattern of horizontal blue, yellow, and black banding along the body makes it unmistakable, and adults can reach a substantial size. Juveniles are secretive and solitary by nature, hiding among rubble in shallow reef areas, but adults in the wild commonly form schools in gutters and along surge channels. A practical caution worth knowing: the caudal peduncle carries venomous spines that can inflict a genuinely painful wound on fish and fishkeeper alike, so handle with care during tank transfers. This is a species best suited to experienced reefkeepers with appropriately large, well-established systems.