The Clown Tang (Acanthurus lineatus), also sold as the Clown Surgeonfish, Lined Surgeonfish, Striped Tang, Pyjama Tang, or Blue-Banded Surgeonfish, is one of the most boldly marked members of the Acanthuridae family. Alternating horizontal bands of electric blue and black-edged yellow-orange run along the upper body, giving way to a bluish-white to pale purple belly, and the forked caudal fin carries a black edge with an asymmetrical blue-and-yellow pattern. Juveniles show a rounded tail that becomes deeply forked with maturity. Adults reach roughly 15 inches, and like all surgeonfish they carry sharp, potentially venomous scalpels at the caudal peduncle. The species ranges widely across the Indo-Pacific, from East Africa and the Mascarene Islands to Hawaii, the Marquesas, and the Tuamotos, north to Japan and south to the Great Barrier Reef and New Caledonia.

In nature this is a fish of turbid surge zones and exposed reef edges down to about 50 feet, where juveniles shelter among shallow rubble. Reproducing that environment is the core challenge of keeping one. Plan on a mature system of at least 250 gallons, with length prioritized over height, since a Clown Tang swims continuously and forcefully throughout the day. Aquascape with plenty of live rock carrying established algae growth for grazing, arranged into caves, crevices, and overhangs that provide shelter and defensible territory without eating into open swimming lanes.

Water quality must be excellent and highly oxygenated. Powerheads or wavemakers should generate strong, even turbulent flow to mimic surge conditions, backed by heavy mechanical and biological filtration and a protein skimmer, because this species reacts poorly to declining conditions and accumulating toxins. A tight-fitting lid is important, as startled or newly introduced individuals will jump. When handling becomes necessary, guide the fish into a container rather than a net; the caudal spines tangle easily and can injure both fish and keeper.