The purple tang (Zebrasoma xanthurum) is a marine reef tang in the fish family Acanthuridae. The fish grows to a maximum length of 25 centimeters (9.8 inches) in the wild but rarely surpasses 20 centimetres (7.9 inches) in captivity. Zebrasoma xanthurum inhabits the Red Sea, the west coast of India, the east coast of Africa, and the Persian Gulf, where it may live at water depths of 1 to 20 metres (3 to 65 feet) or more. Zebrasoma xanthurum is a popular fish in the aquarium trade. It is a herbivorous fish eating primarily filamentous algae. Zebrasoma xanthurum is omnivorous in its juvenile stage, but becomes increasingly herbivorous as it matures.
In the home aquarium, Zebrasoma xanthurum prefers a large, well established tropical marine reef system of 100 gallons or more with ample rock for grazing. Food in the form of marine macroalgae should be offered multiple times daily, Purple Tangs will also readily accept most forms of flake and frozen food. Although this is a generally peaceful fish, it should be introduced last into the home aquarium in order to avoid territorial disputes. In the home aquarium, Zebrasoma xanthurum faces two major challenges. It is especially vulnerable to parasites such as Cryptocaryon Irritans and Amyloodinium Occelatum, and it is susceptible to head and lateral line erosion (HLLE). Both parasites and HLLE are both best addressed by offering a vitamin and highly unsaturated fatty acid (HUFA) enriched diet and by utilizing a thorough quarantine process.