Unicorn Tang

The Unicorn Tang is one of the most distinctive and instantly recognizable fish in the marine aquarium hobby, named for the prominent horn-like projection that develops on the forehead of adults. This bony rostrum grows progressively longer as the fish matures, extending forward from between the eyes in a feature that is unique among commonly kept aquarium fish. The body is olive-gray to brownish-green with fine longitudinal lines, and the tail base features two pairs of fixed, blue-rimmed keeled plates that serve as defensive weapons. Mature males develop long, flowing tail streamers that add to the species' impressive appearance.

In the wild, the Unicorn Tang has an exceptionally broad distribution spanning the entire Indo-Pacific, from the Red Sea and East African coast to Hawaii and French Polynesia. It inhabits outer reef slopes, channels, and lagoons with strong currents, where it feeds primarily on brown leafy macroalgae such as Sargassum. Large adults are powerful, fast swimmers that cover considerable distances, and they can often be seen in small groups patrolling reef walls and surge channels.

With a potential adult size of 24 inches, the Unicorn Tang is one of the largest species kept in home aquariums and requires an enormous system of at least 300 gallons to provide adequate swimming space. This is not a fish for the average home aquarium. However, for aquarists with sufficiently large systems, the Unicorn Tang is a rewarding and impressive specimen. It is a dedicated herbivore, completely reef-safe, and generally peaceful toward dissimilar tankmates despite its imposing size. The development of the horn and tail streamers over time makes it a fascinating long-term project fish.