Paracanthurus hepatus

Common Names: Palette surgeonfish, blue tang, regal tang, flagtail surgeonfish, yellow-tail blue tang, hippo tang, Pacific blue tang, hepatus tang

Type Locality: Ambon Island, Moluccas Islands, Indobnesia

Range: Widespead in the Indo-Pacific, from East Africa to southern Japan to the Great Barrier Reef, New Caledonia, and Samoa

Taxonomic Troubles: Originally described as Teuthis hepatus

Size: 31 cm (12 inches) TL

Preferred Water Chemistry: Tropical marine, 24 to 28 degrees Celsius (75 to 82 degrees Fahrenheit.

Difficulty: Quite hardy once they are established in a mature sytem. Proper care and feeding will preserve health. Very susceptible to Cryptocaryon infection; cleaner shrimps or gobies are a great benefit. A frequent victim of HLLE, which can be prevented with scr

Tank Setup: Needs both open wimming area and ready access to cover. In the wild they forage in open water over hte reef and take refuge among Pocillopora coral branches at the first hint of danger. Reef safe--a natural planktonivore that will not harm any but the t

Feeding: Fully omnivorous. WIll feed on any plankton-like foods in the water column and will usually pick up microfauna from live rock. Should have constant access to macroalgae or prepared marine-algae foods.

Breeding: Not yet bred in captivity, but many captive-reared fish harvested before settling on the reef are available. These make excellent aquarium specimens.

Fish Description

Highly laterally compressed. Brilliant deep blue with yellow tail and pectorals, bold black marking from eye to tail with an open ring int he middle of the back; the black may form a complete or incomplete ring around the blue circle. (Some see a resemblance to the thumb hole of an artist's palette.


One of the two most popular tangs in the hobby, this fish is ubiquitous in reef and fish-only aquaria. It is probably the least aggressive tang, and it typically tolerates other fish, including conspecifics, provided the aquarium is large enough. In truly immense setups, it is possible to maintain a small school if the individuals are added all at one time.


Tankmates should be chosen carefully, as this fish cannot prevail against bullies or aggressive feeders. The hepatus tang is safe with just about any other fish, though long, dangly fins or spines may prove too much of a temptation and elicit a nip or two.

Water Quality

Like all acanthurids, P. hepatus demands pristine, well-oxygenated water. Powerful filtration, protein skimming, and regular water changes are necessary for prolonged health. This fish deserves its popularity, but it also demands strict attention to water quality and to diet to keep it healthy. In other words, it is hardy and long-lived in aquarium conditions, but only when cared for properly.