Blue tangs (Paracanthurus hepatus, Linnaeus, 1766) are one of the most sought after fish in the marine aquarium trade. They have several different common names including Pacific blue tang, Palette tang, Regal tang, and Hippo tang, among others. These fish have a large natural range covering most of the Indo Pacific. In the wild they school together as juveniles and graze on algae and zooplankton. Because of this feeding behavior, they fair better in an established aquarium with good water quality, rock work, and substantial swimming space. This fish may be shy when first introduced to an aquarium but will adjust quickly provided that it has rock or other shelter to hide in. In captivity they will quickly learn to accept most food offerings. At the Sustainable Islands project, we condition our blue tangs to eat our hatchery diet, spirulina brine shrimp, mysis, and nori. They have large appetites and produce large amounts of waste, so adequate filtration and good water quality are essential. If these fish are not properly cared for, they can become susceptible to several diseases including marine ich (Cryptocaryon) and lateral line erosion. This is easily avoided with balanced nutrition and excellent water quality.
Physical Description– Blue tangs are prized for their gorgeous, unique coloration. They are royal blue in color with bold black markings. Their caudal fin is bright yellow, outlined in black which provides a beautiful contrast to their darker body. Both the dorsal and anal fins are rimmed in black. Like all tangs, they have a scalpel on their caudal peduncle which they use for defense. Specimens that are found along the coast of Africa may also have a pale yellow underside, giving them the name Yellow Bellied Blue Tangs.
Temperament– These are one of the more peaceful tangs and get along with most other tank mates. While they will school together as juveniles, they do not get along with others of the same species as adults, and therefore only one should be housed per system. They may also fight with fish that have a similar body shape, so care should be used when selecting tank mates. As stated, these fish can be shy when first introduced to a tank so avoid very aggressive or boisterous companions.
Size– Blue tangs can grow to an impressive size of 12 inches, though captive specimens rarely reach that length. Their large size and constant foraging behavior requires a tank size of 100 gallons or more.
Distribution– These fish have an extremely large range throughout the Indo Pacific. They can be found from the eastern coast of Africa to Fiji, as far north and south as Japan and Australia respectively. They are normally found among coral reefs but can be seen at depths ranging from 6-130 feet.