Regal Tang

The Regal Tang (Paracanthurus hepatus) is one of the most instantly recognizable reef fish in the world, thanks to its brilliant blue body, black palette-shaped markings, and bright yellow tail. Also widely known as the blue tang or palette surgeonfish, it belongs to the surgeonfish family and carries the characteristic sharp, scalpel-like spine near the base of its tail used for defense. It is found across the Indo-Pacific on coral reefs, where juveniles often shelter within branching Acropora coral heads while adults range more openly over reef slopes in loose schools. The species gained enormous popular recognition as the character Dory in animated films, which significantly boosted aquarium demand, though wild populations remain broadly stable across most of its range.

• Color: Bright royal blue body with a bold black 'palette' pattern along the back and flank.
• Tail: Solid bright yellow, crescent-shaped caudal fin.
• Spine: Sharp, retractable scalpel-like spine at the base of the tail, characteristic of surgeonfishes.
• Shape: Oval, laterally compressed body with a small pointed mouth.
• Look-alikes: Juveniles are almost entirely yellow with blue eye-rings, sometimes confused with other juvenile tangs, but the developing black palette pattern quickly distinguishes them.

Regal Tangs inhabit clear coral reef environments across the Indo-Pacific, from East Africa and the Red Sea to Samoa, and north to southern Japan. They favor outer reef slopes and seaward reef faces with strong water flow, typically at depths of 2 to 40 meters. Juveniles are closely tied to branching coral formations, especially Acropora thickets, which provide shelter from predators, while adults move more freely over open reef terrain in loose aggregations. The species requires clear, well-oxygenated tropical water and healthy coral cover, making it a useful indicator of reef condition in areas where it is monitored.

Regal Tangs are primarily planktivorous, hovering above the reef to pick zooplankton from the water column, though they will also graze algae from rock surfaces when plankton is scarce. Juveniles are solitary and highly territorial, darting into coral branches at the first sign of danger, while adults often form loose, mixed-size schools that provide safety in numbers on open reef slopes. When threatened, they can erect the sharp caudal spine as a defensive weapon against predators and rivals. Spawning occurs in open water, typically at dusk, when groups rise off the reef to release eggs and sperm that drift as plankton before larvae eventually settle back onto coral reefs.