Palette Surgeonfish

The Palette Surgeonfish, widely known as the Blue Tang or Regal Tang, is a member of the family Acanthuridae and the sole species in the genus Paracanthurus. It is instantly recognizable for its vivid royal-blue body marked with a black pattern resembling an artist's palette, paired with a bright yellow tail. Native to coral reefs across the Indo-Pacific, from East Africa to the Great Barrier Reef and out to Samoa, it became one of the most recognizable reef fish worldwide after appearing as a popular animated film character. Unlike most tangs, which graze algae, this species feeds mainly on plankton in the water column above the reef. It is not considered globally threatened.

Distinctive features make this species hard to confuse with other tangs:

• Deep, oval, laterally flattened body in bright royal blue
• Bold black 'palette' pattern sweeping from the back down the flanks
• Vivid yellow, triangular tail fin
• Blue dorsal and anal fins narrowly edged in black
• A single sharp, scalpel-like spine at the base of the tail

Adults typically reach 15-31 cm. Juveniles show the same blue-and-black pattern but a more rounded body and shorter fins. No other Indo-Pacific surgeonfish combines this exact blue body with a solid yellow tail, making field identification straightforward even for non-specialists.

Palette Surgeonfish inhabit clear lagoon and seaward coral reefs across the tropical Indo-Pacific, from the coast of East Africa and the Red Sea eastward to Samoa, and from southern Japan south to the Great Barrier Reef. They are most often seen at depths of 2-40 m, hovering near branching coral heads such as Acropora, which provide shelter from predators. Juveniles and adults alike favor areas with strong water flow that delivers plankton, their primary food source. Individuals retreat quickly into coral branches when threatened, relying on the reef structure for protection rather than open-water escape, so healthy hard coral cover is essential to the species' local abundance.

This species is unusual among surgeonfishes for feeding mainly on zooplankton picked from the water column rather than grazing algae, and it is often seen hovering in loose aggregations above coral heads. Juveniles are largely solitary and territorial around a single coral head, while adults may form small groups or schools over more open reef areas. When alarmed, individuals dart into narrow coral branches, using their body shape to wedge in tightly out of reach of predators. Spawning occurs in pairs or small groups near dusk, with eggs released into open water as part of the typical broadcast-spawning strategy of the family. Its plankton-feeding habit links reef productivity to open-water food webs.