[7] The back has a broad black area that encloses at the tip of the pectoral, creating a blue oval on each side of the fish that extends in the direction of the eye.

Black surrounds the triangle on the upper and lower lobes of the caudal fin, in the same hue as the back area.

Scales anteriorly placed on the head between the eye and the upper jaw are larger with tuberculated, bony plates.

[8] Its pelvic fin is made up of one spine and three rays; this characteristic is considered a synapomorphy of the Naso and Paracanthurus genus.

); Madagascar; Malaysia; Maldives; Marshall Islands; Mauritius; Mayotte; Micronesia, Federated States of ; Myanmar; Nauru; New Caledonia; Niue; Northern Mariana Islands; Palau; Papua New Guinea; Philippines; Réunion; Samoa; Seychelles; Singapore; Solomon Islands; Somalia; South Africa; Sri Lanka; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Timor-Leste; Tokelau; Tonga; Tuvalu; United States (Hawaiian Is.

[14] It is found in clear water on exposed outer reef areas or in channels with a moderate or strong current.

Males aggressively court female members of the school, leading to a quick upward spawning rush toward the surface of the water during which eggs and sperm are released.

The fertilized eggs hatch in twenty-four hours, revealing small, translucent larvae with silvery abdomens and rudimentary caudal spines.

[6] Fishes in the family Acanthuridae, including Paracanthurus, produce altricial larvae that receive no v. parental care.

These spines, one on each of the two sides of the caudal peduncle, the area where the tail joins the rest of the body, are extended when the fish is stressed.

The quick, thrashing sideways motion of the tail can produce deep wounds that result in swelling and discoloration, posing a risk of infection.

[18] The regal blue tang is one of the most common and most popular marine aquarium fish all over the world, holding its place as the 8th most traded species worldwide.

[4] In 1997–2002, 74,557 individuals were traded in official tracked sales[4] and in 2011 approximately 95,000 Paracanthurus were imported for use as a marine ornamental fish.

[17] When harvesting Paracanthurus in the wild, juveniles are specifically targeted since they are easiest to collect due to their tendency to travel in schools.

[19] In the 2003 Disney/Pixar film, Finding Nemo, one of the main characters, Dory (voiced by Ellen DeGeneres) is a regal blue tang suffering from short term memory loss.

She and her parents, Jenny and Charlie (voiced by Diane Keaton and Eugene Levy), appear in the 2016 Disney/Pixar film sequel, Finding Dory.

[4] In an endeavor to mitigate the destruction of natural regal blue tang populations, efforts have been made to breed the species in captivity.

It was successfully captive-bred for the first time in 2016, after a 6-year long effort by biologist Kevin Barden of Rising Tide Conservation.