Palette surgeonfish

Paracanthurus hepatus is a species of Indo-Pacific surgeonfish. A popular fish in marine aquaria, it is the only member of the genus Paracanthurus.

A number of common names are attributed to the species, including regal tang, palette surgeonfish, blue tang (leading to confusion with the Atlantic species Acanthurus coeruleus), royal blue tang, hippo tang, blue hippo tang, flagtail surgeonfish, Pacific regal blue tang, blue surgeonfish, hepatus tang, Indo-Pacific blue tang, regal blue surgeonfish, wedge-tailed tang, and wedgetail blue tang.

It is most closely related to genus Zebrasoma, with which it forms a sister group.

Habitat

Paracanthurus is a diurnal marine species that occupies marine neritic habitats along coastlines. It is found in clear water on exposed outer reef areas or in channels with a moderate or strong current. It primarily utilizes coral reef habitats, but is also known to utilize seagrass beds, mangroves, algal beds, and rocky reefs [1]. It has an upper and lower depth limit of 2 meters and 40 meters, respectively . They live in pairs or small groups of 8 to 14 individuals. They can also be found near cauliflower corals on the seaweed side of coral reefs. Juveniles can be found in schools using Acropora for shelter. Numbers of males and females tend to maintain a 1:1 ratio.

The fish is important for coral health, as it eats algae that may otherwise choke it by overgrowth.

Distribution

The regal blue tang can be found throughout the Indo-Pacific. It is seen in the reefs of the Philippines, Indonesia, Japan, the Great Barrier Reef of Australia, New Caledonia, Samoa, East Africa, and Sri Lanka. A single specimen was photographed in 2015 in the Mediterranean Sea off Israel. Vagrants were found two separate occasions in Hawaii, and are assumed to be aquarium releases.

Paracanthurus is an extant resident in the following territories: American Samoa; Australia; British Indian Ocean Territory; Brunei Darussalam; Christmas Island; Cocos (Keeling) Islands; Comoros; Cook Islands; Disputed Territory (Paracel Is., Spratly Is.); Fiji; French Southern Territories (Mozambique Channel Is.); Guam; India (Nicobar Is., Andaman Is.); Indonesia; Japan; Kenya; Kiribati (Kiribati Line Is., Phoenix Is., Gilbert Is.); 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, Republic of China; Tanzania, United Republic of; Thailand; Timor-Leste; Tokelau; Tonga; Tuvalu; United States (Hawaiian Is.); United States Minor Outlying Islands (US Line Is., Howland-Baker Is.); Vanuatu; Viet Nam; Wallis and Futuna.

Behaviour

As a juvenile, its diet consists primarily of plankton. Adults are omnivorous and feed on zooplankton, but will also graze on filamentous algae.