Paracanthurus

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 palette surgeonfish, blue surgeonfish, blue tang (leading to confusion with the Atlantic species Acanthurus coeruleus), flagtail surgeonfish, hepatus tang, Indo-Pacific bluetang, regal blue surgeonfish, wedge-tailed tang, wedgetail blue tang, royal blue tang, hippo tang, blue hippo tang, regal tang, and regal blue tang. It is most closely related to genus Zebrasoma, with which it forms a sister group.