Paracanthurus hepatus

''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 , royal blue tang, hippo tang, flagtail surgeonfish, Pacific regal blue tang and blue surgeonfish.