Xiphochilus fasciatus [now Choerodon fasciatus] - The Harlequin Tusk Wrasse
More colloquially known as the “Harlequin Tusk” by wrasse fanciers, this fish is a difficult keeper in an aquarium, but a very flashy specimen. Illustrations can’t truly capture the low-level bioluminescence or UV reflection in the live animals.
The Harlequin Tusk’s long, sharp teeth would seem to imply a more hostile creature than other wrasse, they’re only semi-territorial, and will tolerate other semi-aggressive fish around (such as blenny and angelfish), so long as no other Harlequin Tusks are present. Their primary foodstuffs consist of small-to-medium sized crustaceans that live in reefs, so they’re not considered “reef-friendly”, though they don’t destroy coral itself.
Proceedings of the Zoological Society of London. 1867.