Plectranthias bennetti | Probably the only one on public display in the world, though they show up in the aquarium trade every few years. Its in the same tank as the Peppermint Angelfish, which makes for a really colorful duo
This species has gotten a name change! A revision of Plectranthias published yesterday has split it into 7 genera, and this species is now Pelontius bennetti.