What an absolutely odd thing!!!!!!!!!!!!!!!!!!!! It have the horned head of an Heniochus and the fins of a Chaetodon, plus a coloration that I can't associate with any species. My guess is that is an intergeneric hybrid (Chaetodon x Heniochus)
No, not a hybrid! This is the Dusky Butterflyfish, Chaetodon flavirostris. The species is fairly widespread in the Pacific, and occasionally appears in the aquarium trade.
