Heniochus

Heniochus is a genus of marine ray-finned fish, butterflyfishes from the family Chaetodontidae. They are native to the Indo-Pacific. Though very similar in appearance to the Moorish idol (Zanclus cornutus), the members of this genus are not closely related to it.

==Characteristics== Heniochus species are distinguished within the Chaetodontidae by having the fourth spine in the dorsal fin elongated, or even forming a filament. The supraorbital crests in adults have spines or horn-like protuberances. They normally have a hump, or at least a robust bony growth on the nape.