Three-banded Butterflyfish

Chaetodon humeralis has an oval disc-like body which is strongly compressed and it has a small mouth positioned at the end of a short snout. The colour of the body is white or silvery white with obvious brownish-black bands on the line of the pectoral fin and another running in from the base of the caudal fin, a third brownish-black band runs from the nape down through the eye to the throat. The median fins all have black bands through them. There are 12–13 spines and 18–20 soft rays in the dorsal fin while the anal fin contains 3 spines and 15–17 soft rays. The maximum total length reached is 25.4 centimetres (10.0 in) but 12 centimetres (4.7 in) is more typical.

Chaetodon humeralis is found in the Eastern Pacific Ocean, its most northerly occurrence is at Redondo Beach in Los Angeles, California and from there, its range extends south to Peru. It is also found around the Galapagos Islands of Ecuador, the Revillagigedo Islands of Mexico, Cocos Island in Costa Rica and Malpelo Island in Colombia.