Threadfin butterflyfish have predominantly white faces and bodies, with yellow hindquarters. They display a thick black stripe across their eyes, and a black eyespot is present on the dorsal fin. Mature adults have a small, yellow trailing filament on their dorsal fins.
Threadfin butterflyfish inhabit the slopes of coral reefs, and their colouration varies depending on where they originate. For example, those found in the Red Sea do not have an eyespot.
These fish usually stay in a pairs while hunting small invertebrates such as shrimp, but the species is omnivorous and will scavenge if food is scarce.
IUCN status is Least Concern, but its populations are decreasing.
Also known as diagonal butterflyfish, cross-stripe butterflyfish and whip butterflyfish.
Common throughout the Indo-Pacific region – South Africa, Red Sea, Hawaii and Japan.
Grows up to 23cm long.