Chaetodon lunulatus, also known as the Redfin butterflyfish is known from the western Pacific widespread from Japan and Australia to Hawaii. To be found in monogamous pairs in coastal coral-rich areas. As many other coral juveniles too, Chaetodon lunulatus hide among branches of small corals.
It has a yellowish tinge with oblique purple-blue stripes and can be recognised very well by its woderful colouration and by grey caudal peduncle. A yellow-edged black bar passes through the eye, and a narrow black line crosses the cheek behind the eye. The red-orange anal fin has a yellow-edged black band along its base.
The Redfin butterflyfish can grow to max. 15 cm in length and feed solely on live corals.
Butterflyfish are not recommended for reefs as they will pick at or eat a wide variety of corals, fan worms, and other invertebrates. Most Butterflyfish are known to pick at Aiptaisia, a parasitic anemone.