Chaetdon lunula is also known as the Half-moon butterflyfish, Moon butterfly fish, Racoon coral-fish, Raccoon butterfly, Raccoon butterflyfish or Red-striped butterflyfish, from the order of Perciformes and family of Chaetodontidae.
Body shape is in the form of a compressed oval disc. It has a small mouth at the end of a pointed snout. It has a continuous dorsal fin and its pectoral fin is rounded. Overall body is of a yellow colour with a brown gradient at the back. There is a broad black streak that crosses the eye, followed by a white one, from which a diagonal broad black streak emerges; from gill cover to the dorsal fin. There are thinner diagonal stripes on the lower side of the body and a black patch on the caudal peduncle. The scales are rough and cover the entire body. It can reach a maximum length of 20cm.
This species is present throughout the Indo-Pacific region and South East Atlantic. It is found from East Africa to the Hawaiian, Marquesan, and Ducie islands, North to Southern Japan, South of Lord Howe and Rapa Islands. In the Southeast Atlantic Ocean, it can be found from East London to South Africa. Some stray individuals have been seen near the Galapagos Islands, Cocos Island, in the Eastern Pacific Ocean. Recorded depth range is between 0 to deeper than 30 m.
The Racoon butterflyfish inhabits in lagoons, outer reefs (rocky areas) and intertidal zones.
Its diet includes tubeworm tentacles, algae and rarely polyps. It is nocturnal, and usually dwell by pairs.
Chaetodon lunula is oviparous; produce eggs that mature and hatch outside of the body and are dispersed by currents. These fish are monogamous.
According to the IUCN Red list, this species is categorized as being of ‘Least Concern’ as it is common and widespread with no major threats. No declines in populations have been documented but this species does feed on live coral and with the event of coral bleaching due to anthropogenic climate change, this species might be at risk. Alongside monitoring of coral cover, this species needs to be monitored as well. It is frequently collected for aquarium trade. No conservation measures are in place for this species but it is present in many MPAs within its range.
This species can live up to 9 years.