The five-lined cardinalfish (Cheilodipterus quinquelineatus) is a small tropical fish recognizable by its pale gray to whitish body marked with five thin black stripes. The base of its caudal fin has a black spot sometimes surrounded by yellow, and its jaws bear large, pointed teeth that resemble canine teeth.

This species lives on Indo-Pacific reefs, where it takes shelter in crevices, under overhangs, or among branching corals. Mainly active at night, it leaves its shelter to search for small prey before returning to the reef for protection.

The five-lined cardinalfish has an elongated body that is slightly compressed on the sides. Its pale gray to whitish coloration is marked with five thin black stripes. At the base of its caudal fin is a circular black spot, sometimes surrounded by yellow. The largest individuals can grow to about 5.1 inches in length.

Its jaws bear large, pointed teeth that are particularly noticeable in this small fish. They resemble canine teeth and are adapted for capturing prey.

The five-lined cardinalfish inhabits tropical waters of the Indo-Pacific, from the Red Sea and the coasts of East Africa to the Pitcairn Islands in the Pacific. To the north, its range extends to southern Japan, while to the south it reaches Lord Howe Island and Rapa.

The five-lined cardinalfish lives on reef flats, in lagoons, and on exposed offshore reefs. It is generally found from the surface to depths of about 131 feet.

The five-lined cardinalfish is mainly active at night. During the day, it takes shelter in reef crevices, under overhangs, among branching corals, or between the long spines of the long-spined sea urchin (Diadema setosum). It sometimes lives alone but can also form groups of several individuals.

The five-lined cardinalfish mainly feeds on small animals it finds around the reef. Its diet includes small crustaceans and gastropods, as well as small fish.

It mainly hunts at night, when it leaves its shelter to explore the surrounding area. It generally stays close to the reef, where numerous crevices and coral structures provide plenty of hiding places in case of danger.

During reproduction, the male and female come together before spawning to form a pair. The male then holds the eggs in his mouth while they develop. This mouthbrooding protects the eggs until they hatch.

As in other cardinalfish that practice mouthbrooding, the eggs remain protected until they hatch. This strategy allows the developing young to grow while sheltered from the many dangers found on the reef.

Despite its small size, this fish has large canine-like teeth that allow it to seize and hold its prey.

The five-lined cardinalfish is listed as many other marine species within The IUCN Red List of threatened species. The five-lined cardinalfish appears in the IUCN Red List since 2022 within the category Least Concern !