Longfin Bannerfish

Overview

The Longfin Bannerfish is a distinctive, deep-bodied species widely distributed across the tropical and subtropical Indo-Pacific. It is easily recognized by its striking white coloration, two broad diagonal black bands, and an exceptionally long, flowing white filament extending from its dorsal fin.

Distribution & habitat

This species is found from the eastern coast of Africa and the Red Sea across to Polynesia, and from southern Japan down to the Great Barrier Reef. It typically inhabits protected lagoons, channels, and the deeper sections of outer reef slopes.

Appearance

Reaching an average length of 15 cm, this fish features a laterally compressed body. Its most notable characteristic is the elongated fourth dorsal spine, which can be as long as or longer than the body itself. The head is white with a black bar across the eyes, and the pectoral, soft dorsal, and caudal fins are yellow. Juveniles are solitary and lack the white area seen in adults behind the second black stripe.

Biology & behavior

Adults are commonly observed in pairs, while juveniles tend to be solitary. Unlike many other reef fish, they are generally not territorial. Juveniles have been known to act as cleaner fish, removing parasites from the skin of other species.

Feeding

This species is primarily a planktivore, feeding on zooplankton within the water column near the reef. It also supplements its diet by consuming small invertebrates found on the reef substrate.