Singular Bannerfish

The singular bannerfish (Heniochus singularius), also known as the singular pennantfish, is the largest member of its genus, reaching up to 30 cm in length. Its body is adorned with alternating black and white stripes, while the tail fin is bright yellow. A distinguishing feature of this species is the white stripe behind the eye and a horn-like projection on the forehead. In adult individuals, the stripes become less pronounced, and the anal fin darkens, setting them apart from similar species such as Heniochus monoceros.

This fish feeds on coral polyps, benthic invertebrates, and algae. During the breeding season, individuals form pairs. Eggs are released into open water, where they drift freely until hatching.

The singular bannerfish is distributed throughout the Indo-Pacific region, including the waters of Thailand. It prefers deep lagoons and outer reef slopes with abundant coral cover and complex topography. Adults inhabit depths ranging from 15 to 40 meters, either solitary or in small groups. Juveniles, on the other hand, favor shallow lagoons, where they lead a more secretive lifestyle.