HomeMarine aquarium fishAngelfish & butterflyfishMasked bannerfish Masked bannerfish (Heniochus monoceros) Scientific name: Heniochus monoceros Cuvier, 1831 The Masked bannerfish (Heniochus monoceros) is a marine fish of the family Chaetodontidae. Native range: Indo-Pacific, East Africa to the Tuamoto Islands, north to southern Japan, south to New South Wales and Tonga. BiologyDorsal spines (total): 12; Dorsal soft rays (total): 24-27; Anal spines: 3; Anal soft rays: 17 - 19. A pair of bony knobs is on the forehead. Juveniles of this species resemble juveniles of H. singularis and may be differentiated by the position of the middle black band that passes behind the white pennant in H. monoceros and in front of it in H. singularis. Adults with short banner.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameHeniochus monocerosFamilyChaetodontidae (Butterflyfishes)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length24.0Depth range2–30 m (7–98 ft)EnvironmentMarine; reef-associated; depth range 2 - 30 mClimateTropicalDistributionIndo-Pacific: East Africa to the Tuamoto Islands, north to southern Japan, south to New South Wales and Tonga.Conservation status (IUCN)Least Concern (LC)Threat to humansHarmlessUsesAquarium: commercialResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) More angelfish & butterflyfishPajama cardinalfishSphaeramia nematopteraSingular bannerfishHeniochus singulariusThreeband pennantfishHeniochus chrysostomusHorned bannerfishHeniochus variusThompson's butterflyfishHemitaurichthys thompsoniPyramid butterflyfishHemitaurichthys polylepisSee all angelfish & butterflyfish SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026