HomeMarine aquarium fishAngelfish & butterflyfishAtoll butterflyfish Atoll butterflyfish (Chaetodon mertensii) Scientific name: Chaetodon mertensii Cuvier, 1831 The Atoll butterflyfish (Chaetodon mertensii) is a marine fish of the family Chaetodontidae. BiologyDorsal spines (total): 12 - 14; Dorsal soft rays (total): 21-23; Anal spines: 3; Anal soft rays: 16 - 17. Body color is white with 4-5 chevron-shaped blackish bands on the sides. The posterior portion of the trunk, the adjacent dorsal and anal fins, and the posterior portion of the caudal fin are yellow. A vertical black bar runs (uninterrupted) across the eye.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameChaetodon mertensiiFamilyChaetodontidae (Butterflyfishes)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length12.5Depth range10–120 m (33–394 ft)EnvironmentMarine; reef-associated; non-migratory; depth range 10 - 120 mClimateTropicalDistributionPacific Ocean: Ryukyu Islands to the Philippines and extending to Lord Howe, Rapa and Tuamoto islands. Replaced by Chaetodon madagascariensis in the Indian Ocean, Chaetodon xanthurus in southeast Asia, and Chaetodon paucifasciatus in the Red Sea.Conservation status (IUCN)Least Concern (LC)Threat to humansHarmlessUsesFisheries: minor commercial; aquarium: commercialResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) More angelfish & butterflyfishPajama cardinalfishSphaeramia nematopteraBlackback butterflyfishChaetodon melannotusScrawled butterflyfishChaetodon meyeriSpot-tail butterflyfishChaetodon ocellicaudusRaccoon butterflyfishChaetodon lunulaEightband butterflyfishChaetodon octofasciatusSee 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