Chaetodon andamanensis
Uncommon but reliable on Maldivian reefs, especially the Northern Atolls, in warm 28-30C water year-round. Here's how to spot one.
A small, disc-shaped reef fish around 10 cm, with a white body crossed by dark chevron-shaped bars that angle back towards the tail. A black band runs vertically through the eye, the classic butterflyfish disguise mark, and the rear fins carry a dark trailing edge. It moves in a slow, deliberate flutter close to the reef structure rather than out in open water.
Usually spotted picking around coral heads and reef crevices alone or in a loose pair, working the same patch of reef rather than roaming. It keeps a cautious distance from divers but rarely bolts, continuing to forage along the substrate if you hold still and let it come to you. Most sightings sit in the 10-40 m range, so it's more a mid-to-deep reef find than a shallow-water regular.
Like most Chaetodon species it feeds on small invertebrates and coral polyps picked directly off the reef surface, so healthy hard-coral cover is a good sign you're in the right spot to find one.
No strong seasonal pattern shows up in the data, and with water sitting between 28.4 and 29.9C year-round across its range, it's a reef fixture in any month rather than a seasonal visitor.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Most reliably logged across the Maldives, especially the Northern, Southern and Central Atolls, with strong numbers also recorded around Phuket, Khao Lak, Koh Lipe and Koh Phi Phi in Thailand. Smaller but consistent populations turn up in India, Sri Lanka, Myanmar's Mergui Archipelago, Indonesia and Malaysia.
Mapping where Andaman Butterflyfish is logged…
The Maldives is the strongest bet, particularly the Northern, Southern and Central Atolls, followed by Thailand's Phuket, Khao Lak, Koh Lipe and Koh Phi Phi. It also turns up in India, Sri Lanka and Myanmar's Mergui Archipelago.
There's no clear seasonal spike in sightings, and the water stays in a narrow 28.4 to 29.9C band year-round, so it's around on the reef in any month you dive.
Look for a small white, disc-shaped fish with dark chevron bars sweeping back across the body and a black vertical band through the eye. It hovers and picks close to the reef rather than swimming in open water.
They're small, topping out at around 10 cm, so they're easy to overlook against a busy reef unless you're looking closely at coral heads.
No. They're harmless, small reef fish with no venom or aggressive behaviour towards divers.
It's logged as uncommon at most sites where divers have recorded it, so it's a real but not guaranteed find, worth a slow look along coral-rich reef sections in the 10-40 m range.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
