A soft-coral feeder, which is why it turns up on muck sites where hard-coral specialists do not.
To about 18 cm, white to pale silver with fine dark stripes running obliquely up the flank, yellow fins and tail, a black bar through the eye and a black wedge across the upper back that runs down onto the tail base. The near-identical spot-tail butterflyfish Chaetodon ocellicaudus carries a discrete black spot on the caudal peduncle instead, with the back left plain; the two are otherwise very hard to split and are frequently logged as one fish. At night the black back darkens and spreads and the body dulls to a blotchy grey-brown, so a torch-lit fish looks nothing like the same species seen at noon.
It feeds mainly on soft coral polyps, taking Sinularia, Sarcophyton and related colonies, and supplements this with hard coral and small invertebrates. That diet matters for where it is found: soft corals persist on silty rubble slopes where branching Acropora does not, so this is one of the few butterflyfishes that remains ordinary at the muck destinations rather than dropping away with the hard coral. Almost always in pairs, and pairs hold a patch of slope over long periods.
It is less nervous than most butterflyfishes and will carry on feeding with a diver a couple of metres off, though it keeps moving along the colony rather than holding station. Approaching along the slope at the fish’s own depth, rather than dropping onto it from above, generally buys more working time. Recorded from about 3 to 25 m.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.