Chaetodon miliaris
A small yellow butterflyfish found almost only around Hawaii, logged uncommonly on reefs in 22 to 27 C water year-round.
Small yellow butterflyfish, around 9 cm, with a body scattered in fine dark speckles that give it the millet-seed look. A black bar runs through the eye and a dark blotch sits near the rear dorsal fin, but there's no bold overall pattern like many reef butterflyfish. It has the typical laterally flattened, disc-shaped body and pointed snout of the family, making it easy to pick out as a butterflyfish even before you clock the speckling.
Usually seen picking at the reef alone or in small loose groups, sometimes forming larger aggregations over open reef flats where it feeds on plankton drifting past. It's not shy around divers and will often keep foraging within easy view rather than bolting for cover. Most sightings are on shallower reef structure rather than deep drop-offs, and it's logged as uncommon at most sites rather than something you'll see in numbers every dive.
It's one of the few butterflyfish that feeds heavily on plankton in the water column rather than picking coral polyps or invertebrates off the reef, which is part of why it's sometimes seen loosely schooling over open reef rather than tucked against structure.
Sightings show no detected season, and the water temperature range logged (22.1 to 27.0 C) covers Hawaii's reefs year-round, so there's no particular month to target. Plan around your Hawaii trip generally rather than chasing a season.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
This one is essentially a Hawaii speciality: nearly all logged sightings come from Hawaiian reefs, with no other region showing meaningful numbers. If you're diving or snorkelling around the Hawaiian Islands, it's one of the more likely butterflyfish to turn up on the reef.
Mapping where Milletseed Butterflyfish is logged…
Almost all logged sightings are from Hawaii, making it effectively a Hawaiian reef speciality rather than a species you'll find on Indo-Pacific or Caribbean dive trips.
There's no clear seasonal pattern in the sightings, and it's found across a wide temperature range (22.1 to 27.0 C), so it's a reasonable year-round sighting on Hawaiian reefs.
Look for a small yellow butterflyfish, about 9 cm, covered in fine dark speckles rather than bold stripes, with a dark bar through the eye and a dark mark near the rear dorsal fin.
They're small, typically reaching around 9 cm, consistent with most Chaetodon butterflyfish.
No, they're harmless to divers and simply carry on feeding on the reef when approached.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
