Pycnochromis hanui
A small reef damselfish logged off Hawaii, comfortable in 25C water and worth a slow, patient look on the reef.
A small damselfish at around 4 cm, with a body that reads dark brown to chocolate along the front half and fades to a paler, almost white rear half and tail, giving it a distinct two-toned split. The body shape is the classic compact, oval damselfish profile with a forked tail. Look for that sharp colour break roughly mid-body, which is the single best clue in the water since size and shape alone won't separate it from other small chromis.
Divers find it hovering in small numbers over reef structure, sticking close to cover rather than venturing into open water. Like most small chromis it's an unhurried, mid-water feeder that doesn't spook easily but also won't hold still for long, so a calm approach and a bit of patience pays off. Expect it low on the list of things you notice on a dive since it's logged as uncommon even at the sites where it occurs.
It's an uncommon find even within its known range, so a confirmed sighting in Hawaii is worth logging carefully, ideally with a photo showing that dark-to-pale body split for a clean ID.
Water temperatures where it's been observed sit steadily between about 25 and 26C, and there's no seasonal pattern in the sighting data, so plan on a year-round reef fish rather than a seasonal target.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Logged sightings currently come from Hawaii, United States, where it's been recorded at a couple of dive sites. It's not yet documented elsewhere in diver logs, so Hawaiian reefs are the reliable bet for this one.
Mapping where Chocolate-dip Chromis is logged…
Sightings are currently concentrated in Hawaii, United States, where it's been recorded at a small number of dive sites. It hasn't yet been documented in diver logs outside Hawaii.
There's no clear seasonal pattern in the sighting data, and it's been observed in steady water around 25 to 26C, so it's best treated as a year-round possibility rather than a seasonal event.
Look for a small, oval damselfish about 4 cm long with a dark brown front half that fades sharply into a pale rear half and tail. That two-toned split is the main feature to key on underwater.
They stay small, typically around 4 cm, which is in line with most reef-dwelling chromis species.
No. They're a harmless, small reef damselfish that poses no risk to divers.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Yellowtail Clownfish
3,523 sites
