Chromis ternatensis
A small blue-grey damselfish hovering in loose clouds over reef slopes in Raja Ampat, the Maldives and Sulawesi, year-round in 25 to 29 C water.
A slim, oval damselfish reaching about 7 cm, with a grey-blue body that shades paler towards the tail and a faint dark smudge near the base of the pectoral fin. It hangs in loose, drifting groups just above the reef rather than sitting still on it, which is often the first clue over close colour matching. No strong sex-based colour difference has been documented for this species.
Look for it hovering in small, loose aggregations a metre or so above coral heads and reef slopes, picking plankton out of the current rather than feeding off the substrate. It barely reacts to divers, drifting back into formation if scattered rather than bolting for cover, and it can be found anywhere from shallow fringing reef down to well past recreational depths.
Like most Chromis, it feeds by picking zooplankton straight out of the water column, so the best sightings are often on current-swept reef edges where plankton concentrates rather than in sheltered coral gardens.
No clear seasonal pattern shows up in the data, and with a comfort range of roughly 24.6 to 28.9 C, it stays on tropical reefs year-round, so any month at the sites above is a reasonable bet.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Most reliably logged across Indonesia, especially Sulawesi, Raja Ampat and Bali, and through the Central Atolls of the Maldives. It also turns up consistently on reefs in Queensland (Australia), Atauro Island in Timor-Leste, Taveuni in Fiji, and around Khao Lak in Thailand and Tanzania's coast. At most of these sites divers log it as an uncommon but steady presence rather than a guaranteed swarm.
Mapping where Ternate Chromis is logged…
Indonesia is the strongest region, particularly Sulawesi, Raja Ampat and Bali, alongside the Central Atolls of the Maldives. Queensland in Australia, Atauro Island in Timor-Leste, Taveuni in Fiji and Khao Lak in Thailand are other reliable spots.
There is no strong seasonal pattern in sightings, and it tolerates a wide tropical range of about 25 to 29 C, so it is present on reefs year-round at the sites where it is found.
Look for a small grey-blue damselfish, around 7 cm, hovering in loose groups just above the reef rather than perching on it. It lacks bold stripes or bright patches, so its plain colouring and open-water hovering habit are the main giveaways.
They stay small, typically reaching around 7 cm in length, which is standard for reef-dwelling Chromis species.
They are carnivores that feed on drifting zooplankton, picking it directly from the water column while hovering above the reef rather than grazing on algae or coral.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Yellowtail Clownfish
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