Apogon robinsi
A small reef cardinalfish logged uncommonly across the Bay Islands, Honduras, in warm 26-28°C water year-round.
A small, chunky cardinalfish reaching about 7 cm, with a big-eyed, blunt-headed profile typical of the family. Body tone runs reddish-brown to dusky, usually seen hovering nose-in near a ledge or crevice rather than out in the open. There's no bold stripe or single obvious marking to key on, so ID often comes down to habitat, posture and ruling out the more patterned cardinalfish species nearby.
Expect to find it tucked close to reef structure, hovering just off a ledge or inside a crevice rather than swimming out over open sand. Like most cardinalfish it's a slow, unhurried mover that holds position with minimal effort and tends to sit tight rather than bolt when a diver approaches, though it will slip back into cover if crowded. Look for it during the day tucked in shaded reef nooks, since many cardinalfish become more active feeders after dark.
Cardinalfish in this family are mouth-brooders, with the male typically holding the fertilised eggs in his mouth until they hatch, a trait worth watching for if you spot a male with a noticeably swollen jaw.
There isn't enough seasonal data to call a best month, and the recorded water temperature sits in a steady 26.4 to 28.2°C band, consistent with year-round tropical reef conditions in the Bay Islands.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Every logged sighting of this species comes from the Bay Islands, Honduras, making it the go-to region if you want to look for one. Within the Bay Islands it's been recorded across a spread of sites, though always in the uncommon category, so it takes a patient, ledge-by-ledge search rather than a guaranteed spot.
Mapping where Roughlip Cardinalfish is logged…
The only confirmed sightings come from the Bay Islands, Honduras, spread across several dive sites there. It's not reported elsewhere in current diver data.
There's no detected seasonal pattern, and water temperatures logged with sightings stay in a steady 26.4 to 28.2°C range, so it's a year-round possibility rather than a seasonal target.
Look for a small, big-eyed, reddish-brown cardinalfish around 7 cm long, hovering close to reef ledges or crevices rather than in open water. It lacks a single bold stripe, so confirming ID often means checking it against similar cardinalfish like the fivelined or twospot.
They're a small reef fish, typically reaching around 7 cm in length, in keeping with most cardinalfish species.
Like other cardinalfish, this species is a mouth-brooder, with the male carrying developing eggs in his mouth rather than the eggs being left on the reef.
No, they pose no danger to divers and are a purely passive reef fish to observe rather than avoid.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Iridescent Cardinalfish
1,784 sites
