Cheilodipterus artus
Striped, sharp-toothed cardinalfish logged uncommonly around Koror & Malakal, Palau, in warm 24.7-29C water year-round.
Grows to about 13 cm, with an elongated body carrying three or four dark brown stripes running the length from snout to tail, the topmost stripe passing straight through the eye. The mouth is noticeably larger and more toothy-looking than most cardinalfish, a giveaway of its predatory habits. A dark blotch often sits at the base of the tail where the stripes converge, and the fins stay mostly clear or lightly dusky rather than boldly marked.
Usually seen hovering alone or in loose small groups close to reef structure, ledges, and rubble patches rather than out in open water. Like other cardinalfish it tends to be more active around dusk and at night, tucking into crevices during brighter daylight hours. It is unbothered by divers at a normal distance, holding position rather than bolting.
Cardinalfish in this genus are mouth-brooders, with the male carrying the fertilised egg mass in his jaws until the larvae are ready to disperse, so a male with a visibly swollen throat is likely holding a brood rather than feeding.
No clear seasonal pattern shows up in the sighting data, and its comfort range of 24.7 to 29 C matches tropical reefs all year, so any month is fair game at its Western Pacific sites.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Most reliably logged around Koror & Malakal in Palau and Apra Harbor in Guam, with single confirmed sightings from Sulawesi in Indonesia and Lomaiviti in Fiji. Palau and Guam currently hold the strongest recorded presence, making them the best bets for a target search on the reef.
Mapping where Wolf Cardinalfish is logged…
They turn up most consistently around Koror & Malakal in Palau and Apra Harbor in Guam, with occasional sightings logged in Sulawesi, Indonesia, and Lomaiviti, Fiji.
There is no strong season in the sighting record, and the species sits comfortably in 24.7 to 29 C water year-round, so it is worth looking for on any dive at its known sites.
Look for a slim 13 cm fish with three or four dark stripes running the body length, a stripe through the eye, a dark tail-base blotch, and a mouth larger and toothier-looking than typical cardinalfish.
They reach around 13 cm in length, a modest size typical of cardinalfish, so they are easy to overlook against reef structure unless you are looking closely.
No, they pose no threat to divers and simply hold position near reef structure when approached calmly.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Iridescent Cardinalfish
1,784 sites
