Myripristis adusta
Deep-red soldierfish with a dark tail margin, most reliably logged in Maldives' Central Atolls and Palau's Rock Islands year-round.
Deep red to brownish-red body, roughly 24 cm, with the big reflective eyes typical of soldierfish that help it feed in low light. The giveaway is the dusky to blackish margin on the tail fin, which gives it its common name and separates it from plainer red soldierfish. Body is oval and deep-bodied in profile, usually seen hovering rather than swimming hard, often tucked partly under a ledge or in a cave mouth.
Typically found hovering in small groups under overhangs, in caves, or tucked against reef structure during the day, staying close to shelter rather than out in open water. Divers usually log it as uncommon rather than abundant, so spotting one often means checking shaded crevices and ledges carefully. Like other soldierfish it is more active after dark, when it moves out to feed, so night dives can turn up more activity than daytime passes.
Those oversized eyes are a real nocturnal-feeding adaptation: soldierfish are most active hunting small invertebrates and zooplankton at night, which is why daytime sightings mostly show them parked motionless in shadow.
No clear seasonal pattern shows up in the sighting data, and it sits comfortably in 25.3 to 29.3 C water, so it is a year-round sighting on the reefs where it occurs rather than a seasonal target.
Most consistently logged in the Maldives, especially across the Central Atolls, and in Palau around Koror and Malakal and the Rock Islands. Also turns up in French Polynesia's Tuamotu Islands and Indonesia's Raja Ampat, with smaller numbers reported from the Seychelles' Inner Islands, the Northern Mariana Islands around Saipan, and Fiji.
Mapping where Shadowfin Soldierfish is logged…
The strongest sightings come from the Maldives' Central Atolls and Palau, particularly Koror & Malakal and the Rock Islands. It also shows up in French Polynesia's Tuamotu Islands, Indonesia's Raja Ampat, and in smaller numbers in the Seychelles and Fiji.
There is no strong seasonal signal in the sighting data, and water temperatures where it is found stay in a fairly narrow tropical band of about 25 to 29 C year-round, so it can be seen on any month's dive trip to the right reefs.
Look for a deep-bodied red fish around 24 cm hovering near reef ledges or cave entrances, with large eyes and a dark, dusky edge along the tail fin. It tends to sit still in shadow during the day rather than swim in the open.
They reach around 24 cm in length, a solid handful of fish that is easy to make out once you spot its red colouring against dark reef crevices.
No, they pose no danger to divers. They are shy reef fish that shelter in ledges and caves and simply retreat further into cover if you approach.
Their oversized eyes are built for low-light feeding, since soldierfish are most active hunting plankton and small invertebrates at night. During the day they mostly rest motionless in shaded reef crevices, which is why divers usually find them tucked under ledges rather than out swimming.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Soldierfish
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