Yellow Boxfish
Ostracion cubicum
Yellow Boxfish is a small Indo-Pacific reef fish with a rigid box-like body that can be brilliant yellow, especially juveniles and females. It is not a typical angling target and is mainly encountered by divers around coral reefs and lagoons.
Identification points
- Rigid, box-shaped body with sharp-edged bony plates
- Bright yellow adult color with small white spots often visible on the face and flanks
- Small mouth on the front of a blunt snout with tiny fins set low on the body
Habitat
Shallow coral reefs, reef flats, protected lagoons, and seaward reef slopes, usually near coral heads, rubble, and mixed reef structure; juveniles often shelter in seagrass or sheltered reef edges.
Bait notes
Not a practical sport-fishing species and usually not targeted. Small live crustaceans or finely chopped meaty baits may attract it in aquarium or observation settings, but capture is generally discouraged.
Behavior
A slow, deliberate swimmer that browses and picks small invertebrates and algae from the reef. When threatened it can release ostracitoxin and inflate slightly by taking in water, making it a poor prey item.
Caution
Do not handle if avoidable: stress can release toxic mucus/ostracitoxin that can harm other fish in confined water. Not recommended for consumption; reef-associated species may also pose ciguatera risk in some areas.
Fishing notes
Best observed rather than fished. If encountered on reef gear, use very light tackle and avoid handling; release quickly and carefully because stress can trigger toxin release and the fish is delicate.