A broad, oval fireworm, golden to olive, patterned with a dark median stripe and a row of paired dark spots down the back, with long white bristles fanning from both sides. At about 8 cm (3 in) it is shorter than its relatives but far wider, and the pattern makes it one of the more striking worms on sand.
It burrows in soft sediment by day and comes out at night to scavenge, sometimes swimming with an undulating motion that no other fireworm here manages. The bristles sting on the same principle - hollow, brittle and toxin-loaded - and the display of them when the animal is disturbed is worth reading as the warning it is. Because this species lives on open sediment rather than in rubble, it turns up on night dives over sand where nothing else seems to be happening.
- oval flattened body, much broader than other fireworms
- golden to olive with a dark stripe and paired dark spots down the back
- long white bristles fanning out from both sides
- length up to 8 cm
