Bearded Fireworm

• It is bioluminescent at night, and quite what that is for is still not fully understood.
• It eats soft and hard corals, anemones and small crustaceans.
• It lives on coral reefs, rock and sandy bottoms of the tropical and subtropical Atlantic, the Caribbean and the Mediterranean.
• It is covered in tufts of hollow, brittle white bristles that pierce the skin at the slightest touch and break off inside, releasing a toxin that causes intense burning for hours. Hence the name fireworm.
• You do not have to handle it for this to happen: brushing it with a glove or a fin is enough.
• It eats live coral, which makes it a serious problem in reef restoration: in the staghorn coral nurseries of the Dominican Republic it was the main cause of death among transplanted fragments.
• And it does something worse: it is a reservoir and vector for the bacterium Vibrio shiloi, which causes coral bleaching. It carries the pathogen between colonies as it feeds.
• It is also a scavenger and is found in large numbers on dead animals.
• It is spreading through the Mediterranean, where it was once scarce, as the water warms.

Skeleton type

Invertebrate - no skeleton (polychaete annelid)

Habitat & environment

Coral reefs, rock and sandy bottoms of the tropical and subtropical Atlantic, the Caribbean and the Mediterranean

Birth weight

A microscopic planktonic larva after external fertilisation

Size at birth

Microscopic planktonic larva after fertilisation

Litter / clutch size

Numerous eggs and sperm released in synchronised seasonal swarming

Sources consulted: Dimensions.com; A-Z Animals; SeaLifeBase; Reef Guide; Manic Fish; MarineBio; Wikipedia (Hermodice carunculata); UWI Life Sciences