Bearded Fireworm ( Hermodice carunculata )

/ / Marine Inverts


There are 7 species within the genus of Hermodice and none of them have been evaluated on the IUCN Redlist (1) (2).  This flattened, segmented worm can reach up to 35cm in length, but is usually 7-10 cm.  It has hollow bristles along each side which are filled with venom and if disturbed, the bristles become flared so that they become more exposed. The setae can easily break off and penetrate flesh if touched, with the venom causing an intense burning irritation (3) (4).


The bearded fireworm is noted to be a highly mobile polychaete, which is mainly active at night (5). One interesting mechanism that fireworms display is during breeding; when the females come to the surface to breed, they emit a green phosphorescent glow. This is thought to attract the males, which then move towards the females, emitting a similar light at each other (6).


H. carunculata occurs to at least 60m, throughout the Mediterranean, and is commonly found on reefs, and beneath stones in rocky or seagrass areas (3).


The fireworm is found throughout the tropical western Atlantic, Mid-Atlantic and the Mediterranean (7).


Fireworms are omnivores and are noted to be selective in which type of prey they choose to eat. They are known to consume zooanthids, sea anemones and small cetaceans (8). They can identify prey using an olfactory organ called a caruncle. The caruncle can also be used to search and track prey across a habitat (8). They are thought to be least active during the middle of the day

Conservation Status

Not evaluated under the IUCN Redlist (2).


Description written by Kathryn Woodward (2009)

(1)   Fauchald, K. & Bellan, G., 2009. Hermodice Kinberg. [Online] Available at: [Accessed 31 July 2009].

(2)   IUCN, 2009. IUCN. [Online] (2009.1) Available at: [Accessed 16 June 2009].

(3), n.d. Hermodice caranculata, Bearded Fireworm. [Online] Available at: [Accessed 31 July 2009].

(4)   Wood, L., 2002. Sea Fishes and Invertebrates of the Mediterranean Sea. London: New Holland Publishers (UK) Ltd.

(5)   Trauth, K., 2007. Night ecology and fluorescence of the fireworms, Hermodice carunculata. Physis: Journal of Marine Science, 2.

(6)   Haywood, M. & Wells, S., 1989. The Manuel of Marine Invertebrates. Salamander Books Ltd.

(7)   Reclos, G.J., 2009. Hermodice carunculata. [Online] Available at: [Accessed 04 Augustus 2009].

(8)   Witman, J.D., 1988. Effects of predation by the fireworm Hermodice caranculata on milleporid hydrocorals. Bulletin of Marine Science, 3(42), pp.446-58.