Ascension Fireworms

Amphinomid polychaetes are commonly known as fireworms due to the burning sensation once their chaetae (fine 'hairs') break after penetrating our skin; however specimens belonging to only a few genera produces the stinging sensation. They are brightly coloured and can reach quite a large size, up to 50 cm long. Fireworms thrive in intertidal zones and can be abundant in coral reefs or rocky areas, although there are some deep-water genera.

During the dive surveys of Ascension Island the SMSG team found two species of fireworms which have now been identified by Beatriz Yáñez Rivera, of the Universidad Nacional Autónoma de México, as  Hermodice carunculata and Eurythoe complanata.

Hermodice carunculata

The first fireworm recorded from Ascension Island was collected in the middle 1800s. This fireworm is Hermodice carunculata, however at the time it was considered to be another species due to great morphological variation. Now, genetic evaluation indicates that Hermodice carunculata have a broad distribution across the Atlantic Ocean. This species shows ecological adaptations according to habitat conditions and different colouration with low genetic divergence. The population from Ascension Island could be playing an important role in the connectivity between both sides of the Atlantic Ocean.

Eurythoe complanata

The discovery of Eurythoe complanata represents the first record from Ascension Island. This species has been reported in mainland and some islands of the Atlantic Ocean. These fireworms are common in shallow waters mainly in rocky shores, and they reproduce sexually and asexually. Sexual reproduction involves a rostraria larvae, which has been hypothesized to enable the long-distance dispersal of this species of fireworm.