These strange worms are a type of polychaete worm that belong to the family Nereididae commonly known as clam worms. Polycheate worms are set apart from other marine worms by bristles (known as cheate) on their parapodia that they use to move and burrow into the sand. Parapodium is a Greek word which translates into para beside + podia feet. During mating cycles, which occur at night during the late spring and early summer, their parapodia enlarge so they can swim greater distances to find mates. These events are triggered by the lunar cycle, so that all of the clam worms mate around the same time, which increases their chances of success. Once the clam worms find mates, they release their eggs or sperm, after which they die and their life cycle is complete.
Clam worms have characteristic pincher teeth made of a strong lightweight material. Their pharynx can be everted to expose their strong jaws and two long conical teeth. Despite these intimidating features this species uses their large teeth to eat seaweed and other small worms. In fact, this worm is mostly harmless, and is used often as fish bait. The bristles that these worms use for locomotion and to burrow can also be a defense mechanism against their many predators and touching the bristles of some species can cause a painful burning sensation.
Polychaetes are incredibly diverse and represent the uniqueness of the ecosystems in which they have been adapted.
UCM 1676