Wonder-worm

• Its strike is so fast and so powerful that it can cut a prey animal in two, and its common name comes from that reputation rather than from any biological trait.
• Fossil burrows attributed to similar ambush worms have been found in Miocene rocks in Taiwan, with the same funnel structure that living ones leave behind.
• In marine aquariums it sometimes turns up with no one knowing how, arriving as a stowaway in live rock, and is discovered when fish start disappearing at night.
• It is a polychaete worm that can exceed three metres in length, and it lives buried in a burrow from which only its head protrudes.
• It hunts from ambush with five sensory antennae spread over the sand. When something brushes them, it strikes with extraordinary speed and chitinous jaws capable of cutting a fish in two.
• It became famous through a real-life case: in 2009, staff at the Newquay aquarium in Cornwall had long been baffled because fish kept disappearing and corals were turning up mutilated. When they dismantled the tank they found a specimen over a metre long that had arrived years earlier hidden in a piece of live rock.
• Its chaetae, the lateral bristles, have an iridescent sheen that makes it unmistakable.
• Its reproductive biology and longevity are poorly known, because it is almost impossible to observe in its natural environment.
• The group's taxonomy is under revision: what is called Eunice aphroditois may correspond to several distinct species.

Skeleton type

Invertebrate - no rigid skeleton (annelid)

Habitat and environment

Sandy, muddy and gravelly bottoms of warm waters, from 10 to 40 m

Sources consulted: https://es.wikipedia.org/wiki/Eunice_aphroditois