King Ragworm

Alitta virens

The king ragworm (Alitta virens) is one of the largest polychaete worms in the northeastern Atlantic, reaching 30-90 cm in length. Adults display a striking iridescent green-blue to bronze sheen along their segmented body, with each segment bearing a pair of paddle-like parapodia used for locomotion and respiration. They possess powerful eversible jaws that can deliver a noticeable nip. They inhabit sandy, muddy, and mixed substrates in estuaries and shallow coastal areas at depths of 0-20 meters, constructing semi-permanent mucus-lined burrows. They are omnivorous scavengers and predators feeding on algae, other worms, and organic detritus. They emerge from their burrows at night to forage, and during breeding season they swarm at the surface in mass spawning events. Their impressive size, iridescent coloring, and active behavior during night dives make them a fascinating encounter for divers exploring temperate sandy habitats.