#ribbonworms

Antarctic Nemertean Worm (Parborlasia corrugatus)

Distribution: Widely distributed in the cold southern seas surrounding Antarctica, as far north as Peru.

Habitat: Epibenthic and marine; found in intertidal zones down to depths of 3590 metres.

Diet: Scavenger and predator; feeds on detritus diatoms, gastropods, amphipods, isopods, vertebrate carrion, sponges, jellyfish, seastars, molluscs, anemones and polychaete worms.

Description: P. corrugatus is a huge ribbonworm that can grow up to 2 metres in length. Like all ribbonworms, this species does not have a dedicated respiratory system, instead breathing through its skin; animals who breathe this way are typically quite small so the oxygen can reach every part of their body, which makes this worm's size even more impressive. Luckily, the Southern ocean is oxygen-rich, and the ribbonworm has a slow metabolism that uses up little oxygen. When it starts to lack oxygen, it flattens itself out to maximize oxygen diffusion throughout its body.

Despite its size, P. corrugatus still has predators. In order to defend itself, it has a proboscis it can deploy in moments, covered in barbs and adhesives (which it also uses to hunt its prey!). If this isn't enough to dissuade predators, it also has an acidic mucus with a pH of 3.5.