Researchers, from Woods Hole Oceanographic Institute in Massachusetts and the Scripps Institute of Oceanography in California named it Teuthidodrilus samae – a new genus and species. They said: "This illustrates how much we have to learn about even the large, common inhabitants of deep pelagic communities."
In a series of exploration dives, researchers spotted the worm, slowly rising and falling in the water around 100m above the seafloor, where it feeds on passing plankton. The worm swims or treads water by waving hundreds of bristles that run along the length of its body on either side.
The 10 slender arm-like appendages that give the worm its unusual appearance are a combination of elongated gills and sensory organs. They are probably used to pick scraps of food from the "marine snow" of organic detritus that constantly falls to the seabed from above. Each is as long or longer than the whole of the worm's body.
Watch the creature swim in a video at the Guardian. Link -via Metafilter