Osedax japonicus is a species of bathypelagic polychaete tube worm that lives at great depths on the seabed and is able to sustain itself on the bones of a dead whale.

The worms were found living on the bones of a decaying gray whale in the Monterey Canyon, at a depth of 2,893 m (9,491 ft).

[2] The discovery caused great excitement among marine biologists, and since then other species of worms of the same genus have been discovered on whale carcases lying in deep water in other parts of the world.

[3] Osedax japonicus was first described in 2006 from a sperm whale carcase that fell to the seabed off Kyushu, Japan, settling at a depth of 200 m (656 ft).

[4] An adult worm has a ringlike crown of feathery plumes which are involved in respiration, a trunk and a rooting structure which contains symbiotic bacteria.