When a whale dies, it often sinks to the ocean floor, where it nourishes an entire ecosystem of organisms. Scavengers like hagfish and some kinds of sharks eat the flesh of the whale. When nothing remains but the bones, bacteria and small invertebrate organisms like worms can obtain energy from the nutrients left behind.
The genus Osedax is a group of polychaete worms discovered in 2002 by remote underwater vehicles in Monterey Bay, California. These small worms secrete an acid which dissolves the whale bones on which they live. Through symbiotic bacteria living in their root-like structures, the worms feed off of the oil left in the bones.
The more visible worms are the females. The males are greatly reduced in size and live within a tube surrounding the body of the female worm.