For at least 30 million years, bone-eating worms have been making their homes in the bodies of decomposing whales on the seabottom, but the rotting cetacean carcasses are not just food sources for the polychaetes.

The term “worm” immediately conjures up images of the red, squiggly things which crawl all over the sidewalk after it rains, but this imagery does not fit the boneworms of the genus Osedax. These worms start off life as sexless larvae, and the timing of their arrival at a whale corpse makes all the difference as to whether they will be male or female. If the larva lands on the bones of a whale first, it will grow into a large female which will