When a whale dies in the ocean, the carcass becomes a feast for countless marine creatures, but what happens to the bones? Scientists had thought they lasted decades, but a recent study discovered that “zombie worms” are making much shorter work of them, "eating" the skeletons by dissolving them with acid.
In a study conducted by the Scripps Institution of Oceanography, it has been discovered that these worms, actually called Osedax, excrete acid to eat the nutrients inside the bones of their next meal. They typically eat whale bones and other larger marine animals.
But these worms have no mouths to bite into the bones. Researcher Martin Tresguerres explained how the mouthless worms feed, saying in a statement, "The acid presumably allows the worms to release and absorb collagen and lipids that are trapped in bone ... This model is remarkably similar to how mammals repair and remodel bone; however, Osedax secrete acid to dissolve foreign bone and access nutrients."
The acid comes from the worms’ skin, and it's produced in large quantities. The mechanism used to produce it is almost the same as what is used in osteoclasts, human cells that break bone down so it can be rebuilt.
In addition to lacking mouths, these worms also have no digestive systems, so it's still unclear how the worms absorb the proteins from the bones they break down.
Scripps postdoctoral researcher Sigrid Katz said in a statement, “"The Osedax symbiosis shows that nutrition is even more diverse than we imagined, and our results are one step closer in untangling the special relationship between the worm and its bacteria."