In much the same way the human body dissolves and then repairs bone, and also extracts nutrients from blood, so-called bone worms have been found at the bottom of California's Monterey Bay consuming the skeletal remains of whales.
In new research conducted by the Scripps Institution of Oceanography, which is part of the University of California, San Diego, the gutless, mouthless worms --- of the scientific genus Osedax - have been found to use a bone-melting acid that enables them to gain access to the nutrients inside of the bones.
A study was published in the May 1 online edition of the Proceedings of the Royal Society B (Biological Sciences.
"The acid presumably allows the worms to release and absorb collagen and lipids that are trapped in bone," said Martin Tresguerres, one of the researchers, in a prepared statement. "This model is remarkably similar to how mammals repair and remodel bone; however Osedax secrete acid to dissolve foreign bone and access nutrients."
Tresguerres explained the bone worms have what can be described as a "proton pump" to apply the acid onto bone surfaces. They typically feed on whale carcases, but also eat fish bones, a hint that the worms have called the plant home longer than have many contemporary sea creatures.
Because the Osedax don't have mouths, they must rely on bacteria that live inside them to process the nutrients.
The new research found the bacteria appear to separate the organic compounds in the bone so that the worms can absorb some of it.
"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," Scripps postdoctoral researcher Sigrid Katz also said in a statement.
To continue learning about bone worms, Scripps scientists expect to collaborate with colleagues at the Monterey Bay Aquarium Research Institute in coming months to collect and study additional bone samples with live worm specimens. They also plan to maintain live Osedax at the Scripps campus to study their physiology.
"Determining how Osedax gets into bones was the first challenge in understanding the nutrition of these bizarre animals," said study co-author Greg Rouse. "Now we'd like to understand how they transport and utilize the nutrients that they have uncovered."