Zombie worms eat whale bones — with acid
Zombie worms don't actually drill through bone, as was previously believed. Instead, their skin produces enough acid to dissolve the zombie worms' path through bone.
Martin Tresguerres et al / Proceedings of the Royal Society B / LiveScience.com
So-called zombie worms — and yes, they actually exist — like to munch on whale bones for dinner. The creatures also use the bones for shelter. Spread throughout the world's oceans, zombie worms are quite adept at making the bones of whales and other large marine animals look like Swiss cheese.
But these worms don't have any mouthparts with which to gnaw the holes. So how do they do it? A study published in the May 1 online edition of the journal Proceedings of the Royal Society B found that rather than being "bone-drilling" worms, they're actually "bone-dissolving" worms: The worms’ skin produces acid in large quantities to break down bones.
The acid is produced by proton pumps, protein-containing structures abundant in the front end of the worm's body, said Martin Tresguerres, a marine physiologist at the Scripps Institution of Oceanography in La Jolla, Calif.
'Off the charts'
Tresguerres has studied these acid-secreting structures in many other animals, including sharks and various fish. But he hasn't seen anything like this before. "The amount of proton pumps they have is off the charts," he told OurAmazingPlanet.
The cellular mechanism used to produce the acid is nearly identical to that used in osteoclasts, the human cells that break down bone so that it can be rebuilt. Insight into how the worm dissolves bone could possibly be applied to osteoclasts, Tresguerres said. Human kidneys also contain similar proton pumps involved in processing bodily waste, he added.