Scientist have discovered a hellish, sulfur-eating, worm-like relative of clams living in a Philippines bay, a new study reports. At more than 1.5m long and 5cm wide, these creatures are the longest members in this family of shellfish that exist today, and they look like massive, ink-black, alien boogers.
They are commonly known as the giant shipworm (Kuphus Polythalamia), even though they aren't worms. The giant shipworm was first categorised as a species more than 200 years ago, and continue to be sold to collectors, but no living specimen had been examined by scientists and almost nothing had been known about it. That changed when Daniel Distel, a researcher at Northeastern University, and his colleagues got their hands on a few of the creatures during a research trip to the Philippines. Their analysis, in a study published April 17 in the journal Proceedings of the National Academy of Sciences, shows that these creatures are quite bizarre.
The scientists painstakingly chipped the giant shipworms out of their shells and dissected them, but the creatures still didn't give up their secrets easily as they are live inside large shells on the seafloor and grow to a length of more than five feet. That is much larger than other shipworms, which are generally quite small. That, of course, led biologists to wonder why these creatures grow so big.
Relatives of the giant shipworm are known to bore into soggy, submerged wood, digesting the wood particles they churn up with the help of symbiotic bacteria that live in their gills. The giant shipworm, though, is less picky, settling down in muddy seafloor sediments or sometimes rotting wood. But clearly, wood isn't its's only, or even its main, food source.
Other shipworms contain bacteria in their guts that break down cellulose, the stiff material of which plant cell walls are made. An investigation by the researchers, including Margo Haygood of the University of Utah College of Pharmacy, showed that shipworms don't contain large amounts of these bacteria, nor do they have other shipworms's large quantities of woody pulp in their guts. Rather, these giant weirdos contain a collection of unique bacteria that actually feast upon hydrogen sulphide. This gas, which to humans reeks of rotten eggs, is produced by rotting wood and other rotting organic material on the seafloor. This unique adaptation allows these huge animals to live in areas of the seafloor that would otherwise be uninhabitable, and it may also help explain their large size, allowing them to feed on residue that moves to them, rather than having to move about nibbling wood.
