We have known this giant shipworm for hundreds of years. Until now, our knowledge of the species was based on the calcium carbonate shells they leave behind and some dead specimens. For the first time, a team of international scientists has been able to capture the live specimens of the elusive shipworm in the Philippines. They look like massive, dark black alien creatures out of a sci-fi movie.
The shipworm discovery was like finding a dinosaur
The species was described Monday in the journal Proceedings of the National Academy of Sciences. The species, named Kuphus polythalamia, measures up to five feet in length and 2.3 inches in diameter. It is covered in a hard calcium carbonate shell and it spends most of its time in the mud of the seabed. The hard shell also covers its head, but the worm can re-absorb the shell when it needs to grow and burrow deeper into the mud.
Kuphus polythalamia is the longest in the family of shellfish. It is a bivalve, meaning it belongs to the same group as mussels and clams. Daniel Distel of the Northeastern University, the lead author of the study, told The Guardian that it was “almost like finding a dinosaur” because until now we have known about the species only through fossils.
Years old documentary helped scientists trace the species
The University of Utah researcher Margo Haygood said they were tipped off to the whereabouts to the worm by a 2010 Filipino documentary featuring a group of local fishermen catching, cooking, and eating the huge shipworms. The fishermen had refused to reveal where the worms could be found. So, scientists followed the clues in the video.
Eventually, they were able to capture five giant shipworms from a lagoon near the Mindanao island in the southeastern Philippines. The lagoon used to be a log farm once. Interestingly, a variety of shipworm species eat rotten wood as food. Researchers released a video showing one of the scientists cutting off the front end of the hard shell and shaking it out to let the giant, black creature slide out of the shell.
It has a unique feeding method
Most shipworms are smaller and feed on rotten wood. But this species has a strange feeding method. Unlike its cousins, the Kuphus polythalamia lives on hydrogen sulfide released from rotting animals and decaying vegetation. It sifts mud and sediment with its gills. A symbiotic bacteria living in its gills breaks down hydrogen sulfide into carbon compounds that the shipworm consumes.
Scientists found that K. polythalamia collaborates with different bacteria than other shipworms. That could be the reason why it evolved from consuming rotten wood to living on hydrogen sulfide in the mud. It doesn’t eat anything else. As a result, the creature’s digestive system is stunted. Researchers found little fecal matter in its body.
There is still a lot to learn about the species. Scientists plan to study its microbiome. At this point, little is known about the shipworm’s life-cycle or behavior. Researchers do not know whether the specimens they have captured are two years old or two hundred years old.