A team of marine biologists led by Dr Robert Vrijenhoek from the Monterey Bay Aquarium Research Institute has discovered a new species of bone-devouring worm in Monterey Bay, California.
A close-up view of a male Osedax priapus. Scale bar – 0.3 mm. Image credit: Greg Rouse.
Osedax (Latin for ‘bone devourer’) worms were first discovered on a whale carcass at about 3,000 m depth in Monterey Canyon in February 2002.
They come from Siboglinidae, a family of worms living in unexpected locations, with their relatives inhabiting the extremely hot and acidic hydrothermal vents in the sea.
Like all worms in the family, they have no mouth, anus, or gut, but are unique in having a unique ability to release bone-melting acid.
Dr Vrijenhoek’s team using a remotely operated vehicle has found a surprising new type of Osedax species in Monterey Bay at a depth of 700 meters.
Females of the new species, named Osedax priapus, are roughly the same size as their previously studied relatives, but males are tens of thousands of times larger than those of other known species, and are roughly the same size as the females.
Also surprising was the discovery that Osedax priapus males consume bone on their own, something their dwarf relatives don’t ever do.
“This worm was weird enough as it was and now it’s even weirder. This shows us that there continue to be mysteries in the sea and there is still so much more to discover, especially since we only found these creatures 12 years ago, said Dr Greg Rouse from Scripps Institution of Oceanography, who is the lead author of the paper describing the new species in the journal Current Biology.
Adding even more peculiarity to the discovery is the mating process for the new species.
Previously studied Osedax male dwarfs are permanently attached to their female hosts, and therefore do not need mobility to mate, so the biologists wondered how Osedax priapus males are able to seek out a mate, given their independence.
“The evolutionary solution they found was to actually make the male’s body very extendable so they can reach far out to find females to mate with – they can extend their body ten-times its contracted state,” Dr Rouse explained.
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