World's Weirdest Worms

Five years after discovering some of the strangest creatures in the world — mouthless worms that live in the bones of dead whales — scientists have taken a peek into their genes. Though not complete, the glimpse shows these creatures to be far more complicated than was known.

The worms, found in a gray whale skeleton off the coast of California, prompted scientists to designate them as representatives of an entirely new genus, dubbed Osedax. They belonged to a taxonomic family of marine worms that lack mouths and anuses, and rely entirely on bacteria to absorb and excrete nutrients. But Osedax was unique: Adult males were extremely small, and lived in colonies inside the females. Even more strikingly, they occupied an evolutionary niche comprised entirely of fallen whales.

Scientists note that anything below 1000 meters is fed entirely by ‘marine snow’ — the things that are supported by photosynthesis at the top of the ocean, and the things that eat them, and eventually fall to the ocean floor.

Since the original discovery, other species have been found in whalebones off the coast of Sweden and Japan. A total of five species have now been named, enough for a comparison of their genetic characteristics to provide insight into their evolutionary history. The analysis suggested at least 12 more as-yet-unidentified lineages of Osedax. The worms might still be out there, though some may have gone extinct.

Since whale carcasses are hard to come by, researches have been able to study the worms by luring them with carcasses of other animals. They can live perfectly happily on cow bones, and researchers have also put down sea lion bones and pig bones.

You can see an ocean-floor webcam here, where researchers recently sank a pig.

Original article here.