Osedax – Bone Devouring Zombie Worms Found on The Ocean Floor
There’s a group of animals in the deep sea that look like tiny plants. They have no mouths, no stomachs and no anuses.
They live inside a tube with a feathery red plume sticking out of one end and a clump of roots at the other.
These odd looking animals were found by deep-sea scientists in 2002. The surprised scientist discovered what looked like a shaggy carpet growing on a whale skeleton they encountered nearly 3,000 metres deep in Monterey Bay, California.
Assuming they’d discovered a new plant species, they sent a deep diving robot to collect samples. Samples which revealed these were not plants at all but worms that eat bones, now officially called Osedax – the bone-devourers in Latin.
Once scientists knew how to look for them, the search for bone-eating worms, also known as zombie worms, began.
Teams dragged dead, beached whales offshore and sank them into the deep. Landing devices deliver parcels of animal bones to the seabed – pigs, cows, turkeys – then retrieve them months or years later to see what has infested them.
“Basically, wherever we put bones, we find [the worms],”Greg Rouse from Scripps Institution of Oceanography, San Diego. One of the team members who found Osedax.
More than 30 species from around the world have been found. There’s the bone-eating snot flower, Osedax mucofloris, first found off Sweden. Osedax fenrisi was discovered near a hydrothermal vent at a depth of more than 2,000 metres in the Arctic, and named in 2020 after the Norse god Loki’s son, Fenris the wolf.
The bone-eating worm ranges in size from the length of a little finger to smaller than an eyelash. Those visible to the naked eye are usually females. Males are mostly tiny and don’t eat bones. They live in “harems” of tens or hundreds inside a female’s mucous tube, and wait for her eggs to emerge so they can immediately fertilise them.
The energy these males get comes from their mothers via their egg yolks. Once they have run down that energy store, they die.
“We called them kamikaze males”Robert Vrijenhoek, retired evolutionary biologist from the Monterey Bay Aquarium Research Institute, California
Studies of Osedax DNA indicate that these worms live in huge, interconnected populations, possibly making stepping stones of whale skeletons and other large vertebrates stripped bare by scavengers.
“Osedax probably just hop, skip and jump all the way across the ocean,”
For more on the Zombie Worms visit Live Science