Zombie worm, sometimes called the bone-eating worm, is an unusual marine worm that feeds on animal bones fallen to the seafloor. Around 25 species (kinds) of zombie worm have been discovered since 2002. Zombie worms were first found living on the bones of dead whales. But they are now known to eat the bones of other mammals and even fish bones.
It is the zombie worm females that eat bones. The female resembles a red, feathery flower on a stalk coming out of the bone. The bright red plume acts as the gills, collecting oxygen from the water. The female zombie worm sits inside a transparent tube. The female can retract into the tube if threatened by predators. The worm does not have a mouth or gut. Most of its body is found inside the bone. Female zombie worms grow into the bone with roots, something like the roots of a plant. The roots dissolve the hard part of the bone with acid. The worms then take in the remaining nutritious tissue in the bone through their skin. This material feeds bacteria living in the roots. Zombie worms then digest the bacteria. Females may reach 4 to 5 inches (10 to 13 centimeters) in length, though some species are much smaller.
The male zombie worm is thousands of times smaller than the female. Hundreds of males can live attached to the tube of one female. The males fertilize the eggs of the female, which can produce hundreds of eggs every day. The eggs become small swimming larvae (young). The larvae must settle on bone to grow. Most larvae do not survive, as there are not many bones on the seafloor.
Researchers first found zombie worms on bones off the coast of California. But the worms have also been spotted off the coasts of Japan and Sweden and even Antarctica. This evidence suggests that zombie worms are probably living in oceans all over the world.
