In a well-explored part of the ocean, researchers have unexpectedly come across a novel species of worm. Biologists with the Monterey Bay Aquarium Research Institute in California were trolling the bottom of the bay with a remote-controlled submarine, looking for clams. What they found instead were exposed bones of a dead whale covered in a red carpet of inch-long worms.

The tubeworms are unlike any previously seen. They have a large bulbous end filled with eggs. Surrounding the large ovary is a green tissue filled with bacteria, which grow down like roots into the marrow of the whale bones. Lacking mouths or guts, the worms depend on the whale-bone-eating bacteria they carry around to provide them with energy.

The oddity continues: as many as 100 microscopic male worms live within a female.

The researchers describe their findings in the current issue of Science. As NPR's Joe Palca reports, the discovery is a reminder that the ocean still holds many mysteries.

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