But their resemblance to snake-haired Medusa (above) wasn't lost on discoverer Ana Hilário, who plans to name at least one after the mythological Greek monster.
Hilário, of Portugal's University of Aveiro, and colleagues recently found 20 species of the tiny worms, called frenulates, in mud volcanoes in the Gulf of Cádiz, an arm of the Atlantic Ocean southwest of Spain.
Mud volcanoes are places where methane-filled fluids seep from the seafloor, providing energy for "exceptionally rich ecosystems," Hilário said in an email.
(Related: "Giant Deep-Sea Volcano With 'Moat of Death' Found" [April 14, 2006].)
But scientists know little about the elusive frenulates, tube-dwelling worms that survive thanks to bacteria that live inside a special organ in their bodies.
The worms absorb chemicals such as methane from sediment and deliver the substances, via their blood, to the bacteria, which in turn produce organic carbon. The carbon nourishes both creatures.
Hilario has already named another genus from the expedition Bobmarleya—the worm's "dreadlocked" appearance reminded her of the Jamaican singer, she said.