Four New Deep-Sea Worm Species Discovered

Posted on February 11, 2016

Xenoturbella churro

Scientists have discovered four new species of deep-sea worms. The species were found living near deep-sea cold seeps, hydrothermal vents, and whale carcasses off the coasts of California and Mexico. The species all belong in the genus Xenoturbella. Previously, only one member of the genus was known.

The unusual worm species were discovered by a team of scientists from Scripps Institution of Oceanography at UC San Diego, the Western Australian Museum, and the Monterey Bay Aquarium Research Institute (MBARI). Before the discovery of these new worms the only known Xenoturbella was a pink flatworm-like animal (Xenoturbella bocki) found in waters off Sweden.

One of the new worms has been named Xenoturbella churro (illustrated above) for its resemblance to the fried-dough pastry. It is about 4 inches (10 centimeters) in length. It was discovered in a 1,700-meter (5,577-foot)-deep cold seep in the Gulf of California.

Scripps marine biologist Greg Rouse, lead author of the study, says in a statement, "The findings have implications for how we understand animal evolution. By placing Xenoturbella properly in the tree of life we can better understand early animal evolution."

Xenoturbella hollandorum


The largest of the new species, Xenoturbella monstrosa, was found in Monterey Bay and the Gulf of California. It measures 20-centimeters (8-inches) long. The smallest species, Xenoturbella hollandorum, is pictured above. It is just 1 inch (2.5 centimeters) long. X. hollandorum was found living near a whale carcass.



A research paper on the new species was published in the journal, Nature.

Illustration: John Meszaros
Photo: Scripps Oceanography/Greg Rouse