What would you call a creature with no brains and no guts – just a mouth where food goes in and waste comes out? Now that you’ve used up all of the names of the U.S. presidential candidates, what would you call it? Marine researchers studying this strange deep-sea creature shaped like a discarded sock say it finally has a name and a genus to belong to.
The first of these brainless, gutless and eyeless creatures was discovered in deep waters off the coast of Sweden in 1950. Researchers at the time tentatively classified it as a flatworm. In the 1990s, genetic tests reclassified it as a mollusk but the test results were discarded when it was determined that the scientists had mistakenly tested the DNA of what this simple creature ate.
It existed as a puzzling orphan oddity until around 2004 when marine biologist Greg Rouse of the Scripps Institution of Oceanography discovered a similar creature in a clam field in Monterrey Bay off the California coast. After 12 years of exploration in the area, Rouse and other biologists found four variations of this living sock near deep-sea cold seeps, hydrothermal vents and occasionally on whale carcasses.
In the current issue of the journal Nature, Rouse announced the true identity of these four creatures, the confirmation that the Swedish one is the fifth and the name of the species: Xenoturbella. The original Swede is the Xenoturbella bocki. The largest – measuring 20-centimeters (8-inches) long and found in Monterrey Bay and the Gulf of California – is the Xenoturbella monstrosa. The smallest, also from Monterrey Bay, is the 2,5 cm (1 in) Xenoturbella hollandorum. The deepest find – at 3,700 meters (12,139 feet) - is the Xenoturbella profunda. And the tastiest-looking one was named the Xenoturbella churro for its resemblance to the delicious fried Spanish pastry.
So what exactly are they? Xenoturbella are a form of bilaterally symmetrical animals, which means if you divide them down the center, their halves are identical. Also when you divide them down the center, you’ll find no brain, gills, eyes, kidneys or anus. The researchers are calling its only opening a mouth, but they’ve never actually seen one eat. All of this puts Xenoturbella pretty close to the bottom of the evolutionary tree.
No brains, no guts, no vision, uses its mouth for both eating and eliminating waste. Sound like anyone you know?