First methane-powered sea spiders found crawling on the ocean floor

Summary

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. CNN — Heat-trapping methane may be best known for the dangers it poses to humans and Earth’s atmosphere, but in the dark depths of the ocean, the greenhouse gas is a nourishing meal for some of the world’s most mysterious creatures, new research suggests. Scientists say they have discovered three previously unknown, unnamed species of sea spider off the US West Coast that could be teaming up with bacteria to thrive off gas bubbling from the seafloor in sparsely studied marine habitats known as methane seeps thousands of feet below the ocean’s surface. In this symbiotic relationship, bacteria take up real estate on the spider’s exoskeletons, and in return, the microbes convert carbon-rich methane and oxygen into sugars and fats the spiders can eat, according to a study published Monday in the journal Proceedings of the National Academy of Sciences. “Just like you would eat eggs for breakfast, the sea spider grazes the surface of its body, and it munches all those bacteria for nutrition,” said Shana Goffredi, a professor and chair of biology at Occidental College in Los Angeles and the study’s principal investigator. This unique nutrition strategy has never been observed in sea spiders before, she said. Other species of sea spider share more in common with their terrestrial cousins, using large tubelike fangs to capture, immobilize and suck the fluids from soft-bodied prey, such as jellyfish, Goffredi explained. But lab observations of the newfound species, part of the Sericosura genus, revealed they lack the necessary appendages to capture prey, making them more akin to farmers harvesting methane-fueled bacteria from their own bodies. It’s possible the spiders and their hitchhiking microbes play a crucial role in preventing methane — a natural gas thought to exacerbate global warming — from reaching Earth’s atmosphere, accor...