Even thousands of feet below the water’s surface, no arachnophobe is truly safe from spiders. And, thanks to a recent discovery by a team of scientists, three more species have been added to the list of sea-dwelling arthropods — with the special distinction of being what researchers called “methane-powered.”

Three new types of spiders were recently found in deep-sea habitats, far beyond the reach of sunlight, according to research published in the Proceedings of the National Academy of Sciences.

Shana Goffredi, the study’s lead author and chair of biology at Occidental College in Los Angeles, told USA TODAY that researchers found the first new species in July 2023 off the coast of Del Mar, California, a beach town about 20 miles north of San Diego.

Scientists then discovered the other new species off the coasts of California and Alaska, Goffredi said, adding they live between 600 and 1,200 meters below the surface.

Some are as large as a grain of rice, according to the professor. Others, much larger.

“They belong to an interesting group of sea spiders that have only ever been found at very specialized habitats on the seafloor called methane seeps,” Goffredi said. Some species also live at hydrothermal vents, or geothermally heated mineral-rich springs on the sea bottom.

“Because they are localized to these specialized habitats, we had a suspicion that they were tied to the high-energy compounds that emanate from the seafloor in those locations,” Goffredi continued. “By conducting shipboard experiments, we were able to show definitively that they use methane, through bacterial epibionts that live on their exoskeleton. By farming them, and then consuming them, they take advantage of a nutritional resource that is not common in the animal kingdom.”

New sea spiders found help prevent methane from escaping deep sea

As of Friday, June 20, scientists said they continued to study the spiders’ complete role in the ecosystem.

“We don’t yet know their full role in their ecosystem just yet. It’s pretty hard to do behavioral observations in the deep sea,” Goffredi said. “But no doubt they are a prey source for other organisms and they probably help distribute organic carbon to other areas of the seafloor.”

By growing what researchers called “a crop of methane-oxidizing bacteria” that consume methane molecules on their exoskeleton, the spiders help the planet’s larger ecosystem by acting as a biological filter to prevent methane from escaping from the deep sea.

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at nalund@usatoday.com and follow her on X @nataliealund.