Scientists discover two new species of sea spiders along Canadian coastline

Tanystylum kiixin, a new species of sea spider, with round eggs inside its legs. Cormac Toler-Scott/The University of British Columbia hide caption

Researchers in Canada have discovered two new species that are related to spiders, but you don't have to worry about them crawling across your living room.

The new species are part of the sea spider family and were found in shallow waters in the Salish Sea between Washington State and the Canadian province of British Columbia. These sea spiders are the first to be found in that area in more than 100 years, according to the researchers. The newly discovered species, which measure about a centimeter across, were collected between September 2023 and August 2024 off of the islands of Vancouver and Quadra in British Columbia.

Sea spiders are marine arthropods that are part of a class called Pycnogonida . Scientists have discovered more than 1,300 species of sea spiders.

Cormac Toler-Scott, lead researcher on the team at the University of British Columbia that discovered the new species, told NPR that some sea spiders not only resemble spiders on land with eight legs, but are also related to them. However, the marine creatures are different from land spiders in several ways.

"They never made that transition to land," Toler-Scott said. "They really need to be in the water. They're quite slow moving. They just kind of crawl on the seafloor."

One of the new species of sea spiders, called Callipallene pilosuspedes , has red eyes, a three-lipped mouth shaped like a triangle and a curved spine that covers its legs. It also has limbs that come from its belly called ovigers that can be used to groom itself and comb off dirt as well as algae. "They're very clean and not all sea spiders can do this," he said.

Callipallene pilosuspedes, another newly discovered sea spider species. Cormac Toler-Scott/The University of British Columbia hide caption