Scientists Discover Two New Species of Sea Spider in the Pacific Northwest—and They Look Like They Came Straight Out of a Horror Movie

No, it’s not a human-made monstrosity or alien attacker from this season’s latest horror movie—it’s real, and it’s lurking along the Pacific Coast. It’s one of two new species of sea spider discovered in the Salish Sea, which stretches along the coastal Pacific Northwest between Washington state and British Columbia in Canada. But there’s no need to fear the newfound creatures; the red-eyed one is only around one-third of an inch across, and the other is even smaller.

Researchers described the itsy-bitsy sea spiders in a study published August 26 in the journal Organisms Diversity & Evolution. He and his colleagues found the strange multi-legged critters during dives at sites including Quadra Island, Vancouver, Bamfield and Victoria between September 2023 and August 2024. They collected more than 150 individual sea spiders from depths of up to 60 feet.

After examining the animals’ physical characteristics and analyzing their DNA, the researchers determined the creatures represented five species of shallow-water sea spiders—two of which had never been described. While scientists know of roughly 50,000 species of land-lubbing spiders, only about 1,400 species of their ocean-dwelling relatives have been documented, Kaija Jussinoja reports for CTV News. New sea spiders can be tough to identify because they’re often small and look like one another, Toler-Scott tells Gizmodo’s Ed Cara.

Still, these two new species have plenty of characteristics that set them apart. One of them boasts ruby eyes; a claw-adorned feeding tube called a proboscis; a three-lipped, triangle-shaped mouth covered in sensory tendrils; and, of course, fine spines on its legs, according to a statement. The researchers found just one individual and named its species Callipallene pilosuspedes—a play on the Latin words for “hairy feet.” The other recently described sea spider resembles something like a swamp monster.

Because of its underdeveloped egg-carrying limbs, or ovigers, the critter cannot clean itself. The research team found 82 individuals, and they were often covered in dirt, debris and tiny parasites, creating an “ecosystem within an ecosystem within an ecosystem,” Toler-Scott says in the statement. The species was dubbed Tanystylum kiixin (pronounced “kee-hin”) to reference the ancient Indigenous village site where the first specimens were collected.

Sea spiders have retained “some weird traits,” Toler-Scott says in the statement. The multi-legged creatures probably stay near hydroids and feast on the stationary animals. Sea spiders evolved roughly 500 million years ago.