Scientists diving in the Salish Sea have discovered two previously unknown sea spider species, including one with hairy legs, red eyes and three lips around its triangular mouth. The strange marine creatures were collected during scuba dives conducted between September 2023 and August 2024.

The dives reached depths of up to 18 meters, or 59 feet, in waters between British Columbia in western Canada and the US state of Washington. Researchers from the University of British Columbia described the species in a study published Wednesday in the journal Organisms Diversity & Evolution.

One species was named Callipallene pilosuspedes because of the long, curved spines covering its lower legs. The name combines “pilosus,” the Latin word for “hairy,” with “pedes,” meaning “feet.”

Beyond its conspicuously hairy limbs, Callipallene pilosuspedes has a slender trunk, claws and red eyes. Researchers also found three lips positioned at the opening of its triangular mouth, adding another unusual feature to the creature’s appearance.

The species possesses highly dexterous ovigers, appendages that resemble legs but are not used for walking. According to the university, the appendages can instead work as grooming tools, allowing the animal to clean its body.

“Under a microscope, researchers observed the animal wrapping the appendages around its legs and using attached comb-like spines to clean itself,” the university said. That grooming ability sharply distinguishes the species from the other sea spider identified during the research.

The second species, Tanystylum kiixin, has much smaller and less dexterous limbs for carrying eggs. The university said those limbs leave the animal unable to groom itself effectively, and researchers frequently found it covered with tiny parasites despite the sea spider itself being a parasite.

Tanystylum kiixin also has black eyes, knob like claws and an abdomen shaped like an hourglass. Its name is pronounced “Kee-hin” and comes from the sound of waves crashing at the base of an ancient Indigenous village site where the species was discovered.

Scientists have identified almost 1,400 sea spider species overall, according to the study. The creatures originated around 500 million years ago and can crawl across ocean floors, move over animals or plants, and in some cases tread water.

Sea spiders vary dramatically in size, ranging from less than 1 centimeter, or under 0.4 inches, to 70 centimeters, or 28 inches. Despite their common name, the marine arthropods are not actually spiders, though they are related to spiders, scorpions and horseshoe crabs.

The animals generally have four trunk segments and four pairs of long legs, but some can possess as many as 12 legs. Species living in shallow water also frequently have four eyes, according to information provided by the university.

Their mouths are typically larger than their bodies and are used to suck juices from soft bodied invertebrates. Their digestive and reproductive systems extend into their legs, while males carry eggs on a separate pair of legs until the young hatch.

Researchers focused on sea spiders in shallow areas of the Salish Sea because only 17 species had been reliably recorded there, despite the area’s rich marine biodiversity. The limited documentation made it difficult to examine how these creatures might be affected by environmental pressures.

Lead study author and biologist Cormac Toler-Scott conducted the research for his master’s degree in zoology at the University of British Columbia. He said he wanted to understand how sea spiders respond to climate change and human disturbance, but found little existing information.

“I was interested in how sea spiders are impacted by climate change and human disturbance, because marine invertebrates in the Salish Sea are particularly at-risk, and I couldn’t find anything,” Toler-Scott said. He added that the shortage of information largely reflects how little is known about the species present and their lifestyles.

Researchers noted that the Salish Sea shoreline is now densely populated and developing rapidly. They said documenting biodiversity in its waters is an important step toward determining where conservation efforts could have the greatest impact in confronting threats linked to human activity.