The oceans are filled with all kinds of wonders and horrors alike. And don’t worry, scientists are still discovering new species of life that fit into the latter camp. Researchers from the University of British Columbia in Canada have been exploring the waters of the Salish Sea in the Pacific Northwest. In a recent study, they described the discovery of two new species of sea spiders in the area, both of which have unique characteristics. One has red eyes, hairy legs, and a three-lipped mouth, while the other, a parasitic creature, was found with its own smaller parasites. The team’s work “is a testament to how effective targeted sampling efforts, such as diving, can be in discovering new species,” the study’s lead researcher, Cormac Toler-Scott, told Gizmodo. A close-up of Callipallene pilosuspedes, also known as the hairy-footed sea spider. © Cormac Toler-Scott Unexplored life of sea spiders Sea spiders belong to the branch of life known as chelicerates, a large group of arthropods that also includes spiders and other arachnids. However, they emerged about 500 million years ago, long before the arrival of the first true spiders, according to Toler-Scott. And unlike most chelicerates today, these animals were perfectly content to stay in the water (horseshoe crabs are another marine cousin of theirs). Sea spiders are also called pycnogonids. There are many species of sea spiders waiting to be classified, but scientists only discover a few each year, says Toler-Scott. In practical terms, this is because they tend to be small and cryptic animals, meaning that species in a region are difficult to detect and often look very similar to each other, at least at first glance. But there aren’t too many scientists around the world actively studying these creatures either, leaving even fewer opportunities for potential discoveries. The Salish Sea is an inland sea located between the Canadian province of British Columbia and the US state of Washington, and we know very little about the sea spiders that inhabit it. However, between September 2023 and August 2024, Toler-Scott decided to explore the area and collect specimens by diving as part of his work to complete a master’s degree in zoology at UBC. Once on land, he and his team closely studied the specimens he found with microscopy and genetic sequencing. Ultimately, the team’s study describes seven species of sea spiders in the Salish Sea in detail (say, three times as fast), including two species never before categorized. The mouth of the “Sarlacc well” of a Callipallene pilosuspedes. © Cormac Toler-Scott One is called Callipallene pilosuspedes; the latter name roughly means “hairy feet” in Latin. The hairy sea spider also has red eyes, a short proboscis with claws that it uses to hold its food before biting into it, and a three-lipped, triangle-shaped mouth covered in tendrils. The UBC press release on the find calls this mouth a “small Sarlacc seawell,” but I’ll let true Star Wars fans decide that for themselves. Under a microscope, the team also observed their single C. pilosuspedes specimen using its ovigers (appendages that males typically use to carry fertilized eggs until they hatch) to groom. The second species is called Tanystylum kiixin and is named after the ancient indigenous village near where the specimens were first collected. Kiixin is pronounced “kee-hin”, which is the sound made by the waves at the base of the village site. Sea spiders are sometimes parasites of larger animals, especially smaller ones that live in shallow water, but they can also have their own freeloaders. And the team detected parasites in the newly described parasite. Unlike C. pilosuspedes, T. kiixin’s smaller ovigers leave it less able to clear out its unwanted luggage. The team’s work was published last month in the journal Organisms Diversity & Evolution. Much more to find A protist parasite found in a Tanystylum kiixin sea spider. © Cormac Toler-Scott The team also created an identification guide for other scientists exploring the Salish Sea to follow in the future. However, these new species are likely just the tip of the sea spider iceberg. Because sea spiders and other invertebrates are vulnerable to pressures like climate change and other human-caused disturbances, it’s even more important to learn everything we can about these mysterious, long-surviving ocean inhabitants, according to Toler-Scott. “If a master’s student can find two new species of sea spiders in one diving season along the British Columbia coast, imagine how many undescribed species of marine invertebrates must be documented before anthropogenic disturbances and climate change completely alter these marine communities forever,” he said. Interestingly, an independent research team recently discovered that other arthropods use giant sea spiders that live in the deep ocean as living taxis.
