Researchers at the University of British Columbia have formally identified two bizarre new sea spider species in the Salish Sea—Callipallene pilosuspedes, featuring hairy legs and red eyes, and Tanystylum kiixin, which carries microscopic debris and parasites. The discovery marks the first new sea spider descriptions in the region in nearly a century.
Divers exploring the cold waters off the Pacific Northwest coast have uncovered two miniature marine invertebrates that are rewriting regional biodiversity records. Described in a study published in Organisms Diversity & Evolution, the animals represent the first new sea spider species formally identified in the Salish Sea in almost 100 years. The research spans collections made between September 2023 and August 2024 at depths reaching up to 18 meters across marine habitats near Quadra Island, Vancouver, Bamfield, and Victoria.
Researchers Fill a Century-Long Blind Spot
The project began with a fundamental question about how local marine life responds to environmental stress. Cormac Toler-Scott quickly discovered a major barrier: baseline scientific data for the animals simply did not exist. That's largely because people don't know much about what species exist here and what their lifestyle is,
he noted.
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.
Cormac Toler-Scott, lead author and zoology researcher
To bridge that gap, the research team combined physical observation with DNA sequencing.
Callipallene Pilosuspedes Features Built-In Grooming Tools
The first new species, Callipallene pilosuspedes, draws its name from the Latin words for hairy feet
due to the long, curved spines covering the lower portions of its walking legs.
Under microscopic examination, researchers observed an unexpected behavioral adaptation. In this species, the animal bends its mobile ovigers around its legs, using comb-like spines on the limbs to clean its body.
Tanystylum Kiixin Hosts a Parasitic Ecosystem
The second newly described species is Tanystylum kiixin.
As a result, specimens are regularly found coated in dirt, debris, and tiny protists living directly on their bodies.
an ecosystem within an ecosystem within an ecosystem.
Cormac Toler-Scott, study lead author
Ancient Marine Lineages Reveal Bizarre Biology
Originating roughly 500 million years ago, sea spiders are classified as pycnogonids—an ancient lineage of marine arthropods linked to the wider family that encompasses horseshoe crabs, scorpions, and spiders. Inhabiting exclusively marine environments, they typically spend their existence either walking across the ocean bottom or moving over various sea life.
Rather than hunting for a traditional meal along the ocean floor, many shallow-water varieties fall on the tinier side of the scale, utilizing their compact dimensions to survive as parasites clinging to bigger hosts. Utilizing a specialized tubular mouth apparatus known as a proboscis to drain the fluids from their host, both newly discovered species were spotted close to a seafloor-dwelling creature termed a hydroid, which looks much like a tethered jellyfish.
How these newly identified species adapt to environmental pressures in the Salish Sea remains unmeasured.