UBC documents two new sea spider species off B.C. coast, first in Salish Sea in nearly a century

The Story

Two newly identified sea spider species have been documented from waters along British Columbia, with researchers saying the find represents the first such records in the Salish Sea in almost a century. The work was led by UBC zoologist and lead researcher Cormac Toler-Scott, who said the discovery adds to a poorly catalogued group of marine arthropods in the region.

UBC said the animals were collected during field sampling from September 2023 to August 2024. Specimens were gathered in multiple locations, including areas around Vancouver, Quadra Island, Bamfield and Victoria, along with other sites along the coast.

One of the species has been named Callipallene pilosuspedes. According to UBC, the name draws on Latin roots associated with “hairy feet,” reflecting long, curved spines on the creature’s lower legs. The university also described physical traits including red eyes, a short proboscis with claw-like structures used to grasp food before biting, and a triangular, three-lipped mouth ringed with sensory tendrils.

UBC said Callipallene pilosuspedes also has specialized appendages for grooming itself. The university provided a microscopic description of the mouth at about 30 micrometres, underscoring the small scale of the anatomy that researchers say helped distinguish the species.

The second newly documented sea spider is named Tanystylum kiixin, pronounced “kee-hin.” UBC said the name is taken from an ancient Indigenous village near where the species was discovered. The university described Tanystylum kiixin as having relatively small limbs and limited ability to groom itself effectively, which researchers say may help explain why it was often observed with debris and tiny parasites.

Toler-Scott said Tanystylum kiixin’s dependence on parasites and associated life forms creates a layered set of relationships. He characterized it as “an ecosystem within an ecosystem within an ecosystem,” referring to the broader biological community built around the sea spider.

Although the common name includes “spider,” UBC emphasized that sea spiders are not arachnids. They are marine arthropods related to groups such as scorpions, spiders and horseshoe crabs, and UBC said the lineage evolved roughly 500 million years ago.

Researchers said sea spiders can have up to 12 legs and possess a sucking proboscis. Their size is highly variable, with UBC noting they can range from less than a centimetre to more than 70 centimetres, depending on species and life history.

UBC described how some shallow-water sea spiders live as parasites on larger organisms. Toler-Scott said the strategy often results in the animals using a specialized feeding apparatus—the proboscis—to draw juices from a host, reflecting adaptations shaped by their ecological niche.

UBC said the two new species have been registered in a global database. Toler-Scott added that additional diversity is likely still undocumented, saying there is more to be found beyond the sampling already completed for the study.

For Vancouver-area residents and coastal communities, the discovery highlights how much remains to be catalogued in the waters of the Salish Sea and adjacent coastal regions. It also points to the likelihood that small, rarely observed marine species—especially those living as parasites—can persist unnoticed despite extensive shoreline and fisheries activity. The work also underscores ongoing research efforts by UBC to map biodiversity in British Columbia’s marine environments, where new findings can emerge from targeted sampling and careful taxonomic documentation.

The sea spider documentation is notable not just because it adds two named species, but because UBC says these are the first sea spider records in the Salish Sea in almost a century, narrowing a long gap in scientific records for the group in that specific area. UBC’s description of the animals’ collection sites and distinguishing anatomical features will help future researchers compare additional specimens and look for related species in nearby waters.