Two previously unknown sea spider species were documented from Salish Sea and west coast of Vancouver Island waters by UBC researchers led by Cormac Toler-Scott.
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Two new species of sea spiders discovered in coastal waters near Vancouver Island have been formally identified, adding to what researchers say is a still-incomplete inventory of marine invertebrates in the Salish Sea region.
The species, identified by a research group led by UBC masters student Cormac Toler-Scott, were collected during diving surveys off mainland Vancouver and Vancouver Island. The team published a related paper this summer describing the findings.
The newly named species are Callipallene pilosuspedes and Tanystylum kiixin. According to the research account, the animals are very small, with an estimated legspan of about a centimetre, and are described as completely new to science.
Toler-Scott said the two species were collected “here in the Salish Sea,” and noted that their discovery increases the documented total of sea spider species in the Salish Sea and west coast of Vancouver Island to 20. He added that his early field work captured only a portion of the local diversity, indicating additional species may yet be found.
Sea spiders are in a broad group of arthropods that also includes land spiders, scorpions and horseshoe crabs, though they are not classified as arachnids. The researchers describe sea spiders as breathing through their skin and note that males play a role in carrying and tending young.
Physical details included in the species descriptions highlight how specialized the animals are for life at the seafloor. For Callipallene pilosuspedes, the research account describes red eyes paired with a translucent white body, along with a short proboscis that functions like a grasping “nose” structure. The same description says it has a triangular, three-lipped mouth used to take in food, surrounded by sensory tendrils.
The report also points to distinctive structures on males of that species: the animals have limbs positioned on the back of the base of the head. Those limbs are described as used to move eggs—gluing them to the male using a secretion produced in the legs—and to clean the male’s own body.
For Tanystylum kiixin, the researchers say it was named after an ancient Indigenous village on Vancouver Island. The description likewise includes features on the head that are involved in dealing with eggs, while also indicating that the species ends up with small parasites. In the account provided, the parasites are described as looking like tiny turtle shells with threadlike projections extending from the base.
The discovery comes as a wider effort to understand what lives in local marine habitats, particularly because sea spider life histories and diversity patterns are still poorly documented in many regions. Toler-Scott said he became interested in whether sea spiders are affected by climate change and by human disturbance, noting that marine invertebrates in the Salish Sea are considered at risk.
He said the research gap is largely driven by limited knowledge of which species exist locally and how they live. In that context, the identification of new species is positioned as a foundational step: documenting organisms is often necessary before researchers can assess their vulnerability to environmental change.
The work also suggests why marine biodiversity surveys remain urgent even in well-studied coastal systems. Toler-Scott said there is “definitely more diversity out there” that was not captured during a single field season, indicating that additional unknown arthropods may be present in local waters beyond the two species newly described.
While the public often associates spiders with land, sea spiders are not arachnids and are adapted to ocean life. Their anatomy and reproductive roles, as described by the researchers, underscore that arthropod relatives can occupy very different ecological niches, from intertidal and shallow habitats to deeper marine environments.
For communities along the British Columbia coast, the practical significance of the findings is closely tied to the ability to monitor ecosystem health. More complete species documentation can support future research into how marine invertebrate communities respond to warming oceans, shifting currents, pollution, and other pressures linked to human activity in the Salish Sea and adjacent waters.
The researchers’ account also frames the new discovery as part of an incremental but growing scientific record: the team’s updated documentation brings the number of sea spider species documented in the region to 20, while also pointing to continued uncertainty about how many species remain undiscovered.
In addition to expanding taxonomic knowledge, the naming of Tanystylum kiixin reflects the connection between local geography and scientific practice, using Indigenous place references in the formal classification of species. That detail, alongside the researchers’ focus on climate-related and human-driven impacts, places the discovery within a broader conservation and stewardship conversation for the region’s marine environments.
Toler-Scott emphasized that the findings were based on limited field time, and that more work is needed to capture the full range of sea spider diversity in coastal waters. As a result, the identification of two new species is both a clear scientific advance and an indicator that local marine biodiversity still holds species that have not yet been catalogued in formal scientific literature.
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