Scientists have identified two new sea spider species in the Salish Sea, marking the first such discoveries in nearly a century. The findings reveal unique adaptations and highlight gaps in understanding marine biodiversity.
The discovery of two previously unknown sea spider species in the Salish Sea has shed light on the region’s underexplored marine biodiversity. Researchers from the University of British Columbia (UBC) documented the species between September 2023 and August 2024 during dives up to 18 meters deep, uncovering details that challenge existing knowledge about these creatures.
The Hairy-Legged Discovery
The first species, Callipallene pilosuspedes, was named for its long, curved spines covering its lower legs, which researchers describe as “hairy feet.” It has red eyes, a short proboscis, and a triangular, three-lipped mouth. Under a microscope, scientists observed its highly dexterous ovigers—egg-carrying limbs used for grooming. Only a single specimen of this species has been found so far, according to UBC News (source).
The second species, Tanystylum kiixin, was named after an ancient Indigenous village site near where it was collected. It has smaller, less flexible ovigers, making self-grooming difficult. Researchers frequently found it covered with tiny parasites, creating what the team described as an ecosystem within an ecosystem within an ecosystem.
Parasites Within Parasites
The Tanystylum kiixin species hosts a community of parasites that live on its body. This layered relationship highlights the Salish Sea’s ecological intricacy.
The study also revealed that sea spiders, despite their spider-like appearance, are marine arthropods. They breathe through their skin and have a unique reproductive system where males carry eggs on specialized limbs.
Why This Matters
The Salish Sea, spanning British Columbia and Washington state, is a biodiversity hotspot, yet its marine invertebrates remain poorly documented. The discovery of these species highlights the need for targeted sampling efforts, such as scuba diving, to uncover hidden diversity.
The research contributes to a global database of sea spiders, with both species registered. However, Toler-Scott believes many more remain undocumented. I only had one field season but there’s definitely more diversity out there that we haven’t documented,
he noted (source). This suggests the Salish Sea may hold other undiscovered species, offering opportunities for future studies.
Unanswered Questions
While the study provides critical insights, several questions remain. How do these species interact with other marine life? What role do their parasites play in the ecosystem? And how will climate change and human activity affect their survival?