Two New Sea Spider Species Discovered in the Salish Sea
Salish Sea Marine Survey Yields Two New Sea Spider Species
Between September 2023 and August 2024, researchers diving in waters up to 18 meters deep around Vancouver, Victoria, Quadra Island, and the west coast of Vancouver Island near Bamfield discovered two new species of sea spiders. Described by University of British Columbia researchers, the finds mark the first new species formally described from the Salish Sea in almost a century, highlighting significant gaps in the baseline taxonomy of regional marine invertebrates.
UBC researchers describe new Salish Sea species
- New Discoveries: UBC researchers formally described Callipallene pilosuspedes and Tanystylum kiixin from Salish Sea dive sites surveyed between September 2023 and August 2024.
- Morphological Traits: C. pilosuspedes features a three-lipped mouth, red eyes, and comb-like spines on its ovigers used for grooming its walking legs.
- Ecosystem Complexity: T. kiixin, named to honor the Huu-ay-aht First Nations capital of Kiix̣in, frequently hosts microscopic protists and parasitic organisms on its body.
Anatomical Analysis of Callipallene pilosuspedes
The first newly identified species, Callipallene pilosuspedes, measures roughly one centimeter in length. Laboratory examination using high-resolution scanning electron microscopy revealed long, curved spines covering parts of its walking legs, which gave the species its Latin-derived descriptor for “hairy feet.” The animal displays conspicuous red eyes and a short feeding apparatus terminating in a triangular mouth divided into three lips fringed with sensory structures.
Lead author Cormac Toler-Scott observed that the species utilizes specialized appendages called ovigers for self-maintenance. While males in pycnogonid species typically employ ovigers to carry developing eggs, researchers watched C. pilosuspedes bend its highly mobile ovigers around its walking legs and pull comb-like spines across them to clean its surface.
Taxonomic Significance of Tanystylum kiixin
The second newly documented species, Tanystylum kiixin, was named to honor Kiix̣in, the traditional capital of the Huu-ay-aht First Nations on Vancouver Island, where archaeological evidence indicates human habitation spanning almost 3,000 years. Unlike its hairy-footed counterpart, T. kiixin possesses smaller and less dexterous ovigers.
This anatomical difference correlates with higher accumulation of environmental dirt and debris. Researchers repeatedly identified tiny protists and parasitic organisms living on the specimens, leading Toler-Scott to describe the animal as an ecosystem within an ecosystem within an ecosystem. The findings demonstrate how small benthic invertebrates can function simultaneously as independent organisms and as micro-habitats.
Broader Ecological Context of Pycnogonids
Sea spiders are pycnogonids, an ancient branch of marine arthropods related to the broader group that includes spiders, scorpions, and horseshoe crabs. Living entirely in marine environments, they crawl across the seafloor or over other organisms. Their morphology often features extreme adaptations, including central bodies so tiny that major organs and branching digestive tracts extend into their limbs. Pycnogonids lack dedicated lungs or gills, relying instead on oxygen passing through their thin outer surface.
Despite their unique evolutionary lineage, pycnogonids remain among the most poorly understood groups of animals. Toler-Scott noted that initial research into how climate change and human disturbance impact Salish Sea invertebrates hit roadblocks due to insufficient baseline data regarding regional species distributions and life histories. The UBC team’s work encompassed detailed examinations of seven local species, five of which required modern descriptions alongside the two newly established species designations.