The sea spider that cleans its legs: Two new species map hidden life in the Salish Sea
Salish Sea
The coastal sea region where the researchers found the animals.
proboscis
A short tube sea spiders use to take in food.
ovigers
Limbs that male sea spiders use to carry eggs.
What happened
Researchers from the University of British Columbia formally described two new sea spider species from the Salish Sea. They are the first new sea spider species formally described from the region in nearly a century. The study appeared in Organisms Diversity & Evolution.
The paper examined seven coastal sea spider species. The team combined detailed physical observations with DNA analysis. Researchers collected the new animals during dives from September 2023 through August 2024. The dives reached 18 meters. They covered sites around Quadra Island, Vancouver, Bamfield, and Victoria.
Two species with very different cleaning problems
The first species is Callipallene pilosuspedes. Its name refers to its long, curved spines, which look like hairy feet. It also has red eyes, a short proboscis with claws, and a triangular mouth with three lips. Fine sensory structures surround the mouth.
The most unusual observation involved its ovigers. These are limbs that male sea spiders use to carry eggs. Under a microscope, the animal wrapped its ovigers around its legs. Comb-like spines on those limbs helped clean its body. However, researchers found only one specimen of this species. They cannot yet say how common this cleaning behavior is.
The second species is Tanystylum kiixin. Its name comes from an ancient Indigenous village site near where researchers first found it. The name is pronounced “kee-hin.” It refers to the sound of waves crashing near that site.
This species has smaller, less flexible egg-carrying limbs. That may make self-cleaning harder. Researchers often found dirt and debris on its body. They also found tiny parasites living there. The research paper says this species closely associates with the hydroid Plumularia setacea, a small marine animal.
Why the discovery matters
Sea spiders are marine arthropods from an ancient lineage. They appeared roughly 500 million years ago. They are related to spiders, scorpions, and horseshoe crabs, but they live entirely in the ocean. Some sea spiders breathe through their skin. Males carry the eggs. Some shallow-water species live as parasites on larger animals.
These unusual animals are also poorly documented in the Salish Sea. Lead researcher Cormac Toler-Scott became interested in how climate change and human disturbance affect marine invertebrates. He found that scientists lacked basic information about which species lived there. That gap matters. Scientists need to identify the animals before they can track changes in their communities.
What the study confirmed
This was the first comprehensive Salish Sea sea spider study to combine detailed imaging with DNA data. The team generated genetic sequences for several species that had never been sequenced. It also created an identification guide for sea spiders in the region and along the west coast of Vancouver Island. Both new species are now registered in a global database.
What remains unknown
The study does not reveal how many sea spider species remain undocumented. The team had only one field season. One new species was represented by only one specimen. Researchers therefore still lack a clear picture of population size, distribution, and behavior. They also do not know whether grooming keeps parasites away.
What to watch next
More surveys across seasons and locations could show how common these species are. Researchers can use the new guide, close-up images, and DNA data to find more animals. That work would create a stronger baseline for watching how coastal biodiversity changes.
Sources: UBC Zoology report and ScienceDaily summary.
One sea spider cleans its legs. Another carries tiny parasites.
📰 Full story: The sea spider that cleans its legs: Two new species map hidden life in the Salish Sea
Researchers found two new sea spider species in the Salish Sea. Their different body parts may explain their different cleaning abilities.
species
A kind of living thing with shared key traits.
parasites
Tiny organisms that live on another animal.
DNA
Information scientists use to compare living things.
💡 The gist
- Scientists found two sea spider species new to science.
- One cleans its legs with comb-like spines.
- The other often carries dirt and tiny parasites.
What did scientists find?
Researchers from the University of British Columbia studied sea spiders in the Salish Sea. The team collected animals during dives from September 2023 to August 2024. The dives reached 18 meters. The study looked at seven coastal species.
One new species is called Callipallene pilosuspedes. It has long, curved spines on its legs. It also has red eyes and a short mouth tube. Under a microscope, researchers watched it use its egg-carrying limbs. It wrapped those limbs around its legs. Comb-like spines helped clean its body.
The second species is called Tanystylum kiixin. Its egg-carrying limbs are smaller and less flexible. This may make cleaning harder. Researchers often saw dirt and debris on the animal. They also found tiny parasites on its body.
Why does this matter?
The researchers used close-up images and DNA. DNA gives scientists information for comparing living things. These tools helped them tell similar sea spider species apart.
The team also made an identification guide. The guide helps researchers recognize sea spiders in the region. This is important because scientists need a species list before measuring change. If a species becomes rare, they must know it lived there first.
The study also added genetic information for several species. Those species had never been sequenced before. Both new species were added to a global database.
What is still unknown?
Researchers found only one specimen of Callipallene pilosuspedes. They do not know how common its cleaning behavior is. They also do not know how many more sea spider species remain hidden in the region.
The researchers had one field season. More surveys could show where these animals live and how many exist. Future work could also test whether cleaning helps remove parasites. The new guide and DNA data give scientists a useful starting point.
A tiny sea spider cleans its legs
📰 Full story: The sea spider that cleans its legs: Two new species map hidden life in the Salish Sea
Scientists found two new sea spiders. One uses tiny combs to clean itself.
parasite
A tiny living thing that stays on another animal.
DNA
A body clue that helps scientists compare animals.
Little legs under the sea
The University of British Columbia is a school where scientists work.
Its scientists found two new sea spiders.
They found them in the Salish Sea.
One sea spider has tiny combs on its legs.
It uses the combs to clean itself.
The other sea spider cannot clean as well.
Dirt and tiny parasites often stay on its body.
A parasite is a tiny living thing on another animal.
Scientists looked at close-up pictures of the animals.
They also studied DNA.
DNA is a body clue that helps scientists compare animals.
Only one cleaning sea spider was found.
So scientists need to look more.
They think more kinds may be hiding under the sea.