How Do Sea Spiders Breathe Through Their Legs?

Sea spiders have way more leg than body, and scientists have never been able to pinpoint how they breathe -- until now. Learn what they found in this episode of BrainStuff.

Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

See omnystudio.com/listener for privacy information.

Episode Transcript

Speaker 1 (00:02):
Welcome to brain Stuff from how Stuff Works, Hey, brain Stuff,
Lauren Vogel bomb here. Unsurprisingly, a human doesn't have much
in common with a sea spider. Actually, no other organism
on Earth has much in common with one of these
spindle legged arthropods that look more like a tinker toy
experiment than a living thing. My favorite top five weird

(00:24):
things about them. Their hearts are so weak that they
require the digestive system to move blood around their body.
Most of their digestive system and their genitals are encased
in their delicate legs. Their males carry their young, They
eat by sticking their probiscus into a mushy sea creature
and sucking out its juices, and until recently, nobody could

(00:46):
figure out how they breathed. Strange as they may be,
sea spiders occupy marine habitats the world over. In deep
and shallow waters. They can be miniscule, with a leg
span of only a millimeter, but antarct sea spiders grow
to be unusually large, about the size of a frisbee.
Polar gigantism is the term that describes the way animals

(01:07):
at our planets poles tend to grow much larger than
in other parts of the world. Even at their biggest
This isn't to say that their bodies are very big.
Their trunks are improbably small in contrast to the sheer
area their legs take up. There's not a lot of
surface area on a sea spiders abdomen and thorax. To
trick it out with unnecessary amenities. A lot of jobs

(01:27):
have to be farmed out to those long, skinny legs.
Scientists have pretty much identified how they pack most of
the necessary physiological processes into such a teen c body
and such delicate appendages, but they haven't been able to
figure out how they breathe until recently. A study published
in a twenty eighteen issue of the Journal of Experimental
Biology has gotten to the bottom of how sea spiders

(01:50):
move oxygen through their bodies by studying several species of
giant Antarctic sea spiders. Most sea creatures have gills like
fish and lobsters, or lungs like ales, and some can
even take oxygen in through their skin. But sea spiders
have a tough exo skeleton and no gills or lungs,
so what gives The research team found sea spiders take

(02:11):
oxygen into their bodies through hundreds of tiny pores in
their cuticle. That's the tough outer skin that gives them
structure and protection. They put giant Antarctic sea spiders in
respiration tanks to see exactly how much oxygen they were absorbing,
and they found that they were taking in enough through
tiny holes all over their legs to run their entire bodies,

(02:31):
which of course is great for the sea spider for now,
but as polar seas warm as a result of global
climate change, their ability to absorb oxygen in this novel
way might be compromised. Today's episode was written by Jescelin
Shields and produced by Tyler Clang. For more on this
and lots of other precarious topics, visit our home planet,

(02:55):
how stuff Works dot com