Sea Spiders Need Their Guts To Pump Oxygen

A biologist studying sea spiders discovered that this species has a very unexpected feature. Instead of using its heart to pump fluids and deliver oxygen, this creature seems to be utilizing its guts.

Insects, in general, and spiders, in particular, have a different way of pumping blood than the one that makes up humans. Instead of veins and arteries, they present a substance known as hemolymph. This was noted to ‘wash over’ their cells, which helps deliver energy and oxygen. Their tube-like heart keeps this fluid in motion.

Sea Spiders and their Unexpected Oxygen Transportation System

However, sea spiders seem to function in another way. The species can usually be found in either the Caribbean or Mediterranean Seas or polar oceans. They were noted to have some 10 to 12 legs, and in these latter regions, to grow to about three feet wide.

Arthur Woods was studying a sea spider specimen under the specimen when he noted a surprising element. While the arthropod’s heart was beating weakly, its guts were in overtime.

In general, spider guts use squeezing motions which helped them break up food. Thanks to the same motion, they can also move this along the digestive tract. In contrast, in sea spiders, the guts seem to also take an additional role.

Their waves of peristalsis appeared to be particularly strong. According to Woods:

“My ‘aha!’ moment was to consider that maybe all that sloshing of blood and guts was not about digestion but instead about moving respiratory gases around.”

Woods is a biologist at the University of Montana, Missoula. He tested his theory through a series of observations and experiments, conducted with his colleagues.

These helped confirm that 12 species of sea spider use their guts as an essential element in their cardiovascular system. Research results on the matter are available in the journal Current Biology.

Observations also showed that the sea spiders’ guts extend from their abdomen and out into their legs. This could help keep the nutrient waves moving.

The research team will now be taking a closer look at the gut systems of other sea creatures, for example, fish lice. They will do so to more closely investigate how oxygen is transported through their systems.

Image Source: Wikimedia