How Do Spiders Hold Their Breath?

Spiders do not have lungs like humans. They instead use an air bubble to breathe underwater. This allows them to stay under water for extended periods without oxygen.

In the past, scientists didn’t know how spiders breathed underwater. A few species of tarantulas have been known to swim, but not all. Some arachnids, such as sea spiders, have been reported to survive in small bodies of water for up to 24 hours.

A diving bell spider uses a bell-shaped silken web as a gill to breath underwater. The spider collects air from the water, traps it in a bubble, and then resurfaces to replenish the air.

Another species, the Trechalea extensa, was found to create an underwater “film of air” using hydrophobic hairs. These hairs entrap the bubble of air and then release carbon dioxide. Eventually, the bubble collapses, as nitrogen diffusion occurs.

Some spiders also have water-repelling hairs, which help to keep the bubble of air in place. These spiders also have light-sensing cells. Light helps the spider to communicate with its brain.

Other arachnids, such a the common house spider, can breathe underwater for up to three hours. But most spiders can only survive for an hour or so before they start to run out of oxygen.

However, some spiders do have an air bubble on their abdomen. In these cases, they can stay underwater for up to 24 hours, if they can get back to the surface in time.