A Spider That Lives Entirely Underwater, But Still Breaths Air

This is the diving bell spider, one of the few species of spider known to live almost entirely under water. The diving bells that this spider produce are irregularly constructed sheets of silk and an unknown protein-based hydrogel, which is spun between submerged water plants then inflated with air brought down from the surface by the builder. Studies have considered gas diffusion between the diving bell and the spiders’ aquatic environment. The silk, while waterproof, allows gas exchange with the surrounding water; there is net diffusion of oxygen into the bell and net diffusion of carbon dioxide out. This process is driven by differences in partial pressure. The production of carbon dioxide and use of oxygen by the spider maintains the concentration gradient, required for diffusion. However, there is net diffusion of nitrogen out of the bell, resulting in a gradually shrinking air bubble which must be regularly replenished by the spider.

Video by Team Candiru