Spider Uses Air Bubble as SCUBA Tank for Diving
A propelling clip from the Smithsonian Channel series Crazy Monster shows how the aptly named scuba spider uses an air bubble as a self-contained underwater breathing apparatus. The spider goes up to the surface of the water, creates a bubble with its bottom end, and uses that air bubble to go diving.
The scuba spider is the only arachnid to live exclusively underwater, despite lacking gills. Its secret, like its name suggests, is a makeshift oxygen supply.