Water Spider Spins Its Own "Scuba Tank"

Water spiders survive below the surface thanks to a rudimentary "scuba tank" they spin from their own silk.

Scientists at the University of Bern, Switzerland, determined that spiders use these scuba tanks, called air bells, as reservoirs, monitoring and replenishing oxygen levels to enable the animals to live underwater.

Found in ponds throughout northern and central Europe, the water spider is the only spider that spends its entire life underwater.