However, only one species of spider has joined them: the diving bell spider, Argyroneta aquatica.
Sadly, diving bell spiders are becoming increasingly rare in Europe; however, after obtaining a permit to collect the elusive animals, the duo eventually struck lucky in the Eider River.
Taking a series of oxygen measurements in the bubble and surrounding water, the team calculated the amount of oxygen flowing into the bubble before calculating the spider's oxygen consumption rate and found that the diving bell could extract oxygen from the most stagnant water even on a hot day.
However, despite satisfying the spider's oxygen demands, the bubble continually shrinks because nitrogen diffuses back into the water, eventually forcing the occupant to venture to the surface to resupply the diving bell.
Diving bells may have their limitations, but insect plastrons could inspire submersible designs, Flynn says.
In contrast, diving bell spiders seem to actively replenish their air bubble--called a diving bell after the antique submarines--by frequently traveling to the surface to grab more air.
Eurasian diving bell spiders (Argyroneta aquatica) survive entirely underwater by living in large air bubbles, which the crawlers trap in silken webs.