Last year, we heard how anole lizards are able to breathe underwater from an air bubble on their nose. One of the scientists involved in that study has now documented a spider doing something similar – although the bubble covers its whole body.
Known by the scientific name of Trechalea extensa, the large semi-aquatic spider's natural habitat ranges from Mexico down to Panama. And while it does venture to the water's surface when foraging for prey, it had previously not been known for diving, and certainly not for completely submerging itself.
That recently changed, however, when Binghamton University's Asst. Prof. Lindsey Swierk and colleagues observed one of the land-living spiders fleeing from humans by going underwater … and remaining there for over 30 minutes.
For that whole time, its body was enveloped in a layer of air, which appeared to be held in place by a covering of hydrophobic (water-repelling) hairs. It's still not clear if the spider was actually breathing that air, but the film certainly seemed to keep the arachnid from drowning.
"The film of air might serve to keep the respiratory openings away from water, since these spiders are air-breathing," said Swierk. "The film of air might also help to minimize thermal loss to the cold stream water that the spider submerges itself in."
A paper on the research – which also involved Macy Petrula from California State University Sacramento, and Patricia Esquete from Portugal's University of Aveiro – was recently published in the journal Ethology.
Source: Binghamton University