I'll begin this new blog with the story of the Diving Bell Spider, from the New York Times. Magnificent.
The water spider weaves a silk bubble, known as a diving bell.
Of the tens of thousands of spider species, only Argyroneta aquatica spends its lifetime underwater — even though, like its terrestrial counterparts, it requires oxygen to survive.
The spider weaves a silk bubble, known as a diving bell, on underwater vegetation. It uses this bell to extract oxygen from water, said the study’s first author, Roger Seymour, a biologist at the University of Adelaide in Australia.
The bell acts as a gill, and pulls in dissolved oxygen from fresh water. Although this was previously known, Dr. Seymour and his colleague Stefan K. Hetz of Humboldt University in Berlin, used a device to measure exact changes in the bell’s oxygen levels for the first time.
Even in warm, stagnant water, the bell extracts oxygen that the spiders can rely on, they found.
“The value of staying underwater is that you don’t scare the prey away,” Dr. Seymour said. “And if you go to the surface often you might alert a bird.”
Water spiders trap insects and small fish in their bell, just as terrestrial spiders capture insects in their webs. They have the ability to sense when something hits their underwater web, and they dash out to paralyze the prey before pulling it into the bell, Dr. Seymour said.
Female spiders lay eggs within the bell, and hatched spiders build bells of their own.
The researchers found that the bell shrinks as nitrogen from the bell diffuses into the water over time. Eventually, the spider must surface to create a replenishing bubble that resupplies the bell with oxygen.
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