The diving bell spider or water spider, Argyroneta aquatica, is a spider which lives entirely under water. Since the spider must breathe air, it constructs from silk a diving bell which it attaches to an underwater plant. The spider collects air in a thin layer around its body, trapped by dense hairs on its abdomen and legs. It transports this air to its diving bell to replenish the air supply in the bell. This allows the spider to remain in the bell for long periods, where it waits for its prey.

The spider is found in ponds in the palaearctic region, which includes Europe, northern Asia, and Africa north of the Sahara desert. It lives for approximately two years. It is velvet-grey, however the trapped air around its body gives it the appearance of being silvery. Unusually for a spider the males (9 - 12 mm) of this species are often larger than the females (8 - 15 mm).

Argyroneta aquatica is the only species in the genus Argyroneta. Recent studies suggest that it should be placed in the family Cybaeidae .

External link

• BBC factfile