Water Spider

• GeneralThe only spider that lives underwater: it builds a bell of air out of silk.
• adaptaciónIt is the only spider known to spend nearly its whole life underwater, building a silk bell that it fills with air trapped on the surface of its body so it can breathe while submerged.
• It is the only spider in the world that spends practically its whole life under water.
• It weaves a silk dome among the water plants and fills it with air fetched from the surface, trapped by the water-repellent hairs on its abdomen and legs. Inside it feeds, moults, mates, lays its eggs and overwinters.
• The bell is not merely a store: it works as a physical gill. Oxygen dissolved in the water diffuses in and carbon dioxide diffuses out. A 2011 study measured that it can cover at least the spider's resting needs even in warm, stagnant water.
• That lets it stay inside for up to a whole day before having to surface and top it up.
• It reverses the dimorphism usual in spiders: the males are larger than the females.
• Under water it looks silvery from the film of air clinging to its body, which is where the genus name, alluding to silver, comes from.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat and environment

Ponds and backwaters with dense water plants

Litter / clutch size

Between 30 and 70 eggs per clutch, laid inside the bell

Sources consulted: https://es.wikipedia.org/wiki/Argyroneta_aquatica