Су астында тіршілік ететін өрмекші (Su astynda tírshilik etetin órmekshi)

Genus of spiders

The diving bell spider or water spider (Argyroneta aquatica) is the only species of spider known to live almost entirely under water. It is the only member of the genus Argyroneta. When out of the water, the spider ranges in colour from mid to dark brown, although the hairs on the abdomen give it a dark grey, velvet like appearance. It is native to freshwater habitats in Europe and Asia.

A. aquatica is the only known species of spider that spends almost all its life underwater, including resting, catching and eating prey, mating, egg laying, and overwintering. It only briefly surfaces to replenish its oxygen supply and occasionally will bring prey to the surface. Several other spiders are semiaquatic, either periodically living underwater or willing to dive. For example, certain Desis species spend the high tide in an air filled underwater retreat made from silk and forage on land in the intertidal zone during low tide. Some spiders living in periodically flooded habitats can survive for an extended period underwater by entering a coma like state, up to 16–36 hours in Arctosa fulvolineata. Numerous species, including some Ancylometes, Dolomedes, Megadolomedes, Pardosa, Pirata, Thalassius and others, live above water at the surface, but may actively submerge for a prolonged period, are strong swimmers and will catch underwater prey. Several of these, as well as a few others, may dive into the water to avoid larger predators.

A. aquatica is found in clean freshwater habitats with aquatic vegetation, such as lakes, ponds, canals, marshes and slow moving streams. It ranges through much of mainland Europe (no records from Portugal, Greece and Albania), the British Isles and central to northern Asia ranging as far south as Iran and as far north as Siberia, up to latitude 62°N. Most of the range is inhabited by the nominate subspecies, but Japan has its own subspecies, the very similar A. a. japonica. South Korea has a protected area, Yeoncheon Eundaeri water spider habitat, for this endangered species in that country.

As with other spiders it breathes air; when submerged in water, an air bubble is trapped by a dense layer of hydrophobic hairs on its abdomen and legs, The spiders themselves fall prey to frogs and fish.

The appearance of the diving bell gave rise to the genus name Argyroneta, from the Greek "argyros" (ἄργυρος), meaning "silver", and "neta", a neologism (perhaps for *νητής) derived from the verb "neo" (νέω) "spin", intended to mean "spinner of silver". Both sexes build diving bell webs which are used for digesting prey, although only the female's larger bell is used for mating and raising offspring. Females spend most of their time within their bells, darting out to catch prey animals that touch the bell or the silk threads that anchor it and occasionally surfacing to replenish the air within the web. The bells built by males are typically smaller than females' and are replenished less often. It is thought that prior to mating, the male constructs a diving bell adjacent to the female's then spins a tunnel from his bell, breaking into hers to gain entrance. The female spider then constructs an egg sac within her bell, laying between 30 and 70 eggs. which is spun between submerged water plants then inflated with air brought down from the surface by the builder. Studies have considered gas diffusion between the diving bell and the spiders' aquatic environment. The silk is waterproof but allows gas exchange with the surrounding water. There is net diffusion of oxygen into the bell and net diffusion of carbon dioxide out. This process is driven by differences in partial pressure. The production of carbon dioxide and use of oxygen by the spider maintains the concentration gradient, required for diffusion. However, there is net diffusion of nitrogen out of the bell, resulting in a gradually shrinking air bubble which must be regularly replenished by the spider. this system is more properly regarded as an inorganic form of gill.

Their bite is often described as being very painful to humans and as causing localised inflammation, vomiting, and slight feverishness that disappears after 5 10 days. However, solid evidence is lacking, with information being based on old and unverified reports because recent confirmed and published reports are lacking, leading some sources to refer to its bite as reputedly painful.