The spider bell spider or the water spider ( Argyroneta aquatica ) is the only species of spider known to live almost entirely in underwater. This is the only member of the genus Argyroneta . When out of the water, the spider ranges in color from mid to dark brown, although the feathers on the stomach give it a dark gray appearance, like velvet. It is the native freshwater habitat of Europe and Asia.
Video Diving bell spider
Uniqueness of aquatic behavior
A. aquatica is the only species of spider that spends most of its life under water, including resting, catching and eating prey, mating, laying and overwintering. Only a short surface to fill the oxygen supply and sometimes will bring prey to the surface.
There are some other semi-static spiders, either living under water periodically or wanting to dive. For example, certain species desis spend the tide in the air-filled silk fissures of the silk and feed on land in the intertidal zone at low tide. Some spiders that live in flood habitats regularly survive for long periods underwater by entering into a coma, up to 16-36 hours in Arctosa fulvolineata . Many species, including some Ancolometes, Dolomedes, Megadolomedes, Pardosa , Pirata
Maps Diving bell spider
Distribution and habitat
A. aquatica is found in freshwater habitats with aquatic vegetation, such as lakes, ponds, canals, swamps and slow-moving streams. These range in many European continents (no records from Portugal, Greece and Albania), the British Isles and northern Asia (Turkey, Caucasus, Russia, Iran, Central Asia, China, Korea and Japan) to latitude 62Ã, Â ° LU. Most ranges are inhabited by the subspecies that run, but Japan has its own subspecies, which look a lot like A. A. japonica .
Ecology
Like any other spider, it breathes air; when submerged in water, the air bubbles are trapped by a dense layer of hydrophobic hair in the abdomen and legs, giving the stomach a silvery appearance. Spiders live for about two years in captivity.
A. aquatica can remain submerged for a long time because the silk-based structure it builds to maintain the oxygen supply, is named in accordance with the dive-like bell structure. The range of species is in size, although female size may be limited because they put more energy in building and maintaining larger bells. Men are more active and on average nearly 30% larger than females, measuring 10-15 mm (0.39-0.59 inches) in head-and-body length compared with 8-12 mm (0.31- 0.47 inches). This measure benefits the unusual male to the spider, where sexual dimorphism usually supports a larger woman. The theory suggests that more active male hunting styles require greater strength to overcome water resistance and counteract the buoyancy of their moving air supply. This larger body size is also associated with longer legs, proving to affect diving skills and give men superiority in diving over the more naked females.
Spiders prey on aquatic insects and crustaceans such as mosquito larvae and Daphnia . The spiders themselves fall prey to frogs and fish.
Diving bells
The appearance of the diving bell gave rise to the name of the genus Argyroneta, from the Greek "argyros" (???????), meaning "silver", and "neta", a neologism (probably for * ?????) comes from the verb "neo" (???) "spin", meant to mean "silver spinner". Both sexes make jumping nets that are used to digest prey, although only larger female bells are used to mate and raise a child. Women spend most of their time in their bells, bolting out to catch the predator animals that touch the bell or the silk thread that extends and sometimes come to the surface to fill the air inside the net. The bells built by men are usually smaller than the bells and are rarely refilled. It is estimated that before mating, the man constructs a diving bell adjacent to the female then turns the tunnel from his bell, breaks into his possession to gain entrance. The marriage takes place in the bell of a woman. The female spider then builds an egg sac inside the bell, putting between 30 and 70 eggs. Where this moults species is less clear, with some sources stating that it happens underwater in diving bells and the other that goes beyond water.
Diving bells are irregular silk sheets and unknown protein-based hydrogels spun between submerged water plants, then inflated with air brought down from the surface by builders. Studies have considered the diffusion of gas between diving bells and spider water environments. The silk is waterproof but allows gas exchange with surrounding water. There is a net diffusion of oxygen into the bell and a net diffusion of carbon dioxide out. This process is driven by a partial pressure difference. The production of carbon dioxide and the use of oxygen by the spider retain the concentration gradient, which is necessary for diffusion. However, there is a net diffusion of nitrogen out of the bell, producing a gradually shrinking air bubble that must be regularly refilled by the spider.
Larger spiders are capable of producing larger bubbles that have higher oxygen conductance, but all of these species' spiders are able to enlarge their bells in response to increased oxygen demand in a low water environment P (O 2 ). The spider voluntarily tolerates low internal oxygen conditions, enlarging their bells with air when P (O 2 ) falls below 1 kPa; This recharge process may not need to happen for several days, in some cases. This system has been referred to as "aqua-pulmonary airborne air bubbles", although aqua-lung has no gas exchange with its surroundings; this system is more appropriately regarded as an inorganic gill shape.
Bite
Their bites are often described as very painful to humans, and cause local inflammation, vomiting and a slight fever that disappears within a few days. However, strong evidence is lacking, with information based on unverified reports that long since recent confirmed reports are lacking, causing some sources to name their bites as being considered painful.
References
External links
- Draw water spiders at Arkive.org
- "Water Spider". eb.archive.org. Archived from original on 2009-11-01 . Retrieved 2014-01-25 .
- The diving of diving bells use a 'gill-like' bubble net
Source of the article : Wikipedia
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