3071 x 5692 px | 26 x 48,2 cm | 10,2 x 19 inches | 300dpi
Data acquisizione:
14 ottobre 2006
Altre informazioni:
The diving bell spider or water spider, Argyroneta aquatica, is the only species of spider known to live entirely under water. Argyroneta aquatica is found in northern and central Europe and northern Asia up to latitude 62°N. It is the only spider known to spend its whole life under water. As with other spiders, it breathes air, which it traps in a bubble held by hairs on its abdomen and legs. This gives it a silvery appearance, despite it being velvet-grey. The spider inhabits ponds in Europe and northern Asia, and lives for approximately two years. Females build underwater "diving bell" webs which they fill with air and use for digesting prey, molting, mating and raising offspring. They live almost entirely within the bells, darting out to catch prey animals that touch the bell or the silk threads that anchor it. However, they have to surface occasionally to renew their personal air supplies and those of their webs. Males also build bells, but these are smaller and the males replenish their bells' oxygen supply less often. The males also have a more active hunting style. Although they are better swimmers than females, they prefer to cling to silk threads or underwater vegetation while moving. Prior to mating, the male constructs a diving bell adjacent to the female's, then spins a tunnel from his bell, breaking into to hers to gain entrance. Mating then takes place in the female's bell. The female spider lays between 30 and 70 eggs in her bell.
