name: Diving bell spider or water spider (Argyronita aquatica)
Where do you live: Europe, Central and Northern Asia, with a separate subspecies in Japan
What does he eat: Other aquatic invertebrates and small fish
Why it's cool: As its name suggests, the diving bell spider lives almost entirely underwater; It is the only spider that does this. However, it still needs to breathe air, so it lives by creating a diving bell – spinning a web between underwater plants – and then carrying air from the surface to its web via its hairy body.
“It has evolved an amazing adaptation for this aquatic life.” Craig McAdam, conservation director of the UK invertebrate charity Buglife, told Live Science in an email. “The spider has many hydrophobic hairs over its body that trap air from the surface of the water. The spider then spins a silk structure where it forms an air bubble, which it uses in the same way as a diving bell.”
The bubble expands so the spider can enter. Rooms Females are twice the size of those made by males, because they need it to serve as a nursing room as well. The air in the diving bell is regularly renewed, and the spider carries with it a bubble of water, giving it a silver color.
Unusually for spiders, male diving bell spiders are larger and heavier than females. a 2003 study In the journal Evolutionary Ecology Research, I looked into why this is, and found that for more mobile males, growing larger – and having longer front legs – means they can move more efficiently underwater. In contrast, female size was limited by the need to construct a larger windbell in which to care for her young, and by the energy costs associated with repeatedly transporting fresh air from the water surface to the bell.
tracking Study published in 2005 In the Journal of Arachnology by the same authors also revealed an interesting insight into the mating behavior of spiders: females seem to prefer to mate with large males, despite the greater risks involved.
The team discovered that larger males sometimes eat females in a state of sexual cannibalism. However, their experiments also showed that large males and females would also kill smaller males.
