Hate spiders? Don't watch this
25 Mayo 2018 14:37
Spiders get a bad reputation. Much like snakes and sharks, people have a predisposition towards considering them one of the worst and most dangerous animals you can encounter, both outdoors and even in the safety of their own home.
But what made us single these animals out and give them human characteristics by suggesting that they're somehow more 'evil' than other predatory species? Human culture and religion have intermingled with an innate, primal revulsion to dangerous creatures. Even if spiders did not have such a special place in popular culture as villains, we would still have an instinctive aversion towards them.
Despite what most people might think, spiders are not insects, they are in the family of arachnids; insects have six legs, while arachnids have eight. Also unlike insects, spiders don't have antennae on their heads. You can find spiders in almost every continent, with the exception of Antarctica, and they are the seventh most diverse organism order in the world. Taxonomists have recorded at least 45,000 different spider species.
Spider abdomens contain certain appendages that have evolved into so-called spinnerets, which expel the spider silk from a number of different glands. Spiders harken back to millions of years, with the earliest species that scientists found encased in rocks dating back to around 300 million years ago.
The spider mating ritual is a complicated one, as they are fierce predators and the male needs to protect itself from the appetites of the larger, female spiders. The male will use its claws to send out soft vibrations — another thing that separates them from insects, which will instead use sharp, erratic movements.
If the female decides to mate with the male and not eat him — even though sometimes she might still eat him afterwards, like a praying mantis — she can lay from two to a whopping thousand eggs. Almost every spider species will then lay these eggs on a silky 'bed' and then coat them in a silky 'blanket' for protection and incubation. Afterwards, she uses more silk to turn the incubating bed into a sac, which she then hangs somewhere for protection. She doesn't go very far though! Mama spiders lurk near the sac until their babies hatch to ensure that they remain safe from would-be predators.
Once their spiderlings hatch, they stay inside the protective cocoon until they are done developing and can protect themselves in the outside world. Mothers in some spider species will hang around until their babies actually leave the sac, but others will either leave them or die before they can see them hatch.
One particular species of spider, the wolf spider, will even carry the baby-sac around with it. She attaches it to her spinnerets and hauls it around with her until the spiderlings hatch. Once they do, they climb onto their mother's back and feed off their yolks until they finish developing. They join their mama in every activity, including hunting, until they are grown up enough to fend for themselves.