During 400 million years of existence, spiders have spread widely across our planet. It is difficult to find places where they would not meet. What characterizes the order of Spiders? What features do its representatives have? You will learn about where and how spiders live in the article.
Spider Squad
Along with insects, crustaceans and centipedes, spiders belong to arthropods, forming a separate class of arachnids, or arachnids. Currently, the order of Spiders includes about 42 thousand species.
Their colors are very diverse - from gray, black and light brown, to bright yellow, red or green. In body size, they reach from a few millimeters to 10-15 centimeters. Together with the span of the legs, the tarantula can reach about 25-30 centimeters. Life expectancy among members of the detachment also varies greatly and can range from one year to 30 years.
Most of them are carnivores and feed on a variety of small animals, from insects to small birds and rodents. Only a few typesfor example, Kipling's bagheera, eat plants. Due to their lifestyle, almost all spiders secrete poison. With it, they paralyze and kill the victim. However, only some members of the order are capable of causing serious harm to humans and other mammals. They usually target small prey and cannot penetrate the skin of large animals, and their venom is too weak. The most dangerous are black widows and steatodes, the bite of which can be fatal.
The structure of spiders is vaguely reminiscent of the structure of crabs or ticks. Despite their possible toxicity, it is the characteristic appearance that often causes arachnophobia. An uncontrollable fear of spiders is one of the most common phobias in the world.
Building features
Like other arthropods, the body of spiders consists of several segments. It is divided into the cephalothorax and abdomen, the shape of which differs depending on the specific species. Four pairs of limbs are placed on the cephalothorax, a mouth apparatus equipped with a pair of chelicerae (jaws) and a pair of short leg tentacles intended for reproduction. On the abdomen are breathing holes and arachnoid warts, from which fiber is secreted for the construction of the web.
Spider chelicerae are located on both sides of the mouth and look like claws. They are shorter than the tentacles and walking legs and are used during hunting. At their end, ducts open, through which poison enters directly from the poisonous glands.
Representatives of the Spider squad have from 2 to12 eyes. One pair is always located in front and is equipped with muscles that allow them to be moved. Side pairs of eyes can be located in front, on the sides or at the top of the cephalothorax and are completely devoid of muscles.
Representatives of some species of spiders see very poorly, distinguishing only the shape and size of objects, and even then close. So, side walkers and lycosides recognize insects like a fly or a bee only at a distance of 3-5 centimeters. Horses have the best vision in the Spider squad. Their eyes are located around the cephalothorax and allow them to view the world in almost 360 degrees. With the front pair, they perfectly distinguish colors, recognize the shape and dimensions of objects, and accurately calculate the distance to them. Side eyes serve mainly for orientation, and when you need to consider something in detail, they simply turn in the right direction.
Peacock spider
The peacock spider from the racehorse family is endemic to Australia. It lives in the eastern part of the mainland and the island of Tasmania. This member of the Spider order has a bright color of red, blue, yellow and green, which is why it got its name. This color is present only in males. During the mating season, they demonstrate it in every possible way to their chosen ones, while performing ritual dances.
Black Widow
The body size of a black widow reaches only 10-15 millimeters. This is a small spider with a round, bulging abdomen and long, thin legs. It has a shiny black color and a bright red spot in the form ofhourglass on the back. In the order of Spiders, the black widow is considered one of the most dangerous species. Its venom contains a strong neurotoxin that is fatal in five percent of cases. The spider got its name from the habit of females to eat males after mating.
Spiky Orbweb
The spiny orbworm is common in hot and humid regions of the tropics and subtropics. It lives in Australia, the countries of South and Central America, as well as in the USA in the states of Florida and California. It weaves a beautiful circular web that can reach up to 30 centimeters in diameter. The appearance of the spider is very different from other types of order. It has short legs, a flat, brightly colored abdomen, which is equipped with six spikes. The color of the spider can be white, red, yellow or orange. It has a pattern of black dots on its back.
Where do they live?
Spider Squad is present on all continents except Antarctica. Its representatives do not live only on some islands and in regions where ice covers the earth's surface all year round, and otherwise there are no barriers to them. The largest number of species inhabits the warm, humid regions of the equatorial and tropical zones.
They equip their homes in underground burrows, in tree trunks, among the branches and foliage of plants. They can live in any cracks and crevices, under stones and other objects. The order of Spiders includes mainly terrestrial species, but there are exceptions among them. Spider-silverfish lives underwater, building funnel-shaped nests of cobwebs there. Its paws are covered with long swimming bristles, and its belly, lubricated with fat, traps air bubbles and allows it to stay under water for a long time.
Human use
Despite their intimidating appearance, spiders are of great interest to humans. They are eaten, bred as pets and studied in every possible way in the hope of using them for the benefit of people.
Due to their predatory nature, spiders reduce the number of garden pests, preventing the destruction of the crop. Their poison can be a real panacea for aphids, Colorado potato beetles and other insects if it is extracted on an industrial scale. Scientists argue that such a tool is much safer for the environment than pesticides. In addition, it does not require large expenditures, and its production is absolutely humane in relation to these eight-legged creatures.
The medical significance of the Spider squad is also great. Tarantula venom is used in drugs to calm the nervous system, used to reduce heart fibrillation during attacks. Some species of venom are expected to be used as a treatment for Alzheimer's disease, stroke prevention, and erectile dysfunction.
