Over 400 million years of existence, spiders have spread widely on our planet. It is difficult to find places where they would not meet. What is characterized by the detachment of Spiders? What features do its representatives have? You will learn about where spiders live and how they live.
Squad Spiders
Along with insects, crustaceans and millipedes, spiders belong to arthropods, forming a separate class of arachnids, or arachnids. Currently, the Spider squad 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 leg span, a tarantula spider can reach about 25-30 centimeters. The life expectancy of members of the squad also varies greatly and can range from one year to 30 years.
Most of them are predators and feed on various small animals, from insects to small birds and rodents. Only a few species, such as Kipling Bagir, consume plants. By virtue of their lifestyle, almost all spiders secrete poison. With it, they paralyze and kill the victim. However, only some members of the squad are capable of causing serious harm to humans and other mammals. Usually they are aimed at small prey and cannot bite through the skin of large animals, and their poison is too weak. The most dangerous are black widows and steatodes, the bite of which can be fatal.
The structure of spiders remotely resembles the structure of crabs or ticks. Despite their possible toxicity, it is a characteristic appearance that is often the cause of arachnophobia. Uncontrolled fear of spiders is one of the most common phobias in the world.
Structural 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 particular species. Four pairs of limbs are placed on the cephalothorax, the oral apparatus is equipped with a pair of chelicera (jaws) and a pair of short tentacles intended for reproduction. On the abdomen are respiratory openings and spider warts, from which fiber is released for the construction of the web.
Spider chelicerales 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 to 12 eyes. One pair is always located in front and equipped with muscles that allow them to move. Side pairs of eyes can be 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, the sidewalks and lycosides recognize insects like flies or bees only at a distance of 3-5 centimeters. The best vision in the Spider squad is horses. Their eyes are located around the cephalothorax and allow them to view the world 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 are mainly for orientation, and when you need to consider something in detail, they simply unfold in the right direction.
Peacock spider
Peacock spider from the family of horses is endemic to Australia. It lives in the eastern part of the mainland and the island of Tasmania. This representative of the Spider squad has a bright color of red, blue, yellow and green colors, which is why it got its name. Such a coloring is present only in males. During the mating season, they in every possible way demonstrate to his 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 convex abdomen and long thin legs. It has a shiny black color and a bright red spot in the form of an hourglass on the back. In the Spider squad, the black widow is considered one of the most dangerous species. Its venom contains a strong neurotoxin, which leads to death in five percent of cases. The spider got its name because of the habit of females to eat males after mating.
Spiked Orb
Spiked orbiting is common in hot and humid areas 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. He weaves a beautiful circular web, which can reach up to 30 centimeters in diameter. The appearance of the spider is very distinguished from other types of squad. He 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. On the back of it is a pattern of black dots.
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 for the rest there are no barriers for them. The largest number of species inhabits warm, humid areas of the equatorial and tropical zones.
They equip their dwellings in underground burrows, in tree trunks, among branches and foliage of plants. They can live in any cracks and crevices, under stones and other objects. The Spider detachment includes mainly terrestrial species, but there are exceptions among them. A silver spider lives underwater, building there funnel-shaped nests from the web. Its paws are covered with long swimming bristles, and the belly, greased, retains air bubbles and allows you to stay under water for a long time.
Human use
Despite the awesome appearance, spiders are of great interest to humans. They are eaten, bred as pets and thoroughly studied in the hope of using it for the benefit of people.
Due to its predatory nature, spiders reduce the number of garden pests, preventing the destruction of the crop. Their poison can become a real panacea for aphids, Colorado potato beetles and other insects, if obtained 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 great. The poison of tarantulas is used in drugs to calm the nervous system, and is used to reduce cardiac fibrillation during seizures. It is assumed that some types of poison can be used as a remedy for Alzheimer's disease, for the prevention of stroke and the treatment of erectile dysfunction.