Features of the web. How does a spider weave a web, where does spider silk come from? Why do spiders build trapping webs?

Representatives of the arachnid order can be found everywhere. These are predators that hunt insects. They catch their prey using a web. This is a flexible and durable fiber to which flies, bees, and mosquitoes stick. How a spider weaves a web is a question often asked when looking at an amazing catching net.

What is a web?

Spiders are one of the oldest inhabitants of the planet, due to their small size and specific appearance they are mistakenly considered insects. In fact, these are representatives of the order of arthropods. The spider's body has eight legs and two sections:

• cephalothorax;
• abdomen.

Unlike insects, they do not have antennae and a neck separating the head from the chest. The abdomen of an arachnid is a kind of factory for the production of cobwebs. It contains glands that produce a secretion consisting of protein enriched with alanine, which gives strength, and glycine, which is responsible for elasticity. According to the chemical formula, cobwebs are close to insect silk. Inside the glands, the secretion is in a liquid state, but when exposed to air it hardens.

Information. Caterpillar silk silkworm and spider webs have a similar composition - 50% is fibroin protein. Scientists have found that spider thread is much stronger than caterpillar secretion. This is due to the peculiarity of fiber formation

Where does a spider's web come from?

On the abdomen of the arthropod there are outgrowths - arachnoid warts. In their upper part, the channels of the arachnoid glands open, forming threads. There are 6 types of glands that produce silk for different purposes (moving, lowering, entangling prey, storing eggs). In one species, all these organs do not occur at the same time; usually an individual has 1-4 pairs of glands.

On the surface of warts there are up to 500 spinning tubes that supply protein secretion. The spider spins its web as follows:

• spider warts are pressed against the base (tree, grass, wall, etc.);
• a small amount of protein adheres to the selected location;
• the spider moves away, pulling the thread with its hind legs;
• for the main work, long and flexible front legs are used, with their help a frame is created from dry threads;
• The final stage of making the network is the formation of sticky spirals.

Thanks to the observations of scientists, it became known where the spider’s web comes from. It is produced by movable paired warts on the abdomen.

Interesting fact. The web is very light; the weight of a thread wrapping the Earth along the equator would be only 450 g.

Spider pulls thread from abdomen

How to build a fishing net

The wind is the spider's best assistant in construction. Having taken out a thin thread from the warts, the arachnid exposes it to an air flow, which carries the frozen silk over a considerable distance. This is the secret way a spider weaves a web between trees. The web easily clings to tree branches, using it as a rope, the arachnid moves from place to place.

The structure of the web can be traced specific scheme. Its basis is a frame of strong and thick threads arranged in the form of rays diverging from one point. Starting from the outer part, the spider creates circles, gradually moving towards the center. It is amazing that without any equipment it maintains the same distance between each circle. This part of the fibers is sticky and is where insects will get stuck.

Interesting fact. The spider eats its own web. Scientists offer two explanations for this fact - in this way, the loss of protein during the repair of the fishing net is replenished, or the spider simply drinks water hanging on the silk threads.

The complexity of the web pattern depends on the type of arachnid. Lower arthropods build simple networks, while higher ones build complex geometric patterns. It is estimated that it builds a trap of 39 radii and 39 spirals. In addition to smooth radial threads, auxiliary and catcher spirals, there are signal threads. These elements capture and transmit to the predator the vibrations of the caught prey. If a foreign object (a branch, a leaf) comes across, the little owner separates it and throws it away, then restores the net.

Large arboreal arachnids pull traps with a diameter of up to 1 m. Not only insects, but also small birds fall into them.

How long does it take a spider to weave a web?

A predator spends from half an hour to 2-3 hours to create an openwork trap for insects. Its operating time depends on weather conditions and the planned size of the network. Some species weave silk threads daily, doing it in the morning or evening, depending on their lifestyle. One of the factors determining how long it takes a spider to weave a web is its type – flat or voluminous. The flat one is the familiar version of radial threads and spirals, and the volumetric one is a trap made from a lump of fibers.

Purpose of the web

Fine nets are not only insect traps. The role of the web in the life of arachnids is much broader.

Catching prey

All spiders are predators, killing their prey with poison. Moreover, some individuals have a fragile constitution and can themselves become victims of insects, for example, wasps. To hunt, they need shelter and a trap. Sticky fibers perform this function. They entangle the prey caught in the net in a cocoon of threads and leave it until the injected enzyme brings it into a liquid state.

Arachnid silk fibers are thinner than human hair, but their specific tensile strength is comparable to steel wire.

Reproduction

During the mating period, males attach their own threads to the female's web. By striking the silk fibers rhythmically, they communicate their intentions to a potential partner. The female receiving courtship descends onto the male’s territory to mate. In some species, the female initiates the search for a partner. She secretes a thread with pheromones, thanks to which the spider finds her.

Home for posterity

Cocoons for eggs are woven from the silky web secretion. Their number, depending on the type of arthropod, is 2-1000 pieces. The females hang the web sacs with eggs in a safe place. The cocoon shell is quite strong; it consists of several layers and is impregnated with liquid secretion.

In their burrow, arachnids weave webs around the walls. This helps create a favorable microclimate and serves as protection from bad weather and natural enemies.

Moving

One of the answers to why a spider weaves a web is that it uses threads as a vehicle. To move between trees and bushes, quickly understand and fall, it needs strong fibers. To fly over long distances, spiders climb to elevated heights, release a quickly hardening web, and then with a gust of wind they fly away for several kilometers. Most often, trips are made on warm, clear days of Indian summer.

Why doesn't the spider stick to its web?

To avoid falling into its own trap, the spider makes several dry threads for movement. I know my way around the intricacies of nets perfectly, and he safely approaches the stuck prey. Usually, a safe area remains in the center of the fishing net, where the predator waits for prey.

Scientists' interest in the interaction of arachnids with their hunting traps began more than 100 years ago. Initially, it was suggested that there was a special lubricant on their paws that prevented sticking. No confirmation of the theory was ever found. Filming with a special camera the movement of the spider's legs along fibers from the frozen secretion provided an explanation for the mechanism of contact.

A spider does not stick to its web for three reasons:

• many elastic hairs on its legs reduce the area of ​​contact with the sticky spiral;
• the tips of the spider's legs are covered with an oily liquid;
• movement occurs in a special way.

What is the secret of the structure of the legs that helps arachnids avoid sticking? On each leg of the spider there are two supporting claws with which it clings to the surface, and one flexible claw. As it moves, it presses the threads against the flexible hairs on the foot. When the spider raises its leg, the claw straightens and the hairs push away the web.

Another explanation is the lack of direct contact between the arachnid's leg and the sticky droplets. They fall on the hairs of the foot, and then easily flow back onto the thread. Whatever theories zoologists consider, the fact remains unchanged that spiders do not become prisoners of their own sticky traps.

Other arachnids, such as mites and pseudoscorpions, can also weave webs. But their networks cannot be compared in strength and skillful weaving with the works of real masters - spiders. Modern science is not yet able to reproduce the web using a synthetic method. The technology for making spider silk remains one of the mysteries of nature.

Practical benefits of the web.

Every Most of us are well aware of the web: we have repeatedly encountered cobwebs in the forest, and even in our own home. They brush cobwebs out of the corners with a broom, and in the forest, when they accidentally land their face in them, they shake them off with displeasure.

Meanwhile, the web is a very interesting and useful in practical application natural material, great value which has been undeservedly eclipsed today by numerous synthetic polymers.

The finest threads of the oldest web were discovered in a piece of amber by workers at the University of Oxford in East Sussex. The age of the unique find is estimated at approximately 140 million years. Until this point, the oldest was considered to be a web in a piece of amber found in Lebanon, dated 130 million years ago, and the oldest spider was found in amber about 120 million years old. Amber, formed more than 100 million years ago, is extremely rare.

With the help of the most modern technologies Using ultramicroscopy, scientists were able to identify the oldest spider web, the length of the threads of which was slightly more than a millimeter. Interestingly, the web is similar to the one weaved by modern spiders. The location of the discovered threads made it possible to establish that they were supports for the orb web. The same piece of amber preserved two skeins of ancient cobwebs.

Thanks to this discovery, the paleobiologists who studied it suggested that arachnids are actually much more ancient creatures than previously thought. Previously, it was believed that the wide distribution of flying insects, which served as prey for arachnids, was caused by the appearance of flowering plants on our planet. After studying the discovery of Oxford scientists, it was suggested that the oldest arachnids hunted crawling and jumping insects by weaving webs on the soil surface.

In addition to the cobwebs, the same piece of amber retained charred particles of burnt bark and sap coniferous tree. Presumably, the tree released resin that absorbed the cobwebs and subsequently turned into amber during a forest fire.

Spiders themselves use webs to build shelters, lining burrows, trapping nets and egg cocoons; males make a sperm net out of it for the purpose of reproduction. In the juveniles of some spiders, long threads of web serve as parachutes when dispersing by wind. When making a catch net, the spider first tensions the frame and radial threads, then lays a temporary support spiral thread, and only after that weaves an adhesive spiral catch net, after which the cut bites off the support thread.

Spider web is a protein enriched in glycine, alanine and serine. Inside the arachnoid gland it exists in liquid form. When secreted through numerous spinning tubes that open on the surface of the arachnoid warts, the structure of the protein changes, as a result of which it hardens in the form of a thin thread. Subsequently, the spider weaves these primary threads into a thicker web fiber.

The backbone of the web consists of two proteins: the stronger spidroin-1 and the more elastic spidroin-2. It is the combination of their properties that determines the unique properties of the web.

The web can have a diameter of up to several millimeters and consists of very thin threads. The web is extremely thin and light. To encircle the equator of our planet, it would take only 340 g!

Scientists are most interested in the frame thread of the web, which is unusually strong and elastic. Few people know that spider thread is close to nylon in strength - its tensile strength ranges from 40 to 260 kg/mm2, which is several times stronger than steel. If the web had a diameter of 1 mm, it could support a load weighing approximately 200 kg. Steel wire of the same diameter can withstand significantly less: 30-100 kg, depending on the type of steel. In addition, it is unusually elastic.

Interestingly, when the web gets wet, it contracts greatly (this phenomenon is called supercontraction). This occurs because water molecules penetrate the fiber and make the disordered hydrophilic regions more mobile. If the web has stretched and sagged due to insects, then on a humid or rainy day it contracts and at the same time restores its shape.

Another unusual property of a spider's web is its internal articulation: an object suspended on a spider's web fiber can be rotated indefinitely in the same direction, and at the same time it will not only not twist, but will not create a noticeable counterforce at all.

As you know, people extracted natural threads from natural materials with quite a lot of ingenuity. Subsequently, fabrics appeared from such threads - from wool, cotton, flax, nettle, and even from the finest threads of silkworm cocoons. However, the use of the web opens up new prospects in this direction, because is an excellent material for making durable and lightweight fabrics.

The first attempt to make such fabric was made three centuries ago by the French entomologist Bon, who presented his proposals to replace imported silk with spider silk to the Royal Scientific Society. As a sample, stockings and gloves made from spider silk were included. The scientist’s idea did not find support due to the difficulty of mass breeding of spiders. IN present time There is a solution to this problem, but the emergence of a large number of synthetic threads has sharply reduced the demand for spider silk.

Exceptional in strength, lightness and beauty, spider web fabric is still used today and is known in China under the name “Eastern Sea Fabric”. Polynesians used the web of large web spiders as thread for sewing and weaving fishing gear. IN early XVIII century in France, gloves and stockings were made from the web of crosses, which aroused universal admiration. It is known that up to 500 m of thread can be obtained from one spider at once. In 1899, they tried to obtain fabric to cover an airship from the web of a large Madagascar spider and managed to produce a sample of luxurious fabric 5 m long.

Today, spider web threads are used mainly in the optical industry for applying crosshairs in optical instruments and as threads in microsurgery, and due to their high content of bactericidal properties, they can be successfully used in medicine as suture material, artificial ligaments and tendons, films for healing wounds, burns, etc.

It is impossible to synthesize this kind of proteins in the laboratory chemically - they are too complex. However, scientists managed to create some kind of artificial analogue using biotechnological technologies. This thread was tested for strength by specialists at the Uglekhimvolokno Research Center in Mytishchi. A thread just a few microns thick can withstand 50-100 mg of load at break. It turned out to be only four times less durable than that of a spider, and this is very good result. At the same time, the value of the rupture energy (elasticity) of this thread is already higher than that of bone or tendon.

Not only threads, but also films can be made from cobwebs. It is in this form that it is planned to use “artificial web” to make healing coverings for wounds and burns, which will not be rejected by the body and will stimulate the regeneration of its own epithelium.

Tried and received cobwebs naturally, similar to silk. Various devices were even invented for “milking” the spider and carefully winding the delicate threads onto a slowly rotating spool.

There were several obstacles. Firstly, the quarrelsome nature of spiders: when kept together, these animals quarrel and eat each other. Secondly, each spider produces very little web: it is estimated that 27 thousand average-sized spiders will be needed to produce 500 g of fiber. It is clear that the productivity of arthropods is unlikely to satisfy industrial demands. There is only one way out: learn to obtain it artificially.

Islanders Pacific Ocean“force” spiders to weave fishing nets, which are unusually strong and almost invisible in the water. And on the island of Madagascar, located near the eastern coast of Africa, many villagers still use spider webs instead of threads.

The technology, developed about a hundred years ago by a French preacher, made it possible to collect golden webs from a million Madagascar spiders.

Art critic Simon Peers and his American business partner Nicholas Godley hired several dozen workers to create a unique canvas measuring 3.4 by 1.2 meters.

The suppliers of “threads” were a million orb-weaving spiders (golden orb spiders), belonging to the genus Nephila. The scientist and entrepreneur spent almost five years of his life and about $500 thousand to produce a piece of perhaps the most unusual fabric.

Goodley first came to Madagascar in 1994, where he created a small company producing goods from fibers of the Raphia palm tree. In 1999, Nicholas released his first collection of fashion bags (apparently from the same material), and in 2005 he closed the factory and completely switched to the production of “spider fabric” together with Pierce.

Goodley was inspired to create this unusual painting by stories about how, in the 19th century, the French governor of one of the Madagascar provinces tried to do something similar. However, Nicholas did not know for certain whether these stories were true or fiction.

In fact, spider silk is not particularly popular among the inhabitants of Madagascar (this is understandable, since the “standard” silkworm is much easier to grow). However, in the 19th century, subjects of the Merina Kingdom still decided to work with him. Products made from cobwebs were presented to members royal families. There was even a special tradition of weaving threads.

Pearce and Goodley's work began when they hired 70 workers to collect spiders of the species Nephila madagascariensis near the capital of Madagascar, Antananarivo.

Only females create a unique, durable web with a golden hue. The collection took place during the rainy season, since arthropods produce their webs only at this time of year (which imposes additional restrictions on the production process of the web).

To create a kind of spinning factory, the spiders were placed in special chambers where they were kept motionless. It must be said that Nephila madagascariensis are not poisonous, but bite. They may also escape or eat each other. “At first we had 20 females, but we soon ended up with three, but they were very fat,” says Pierce.

So, in the end, the restless creatures were isolated from each other, while simultaneously increasing the number of individuals simultaneously living in the factory.

Ten workers were collecting webs hanging from the spiders' spinning organs. In this way, it was possible to obtain about 25 meters of precious material from one individual.

Pearce notes that fourteen thousand spiders produce approximately 28 grams of spider silk, and the total weight of the final piece of fabric was as much as 1180 grams!

Next, to create the primary thread, weavers manually twisted 24 pieces of web into one, four primary ones were then turned into one main thread (a total of 96 pieces), and only from this they wove the fabric. You can imagine how painstaking the work must be.

Material from spider webs will be useful on the battlefield, in surgery and even in space, many experts are sure. The Institute of Bioorganic Chemistry of the Russian Academy of Sciences, as well as the Institute of Transplantology and Artificial Organs, are interested in obtaining products from spider web proteins.

In folk medicine there is such a recipe: to stop the bleeding, you can apply a cobweb to a wound or abrasion, carefully clearing it of insects and small twigs stuck in it. It turns out that spider webs have a hemostatic effect and accelerate the healing of damaged skin. Surgeons and transplantologists could use it as a material for suturing, strengthening implants, and even as a blank for artificial organs. Using spider webs, the mechanical properties of many materials currently used in medicine can be significantly improved.

Spider (lat. Araneae) belongs to the phylum arthropod, class Arachnida, order Spiders. Their first representatives appeared on the planet approximately 400 million years ago.

Spider - description, characteristics and photographs.

The body of arachnids consists of two parts:

• The cephalothorax is covered with a shell of chitin, with four pairs of long jointed legs. In addition to them, there is a pair of claws (pedipalps), used by mature individuals for mating, and a pair of short limbs with poisonous hooks - chelicerae. They are part oral apparatus. The number of eyes in spiders ranges from 2 to 8.
• Abdomen with breathing holes located on it and six arachnoid warts for weaving webs.

The size of spiders, depending on the species, ranges from 0.4 mm to 10 cm, and the span of their limbs can exceed 25 cm.

Coloring and pattern on individuals different types depend on the structural structure of the integument of scales and hairs, as well as the presence and localization of various pigments. Therefore, spiders can have either a dull solid color or bright color various shades.

Types of spiders, names and photographs.

Scientists have described more than 42,000 species of spiders. About 2,900 varieties are known in the CIS countries. Let's consider several varieties:

Blue-green tarantula (lat. Chromatopelma cyaneopubescens)– one of the most spectacular and beautifully colored spiders. The tarantula's abdomen is red-orange, its limbs are bright blue, and its carapace is green. The size of the tarantula is 6-7 cm, with a leg span of up to 15 cm. The spider’s homeland is Venezuela, but this spider is found in Asian countries and in African continent. Despite belonging to tarantulas, this type does not bite spiders, but only marks special hairs located on the abdomen, and only in case of severe danger. The hairs are not dangerous for humans, but they cause minor burns on the skin, similar in effect to nettle burns. Surprisingly, female chromatopelma are long-lived compared to males: the lifespan of a female spider is 10-12 years, while males live only 2-3 years.

Flower spider (lat. Misumena vatia) belongs to the family of side-walking spiders (Thomisidae). Color varies from absolutely white to bright lemon, pink or greenish. Male spiders are small, 4-5 mm long, females reach sizes of 1-1.2 cm. The species of flower spiders is distributed throughout European territory(excluding Iceland), found in the USA, Japan, and Alaska. The spider lives in open areas with an abundance of flowering herbs, as it feeds on the juices of those caught in its “embraces” and.

Grammostola pulchra (lat. Grammostola Pulchra)- a variety that is natural environment lives only in Uruguay and southern regions Brazil. A rather massive spider, reaching a size of 8-11 cm, with a dark color and a characteristic “metallic” sheen of hairs. In nature, it prefers to live among the roots of plants, but almost never digs its own burrows. Pulhra often becomes a pet among connoisseurs of exotic pets.

Argiope Brünnich or wasp spider (lat. Argiope bruennichi) – a spider with an unusual coloring of the body and limbs - yellow, black and white stripes, for which it received its name. True, the male wasp spiders are not so bright, and they are smaller in size than the females: the “young ladies” reach a size of 2.5 cm, and together with the legs - 4 cm, but the male rarely grows more than 7 mm in length. The species is widespread in Europe, Asia and southern Russia, in the Volga region and in North Africa. The Argiope spider lives in meadows with an abundance of grass, on the edges of forests. The web of the argiope is very strong, so it is difficult to tear it, it will only stretch under pressure.

Hunter bordered (lat. Dolomedes fimbriatus) widespread on the Eurasian continent and found along the shores of bodies of water with standing or very slowly flowing water. Often settles in marshy meadows, shady forests or gardens with high humidity. The body length of the female edge hunter varies from 14 to 22 mm, the male is smaller and rarely larger than 13 mm. The color of spiders of this species is usually yellowish-brown or almost black, with light yellow or white stripes on the sides of the abdomen.

(lat. Lycosa tarantula)- a species of spider belonging to the family of wolf spiders (lat. Lycosidae). Lives in the open spaces Southern Europe: often found in Italy and Spain, digs burrows half a meter deep in Portugal. The size of the tarantula is impressive - up to 7 cm in length, individuals are usually colored red, less often - brown, with several transverse stripes on the body light color and one longitudinal.

Spiny orb-weaving spider or " horned spider» (lat. Gasteracantha cancriformis) distributed in the tropics and subtropics, in the southern part of the USA, Central America, the Philippines, and Australia. The size of the female is 5-9 mm, the width reaches 10-13 mm. Males are 2-3 mm long. The legs of the spiny spider are short, and there are 6 spines along the edges of the abdomen. The color of the spider is very bright: white, yellow, red, black. On the abdomen there is a pattern of black dots.

Peacock spider(lat. Maratus volans). This spider comes in all sorts of colors: red, blue, light blue, green, yellow. The coloring of females is paler. An adult reaches a size of 4-5 mm. Males attract females with their beautiful outfit. The peacock spider lives in Australia - in Queensland and New South Wales.

Smiling spider (lat. Theridion grallator) or a spider with a happy face is completely harmless to humans. This one lives unusual spider on the Hawaiian Islands. Its body length is 5 mm. The color of the spider can be varied - pale, yellow, orange, blue. This species feeds on small fish, and the bright color of the individual helps confuse enemies, especially birds.

Black Widow (lat. Latrodectus mactans)- it is very dangerous and poisonous species spiders It lives in Australia, North America, and is also found in Russia. The size of females reaches 1 cm, males are much smaller. The body of the black widow is black, and on the abdomen there is a characteristic red spot in the form hourglass. Males are brown with white stripes. The bite is deadly.

Karakurt (lat. Latrodectus tredecimguttatus)- this look is deadly poisonous spiders from a family of black widows. The female karakurt has a size of 10-20 mm, the male is much smaller and has a size of 4-7 mm. There are 13 red spots on the abdomen of this scary spider. In some varieties, the spots have borders. Some mature individuals are devoid of spots and have a completely black shiny body. Lives in Kyrgyzstan, in Astrakhan region, in countries Central Asia, in the south of Russia, Ukraine, in the Black Sea and Azov regions, in the south of Europe, in North Africa. Karakurt was also spotted in the Saratov region, Volgograd region, Orenburg region, Kurgan region, and in the south of the Urals.

Spiders live everywhere and are found in all corners globe. They do not live only in areas where the surface of the earth all year round hidden under an ice shell. The number of species in countries with humid and hot climates is greater than in temperate or cold ones. With the exception of a few species, spiders are ground dwellers and live in built nests or burrows, being active at night.

Tarantula spiders and other species of mygalomorph spiders live in the crowns of equatorial trees and shrubs. “Drought-resistant” species of spiders prefer burrows, ground crevices and any shelter at ground level. For example, digger spiders (atypical tarantulas) live in colonies, settled in individual burrows located at a depth of up to 50 cm. Some species of mygalomorphic spiders close their burrows with special flaps made of soil, vegetation and silk.

Sidewalk spiders (crab spiders) most They spend their lives sitting on flowers waiting for prey, although some members of the family can be found on the bark of trees or the forest floor.

Representatives of the family of funnel-web spiders place their webs on tall grass and branches of bushes.

Wolf spiders prefer damp, grassy meadows and swampy wooded areas, where they are found in abundance among fallen leaves.

The water (silver) spider builds a nest underwater, attaching it to various bottom objects with the help of webs. He fills his nest with oxygen and uses it as a diving bell.

What do spiders eat?

Spiders are quite original creatures that eat very interestingly. Some types of spiders may not eat for a long time - from a week to a month or even a year, but if they start, there will be little left. Interestingly, the weight of food that all spiders can eat during the year is several times greater than the weight of the entire population living on the planet today.
How and what do spiders eat? Depending on the species and size, spiders forage and eat differently. Some spiders weave webs, thereby organizing clever traps that are very difficult for insects to notice. Digestive juice is injected into the caught prey, corroding it from the inside. After some time, the “hunter” draws the resulting “cocktail” into his stomach. Other spiders, while hunting, “spit” sticky saliva, thereby attracting prey to themselves - beetles and orthoptera, and some species are able to drag them into their home or earthworm and eat them there in peace.
The queen spider hunts only at night, creating a sticky web bait for unwary moths. Noticing an insect next to the bait, the queen spinner quickly swings the thread with her paws, thereby attracting the attention of the prey. The moth happily hovers around such a bait, and having touched it, it immediately remains hanging on it. As a result, the spider can calmly attract it to itself and enjoy its prey.

Large tropical tarantula spiders happily hunt small frogs

Aquatic species of spiders get their food from the water, catching tadpoles with the help of a web, small fish or midges floating on the surface of the water. Some spiders, which are predators, due to the lack of victims, can get enough and plant foods, which can include pollen or plant leaves. Haymaking spiders prefer cereal grains.

Judging by numerous notes by scientists, a huge number of spiders destroy small rodents and insects several times more than the animals living on the planet.

Yulia Mikhailova - Gertrude, friend, and from season 4 - wife of Tumanov (died from a blow to the head with brass knuckles in episode 12 of season 5)

Marina Weinbrand - Marina Solomatina, captain/junior adviser of justice, investigator of the prosecutor's office/investigative committee, ex-girlfriend Tumanova is expecting a child from him

Ksenia Dementieva - Natalya Maretskaya, Grekov's wife

Ilya Rogovin - Ilya Golitsyn, forensic expert, computer scientist(from season 6)

Sergey Plaskin - Stepanych, forensic expert(from season 6)

Kirill Gratsinsky - Grigory Zhurbin, police lieutenant, former employee of department “K”, technician(from season 6)

Anna Bachalova - Anastasia Malinkina, cardiologist, Tumanov’s lover(from season 7)

Anastasia Sapozhnikova - Olga Medyanik, employee of the Department of Internal Security(from season 8)

Television ratings

Candidate of Physical and Mathematical Sciences E. Lozovskaya

Science and life // Illustrations

The adhesive substance covering the thread of the catching spiral is evenly distributed throughout the web in the form of bead droplets. The picture shows the place where two fragments of the catcher spiral are attached to the radius.

Science and life // Illustrations

Science and life // Illustrations

Science and life // Illustrations

Science and life // Illustrations

Initial stages construction of a catching net by a cross spider.

The logarithmic spiral approximately describes the shape of the auxiliary spiral thread that the spider lays when constructing a wheel-shaped catching net.

The Archimedes spiral describes the shape of the adhesive trapping thread.

Zigzag threads are one of the features of the webs of spiders of the genus Argiope.

The crystalline regions of the silk fiber have a folded structure similar to the one shown in the figure. The individual chains are connected by hydrogen bonds.

Young cross spiders that have just emerged from their web cocoon.

Spiders of the family Dinopidae spinosa weave a web between their legs and then throw it over their prey.

The cross spider (Araneus diadematus) is known for its ability to weave large, wheel-shaped trapping webs.

Some types of spiders also attach a long “ladder” to the round trap, which significantly increases the efficiency of hunting.

Science and life // Illustrations

This is what the spider tubes from which the threads of spider silk emerge look like under a microscope.

Spiders may not be the most attractive creatures, but their creation, the web, is nothing short of awe-inspiring. Remember how the geometric regularity of the finest threads shimmering in the sun, stretched between the branches of a bush or among tall grass, captivates the eye.

Spiders are one of the oldest inhabitants of our planet, having settled on land more than 200 million years ago. There are about 35 thousand species of spiders in nature. These eight-legged creatures, which live everywhere, are recognizable always and everywhere, despite differences in color and size. But the most important thing is distinctive feature- is the ability to produce spider silk, a natural fiber unsurpassed in strength.

Spiders use webs for a variety of purposes. They make cocoons for eggs from it, build shelters for wintering, use it as a “safety rope” when jumping, weave intricate trapping nets and wrap up caught prey. A female ready for mating produces a web thread marked with pheromones, thanks to which the male, moving along the thread, easily finds a partner. Young spiders of some species fly away from the parental nest on long threads carried by the wind.

Spiders feed mainly on insects. The hunting devices they use to get food are of the most different forms and types. Some spiders simply stretch out several signal threads near their shelter and, as soon as an insect touches the thread, they rush at it from ambush. Others throw a thread with a sticky drop at the end forward, like a kind of lasso. But the pinnacle of the design activity of spiders is still round wheel-shaped nets, located horizontally or vertically.

To build a wheel-shaped catching net, the cross spider, a common inhabitant of our forests and gardens, produces a fairly long, strong thread. A breeze or rising air flow lifts the thread upward, and, if the place for building the web is chosen well, it clings to the nearest branch or other support. The spider crawls along it to secure the end, sometimes laying another thread for strength. Then he releases a freely hanging thread and attaches a third to its middle, so that a Y-shaped structure is obtained - the first three radii out of more than fifty. When the radial threads and frame are ready, the spider returns to the center and begins to lay out a temporary auxiliary spiral - something like "scaffolding". The auxiliary spiral holds the structure together and serves as a path for the spider when constructing a catching spiral. The entire main frame of the net, including the radii, is made of non-adhesive thread, but for the catcher spiral, a double thread coated with an adhesive substance is used.

What's surprising is that these two spirals have different geometric shapes. The temporary spiral has relatively few turns, and the distance between them increases with each turn. This happens because, when laying it, the spider moves at the same angle to the radii. The shape of the resulting broken line is close to the so-called logarithmic spiral.

The sticky trapping spiral is built according to a different principle. The spider starts at the edge and moves towards the center, keeping the same distance between the turns, creating an Archimedes spiral. At the same time, it bites off the threads of the auxiliary spiral.

Spider silk is produced by special glands located in the back of the spider's abdomen. There are at least seven types of arachnoid glands known to produce different threads, but no known spider species has all seven types at once. Usually a spider has from one to four pairs of these glands. Weaving a web is not a quick task, and it takes about half an hour to build a medium-sized trapping net. To switch to the production of a different type of web (for the catching spiral), the spider needs a minute's respite. Spiders often reuse webs by eating leftover webs that have been damaged by rain, wind, or insects. The web is digested in their body with the help of special enzymes.

The structure of spider silk has been perfectly developed over hundreds of millions of years of evolution. This natural material combines two wonderful properties - strength and elasticity. A web made of cobwebs can stop an insect flying towards full speed. The thread from which spiders weave the base of their hunting web is thinner than a human hair, and its specific (that is, calculated per unit mass) tensile strength is higher than that of steel. If you compare spider thread with steel wire of the same diameter, they will support approximately the same weight. But spider silk is six times lighter, which means six times stronger.

Like human hair, sheep wool and silk cocoons of silkworm caterpillars, the web consists mainly of proteins. In terms of amino acid composition, the spider web proteins - spidroins - are relatively close to fibroins, the proteins that make up the silk produced by silkworm caterpillars. Both contain unusually high amounts of the amino acids alanine (25%) and glycine (about 40%). Areas of protein molecules rich in alanine form crystalline regions densely packed into folds, providing high strength, and those areas where there is more glycine represent a more amorphous material that can stretch well and thereby impart elasticity to the thread.

How is such a thread formed? There is no complete and clear answer to this question yet. The process of web spinning has been studied in most detail using the example of the ampullaid gland of the orb-weaving spider Nephila clavipes. The ampullaid gland, which produces the strongest silk, consists of three main sections: a central sac, a very long curved canal, and a tube with an outlet. From the cells on the inner surface of the sac emerge small spherical droplets containing two types of spidroin protein molecules. This viscous solution flows into the tail of the sac, where other cells secrete a different type of protein - glycoproteins. Thanks to glycoproteins, the resulting fiber acquires a liquid crystalline structure. Liquid crystals are remarkable in that, on the one hand, they have a high degree of order, and on the other, they retain fluidity. As the thick mass moves towards the outlet, the long protein molecules are oriented and aligned parallel to each other in the direction of the axis of the forming fiber. In this case, intermolecular hydrogen bonds are formed between them.

Humanity has copied many of nature's design discoveries, but such a complex process as spinning a web has not yet been reproduced. Scientists are now trying to solve this difficult problem using biotechnological techniques. The first step was to isolate the genes responsible for the production of the proteins that make up the web. These genes were introduced into the cells of bacteria and yeast (see "Science and Life" No. 2, 2001). Canadian geneticists have gone even further - they have bred genetically modified goats whose milk contains dissolved spider web proteins. But the problem is not only in obtaining the spider silk protein, it is necessary to model natural process spinning. But scientists have yet to learn this lesson from nature.