What is the importance of the web in the life of spiders? The technology of using the web in medicine Spiders of some species leave an electric charge on the web
The web is a kind of secret produced by the spider glands. Such a secret, after a short time after isolation, is able to solidify in the form of strong protein filaments. The web is secreted not only by spiders, but also by some other representatives of the arachnid group, including false scorpions and ticks, as well as millipedes.
How do spiders produce webs?
A large number of spider glands are located in abdominal cavity spider. The ducts of such glands open into the smallest spinning tubes, which have access to the end part of special spider warts. The number of spinning tubes can vary depending on the type of spider. For example, a very common cross-spider has five hundred of them.
It is interesting! In the arachnoid glands, it produces a liquid and viscous protein secret, a feature of which is the ability to almost instantly harden under the influence of air and turn into thin long threads.
The process of spinning the web consists in pressing the spider web warts to the substrate. The first, insignificant part of the released secret solidifies and securely sticks to the substrate, after which the spider draws out the viscous secret with the help of its hind legs. In the process of removing the spider from the place of attachment of the web, the protein secret is stretched and quickly hardens. To date, there are seven well-known and well-studied different types spider glands that produce different types threads.
The composition and properties of the web
Spider web is a protein compound, which also includes glycine, alanine and serine. Inner part The formed threads are represented by rigid protein crystals, the size of which does not exceed a few nanometers. The crystals are held together by highly elastic protein bonds.
It is interesting! An unusual property of the web is its internal hinge. When suspended on a spider web, any object can be rotated an unlimited number of times, without twisting.
The primary threads are intertwined by the spider and become a thicker arachnoid fiber. The strength indicators of the web are close to those of nylon, but much stronger than the secret silkworm. Depending on the purpose for which the web is supposed to be used, not only a sticky, but also a dry thread, the thickness of which varies considerably, can be released by the spider.
Web functions and its purpose
The web is used by spiders for a variety of purposes. A shelter woven from a strong and reliable web allows you to create the most favorable microclimatic conditions for arthropods, and also serves as a good shelter, both from bad weather and from numerous natural enemies. Many arthropod arachnids are able to braid the walls of their mink with their web or make a kind of door into a dwelling out of it.
It is interesting! Some species use the web as a form of transport, and young spiders leave the parental nest on long cobwebs that are picked up by the wind and carried over considerable distances.
Most often, spiders use webs to weave sticky trapping webs, which makes it possible to effectively catch prey and provide food to the arthropod. No less famous are the so-called egg cocoons from the web, inside which young spiders appear.. Some species weave web safety threads to protect the arthropod from falling during the jump and to move or catch prey.
Web for reproduction
The breeding season is characterized by the allocation of cobweb threads by the female, which allow you to find the optimal pair for mating. For example, male snails are able to build, next to the nets created by females, miniature-sized mating cobweb laces, into which spiders are lured.
Male cross spiders deftly attach their horizontal webs to radially arranged threads of trapping webs made by females. Striking on the web strong blows limbs, males cause network vibrations and, thus in an unusual way, invite females to mate.
Web for catching prey
In order to capture their prey, many species of spiders weave special trapping nets, but some species are characterized by the use of peculiar spider lassoes and threads. Spiders that hide in burrow dwellings place signal threads that stretch from the abdomen of the arthropod to the very entrance to its shelter. When the prey falls into the trap, the vibration of the signal thread is instantly transmitted to the spider.
Sticky trapping spiral nets are built on a slightly different principle.. When creating it, the spider starts weaving from the edge and gradually moves towards the central part. In this case, the same gap between all the turns is necessarily maintained, resulting in the so-called "Archimedes' spiral". The threads on the auxiliary spiral are specially bitten by the spider.
Web for insurance
Jumping spiders use web threads as insurance when attacking a victim. Spiders attach the safety thread of the web to any object, after which the arthropod jumps on the intended prey. The same thread, attached to the substrate, is used for lodging for the night and insures the arthropod from the attack of all kinds of natural enemies.
It is interesting! South Russian tarantulas, leaving their dwelling-burrow, pull the thinnest cobweb thread behind them, which allows them to quickly find, if necessary, a way back or an entrance to a shelter.
Web as transport
By autumn, some species of spiders hatch juveniles. Young spiders that survived in the process of growing up try to climb as high as possible, using trees, tall shrubs, roofs of houses and other buildings, fences for this purpose. Waiting for enough strong wind, a small spider releases a thin and long cobweb.
The distance of movement directly depends on the length of such a transport web. After waiting for a good tension of the web, the spider bites off its end, and takes off very quickly. As a rule, "travelers" are able to fly several kilometers on the web.
Silver spiders use the web as a water transport. This spider needs to breathe to hunt in water atmospheric air. When descending to the bottom, the arthropod is able to capture a portion of air, and on aquatic plants a kind of air bell is constructed from the web, which holds the air and allows the spider to hunt its prey.
Arachnids stand out from all insects with the ability to weave amazing cobweb patterns.
How a spider spins a web is unimaginable. small creature creates large and strong networks. Amazing Ability formed 130 million years ago.
All possibilities in animals appear and are fixed when natural selection not by chance. Each action has a strictly defined purpose.
The spider spins a web to achieve vital goals:
- catching prey;
- breeding;
- strengthening their minks;
- fall insurance;
- deception of predators;
- facilitate movement on surfaces.
The order of spiders consists of 42 thousand species, each of which has its own preferences in the use of the arachnoid structure. To hold the victim, the grid is used by all representatives. Males - aranemorphs on the grid leave secretions of seminal fluid. Then the spider on the web walks, collecting secretions on the organs of copulation.
After fertilization, the babies are formed in a protective web cocoon. Some females leave pheromones on the net - substances that attract partners. Spinners wrap threads around leaves and twigs. The result is dummies to distract predators. Silverfish living in the water make houses with air cavities.
The size of the web depends on the type of spider. Some tropical arachnids create "masterpieces" with a diameter of 2 m, capable of holding even a bird. Ordinary spider webs are smaller.
It is interesting to know how much a spider weaves a web. Zoologists managed to find out that the cross-piece copes with the work in a few hours. Representatives of hot countries take several days to create patterns of a large area. The main role in the process is played by special bodies.
The structure of the spider glands
On the abdomen of the insect there are outgrowths - arachnoid warts with holes in the form of tubes.
Through these ducts, a viscous liquid flows out from the arachnoid gland. When exposed to air, the gel turns into thin fibers.
The chemical composition of the web
The unique ability of the released solution to solidify is explained by the structural components.
The composition of the liquid contains a high concentration of protein containing the following amino acids:
- glycine;
- alanine;
- serine
The quaternary structure of the protein, when pushed out of the duct, changes in such a way that filaments are formed as a result. From the filamentous formations, subsequently, fibers are obtained, the strength of which
4 to 10 times the strength of a human hair.,
1.5 - 6 times stronger than steel alloys.
Now it becomes clear how a spider weaves a web between trees. Thin strong fibers do not break, they are easily compressed, stretched, rotated without twisting, connecting the branches into a single network.
The purpose of the life of a spider is the extraction of protein food. The answer to the question "Why do spiders weave webs" is obvious. First of all, for hunting insects. They make a trapping net of complex design. Appearance patterned structures is different.
- Most often we see polygonal networks. Sometimes they are almost round. Weaving from spiders requires incredible skill and patience. Sitting on the top branch, they form a thread that hangs in the air. If you're lucky, the thread will quickly catch on a branch in a suitable place and the spider will move to new point for further work. If the thread does not catch in any way, the spider pulls it towards itself, eats it so that the product does not disappear, and begins the process again. Gradually forming a frame, the insect proceeds to create radial foundations. When they are ready, the only thing left is to make connecting threads between the radii;
- Funnel representatives have a different approach. They make a funnel and hide at the bottom. When the victim approaches, the spider jumps out and pulls it into the funnel;
- Some individuals form a network of zigzag threads. The probability that the victim will not get out of such a pattern is much greater;
- The spider with the name "bola" does not bother itself, spins out only one thread, on which there is a drop of glue at the end. The hunter shoots the thread at the victim, sticking it tightly;
- Spiders - ogres were even more cunning. They make a small mesh between the paws, then cast on the desired object.
Designs depend on the living conditions of insects, their species.
Conclusion
Having found out how a spider weaves a web, what are its features, it remains to admire this creation of nature, to try to create something similar. In delicate patterns of knitted shawls, craftswomen copy patterns. Antennas, nets for catching fish and animals are made according to similar schemes. So far, a person has not been able to fully simulate the process.
Video: Spider weaves a web
The web is the very essence of the spider. Although other arthropods also produce webs, no more group, all representatives of which could do this. Those who still can do it usually in strictly defined periods. life cycle, and the web itself is used for one or two purposes (for example, butterfly caterpillars build a cocoon). In contrast to them all spiders produce webs throughout all life, using it wherever possible. The tarantulas are no exception. They use the web for a variety of purposes:
1. For lining the lair. Moreover, many tree species(e.g. kind Avicularia) make nests in the crevices of the bark entirely from cobwebs. In fact, these are air holes.
2. Terrestrial views often use cobwebs to tightly braid the entrance to the hole when they do not want to be disturbed.
3. The web can become Ariadne's thread, along which a wandering spider can find its way to a hole.
4. Cobwebs are covered with lumps of earth that the spider throws out of the hole as the dwelling expands.
5. In captivity, many spiders weave a "tablecloth" when feeding. It is not known if their wild counterparts do anything similar.
6. A molting mat is made from the web.
7. The web becomes a temporary store of sperm when the male prepares to meet the female.
8. The male most often determines the presence of a female, by chemical signals (it is hardly possible to say “smell” here) on the web surrounding the entrance to the hole.
9. Finally, the female weaves an egg cocoon from the web, a receptacle for developing eggs.
Why tarantulas do not use webs is to make nets and traps, which many do Araneomohrhae, the so-called higher spiders. Although some species of tarantulas stretch signal threads radially at the entrance to the hole, the oscillation of which warns the spider of the approach of prey or a potential predator. Due to the fact that tarantulas do not weave nets and traps, they were considered more primitive. This argument seems unconvincing. These creatures have just as much web-weaving ability as the higher spiders. But since they are significantly heavier than higher spiders, even underground ones, the manufacture of openwork structures for catching prey is simply impractical.
From a chemical point of view, the web is almost entirely a protein product. The arachnoid glands produce the web as needed, and it is secreted through microscopic holes in the arachnoid appendages. When released, it is stretched, which allows protein molecules to interact with each other, as a result of which the thread hardens and acquires fantastic strength. Please note that the hardening of the thread is not drying, as it can just as well harden under water (an example is the European water spider Argyroneta aquatica, family Argyronetidae).
The most surprising thing about the web is its amazing strength. Many peoples of the world even use it to make fishing nets (for small fish), as well as threads when several silks are twisted. Some varieties of cobwebs are stronger than steel wire of the same diameter. Great tensile strength combined with microscopic thickness made the web indispensable in the manufacture of crosshairs during the Second World War. Compared to nylon thread, it can withstand twice the stretch.
Finally, despite the fact that it is almost pure protein, the web breaks down extremely slowly. In nature, it can hang on a branch for many weeks after its creator has disappeared. In the house, she can remain for an almost unlimited time until she is swept away by a broom of an indignant hostess. In a terrarium, it will last a year or more, showing only slight signs of degradation. Bacteria and fungi grow very poorly on it, and only a few organisms eat it, despite its obvious nutritional value. Why? Unknown.
Web production is associated with the consumption of both protein and energy. If there were no way to recycle it, it would cost the spider dearly. Most spiders eat at least some of the end-of-life silk constructs. Although tarantulas do this much less frequently than most other spiders.
It is easy to decide that this proves the primitiveness of tarantulas, which have not yet developed the instinct to preserve valuable material to the same extent as more advanced spiders. But no less convincing is the fact that the consumption of energy and protein in weaving tarantulas is relatively small, significantly less, especially compared to body weight. Accordingly, the need to save is not so great, and they can afford some extravagance.
Although tarantulas may eat the "tablecloth" that is sometimes woven when feeding in captivity, they usually do not eat other arachnid structures. These latter should be removed from time to time.
It is not known what happens to all the webs that tarantulas produce in nature. Buildings of many tropical species quite large and have considerable strength. However, it is not typical for the tarantulas of the American Southwest a large number of cobwebs around the hole, and inside it happens even less. Are they weaving a little web? Or eat most old? And if they eat, then why don't they do it when they are kept in captivity? The mystery remains a mystery.
How a spider weaves a web, what are its features, you will learn from this article.
What is a web?
The web is a protein mass secreted by the specific glands of the spider. This is a liquid substance that, when exposed to air, very quickly turns into a polymer, forming sticky threads. By the way, the web is considered enough durable material. In terms of stability, even steel is inferior to it. The strength of the web is amazing. What makes it so strong? It's all about the specific components - these are 2 proteins. One of the proteins is responsible for the strength of the web, and the second for elasticity. In the web, each thread is covered with a sticky special substance that should hold the prey at the moment it enters the net. The victim, trying to get out of the trap, gets entangled in the web even more and is finally absorbed by this substance.
The most durable web is found in orb-weaving spiders, which have a large number of glands, "weaving" strong threads.
How do spiders weave their threads?
Weaving a web is not the easiest process. It all depends on what type of web. Very often, the spider produces quite complex threads for weaving, which require the participation of different glands. In addition, the spider itself needs to work actively to produce such a durable material.
Here's how it goes. First, the tip of the future adhesive thread must be hooked onto something (for example, a branch). But the ends on which it is attached must be three, in order to end up with an isosceles triangle. The spider attaches the opposite end to the surface on the corresponding side of the corner. After that, the formation of threads begins, which in the center cross each other from one attachment point to the opposite one. After starts new stage spider work. A thread is woven to the edges from the center, connecting the previous threads to each other. The last thing to do is to create a special signal thread. Its task is to inform the spider that prey has been caught in its web. It is also worth noting the following: the spider itself in its network is located in the very center, filling the gaps in it.
Surely each of you paid attention to the delicate, delicate, silky "handkerchiefs" that spiders hang on trees and grass in sunny summer. When silvery dewdrops glisten on openwork spider yarn - the spectacle, you see, is insanely beautiful and bewitching. But several questions arise: "where is the web formed and how is the spider used", "where does it come from and what does it consist of." Today we will try to figure out why this animal decorates everything around with its “embroidery”.
Stopped for a moment
Many scientists devoted to spiders and their webs not only whole treatises and hours, but also years of their lives. As Andre Tilkin said, famous philosopher from France, the weaving of the web is an amazing performance that can be watched for hours and hours. He wrote over five hundred pages of a treatise on the web.
The German scientist G. Peters claimed that when you watch spiders for hours, you don’t even notice how time flies. Even before Tilkin, he told the world about who these amazing creatures how a spider weaves its web, for which it needs it.
Surely, more than once, when you saw a small spider doing its painstaking work on a leaf, you stopped and watched. But we always do not have enough time for wonderful little things, we are always in a hurry, so we cannot stop, stay a little longer. If there was this very time, each of us could certainly answer the question: “How does the web appear, why does the spider not stick to its web?”
Let's stop for a moment and figure it out. After all, the question is really interesting, and the process is fascinating.
Where does it come from?
Spiders - ancient creatures living on earth for more than two hundred million years. Without their web, they, perhaps, would not be so interesting to mankind. So where does the spider web come from and what is it?
The web is the content of special glands that many arthropods have (false scorpions, spiders, spider mites, etc.). The liquid content is able to stretch and not tear at the same time. The thinnest filaments formed very quickly harden in air.
Each spider has several specific glands on its body that are responsible for the production of webs. Various glands form different kind and web density. They are located on the abdomen in the form of the thinnest ducts and are called "spider warts". It is from these holes that a liquid secret is released, which soon turns into a beautiful web.
With the help of paws, the spider distributes, "hangs" the web where it needs it. The spider has the longest front legs, they protrude into leading role. And with the help of its hind legs, it captures drops of liquid and stretches them to the required length.
wind to help
The breeze also contributes to the correct distribution of the web. If the spider chooses right place for placement, for example, between trees or in leaves, the wind helps to spread the threads to the right place. If you wanted to answer for yourself the question of how a spider weaves a web between trees, then here is the answer. The wind helps him.
When one thread is caught on the desired branch, the spider crawls, checks the strength of the base and releases the next one. Attaches the second to the middle of the first and so on.
Construction stages
The base of the web is very similar to a snowflake or a dot, from the center of which several rays diverge. These central filaments are the densest and thickest in their structure. Sometimes a spider makes a base from several threads at once, as if strengthening its paths in advance.
When the base is ready, the animal proceeds to the construction of "trapping spirals". They are already made from a completely different type of web. This liquid is sticky, sticks well. It is from the sticky web that circles are built on the base.
The spider begins its construction from the outer circle, gradually moving towards the center. He miraculously feels the distance between the circles. Completely without a compass or special measuring instruments, the spider unmistakably distributes the web so that the distance between the circles is exceptionally equal.
Why doesn't it stick?
Surely all of you know how spiders hunt. How their prey gets entangled in the sticky web and dies. And, perhaps, everyone at least once wondered: “Why doesn’t a spider stick to its web?”
The answer lies in the specific tactics of building a web, which we described a little higher. The web is made from several types of threads. The basis on which the spider moves is made from an ordinary, very strong and completely safe thread. But the “trapping” circles are made, on the contrary, from a thread that is sticky and deadly for many insects.
Web functions
So, we figured out how the web appears and where it is formed. And how the web is used by the spider, we can also now answer. The primary task of the web is, of course, the extraction of food. When "food" enters the web, the spider immediately feels the vibration. He approaches the prey, quickly wraps it in a strong “blanket”, opens the edge and takes the food to the place where no one will stop him from enjoying the meal.
But besides the extraction of food, the web serves the spider for some other purposes. A cocoon for eggs and a house for living are made from it. The web acts as a kind of hammock on which mating games and mating. It acts as a parachute, which allows you to quickly escape from dangerous enemies. With its help, spiders, if necessary, can move through the trees.
Stronger than steel
So, we already know how a spider weaves a web and what are its features, how it is formed and how sticky webs are built for food. But the question remains as to why the web is so strong.
Despite the fact that all spider structures are diverse, they have the same property - increased strength. This is ensured by the fact that the composition of the web includes a protein - keratin. By the way, it is also found in the claws of animals, in wool, in the feathers of birds. The fibers of the web stretch perfectly and then return to their original form, while not tearing.
Scientists say that the cobweb is much stronger than natural silk. The latter has a tear strength of 30-42 g / mm 2, but the web is about 170 g / mm 2. Feel the difference.
How a spider weaves a web is understandable. That it is strong - also decided the issue. But did you know that despite such strength, the web is several thousand times thinner than human hair? If we compare the breaking performance of the web and other threads, it surpasses not only silk, but also viscose, nylon, orlon. Even the strongest steel cannot be compared in strength with it.
Did you know that how a spider spins its web will determine the number of victims that will be in it?
When the prey is in the web, it not only sticks to the “trapping” network, but is also affected by an electric charge. It is formed from the insects themselves, which accumulate a charge during the flight, and when they get into the web, they give it to the threads and hit themselves.
Knowing how a spider weaves a web and what “strong” qualities it has, why don’t people still make clothes from such threads? It turns out that at the time Louis XIV one of the craftsmen tried to sew gloves and socks for the king out of spider threads. However, this work turned out to be very difficult, painstaking and lengthy.
AT South America spider webs help not only the manufacturers themselves, but also the local monkeys. Animals, thanks to the strength of the nets, dexterously and fearlessly move along them.