Is it possible to live at the bottom of a reservoir and breathe at the same time? atmospheric air? Many will consider this question stupid. Yes, that’s understandable. Where does atmospheric air come from at the bottom of a reservoir? As for aquatic inhabitants, they either breathe oxygen dissolved in water, using gills for this, or periodically float to the surface to take atmospheric air into their lungs.

And yet, this question is not as stupid as it seems at first glance. The silverback spider can breathe atmospheric air and at the same time constantly remain at the bottom of the reservoir. Scientists even joke about this, saying that this insect managed to build a real castle in the air underwater. But at the same time, they are not far from the truth. The spider sinks to the bottom of the reservoir along with an air bubble that is attached to its abdomen. In addition, he himself is inside an air bell, which communicates with the air bubble.

You can meet this original insect in Europe, Kazakhstan, Asia and the Caucasus. It is unremarkable, and appearance no different from theirs at all land relatives. The spider's body is brown in color, with many black spots. The cephalothorax is devoid of hair. The silverfish has eight eyes. Females are smaller than males. Scientists agree that thanks to larger size The male does not become a victim of the female after mating.

You can meet this spider in bodies of water with stagnant water and dense aquatic vegetation. As you may have guessed, it breathes with the help of its lungs. The body of the insect is covered with small hairs, which are lubricated with a water-repellent liquid produced by its glands. It is on these hairs that air bubbles linger and supply the spider with air. It is quite enough for a long stay under water.

The air bubbles in females and males are different. In the male, the air reservoir is attached to the lower part of the abdomen. In the female, it occupies its entire surface. That is why she can only swim upside down. The male, in this regard, is much more agile. It can swim both horizontally and vertically. To assume a horizontal position, he carefully works with his paws.

The air bell in which the silverfish lives is the size of a pigeon egg. The spider attaches it with a web to aquatic plants and various objects located at the bottom of the reservoir. Periodically, the spider replenishes the bell with air, which is delivered from the surface in the form of air bubbles attached to the body. Having reached the goal, the spider separates the bubble from the body with its legs and attaches it to the dome. To attach an air bubble to the body, the spider rises to the surface, sticks part of its abdomen out of the water, captures the bubble with arachnoid warts, and quickly dives under the water. The air supply is enough for about a day.

In addition to the air bubbles delivered by the spider from the surface, the bell is replenished with oxygen through gas exchange. In other words, it is extracted from water, with simultaneous removal carbon dioxide. At the same time, the need to replenish it with air bubbles remains.

The spider's diet consists of small crustaceans and invertebrates, which it catches in its webs. The silverfish's vision is poor, so it is forced to navigate in space with the help of its legs, which are equipped with sensitive receptors and can perceive even the slightest fluctuations in water. When receiving such a signal, the spider jumps out from its shelter and pounces on the victim stuck in its web. He injects digestive fluid into it and waits for it to digest. As soon as the process is completed, the spider drags food into its home and feasts on it while lying on its back. In this position, the nutrient broth does not leak, but goes directly into the insect’s stomach. The spider removes the remaining organic matter outside the bell.

To breed, the female silverfish braids the top of the dome with a soft web, on which she subsequently lays up to 150 eggs. She vigilantly guards the clutch, hanging upside down on the web. At this time, she practically stops eating and only replenishes the dome with air. After ten days, the spiderlings hatch from the eggs. They are completely bald and cannot exist independently outside the dome. They will be ready for independent life only after the second molt.

With the onset of cold weather, the silver spider builds winter shelter using an empty mollusk shell. He attaches it to algae floating on the surface of the reservoir, fills it to capacity with air bubbles, climbs inside, and tightly seals the inlet. To minimize air consumption, the spider falls into torpor. In winter, algae sink to the bottom of the reservoir, dragging the shell with them. The spider will wake up with the onset of spring warmth. sun rays warm the water, the algae will float to the surface along with the shell, and the spider will be able to leave its winter refuge.

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What does the silver spider fill its underwater nest with?

• wings of flies
• algae
• air bubbles
• pearls

Waterflies also build their nests for overwintering. Degeer, as Schmit says, caught a male spider in September and kept him for four months in a vessel with water. The spider built a very thin bell, the size of half a pigeon's egg, and attached it to the wall of the vessel with irregularly placed threads. In the middle of this diving bell filled with air, the spider sat with its head turned upward and its legs pressed to the tattoo.

On December 15, the lower hole was closed, and the spider was found motionless in its air bubble. The pressure caused the bell to burst and air began to come out of it in bubbles. Then the spider left its destroyed home. Degeer gave him a fly, which the spider immediately grabbed and sucked. After three months of fasting, the spider seemed cheerful and had a special appetite. In the wild, however, waterflies willingly overwinter in empty shells, closing only the openings with skillful fabric.

The correct answer in the game is Air bubbles

The water spider (lat. Argyroneta aquatica) is a common species of spider in Europe from the family Cybaeidae.

The male, which is larger than the female (this prevents cannibalism of females), reaches 15 mm in length, the female - up to 12; almost naked cephalothorax of a brownish color, turning blackish, with black lines and spots; the abdomen is brown, covered with many velvety hairs and has two rows of depressed points on the dorsal side. When a silverfish is immersed in water, the hairs of the abdomen, covered with a special fatty substance, are not wetted; air is retained between them (as it is not displaced due to the forces of surface tension of water) and therefore it appears silver under water. This layer of air allows the silverfish to remain under water for a long time; he occasionally rises to its surface to renew his supply of air.

IN underwater world with special equipment there was a diving bell. This structure was the prototype of the space suit. The oldest mentions of it date back to 1531. But thousands of years earlier, the Argyronet spider solved the problem of staying under water in a similar way.

The amazing house of the silver spider

The silver color of the spider is an optical illusion. The coloring of the Argyronet is usual for most spiders - a cephalothorax and a brown abdomen covered with many hairs. It is these hairs, lubricated with a special secretion, that trap air when rising to the surface of the reservoir. Additionally, a tiny air bubble is transported at the tip of the abdomen, “caught” with the help of arachnoid warts.

It is a tiny semblance of a man-made diving bell. Attached to the stems of underwater plants by cobwebs and woven from them, the nest, reaching the size of a hazelnut, has a supply of air under the dome. An amazing spider, tirelessly diving for the next portion of silver bubbles, is freed from air reserves and can be underwater in its house.

The amazing insect weaves four types - for the bell, threads holding the nest, catching nets and for the egg cocoon. Females build their nests with greater diligence than males.

Peculiarities of everyday life of the Argyronets

The underwater environment provides silverfish with an abundant supply; small aquatic inhabitants become prey for clever predators. Sometimes they fall into the clutches of a hunting spider, sometimes they become entangled in the threads of the web. A well-fed argyronet hangs its prey under the dome of the nest, wrapped in a cobweb cocoon, counting on bad days.

Here, under water, spider offspring are hatched. Having laid eggs, the spider places them in an air-filled cocoon in or near the nest, and protects the precious clutch. A male spider that takes part in the fertilization of a female spider does not suffer the fate of being eaten by the female - an ending that is characteristic of the mating traditions of most arachnids. He continues to live nearby, in the same underwater bell, with the same eating habits, with the same responsibilities for delivering air.

Arachnologists believe that among the reasons for refusing cannibalism is the male. Argyronetes are the only species of spider with a male larger than 1.5 and 1.2 cm, respectively. By the way, larger males have smaller nest sizes.

The silverback spider, an inhabitant of European water bodies, recently had its closest relative in Japan. As it turned out, the Japanese argyronet, previously considered a complete analogue of the European one, has much larger organs that perform reproductive functions.

This species lives throughout the vast territory of Eurasia, from Portugal to Japan. unusual look spiders

It is unusual because it is the only spider in the world whose habitat is water. Water spider - it received this name due to its peculiarity.

It can live and move on land, but does so extremely rarely.

Silver spider

He lives in ponds coastal waters lakes - in stagnant waters. It is extremely rare to find it in small rivers or streams with a weak current.

Externally, the silver water spider is practically no different from ordinary ones.

As can be seen from the photo, the water spider has a cephalothorax and abdomen, which are separated by a thin interception. Eight legs emerge from the breast. In front are 16 eyes, four jaws.

Appearance of a water spider

The first two are claw-shaped and, equipped with a poisonous gland, are used for hunting. The second two are jaw tentacles. Males are larger than females, which excludes manifestations of cannibalism.

The usual size of a water spider does not exceed one and a half centimeters, although sometimes a large water spider up to three centimeters long can be found. IN specialized literature given detailed description silver spider, its appearance, lifestyle.

A young silverback spider is gray or brown with a yellowish tint. It darkens with age, sometimes becoming completely black. This makes it possible to determine the age of the animal by color.

Lifestyle of silverfish

Finding the place where the silverback spider lives is not difficult. This coastal zones reservoirs with standing water - ponds, shallow lakes, with a large number seaweed

It is in these algae that the silver spider builds its nest. Despite the fact that it runs very quickly on land, it prefers to live and hunt under water. In and under water, his legs act like oars.

The silverback water spider breathes oxygen obtained from atmospheric air, like all representatives of this class. To capture air, it rises to the surface of the reservoir.

Then he dives towards his nest, dragging down with him an airy film that envelops the animal’s body. This air film envelops the bodies of males and females differently. In the female, air envelops part of the cephalothorax and the entire abdomen, so she swims upside down.

In the male, only the lower part of the abdomen is enveloped in air, so the underwater silverback spider swims more deftly than the female, can stay horizontal, and can swim a distance of up to two centimeters in one second.

Male water spider

This difference in the air enveloping the body of spiders is explained by the difference in the secretion of the web and the weaving of the mesh from it that surrounds the body. It is this web that traps air when the spider dives underwater.

Serebryanka's home

Spiders build their homes from their webs. It is built in the form of a funnel, the size of a pigeon egg.

This cocoon is attached to a web, which is stretched between underwater plants. This cocoon stores air bubbles necessary for spiders to breathe.

The spider delivers air bubbles to the nest

The owner of the home delivers these bubbles from the surface of the water, specially rising for air. Having risen to the surface, the spider sticks the tip of its abdomen out of the water, captures the air with its web and dives towards the nest.

This is how it replenishes the air supply in the home. The silver spider solves the wintering problem in a very interesting way. The silver spider attaches its nest to plants with a web. And in this cocoon he plunges into hibernation.

But some spiders choose more substantial dwellings for wintering. They find empty mollusk shells, abandoned for some reason by their owners, and settle in them.

When a spider finds such a shell, it must inhabit it. How and with what does the silverback spider fill its underwater nest? First, he fills the sink with air drawn from the surface. Fills until the shell floats.

Silver spider's home

Then he attaches the shell with a web to small floating algae - duckweed. Then he hides in this shell, closes the hole with the remains of plants, which he fastens with a web.

When it gets colder, the duckweed sinks to the bottom, and along with it, the shell with its inhabitant also sinks to the bottom of the reservoir. In the spring, algae rise to the surface, lifting the shell with the spider.

How water spiders breed

To breed offspring, a special cocoon is built. In this cocoon, after fertilization, the female separates a small compartment, constructing something like a two-room apartment with a nursery and a living room.

In this compartment, the female lays from 100 to 160 eggs. Until the young spiders hatch from the eggs, the female faithfully and bravely protects the clutch from any attacks.

The hatched young grow very quickly, gain weight and height, and within two weeks they leave the parental nest and begin an independent life.

Silver spider with brood

Most often, young spiders try to move to another body of water, away from their parents, but it happens that they remain in this pond or lake. As a rule, this happens if another body of water is located at a considerable distance.

Where does the silverfish live and what does it eat?

Water spiders live throughout Europe and Asia. Some species, in particular funnel-web water spiders, are common in Australia. Russian water spiders live in ponds with stagnant water rich in algae.

These spiders lead strictly night look life. When it starts to get dark (and in the underwater kingdom, among the algae it gets dark very quickly), the spiders get out of their nests and go hunting.

Like all spiders, the silverback is a predator. It feeds on small fish and crustaceans, and insect larvae. The silverfish hunts in a unique way. It stretches a web between the stems and leaves of algae and hides in its nest.

Water spider catching a fish

Fry and small crustaceans that get caught in the web become entangled in it. The spider jumps out of the nest and completely entangles the victim in its web, after which it drags it into the nest.

In the nest, it digs into the victim with its claw-shaped chelicerae and injects its poison into it, killing it. Then, through the mouth opening, he fills the victim with secretions digestive organs. Under their influence, the insides of the victim dissolve, after which the spider sucks them out. Everything else is thrown away.

Silver spider after a successful catch

In fry and crustaceans, after dissolution, the insides fall into the water, turning into a kind of broth, which the silverfish drinks.

How dangerous is a water spider bite?

The venom of the water spider is third in strength after the venoms of the tarantula and karakurt.

Despite this, the bite of a silverback spider is not fatal to humans. These spiders are not aggressive. They kill only and exclusively for satiation.

But, in defense, they can bite a person. In this case, there are enough discomfort– the bite site will ache, the pain will intensify, and numbness may appear.

But after a couple of days the discomfort goes away. This limits the negative impact of our water spider bite on humans.

Unlike our silverfish, the bite of an Australian funnel-web water spider can lead to much more serious consequences.

Conclusion

Any living creature brings its benefits. Silverfish destroy mosquitoes, flies and other flying pests.

By eating weak and sick fry, they contribute to natural selection. Therefore, you should not kill them just because you don't like them.

Video: Silver spider

Water spider (Argyroneta aquatica)

– a common species of spider in Europe from the family Cybaeidae. An exceptional creature, it spends most of its life underwater. It is safe for humans, but its bite is very painful. In winter, the water spider hides in a cocoon. Females and males of this species are almost the same size (approximately 12-15 mm).

By appearance The water spider is almost no different from other spiders. Its body is divided into a cephalothorax and abdomen, separated by a deep interception. Both parts of the body are unarticulated. Four pairs of long, jointed legs sit on the chest. On the cephalothorax, in the front part, we notice eight pairs of small shiny eyes. There are two pairs of jaws: the first pair is called chelicerae and is used for grasping and killing prey; it is claw-shaped and equipped with a poisonous gland; the second pair, called pedipalps, plays the role of jaw tentacles.
In most spiders, males are smaller than females. In silverfish, males and females are almost the same size; often comes across large variety males, which are even significantly larger than females. Young animals are yellowish-gray or yellow-brown in color, old ones are much darker than young ones, sometimes almost black. Females differ from males, except for size, in the light gray color of the rear part of the body. In addition, males have a more elongated abdomen. Most often, the water spider is found in standing or slowly flowing waters rich in vegetation.
Movements. Having been snatched from its native element by a net, the water spider tries to escape and immediately reveals itself to the observer. On land, it moves very quickly and dexterously, no worse than many land spiders. But at the same time, it swims quite well, using all its legs like oars.
Breathes The silverfish, like other spiders, is captured by atmospheric air, rising to the surface of the reservoir. When immersed in water, part of the air is carried along with it in the form of an air film that envelops the body. This phenomenon is usually explained by the fact that the spider’s body is covered with fine hairs that are not wetted by water. However, the problem here, apparently, is not the hairs, but the thin mesh of cobwebs with which the spider surrounds its body. With the help of this mesh, it captures an air bubble when immersed under water.
Having placed the caught spider in a vessel with water, you can immediately observe a very beautiful sight during the excursion: the air enveloping the abdomen glitters under the water like silver (hence the name - silverfish).
It is interesting that the air bubble covers the body of the male and the body of the female differently: in the female, air surrounds the entire abdomen and part of the cephalothorax, while in the male the upper part of the abdomen remains free of air. Because of this, the air bubble of the male is smaller in volume, not so much pulls him upward and gives him the opportunity to make more dexterous movements in the water and swim not only head down, as females swim, but also holding horizontally (according to V.A. Wagner).
When breathing air is carried into the pulmonary sacs, which are located on the underside of the abdomen and open with paired respiratory openings. The silverfish has only one pair of lungs, which is why it is classified as a group of two-lunged spiders (Dipneumones). In addition, the silverfish also has a system of tracheal tubes, which open with two holes on the lower part of the abdomen.
Feeds silverfish with various small aquatic animals, for example, insect larvae, water donkeys, etc. When attacking prey, it envelops it in a web and then sucks it out; at the same time, it uses its claw-shaped chelicerae, with which it bites into the victim, poisoning it with the secretion of its poisonous glands.
Construction of a home is a remarkable feature of the water spider. It builds air-filled dwellings underwater from the secretions of its arachnoid glands, shaped like a thimble or a bell. The arachnoid substance necessary for construction is secreted, like in other spiders, from spinning glands that open on special papillae, which, among two pairs, are located at the posterior end of the abdomen and are called arachnoid warts. The sticky liquid they release quickly hardens in air and in water, forming strong transparent threads.
Buildings it is difficult to detect spiders on the excursion itself. Having, however, been planted in an aquarium, the spider quite soon arranges an airy home for itself in captivity, making it possible to conveniently observe the techniques of its construction. First of all, it constructs a braid underwater from rare strands of cobwebs, attaching it to aquatic plants or other objects. Then the spider begins to pull air under this network, capturing it from the surface. The air held under water by the spider web mechanically lifts it and forms a dome shape. The resulting formation is covered with new threads of the web; the end result is a transparent, air-filled structure reaching the size of a pigeon egg. The bell serves as a reliable underwater shelter for the spider; here he rests, here he eats caught prey, etc.
If the spider is healthy and well-fed, then its bell is large and well filled with air. In starving, weak animals, the bell gradually collapses. Sick spiders gradually lose even the ability to envelop their bodies with air, begin to become wet with water and drown.
Wintering spiders is an interesting phenomenon, which can be partly covered by a guided tour. For the winter, spiders make cocoons underwater, in which they hibernate. But sometimes they overwinter in the empty shells of mollusks (pond snails, reels, etc.). Having found such a shell, the spider forces air into it until it floats to the surface. The shell is attached by spider threads to aquatic plants (duckweed) floating on the surface. The spider hides in the shell and closes its opening with plant debris held together by cobwebs.
Such floating cocoon shells can be seen on the surface of reservoirs in the fall. It is enough to open the shell to find its inhabitant. V.A. Wagner says that, having once examined a hundred of these shells collected from ponds in the vicinity of Moscow, he did not find a spider sitting inside in only two of them.
With the onset of cold weather, aquatic plants sink to the bottom of the reservoir and, along with them, submerge the silverfish in its shell. In the spring, the duckweed emerges, and the shelter of the overwintered spider is again brought to the surface, freeing the captive.
Reproduce water spiders, like others, have eggs. The eggs are laid in an underwater cocoon, which is similar in construction to an ordinary bell, but its walls are much denser. The eggs are laid at the top of the bell and secured with spider threads. Young spiders emerging from eggs soon begin to build small underwater lairs for themselves, resembling adult spiders.