Is it really possible to build a castle in the air? You can if you are a silver spider. A small, most ordinary-looking spider is the only one who has perfectly mastered this complex art.

Silver grass is widespread in Europe. It can also be found in Asia Minor, the Caucasus, in Siberia, with its air, in Tibet, Sakhalin, the south Far East dome and in Korea.

PORTRAIT OF A HERO

In appearance, the silverfish is not easy to distinguish from its land-based relatives. The spider's cephalothorax is dark brown, with black lines and spots, and almost naked. It has eight eyes. On the dorsal side of the brown abdomen, covered with velvety hairs, two rows of depressed points are noticeable. Young spiders are yellowish-gray, old ones are much darker, sometimes almost black. The male is larger than the female - a rare occurrence among spiders. Perhaps this is why he remains alive after mating and lives peacefully side by side with his wife. In addition to its smaller size, the female is distinguished by a light gray coloration of the rear part of the body, and the male’s abdomen is more elongated.

SCUBA DIVERS

The silverfish lives in stagnant and slowly flowing bodies of water, rich in vegetation, which is why its second name is the water spider. At the same time she breathes | lungs and trachea, which open on the underside of the abdomen. The spider lubricates the hairs on its body with a water-repellent substance - a modified secretion of the arachnoid glands. When submerged, they trap air bubbles, and the spider appears silvery. This reserve is enough for the silverfish to not float to the surface for a long time.

The male can be distinguished from the female by the appearance of the bubble: the upper part of his abdomen is free of air. In the female, it surrounds the entire abdomen and part of the cephalothorax, so she always swims head down. Males can also swim horizontally, rowing with all their legs, like oars.

BUBBLE HOUSE

The silver fish not only hunts under water, but also lives in the full sense of the word. The home of this spider is an air dome, shaped like a bell, the size of a hazelnut, or even the size of a pigeon egg. It is held in place by a web stretched between aquatic plants. The spider delivers building materials - air bubbles - on its body from the surface. To do this, he sticks the end of his abdomen out of the water and pushes apart the arachnoid warts, after which he quickly dives, carrying away the bubble. Then he separates it with his hind legs and attaches it to the dome.

A spider can spend a whole day in its house without replenishing its oxygen supply. Scientists have found that the air bell itself carries out gas exchange. Oxygen enters it from water when its concentration becomes lower than in environment, and carbon dioxide, on the contrary, goes into the water. But it is still necessary to replenish air reserves: over time, nitrogen begins to leak out of the spider’s house, the pressure drops, and it shrinks like a pierced ball.

MEAL LYING ON YOUR BACK

Silverfish feed on various small crustaceans and other invertebrate animals that fall into their fishing net or directly into their tenacious paws. Spiders don't see well, but the hairs on their legs allow them to feel the smallest vibrations of the web, jump out and grab potential food. Digestion in silverfish is extraintestinal, like in all spiders. Enzymes injected into the victim's body digest soft fabrics, after which the spider sucks out the resulting nutrient broth. To do this, he brings food to his bell and, lying on his back, rests his front legs against the wall of the dwelling. In this position, liquid food does not flow down, but falls directly into the spider’s mouth. Then the clean silverfish takes the undigested remains outside.

HURTING WITH HEAD DOWN

To reproduce, the female rebuilds the house: she lines the top of the bell with loose cobwebs, on which she lays from 15 to 160 eggs. The mother sits on them head down and guards them, without even taking food and only occasionally replenishing her air supply. This “incubation” takes about ten days. Young spiders emerge from the eggs bald and therefore can only breathe while inside the mother's bell. This is where their first two molts take place, after which they move on to independent life.

UNDER-ICE BATHYSCAPH

Silverfish overwinter in a special, especially durable air dome. Sometimes they even use pond snail shells for this. Having carried a supply of air there and attached the shell to duckweed floating on the surface of the water, the spider seals the entrance and falls into a state of deep rest. During the winter, the duckweed drowns, taking the shell with it, and in the spring, when the water warms up, it floats up again. Now the overwintered spider can leave its winter apartment.

Young spiders and males spend the winter most of the time; females are less numerous. Sometimes late egg cocoons overwinter together with the females.

For molting, young silverfish build a special bell. The spider gradually crawls out of the old skin, pulls out its legs and, exhausted and still soft, lies down to rest. After waiting for the new covers to harden, the silverfish leaves the moulting bell.

BRIEF CHARACTERISTICS

Class: arachnids.
Squad: spiders.
Family: cibeids.
Genus: Argyroneta.
Species: water spider, or silver spider.
Latin name: Argyroneta aquatica.
Size: female body length up to 12 mm, male up to 15 mm.
Color: from yellow-gray to almost black.
Life expectancy: up to 18 months.

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The world's only underwater spider July 4th, 2015

Representative of the family Argyronetidae - Argyroneta aquatica the only spider that has perfectly adapted to underwater existence. It is most often found in stagnant or slow-moving waters rich in vegetation.

Silver spiders adapt well to aquarium conditions. They can be kept in any vessels - both in glass jars (one copy at a time) and in large containers (several adult individuals). In this case, the presence of aquatic plants is mandatory, among which spiders build their homes.

Let's look at it in more detail...

Photo 2.

By appearance The water spider is almost no different from its land counterparts. The body consists of a cephalothorax, where eight pairs of small eyes are located, and an abdomen, separated by a deep interception. The spider has four pairs of long jointed legs and two pairs of jaws: the first pair (chelicerae) serves to grasp and kill prey, the second (pedipalps) plays the role of jaw tentacles.

The silverfish breathes air, which it captures as it rises to the surface of the water. This occurs with the help of hairs that densely cover the entire body. They are fluffy at the ends and are not wetted by water. To prevent the hairs from sticking together, the spider lubricates them with a transparent secretion secreted by the chelicerae. Underwater, some of the air is trapped by the hairs, forming a silvery film of air (hence the name water spider).

Photo 3.

The silverfish feeds on various small aquatic organisms - insect larvae, water donkeys, etc. When attacking, it envelops its prey in a web, digs into it with chelicerae and poisons it with secretions of poisonous glands. Then it injects digestive secretions and, after liquefying the tissues, sucks the contents out of its victim.

Photo 4.

In captivity, these spiders can be fed with bloodworms, as well as flies, cockroaches and other insects that are thrown onto the surface of the water.

An interesting feature of silverfish is the construction of a dwelling - the so-called bell - from the secretions of the arachnoid glands. The necessary building substance is secreted, like in other spiders, from special glands - arachnoid warts located at the posterior end of the abdomen. The sticky liquid quickly hardens, turning into strong transparent threads. The air-filled web forms a bell.

Photo 5.

This happens as follows. The spider weaves a network of web threads underwater, attaching it to aquatic plants and other objects. Then he begins to draw air inside, bringing it from the surface of the water. To do this, the spider crawls along plant stems and pulls a thread along which it returns, as an air bubble pushes it upward.

It takes about three hours to build a small bell. During this time, the spider rises to the surface up to 80 times. The air is held underwater by a spider web. The resulting dome reaches the size of a pigeon egg. There can be several bells in an aquarium different shapes. In them, spiders eat caught prey, take care of hairs, etc.

In nature, during the winter, spiders create a bell-cocoon underwater, in which they hibernate. In an aquarium, with enough food, they always lead an active lifestyle.

Photo 6.

Typically, silverfish have males and females of almost the same size, but there is a species in which the males are much larger. Sex can be determined by the light gray coloration of the back of the body in females and a more elongated abdomen in males. Unlike other spiders, silverfish have a peaceful relationship between the sexes.

When breeding, water spiders lay eggs in an underwater cocoon that resembles a bell, but its walls are much denser. The masonry is located in the upper part of the cocoon and is secured with spider threads. The female guards the clutch and looks after it.

Photo 7.

The spiders that hatch after 10 days do not immediately leave their mother. They molt, grow, and only then, emerging from the cocoon, scatter to begin building their underwater homes.

Juveniles are yellowish-gray or yellow-brown in color. With age, spiders darken and a black tint begins to predominate in color. In an aquarium, young spiders must be isolated from adults, since even the mother can eat them.

Photo 8.

Since spiders emerge from the water and travel on land, when keeping them in captivity, it is necessary to tightly close the aquarium (jar) with a cover glass, leaving an air space above the surface of the water.

Photo 9.

In order to breathe, water spiders build nests from webs that visually resemble domes - in these nests they store an air supply, and to replenish it they swim to the surface and from there carry air bubbles on their own hairs growing on the abdomen and legs.

Scientists have long established the ability of spiders to transport air bubbles under water, but no one had previously paid attention to the ability of a spider’s air capsule to absorb oxygen in water. Two Australian scientists Stefan Hatz and Roger Seymour tried to find out whether this feature is inherent in underwater spider nests that store oxygen. To understand how water can satisfy the oxygen needs of spiders, scientists began experiments. It was assumed that it is from water that spiders capture oxygen, the concentration of which in the domes decreases from time to time.

Argyroneta aquatica (Cl.) Water Spider Status. 3 (VU) - vulnerable species. It is protected in a number of countries in Central Europe and some regions of Russia.

Brief description. For the silver spider (another name dropsy vulgaris) is characterized by sexual dimorphism, unusual for spiders: the male (10-15 mm) is longer than the female (8-10 mm) due to a drop-shaped elongated olive-brown abdomen, covered with delicate light gray hairs. Underwater, these hairs trap a layer of air, causing the abdomen to turn silver. The cephalothorax is rusty-red with a slight brown pattern. almost naked.

Spreading. Transpalearctic. In the Leningrad region it is found everywhere and is associated with a wide variety of water bodies. Here it is quite rare, although in neighboring Finland it is not a species requiring special protection.

Ecology. The silverback is a true aquatic spider, building its bell-nests underwater in stagnant bodies of water or in streams and river backwaters with weak currents. The nests, the size of a small nut, are built from cobwebs, into which the spider brings air bubbles on its abdomen. It spends most of its life in nests. Adults are found from late May to June. For laying eggs, the female often builds a separate small bell, which she hangs next to the nest. The spider feeds on the larvae of aquatic insects and water donkeys; it eats prey in the bell or on the surface of the water. All finds over the last hundred years are isolated; only in the northeast of the region can it be considered a common species (Oliger. 1996).

Limiting factors. All forms of pollution of water bodies and destruction of aquatic vegetation.

Security measures. Inclusion of the species in the lists of specially protected objects of the Nizhnesvirsky Nature Reserve. Identification of species habitats in existing and planned protected areas with subsequent development of protection measures.

Sources of information. Oliger. 1996; Kharitonov. 1932: data from Y. Terhivuo.
V. A. Krivokhatsky, A. V. Gromov

Status. 3 (VU). Vulnerable. Protected in some Central European countries and Red Data Books of some regions of the Russian Federation.

Description. The Water Spider is characterized by sexual dimorphism, uncommon in spiders. The male (10-15 mm) is larger than the female (8 10 mm) because of a drop-like elongated olive-brown abdomen, covered with soft pale-gray short hairs. Under water these hairs bind air. and the abdomen becomes silvery. The cephalothorax is rusty-red w ith an undistinguished pattern, almost without hairs.

Distribution. Transpalaearctic species. In the Leningrad Region the species is distributed everywhere. It is rare in this region, though it is not a threatened species in neighboring Finland (J. Terhivuo, personal communication).

Ecology. An aquatic species. It builds a nest under water in stagnated lakes, slow springs or river backwaters. The nest, sized like a small nut. consists of a silk-like cobweb, which is filled with air. The spider brings air from the surface in bubbles on its abdomen. The spider spends most of its life in the nest. Adults can be found from the end of May to June. The female builds a separate small nest for the oviposilion. It feeds on water invertebrates, eating prey inside the nest or under the water surface. All present records of the species are single and sporadic, it is common only at the NE of the region (Oliger. 1996).

Limiting factors. The pollution of water reservoirs and the destruction of water plants.

Conservation measures. The species should be included in the list of specially protected objects in the Nizhnesvirsky strict nature reserve.

Sources of information. Oliger. 1996: Kharitonov. 1932: data from J. Terhivuo. I. I. Krivokhutsky, I. Gromov

Water spider or silver spider

Representative of the family Argyronetidae - Argyroneta aquatica the only spider that has perfectly adapted to underwater existence. It is most often found in stagnant or slow-moving waters rich in vegetation.

Silver spiders adapt well to aquarium conditions. They can be kept in any vessels - both in glass jars (one copy at a time) and in large containers (several adult individuals). In this case, the presence of aquatic plants is mandatory, among which spiders build their homes.

In appearance, the water spider is almost no different from its land counterparts. The body consists of a cephalothorax, where eight pairs of small eyes are located, and an abdomen, separated by a deep interception. The spider has four pairs of long jointed legs and two pairs of jaws: the first pair (chelicerae) serves to grasp and kill prey, the second (pedipalps) plays the role of jaw tentacles.

The silverfish breathes air, which it captures as it rises to the surface of the water. This occurs with the help of hairs that densely cover the entire body. They are fluffy at the ends and are not wetted by water. To prevent the hairs from sticking together, the spider lubricates them with a transparent secretion secreted by the chelicerae. Underwater, some of the air is trapped by the hairs, forming a silvery film of air (hence the name water spider).

The silverfish feeds on various small aquatic organisms - insect larvae, water donkeys, etc. When attacking, it envelops its prey in a web,penetrates into it with chelicerae and poisons it with secretions of poisonous glands. Then it injects digestive secretions and, after liquefying the tissues, sucks the contents out of its victim.

Silver spider. Below is an unfinished bell-cocoon

In captivity, these spiders can be fed with bloodworms, as well as flies, cockroaches and other insects that are thrown onto the surface of the water.

An interesting feature of silverfish is the construction of a dwelling - the so-called bell - from the secretions of the arachnoid glands. The necessary building substance is secreted, as in other spiders, from special glands - arachnoid warts located at the posterior end of the abdomen. The sticky liquid quickly hardens, turning into strong transparent threads. The air-filled web forms a bell.

This happens as follows. The spider weaves a network of web threads underwater, attaching it to aquatic plants and other objects. Then he begins to draw air inside, bringing it from the surface of the water. To do this, the spider crawls along plant stems and pulls a thread along which it returns, as an air bubble pushes it upward.

It takes about three hours to build a small bell. During this time, the spider rises to the surface up to 80 times. The air is held underwater by a spider web. The resulting dome reaches the size of a pigeon egg. There may be several bells of different shapes in an aquarium. In them, spiders eat caught prey, take care of hairs, etc.

In nature, during the winter, spiders create a bell-cocoon underwater, in which they hibernate. In an aquarium, with enough food, they always lead an active lifestyle.

Typically, silverfish have males and females of almost the same size, but there is a species in which the males are much larger. Sex can be determined by the light gray coloration of the back of the body in females and a more elongated abdomen in males. Unlike other spiders, silverfish have a peaceful relationship between the sexes.

When breeding, water spiders lay eggs in an underwater cocoon that resembles a bell, but its walls are much denser. The masonry is located in the upper part of the cocoon and is secured with spider threads. The female guards the clutch and looks after it.

The spiders that hatch after 10 days do not immediately leave their mother. They molt, grow, and only then, emerging from the cocoon, scatter to begin building their underwater homes.

Juveniles are yellowish-gray or yellow-brown in color. With age, spiders darken and a black tint begins to predominate in color. In aquarium conditionsYoung spiders must be isolated from adults, since even the mother can eat them.

Since spiders emerge from the water and travel on land, when keeping them in captivity, it is necessary to tightly close the aquarium (jar) with a cover glass, leaving an air space above the surface of the water.

More interesting articles

Spiders, widespread almost everywhere, belong to the order of arthropod predators. Spiders are a terrestrial species, with the only exception being the water spider.

The water spider is common in areas from the British Isles to Japan. It settles in stagnant bodies of water, as well as in rivers and streams with weak currents.

The spider is able to move both on land and on the water surface, but it spends the main part of its life under water.

The presence of small hairs coated with a special lubricant on the limbs and abdomen allows water spiders to stay under water for a long time and take oxygen with them in the form of small air bubbles.

Water spiders weave a funnel- or bell-shaped nest underwater. The nest, no larger than a nut, is held in place by attaching strands of web to underwater plants or sunken driftwood. The nest is open at the bottom and a net at the top. This device allows you to collect air bubbles in it, which over time form a real air dome.

Description of the insect

Juvenile

Individuals that are barely born have a gray or brownish-yellow color, which darkens over time.

The spiders spend 10 days in a cocoon, where they grow a little and molt, then they scatter and begin an independent life.

Adult

The body structure of a water spider is the same as that of terrestrial species: the body, consisting of the abdomen and cephalothorax, has a clear, deep division. On the smooth cephalothorax there are four pairs of visually impaired eyes and two pairs of jaws - chelicerae (for grasping and killing prey) and pedipalps (perform the function of tentacles).

The body of a water spider has the shape of a cylinder. The abdomen and all eight segmented legs are covered with bristles, lubricated with the water-repellent secretion of the arachnoid glands. It is thanks to this feature that a silvery air cocoon is created around the spider when immersed, allowing it not to rise to the surface of the water for a long time.

Reproduction

Water spiders of different sexes form pairs and are able to live side by side for a long time. The reproductive process takes place mainly in the female's summer bell.

Before starting reproduction, the male spider pulls out separate threads that do not stick together from the arachnoid warts. He releases sperm on them, then collects it with his tentacles and goes to the female’s nest.

Having met, the arthropods take a characteristic position, after which the male uses the appendage of the palp to introduce sperm into the female’s genital slit.

The fertilized female lays down top part nests with a cobweb, after which it lays up to 160 eggs on it. The eggs are strengthened and covered with cobwebs, creating a partition between the compartment with the eggs and the living part of the nest. The female spider sits on this partition upside down and guards the clutch until the hatched offspring leaves the cocoon. All this time, the female does not eat anything and leaves the nest only to rise for a new portion of air.

What does the animal eat?

Water spiders feed on insect larvae, small crustaceans, and fry entangled in underwater webs. Having discovered prey, the spider entangles it in its net and carries it to its dome. Once in the home, the spider lies on its back. Its front legs rest against the wall of the dome, and the tentacles hold the victim so that it comes into contact with the spider’s mouth. The secreted digestive juice softens the insides of the prey. The enzymes processed by the juice are absorbed by the spider, and inedible remains are thrown out of the nest.

Varieties

There are several types of water spiders.

Hydrachna cruenta Mull

This species is sometimes called the red spider water mite.

The arthropod lives in swampy bodies of water with warm, standing water. The spider looks like a small red ball and moves quite quickly across the surface of the water. It feeds on larvae and small crustaceans, but quite often it itself becomes prey to predatory insects or fish.

Red spiders lay eggs on the inner parts of the leaves of aquatic plants, connecting the eggs with each other with an adhesive solution.

A type of red spider. It has a square-shaped body and mostly rests on the bottom of the reservoir.

Dolomedes fimbriatus L

Hunter spider. This species does not live in water, but next to it or on its surface.

The arthropod has a gray-brown color with white or yellow running along the sides of the body. stripe. In the middle of the body you can see two rows of light gray dots, the chest part is predominantly colored yellow, the abdomen is gray. The female huntsman spider reaches 2.5 cm in size, the male is several times smaller.

The huntsman spider is remarkable because it builds rafts. Due to the lack of the ability to move along the water surface, the arthropod collects leaves and sticks floating in the water and binds them with a web. Having discovered prey, the spider quickly gets to it on its floating island, drags the victim onto the raft and eats it there.

Females lay eggs on plants growing along the banks of a reservoir, cover them with a cocoon of cobwebs and guard them until the offspring appear.

Clubionafallax

The silver spider (or dropsy) is the most common aquatic species in Russia. spiders This population has adapted to living underwater, where spiders build several types of oxygen-filled domes that have different purposes:

• summer (for shelter, eating food and mating);
• sperm (for sperm collection);
• ovarian (for laying eggs and producing offspring);
• for molting;
• wintering

To fill the nest with air, the spider has to follow it to the surface at least 80 times.

Males are gray-green or black in color and reach 15 mm in size. Females are lighter in color and 2–3 mm smaller than their partners.

Benefits and harms

Water spiders bring benefits by destroying insects and their larvae: food for arthropods is adult flying individuals that have fallen into the water, mosquito larvae, etc. Often, water spiders eat fry, but these are mostly weak from birth or defective individuals.

They can cause little harm as they are very painful.

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Is a water spider bite dangerous?

Water spiders rarely attack first: they are not very aggressive. However, if a threat arises, the spider may bite.

An arthropod bite is not life-threatening, but causes severe pain.

The wound left by the poisonous jaws first aches, then the pain spreads around it. Numbness may occur. As a rule, after a few days the pain disappears.

Some species of water spiders, such as the silver spider, are considered endangered species and are listed in the Red Book, so even if such a spider bites you, do not harm it.