The organs of vision of a spider and the important question is how many eyes they have. How many eyes does a spider have? Organs of vision of spiders

Ecology

The eight-eyed jumping spider has a field of view of nearly 360 degrees, according to new research. Scientists have found that these "all-seeing spiders" can perfectly see a person, and can also watch videos with nature.

This study tried to describe how each of the spider's 8 eyes work. During the experiments, the researchers also found that spiders can sometimes focus on videos or people.

"Many spiders, such as the black widow or brown recluse, try to avoid humans, and jumping spiders often look completely fearless., says the researcher Elizabeth Jacob.“I doubt they can confuse large objects like people and prey, but they definitely show interest in knowing if you are a threat.”

"If you start pulling the thread near the spider, it will more likely will rush at her, as happens with cats that attack a moving rope", added Jacob, a professor at the University of Massachusetts and a researcher in organismic and evolutionary biology.

She said that there is a lot of misinformation on the net that the bite of these spiders is supposedly quite dangerous for humans. These creatures rarely bite a person, but even if they do, you will get off with a slight fright and a small red spot on the skin, which will quickly pass.

During the experiment, Jacob and her colleagues showed jumping spiders (lat. Salticidae) video clips and conducted a series of tests to better understand how the visual system of these creatures works. Some spiders have only 2 eyes, but jumping spiders have as many as 4 pairs of eyes!

The two main eyes look straight ahead. "If you look at the spider from the front, you will see two large main eyes that will look directly at you, Jacob said. - These eyes have a very unusual structure. They have large, fixed lenses and a tiny, boomerang-shaped retina that provides a high resolution images and allows the spider to see both color and ultraviolet images."

The retina of each of the main eyes is located on reverse side a long moving tube inside the spider's head. The spider can move these tubes in order to scan everything around. One of the researchers said that it looks like a spider is looking at the surroundings with a flashlight.

The other three pairs of eyes are called secondary or secondary eyes. They also see very well and can distinguish movements well. Of these, one pair is directed forward and to the sides. Another pair is very tiny and also looks away. The last pair is located on the sides and at the back of the spider's head.

Jumping spiders not only have excellent eyesight, they prefer to stay in groups and seem extremely curious about a person, and everything that surrounds them.

"If a spider is staring at you, it's safe to say it will be a jumping spider", Jacob said. These spiders react to their reflection in the mirror and can even watch videos of insects.

If the spiders are shown a video with a moving cricket, it will attack the screen. IN wild nature spiders chase prey in much the same way as cats do, if they notice a moving mouse, they will carefully follow it, waiting for the right moment to attack.

Jakob and her colleagues plan to create a special device in the future - i-tracker, which allows you to follow the movement of the main pair of spider eyes as they explore objects. This will help scientists look at the world through the eyes of spiders and look into their brains, which could not be done before.

I fit after death in the minds of a hundred sparrows and it was fun and strange when they scared them away

"The eyes of spiders of different families are very different. Spiders that hunt without a trapping net, like wolf spiders (Lycosidae), lynx spiders (Oxyopidae) and jumping spiders (Salticidae), have a very good developed vision. Jumping spiders can see almost as well as humans. Experiments have shown that they can even distinguish colors. Cave spiders that live in the dark do not see at all or see very poorly. They are completely dependent on sounds and sensations.
Orb-web spiders, such as Araneus diadematus, have very small eyes. They don't need much vision to catch prey."

"The tenet forms see the worst. Wandering spiders have the best eyesight among spiders. There are even blind cave spiders.
The eyes of web spiders cover a large field of view, but they only detect the movement of large objects and distinguish the direction and brightness of light."

"But, as you know, there are exceptions to all rules. These exceptions are jumping spiders (Salticidae). Their main eyes have a very small field of view, but they give a fairly large image on the retina, due to the long focus, like in a telephoto camera. Except In addition, due to the dense arrangement of the visual elements of the retina, the vision of these spiders is objective, so at a distance of 8 cm the spider can see the fly in detail.

"Experimentally, it has been proven that horses, as well as some other spiders, distinguish colors."

"Jumping spiders do not weave trapping webs, they track down prey and jump on it from a distance of several centimeters. Obviously, this method of hunting involves good vision, and this is true: studies have shown that horses have some of the sharpest eyes among spiders; in addition, they see colors. But for a jump, you need to accurately calculate the distance, and how spiders manage to do this is not entirely clear. As for other animals facing a similar problem, the most common solution here is to binocular vision with overlapping fields of view of both eyes. In this case, the brain determines the distance to an object by comparing information from one eye to the other. Some animals can get by with one eye - for example, a chameleon: he just changes focal length lens. For the same purpose, insects twist their heads from side to side.
Horse spiders have four eyes on the front (“front”) of the head, two central ones are larger, two extreme ones are smaller. Studies have shown that the extreme (small - see photo) eyes do not affect the accuracy of the jump. On the other hand, the field of view central eyes spiders do not overlap. They also cannot change the focal length in any other way. It turned out that in determining the distance to jump, spiders, surprisingly, rely on color vision.
In 1981, Japanese scientists from Osaka University found that the retina of horses is arranged in an unusually complex way: it is formed from four layers of light-sensitive cells. One of them consists entirely of receptors Green colour. But at the same time, the green of the spiders is never in focus, so any image is blurry.
As researchers write in the journal Science, spiders determine the distance to the prey due to the contrast between the blurry image on the “green” layer and the focused image on other layers of the retina. If spiders saw everything in perfect focus, then with non-overlapping fields of view, they would not be able to accurately estimate the distance to an object. In the experiment, the horses began to miss their prey if the green spectrum was removed from the lighting.
Thus, in order to accurately aim, the spiders need to keep the target defocused. Although only horses of the Hasarius adansoni species participated in the experiment, scientists have no doubt that the vision of all other spiders of this vast group is similar.
These are the only animals that use this kind of engineering solution to obtain a three-dimensional image, and the only animals with such a peculiar retinal device. Yes, there are microscopes that determine the depth of the image according to the same scheme, but the patent here clearly belongs to the spiders.

Banned on Google?

Unlike advanced arthropod species, the vision of arachnids is poor. Their eyes are simple. There can be up to six pairs on their body, but this rather confirms the fact of the imperfection of their perception of the world around them. The answer to the question of how many eyes a scorpion has cannot be given clear understanding about the quality of it visual system. Therefore, it makes sense to figure out how he adapted to survive with such imperfect "optics".

Features of vision of arachnids

Various species groups in this class have adapted well. For many, it is not the eyes that play the primary role, but on the surface of the body they have areas with hypersensitivity. There are especially many tactile hairs on the jointed legs responsible for movement, and on the pedipalps (leg tentacles).

Many arachnids weave trapping webs. By the smallest fluctuations of the threads, they learn about the prey they have caught. Visual perception is less important. Species that lead a nomadic lifestyle and hunt without a web have more developed vision. To move around unfamiliar terrain, they must be able to distinguish between the surrounding reality.

However, their visual system cannot be compared with the "optics" of developed higher insects. The eyes of a scorpion (photo below) also do not differ in either the complexity of the device or the color rendering features. It is believed that representatives of this suborder see even worse than spiders and are able to distinguish their own kind only from a distance of several centimeters.

Simple and complex vision of arthropods

Vision in insects is the most developed. In this regard, the eyes of arachnids are often called simple. In developed representatives of insects - bees, dragonflies, flies and other similar ones - compound eyes have a faceted structure. The structural visual unit is the ommatidia. Of these, in fact, a complex optical system consists. Located side by side, they make up the visual complex. Ommatidium consists of a biconvex lens (cornea), under which there is a transparent cone, similar in properties to the lens.

Below is a layer of cells (retina) that can perceive light radiation. They connect with nerve endings that send signals to the brain. Each ommatidium receives information separately. As a result, the picture consists of many dots and resembles a mosaic image.

Flies have a number of such structural elements reaches 4 thousand in each eye. Dragonflies more developed in this regard have even more - up to 28 thousand. In arachnids, several pairs of scorpions are known to have complex structure? They do not have a complex visual system. It is represented by several separately located ommatidia eyes. Moreover, one of their larger pair is considered the main one. The rest (up to 5 pairs) are located on the side and are considered auxiliary.

Simpler lateral eyes (stemmas) are found in insect larvae. Turning to the highest stage development, their visual system becomes more complex. Another type of simplified eyes (dorsal) does not "regenerate", but remains at the same level in adults. Ommatidium is not formed in them (there is no cone and lens). Light-receiving cells are located under the cornea. Even lower is the pigment layer, connected to the nerve endings.

Scorpios: lifestyle

Most often found in regions with tropical climate. Some species are diurnal, but the vast majority of them are still nocturnal hunters. They prefer to hide from the scorching heat and hide during this period under stones, snags and in other secluded places.

This is partly due to their imperfect vision. They can notice the danger only at close range, and they are better adapted to hunt at night. But this is not only because of the specific features of vision. It does not matter how many eyes a scorpion has (photo below) - they do not play a decisive role in catching prey. It is believed that the main merit of accurate attacks is the sensitive sensors on their paws.

The circular setting of the legs gives the scorpion the opportunity to feel the smallest vibrations of the soil from all sides. By the speed of propagation of such signals (the middle paws feel them earlier), he determines the exact location of the victim. The eyes play a secondary role in this. It has been noted that if a scorpion and a victim are separated by a thin cleft, it will not be able to attack it even at close range. Signals on the ground from the movement of the prey to its sensitive paws in this case do not reach.

The habitat and characteristics of life have significantly changed appearance these creatures. Not only the overall dimensions of the body and its individual parts differ, but also the number of eyes. Regardless of their total, they all have a simple structure.

How many eyes does a scorpion have, and where are they located on the body? Some species have adapted to live with one pair. The maximum number is 12 simple eyes. Moreover, one pair of them (obviously larger) is in the center and plays a major role. The rest are located on the sides and below the perimeter.

Having caught the prey with its front claws, the scorpion raises it above its head and pierces it with the tip of the sting at the end of the tail. How many eyes does a scorpion have to control this process? Presumably, the couple on top is to some extent responsible for this. Whether simple additional eyes are a complication of the visual system (developed to improve) or its simplification (did not have time to completely atrophy), it is not possible to establish for certain.

The number of spiders known to science is amazing - only modern species there are about 42 thousand, plus more than a thousand fossil arachnids. Distributed everywhere, living not only on land, but also in water, predators and, with rare exceptions, vegetarians, harmless and deadly to humans, living on earth for over 100 million years, spiders are also interesting because they, like a few insects , have a unique external structure. First of all, it concerns the organs of vision. Therefore, the question of how many eyes a spider has is interesting.

Number of eyes in spiders

Zoo-ophthalmologists (specialists in the field of vision in animals), having heard the question of how many eyes a spider has, will not give a definite answer. The fact is that the number of eyes in spiders varies depending on the species.

But still, it is known how many eyes most species of spiders have - four pairs. However, the owners of 12 (!) organs of vision are known. In the course of evolution, nature left the spiders as many organs of vision and just such strength as they needed for survival and reproduction. At opposite poles in terms of visual power are cave spiders - almost blind - and jumping spiders, in which the power of vision is equivalent to that of a human and, at the same time, they are still able, as proven, to distinguish colors.

eye types

The eyes, usually located in two rows, have different functionality. The so-called medial, it is also the front pair, is called the main eyes. All other organs of vision are called secondary. In contrast to insects that have so-called compound eyes, where separate parts of the eyes perform functions peculiar only to them, in spiders, separate eyes play the role of such facets. An example is side eyes, the main task of which is to warn their owner of an approaching danger.

The power of vision

The main eyes of spiders are able to see even what a person cannot distinguish. In particular, the sensitivity of these creatures to ultraviolet radiation has been proven. Almost 6 thousand species of jumping spiders have this ability, which, unlike other representatives of arachnids, prefer not to wait for the victim in an ambush, but rather actively hunt it.

Poor eyesight is possessed by spiders - spiders that catch prey with the help of cobwebs. Their vision allows them to fix the movement of relatively large objects (moths, flies), respond to changes in the direction and strength of light.

Eye Features

Scientists have determined that no matter how many eyes a spider has (cross, crab, sand or other species of these invertebrates), all eyes function as a single organ. First, the presence of a potential victim (fly) is determined by the rear or lateral eyes. This happens at a distance between the spider and the fly, which is at least 20-25 cm. Then the main eyes come into play, to which the main focus is transferred. It is they who determine that the desired object of hunting is in front of the spider, and not a foreign object.

Thus, the answer to the question, how many eyes does a spider have, requires counter clarifying questions - what kind of spider and living in what habitat? Only after determining these parameters can an exact answer be given to the question.

Spiders are all around us. Therefore, it is important to know which spiders are safe and which ones should be avoided.

Spiders are one of ancient inhabitants planets known since the Devonian and Carboniferous periods. It is believed that they appeared about 400 million years ago. The creations of the Paleozoic era had a characteristic web apparatus, but were more primitive. Their habitat is the widest - the entire planet, not counting the Antarctic.

Spider science: what is it called?

Araneology is the science of spiders, which is part of the branch of zoology - arachnology. Arachnology is the study of arthropods, invertebrates, arachnids. The origin of the name is ancient Greek.

Also, arachnology is the art of weather prediction based on observing the actions of spiders.

Spiders - what are: types

Researchers know about 42 thousand species of spiders. Spiders can be divided into three large suborders, which mainly differ in the structure of the jaws, more precisely, in the position of the chelicera relative to the longitudinal axis of the body.

Suborder Orthognatha

More often, representatives of this suborder are called migalomorphs. Characterized by the presence of dense hairs, large sizes and the primitive structure of the jaws - the claw is directed downward and grows only on upper jaw. Respiratory system represented by lung sacs.

Most migalomorphs live in warm climates. Burrows suit themselves underground.

Orthognatha include:

• tarantulas
• funnel spiders
• ctenizides
• spiders - diggers

Suborder Araneomorpha

Almost all other spider species known to naturalists belong to the large Labidognatha or Araneomorpha group. They differ in that they have claws equipped with both jaws. The respiratory system is represented by the trachea.

Types of spiders that catch prey without a net:

• crab spiders
• jumping spiders
• wolf spiders

Types of spiders using a trapping web:

• linifid spiders
• web spiders
• funnel spiders, or brownies
• centipede spiders
• orb weaving spiders

Among the araneomorphic spiders, there are also those that are not able to produce cribellum - the substance from which spiders produce durable spider silk, and those who produce it.

Suborder Mesothelae

Lyphistiomorphic spiders are distinguished by the fact that the chelicerae are spaced to the side, and not directed downwards. This position is considered more evolutionarily advanced. But, this suborder is considered the most primitive, its traces were found in carbon deposits. Spiders have archaic lung sacs, four pairs of arachnoid warts that have not yet been shifted to the end of the abdomen. They live in earthen burrows that are closed with a lid. Signal threads diverge from minks. Although one species prefers caves, where it makes spider tubes on the walls.

These include:

• arthropod spiders
• primitive arthrolycosid spiders
• primitive spiders arthromygalides

Spider: insect, animal or not?

Spiders belong to a type of animal - an order of arthropods in the arachnid class. Therefore, spiders are animals, not insects.

Differences between a spider and an insect:

• Spiders have four pairs of legs, and insects have three pairs.
• spiders do not have antennae characteristic of insects
• many eyes, up to twelve pairs
• the body of a spider always consists of a cephalothorax and an abdomen
• some types of spiders have intelligence: they distinguish strangers from their own, can protect the owner, feel the mood of the owner, even dance to the music. Not a single insect can do this, unlike an animal.

Spider body structure

The body of spiders, covered with an outer skeleton of chitin, consists of two sections, which are connected by a small tube:

• the cephalothorax is formed by the head merged with the chest
• abdomen

cephalothorax

• The cephalothorax is divided by a groove into two sections: head and chest. In the anterior head section are the eyes and jaws - chelicerae. In most spiders, the chelicerae are directed downwards, ending in a claw. The claws contain venom glands.
• The lower part of the jaws - pedipalps, are used as palps and grasping elements. Between the pedipalps is a mouth that serves for sucking. In some mature males, the pedipalps are also cymbium - the copulatory apparatus.
• Simple eyes are also found in the anterior head region.
• Four pairs of jointed legs are also located on the cephalothorax in thoracic region. Each spider leg consists of 7 segments. The last segment of each leg has two or more smooth or serrated claws.

Abdomen

• The abdomen can have a shape: round, oval with processes, angular, elongated worm-shaped. On the abdomen are stigmas - breathing holes.
• On the underside of the abdomen are arachnoid warts, in which the arachnoid glands are located. Near the base of the abdomen is the genital opening. In females, it is surrounded by a thickened chitinous plate, while in males, the genital opening looks like a simple gap.

Spiders can grow up to 10 cm in size, and their limb span can exceed 25 cm, it all depends on the species. The smallest representatives are only 0.4 mm in size.

Color, pattern depends on the structure of the scales and hairs covering the body, the presence of pigment and the type of spider.

How many legs does a spider have?

• All spiders have four pairs of legs, which are located on the cephalothorax and are usually covered with hairs.
• Each foot has crescent-shaped, comb-like claws. Between the claws, most often, there is a sticky pad - a claw-like appendage.
• Web-weaving spiders have auxiliary serrated claws that allow the spider to move freely along the web.

How many eyes does a spider have?

• Depends on the type. Some species have only two eyes, and some have up to twelve. Most species have 8 eyes, which are arranged in two rows.
• In any case, the two front eyes are the main (master). They differ in structure from other side eyes: they have muscles to move the retina and do not have a reflective shell. Also accessory eyes characterized by the presence of light-sensitive retinal cells. The more there are, the sharper vision spider.
• Some spiders can see as well as humans and distinguish colors. For example, jumping spiders. Night hunters, for example, sidewalker spiders, see perfectly not only at night, but also during the day. But wandering spiders see best.

How does a spider spin its web?

The thread of the web consists of many thin threads that the spider glues together with a special liquid that quickly hardens in air. Thanks to this, such a high strength of the web is achieved that spiders even travel with it, overcoming kilometers of distance.

The web can be dry, sticky, elastic - it all depends on the purpose of the thread.

Types of threads for cobwebs:

• for cocoon
• sticky thread
• for moving
• to confuse prey
• thread for fastening

The design of the web depends on the method of hunting. Spiders use a thread that reflects ultraviolet rays, which most insects see, when weaving. Moreover, the spider weaves ultraviolet-reflecting threads in such a way that they look like flowers, which also reflect ultraviolet. Therefore, insects fly to the inviting and sweet flower, but fall into the web.

Stages of weaving a web:

1. The first spider releases a long thread. Such a thread is picked up by the air flow, rushes to the nearest branch and clings to it (Fig. 1, 2).
2. Then another free-hanging thread parallel to the previous one is woven. The spider moves to the middle of this thread, which is stretched under its weight, and weaves another thread in a downward direction until it finds the third support (Fig. 3).
3. On the support, the spider fastens the thread and a Y-shaped frame is obtained.
4. Next, a general contour is woven and a few more radii (Fig. 4).
5. At these radii, an auxiliary spiral is woven (Fig. 5). This whole frame is woven from a non-sticky thread.
6. Next, the spider weaves a second spiral with a sticky thread, towards the middle of the web from its edge.

Construction may take 1-2 hours.

How do spiders reproduce?

• Males usually differ from females in size (male is smaller), long legs, brighter coloration, the presence of pedipalps, which appear in males only during the last molt.
• First, the males weave a special sperm web. Although some species are limited to a few stretched threads. Then the spider puts a drop of sperm on the web and fills the pedipalps with sperm, with the help of which it injects the sperm into the female's seminal receptacle. And goes in search of a female.
• The spider finds the female by smell. Having found a suitable female, the male begins to cautiously approach. If the female is not disposed to courtship, then she attacks the spider, and may even eat it.
• If the female looks at the male favorably, then the male begins to lure the female: he performs “wedding dances”, “tinkles” his feet, and brings prey. Having appeased the female, the spider carefully approaches her, touches her with the tips of her legs, then with her pedipalps and retreats. Also, the male "drums" on the substrate.
• If the female does not show aggression and "drums" herself, then the male carefully approaches and brings his pedipalps to the female's genital opening. The act lasts a few seconds.
• The male then runs away to avoid being eaten by the female. Although this happens quite rarely. A female can have several males in one season.
• After 6-10 weeks, the female spins a cocoon, in which she lays up to 500 eggs. The female carefully guards the cocoon, holding it between the chelicerae. After another 5 weeks, spiders appear.

How long do spiders live?

Most spiders live for a year. But some species, such as Grammostol pulchra from tarantulas, can live 35 years. And this applies only to females, males even tarantulas live 2-3 years.

Non-poisonous spiders: a list with names

There are no completely non-venomous spiders. Poison is necessary in order to paralyze the victim, for protection.

But the venom of most spiders encountered is not dangerous. In some cases, it is so small that no one will notice, or redness and swelling will appear. Although in isolated cases possible allergy to spider venom.

Safe for humanscommonspiders:

Common Harvester Spider. The size of the male is up to 7 mm, the female is up to 9 mm. Leggy. Hunted in dark time days. They like to gather in a pile so that they seem to be a tuft of wool. Weaves a non-sticky web. They scare off enemies with the release of an unpleasant odor.

More than 5 thousand species. This small size A 5-6 mm spider that loves to bask in the sun and climbs glass very well. Good jumpers, they can jump up to 20 cm. Webs do not weave, they attack by jumping, they have excellent eyesight.

More than 1 thousand species. Size up to 25 mm - females, up to 10 mm - males. It has several white spots on its abdomen, forming a cross. They hunt with the help of a round hunting net, which can reach 1.5 m in diameter.

Size up to 10 mm. Hunts from an ambush, instantly grabs the victim and paralyzes her with poison. Networks do not weave. It has camouflage - if necessary, changes color from rich yellow to white. Those that hunt on the bark of trees have Brown color, and those in the leaves are variegated.

House spider or funnel spider, the most famous and widespread. Weaves a web in a secluded place: on the ceiling, in the corner, behind the closet. The male is up to 10 mm in size, the female is slightly larger - up to 12 mm. The color is yellow-gray with brown spots.

The size of the female is up to 10 mm, the male is slightly smaller. The color is light yellow, sometimes greenish. On the underside of the belly, elongated in the form of a seed, there are two light stripes. They build circular networks with large "holes" designed for centipede mosquitoes. The web is built near water, they know how to run on water.

The size of the male is up to 16 mm, the female is up to 12 mm. A rare spider, adapted to live in freshwater sluggish water. Can swim. The abdomen is covered with hairs to hold air, so under water the spider appears "silver". A “bell” filled with air spins in the water, where it lives: rests, leaves reserves, eats caught prey.

Spider-tarantula (tarantula). Large, up to 20 cm with a leg span. They have a beautiful variety of colors. Weave a web. Some species are completely harmless to humans; others may cause swelling, redness, itching, fever, muscle cramps. No deaths have been described. It is they who are most often kept in homes, females of some species live up to 35 years. Very unpretentious in care. Bird-eaters can even be trained.

Top 10 most dangerous, poisonous, deadly spiders in the world, on the planet: a list with names

A resident of the tropics and subtropics of South America is the most dangerous spider according to the Guinness book. The size of the spider is 10-12.5 cm. It is fast, active, does not spin webs, and constantly moves in search of prey. Likes bananas. It feeds on other spiders, insects, lizards, birds.

In danger, it rears up, shows fangs. Deadly poison for weakened people, children. Without assistance, death from the bite of some individuals can occur in 20-30 minutes. In an adult healthy person a severe allergic reaction usually occurs.

The habitat is the deserts of South America, Africa. They can go without water and food for a long time - up to a year. Size taking into account the span of the paws up to 5 cm.

When hunting, it burrows into the sand, lets it get closer and attacks from cover. The poison is a hemolytic-necrotic toxin that thins the blood and causes tissue decomposition. The victim dies from internal bleeding. No antidote has been created, but people die extremely rarely.

Habitat - Australia, within a radius of 100 km from Sydney. Size - up to 5 cm. Lives and hunts in stumps, under stones, on trees or open areas. The venom is harmless to most mammals, but deadly to humans and primates.

The spider, in danger, rears up, shows fangs. When bitten, it digs into the body of the victim and bites many times in a row. At the same time, it is difficult to tear it off. Poison is dangerous because large doses. First, the state of health worsens: nausea, vomiting, sweating. Then - decreases arterial pressure and blood circulation is disturbed, and in the end - the respiratory organs fail.

One of the most known species. Habitat - Mexico, USA, southern Canada, New Zealand. They prefer to live in the desert and prairies. The size of the female is up to 1 cm. Females are more dangerous than males. If bitten by a female, then the antidote must be administered within 30 seconds.

Spider venom is 15 times stronger than rattlesnake venom. The bite site heals up to 3 months. The bite is characterized by acute pain, which after 1 hour spreads throughout the body, causing convulsions. Difficulty breathing, vomiting, sweating, headache, paresthesia of limbs, fever.

It looks like a black widow. Originally lived in Australia, now spread throughout the world, with the exception of the poles. Up to 1 cm in size. It feeds on insects, flies, cockroaches, even lizards.

The poison is not able to kill a person, but after a bite, pain, cramps, nausea are felt, increased sweating, general weakness.

6. Karakurt - "black worm"

From the genus of black widows, lives in the steppe and desert zones of Russia. The size of the male is up to 0.7 cm, the female is up to 2 cm. The most dangerous is the poison of females with red dots on their abdomen.

The bite of the spider itself is practically not felt, but after a few minutes it is felt sharp pain gradually spreading throughout the body. Convulsions begin, a red rash appears, the victim may feel causeless fear, depression. Without assistance, a bite can become fatal for 5 days.

The second name is violin spider. Habitat - northern Mexico, southern USA, California. Sizes of males - 0.6 cm, females - up to 20 cm. Not aggressive. Lives in dark, dry places: attics, sheds, closets.

The bite is almost insensitive. After a bite, the effect of the poison begins to be felt after it spreads throughout the body, in a day. The temperature rises, nausea, rash, pain throughout the body, tissue swelling appear. In 30%, tissue necrosis begins, sometimes organs fail, deaths only a few have been registered.

Originally inhabited only South America(Chile), now also found in North America, found in Europe and Australia. Lives in abandoned places: sheds, woodpile, attics. Feeds on insects and other spiders. Size including paws - up to 4 cm.

The bite is painful, similar in strength to a cigarette burn. The poison has a necrotic effect. The victim feels severe pain. May develop kidney failure. Treatment takes many months, and 1 in 10 people die.

9 Wolf Spiders

Habitat - the whole world, except for Antarctica, but prefer warm countries. They live in bushes, in grassy meadows, in forests near water sources, in fallen leaves, under stones. Sizes - up to 30 mm. They feed on cicadas and bedbugs.

The bite of tropical species can cause prolonged pain, dizziness, swelling, severe itching, nausea, rapid pulse. Their venom is not lethal.

10. Blonde Theraphosa

One of the largest spiders, the second name is the goliath tarantula. Body size - up to 9 cm, leg span - up to 25 cm. It feeds on toads, mice, small birds and snakes. It bites only in cases of danger.

The poison has a paralytic effect. But for a person it is fraught with only swelling and itching. When bitten by large animals and humans, venom is usually not injected. In case of danger, the tarantula shakes off sharp hairs from the back, which cause irritation of the mucous membranes.

Although there are many dangerous spiders, they rarely attack. Attack, as a rule, is associated with protection, and in ordinary life, spiders shy away, preferring secluded places for life. There are few deaths, but care is always needed in handling these animals.

Video. The strangest spiders and unusual spiders in the world