The number of eyes in arachnids. The organs of vision of a spider and the important question of how many eyes they have

Spider (lat. Araneae) belongs to the type of arthropods, class of arachnids, order of spiders. Their first representatives appeared on the planet about 400 million years ago.

Spider - description, characteristics and photos.

The body of arachnids consists of two parts:

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

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

The coloration and pattern on individuals of different species depend on the structural structure of the integument of scales and hairs, as well as the presence and localization of various pigments. Therefore, spiders can have both a dull solid color and a bright color of various shades.

Types of spiders, names and photos.

More than 42,000 species of spiders have been described by scientists. About 2900 varieties are known on the territory of the CIS countries. Consider several varieties:

blue-green tarantula (lat. Chromatopelma cyaneopubescens)- one of the most spectacular and beautiful in color spiders. The belly of the tarantula is red-orange, the limbs are bright blue, the carapace is green. The dimensions of the tarantula are 6-7 cm, in the span of the legs up to 15 cm. The homeland of the spider is Venezuela, but this spider is found in Asia and African continent. Despite belonging to tarantulas, this species does not bite spiders, but only throws special hairs located on the abdomen, and even then in case of severe danger. For humans, the hairs are not dangerous, but cause small burns on the skin, resembling a nettle burn in effect. Surprisingly, female spiders are long-lived compared to males: the life expectancy of a female spider is 10-12 years, while males live only 2-3 years.

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

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

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

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

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

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

Peacock spider(lat. Maratus volans). All kinds of colors are found in the color of this spider: red, blue, blue, green, yellow. The color of females is paler. An adult individual reaches a size of 4-5 mm. With their beautiful outfit, males attract females. The peacock spider lives in Australia - in Queensland and New South Wales.

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

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

Karakurt (lat. Latrodectus tredecimguttatus)- it's kind of deadly poisonous spiders of the black widow family. The female karakurt has a size of 10-20 mm, the male is much smaller and has a size of 4-7 mm. On the belly of this scary spider there are 13 red spots. In some varieties, the spots have borders. Some mature individuals are devoid of spots and have a completely black shiny body. Lives in Kyrgyzstan, in the Astrakhan region, in the countries Central Asia, in the south of Russia, Ukraine, in the Black Sea and Sea of ​​\u200b\u200bAzov, in southern Europe, in North Africa. Also karakurt was seen in Saratov region, Volgograd region, Orenburg region, Kurgan region, in the south of the Urals.

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

Tarantulas and other species of mygalomorph spiders live in the crowns of equatorial trees and shrubs. The "drought tolerant" species of spiders prefer burrows, crevices in the ground, and any cover at ground level. For example, digging spiders (atypical tarantulas) live in colonies settled in individual burrows located at a depth of up to 50 cm. Some species of mygalomorph spiders close their burrows with special dampers made of soil, vegetation and silk.

Spiders-haymakers (long-legs) like to settle in damp, dark caves, in abandoned animal dens, cellars and old barns. In residential buildings, weevils are found hanging upside down on warm, southern windows.

Jumping spiders live in a wide variety of places: in forests, deserts, highlands, and also build webs on stone and brick walls houses.

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

Representatives of the funnel spider family place their web on tall grass and shrub branches.

Wolf spiders prefer damp, grassy meadows and wetlands. wooded area, where they are found in abundance among the fallen leaves.

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

What do spiders eat?

Spiders are rather original creatures that feed very interestingly. Some species of spiders may not eat for a long time - from a week to a month or even a year, but if they start, then there will be little left. Interestingly, the weight of food that all spiders can eat during the year is several times more than the mass of the entire population living on the planet today.
How and what do spiders eat? Depending on the type and size, spiders get food and eat differently. Some spiders weave a web, thereby organizing ingenious traps that are very difficult for insects to notice. Digestive juice is injected into the caught prey, corroding it from the inside. After a while, the “hunter” draws the resulting “cocktail” into the stomach. Other spiders during the hunt "spit" with sticky saliva, thereby attracting prey to themselves. beetles and orthopterans, and some species are able to drag them into their homes or earthworm and eat them in peace.
The queen spider hunts only at night, creating a sticky web bait for careless moths. Noticing an insect near the bait, the spinning queen quickly swings the thread with her paws, thereby attracting the attention of the victim. The moth happily curls around such a bait, and touching it, immediately remains hanging on it. As a result, the spider can easily pull it towards itself and enjoy the prey.

Large tropical tarantulas are happy to hunt small frogs

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

Judging by the numerous notes of scientists, great amount Spiders destroy small rodents and insects several times more than animals living on the planet.

I have very mixed feelings about spiders. On the one hand, as a child, I was a big fan of Spider-Man, like many boys. :) And this left me with only exceptionally warm feelings. :) However, when I see a spider in my house, then all this spiritual warmth disappears. :) Well, they do not cause me sympathy and all. :)

However, this amazing creatures. I would like to talk about how many spiders have eyes. :)

How many eyes does a spider have

Since in my region it is rare to see big spiders, then, and, as it should, to see how many eyes they have, I could not in any way. However, I always assumed that it was about 6 or 8. But not everything is so simple. :) At different types spiders available different amount eye:

• Spiders that are forced to hunt their prey without the use of a web usually have 8 or more eyes. The maximum number is 12. It doesn't happen anymore. :) In such spiders, the eyes are located almost around the entire cephalothorax. This gives them the opportunity to see all 360 degrees around them.

• Spiders that hunt with webs do not need to have good eyesight. Therefore, evolution did not give them an extra organ of vision unnecessarily. Such spiders usually have four or six eyes.
• In addition, there are amazing views spiders that have only 2 eyes. Just like ordinary people. :)

I also made a small selection interesting facts about these amazing creatures:

• Spiders also do not like annoying insects, just like people. :) On average, spiders kill several thousand flies and other winged insects per year. And since there are a huge number of spiders, hundreds of millions of these creatures die every year from the paws of a spider on the territory of a small region.
• Most huge spider- Goliath. This spider reaches a size of 30 cm. Just imagine that you saw it at home. :) Your actions? I would immediately announce the sale of the apartment. :)

• PAuki is almost everywhere! These insects live everywhere, except for one place - Antarctica. This mainland is too cold for them. In all other parts of the world, spiders live in clover. :)

The variety of spiders on Earth amazes even the most inquisitive, because more than 42 thousand species have been found by science, and also, thousands of arachnid fossils can be safely added to this figure. Fart habitats are very diverse: many species can live not only on land, but even on water.

Spiders are interesting not only for this. They exist as vegetarians, harmless to other living beings; and poisonous, capable of killing a person in a few hours. This type of insect has been living among us for over 100 million years, has a unique external structure, an interesting texture, but its organ of vision deserves special attention: the number of eyes in each species and their features.

How many eyes do spiders have

There are specialists who study the field of vision of animals, these are zoophthalmologists, who, having heard such an interesting question, will not give an exact answer. At a minimum, you need to know what species the insect belongs to. Indeed, in fact, everything is different: the number of eyes can vary depending on the genus and species. In most cases, this figure will be 4, but there are species that have 6, 8 each, and the owners of 12 eyes are also known.

The fact is that in the process of evolution, nature awarded each species of insect with exactly the number of eyes, the power of vision that was necessary for survival in the habitat where they developed. For example, at different poles of the globe there are cave views, their power of vision is very low, and they are almost blind, but on the surface there are jumping spiders, whose power of vision is comparable to that of a human, and they are even able to distinguish some colors.

eye types

In all species, the arrangement of the organs of vision occurs in two rows, and they are responsible for a different function:

1. The front pair is medial- Responsible for basic vision.
2. Other pairs of eyes are called by-products- they are responsible mainly for all other functions, as well as to warn the insect of an approaching danger.
3. Just like other insects have compound eyes, which have separate areas responsible for certain functions, but in spiders these are special additional pairs of eyes, because of this they can have more than 4 eyes.

The power of spider vision

The front pair of spider eyes can see things that even humans cannot see. Studies have been conducted and it has been proven that some types of spiders have the ability to feel even ultraviolet light. For example:

Eye Features

All individuals differ not only in the number of eyes, but also in characteristic difference buildings, run various functions organs of vision. For example, zoophthalmologists are very interested in the family of individuals Salticidae, because in this species the anterior or, as they say, the main, main pair of eyes, has the largest lens among other species, that is, the very shape of the organs of vision is similar to the structure of a telescope.

Scientists have found a pattern that, regardless of the number of eyes, whether they are crosses, crab spiders, sand or other species, the organ of vision functions as a whole in all. This is expressed as follows:

1. First of all, the side or back eyes are included in the work, they find a potential victim even 20–30 cm before it approaches.
2. The second stage, the main eyes are included in the work; it is they who convey information and the main focus, determining whether the object of the hunt is in front, or some kind of foreign object that does not need to be paid attention to.

Interesting facts related to sensory

In addition to the eyes, spiders also have separate organs for interacting with environment in which they live. For example, all species do not have ears, the insect can only hear due to the tiny hairs of thrichobotria that are found on its limbs. These hairs, as an organ of hearing, allow the spider to determine to the nearest millimeter where the source of sound radiation and air movement is located. Also, this organ on the limbs allows you to capture taste. It can be concluded that spiders do not have receptors responsible for the taste in the mouth, and all information about the prey, whether it is suitable for food, he receives due to the same special hairs on his legs.

Even knowing this brief information about the structure of vision, it is impossible to give an unambiguous answer, how many eyes spiders have. After all, in order to more specifically answer this question, you need, at a minimum, to know the habitat of the spider, and better, to which species and subspecies it belongs. If there is all the information about the spider, you can answer with accuracy how many eyes it has.

A spider can have a different number of eyes depending on the species it belongs to. Their number can vary from two to twelve. Some arthropods do without organs of vision at all. For example, cave spiders, who spend their entire lives in the dark, do not have eyes, since they simply do not need them.

Although most spiders have eight eyes arranged in two rows, vision in the life of these animals is far from leading role, and, despite the number of visual organs, they see poorly. A spider that can see an object at a distance of thirty centimeters can already be considered sharp-sighted. However, the vast majority of spiders do not require good eyesight. They weave webs where they wait for their prey.

The fact that a mosquito or a fly got caught in their nets, these arthropods learn from the vibration of the web, which is created by the fluttering victim.

Spider eye structure

The spider's many organs of vision do not work in the same way. The middle pair of eyes usually has large sizes than additional eyes. The main organs of vision are devoid of mirrors that reflect sunlight, but on the other hand, bundles of muscles are attached to them, thanks to which the eyes can move. The lateral organs, on the contrary, are equipped with mirrors, but lack muscle bundles.

Apparently, this is due to the fact that the eyes perform different functions: the anterior ones in hunting species follow the prey, and the lateral ones observe the approach of danger.

Eagles among spiders

There is, however, a group of spiders that have extremely sharp eyesight. These are wandering jumping spiders that do not sit still, waiting for their prey, but are actively engaged in its search. The vision of these representatives of arthropods is comparable in acuity to human vision. In addition, they are able to distinguish colors, which is not typical for such primitive animals.

The horses have well-developed eye muscles, which allows these animals to follow the prey, and the main eyes are equipped with a large lens and somewhat elongated like a telescope. Lateral eyes allow the wandering spider to fix movement from the side, behind it and above it. Despite the fact that this spider has eight eyes, and they have different functions and show different picture, together they act as a harmonious

The number of eyes depends on the place of residence and the way the spider hunts. Maximum 2 rows of 4 pieces total 8.

In different types of spiders different quantity eye. There may be only 2 of them, like in insects, but there may be 12.

Most spiders have 8 gas, which usually form 2 rows. It should be borne in mind that the main eyes are devoid of a mirror, that is, an inner, reflective shell. The secondary eyes have a mirror, but are always devoid of muscles.

Despite this, among the spiders there are also those that do not have eyes at all, these are the so-called cave spiders (they simply do not need them). But spiders - horses, on the contrary, see almost the same as a person, even though they can distinguish colors.

2 to 12 eyes various kinds spiders. The most common spiders have 8 eyes. But with so many eyes, spiders cannot boast of good eyesight; they can see the victim in best case at a distance of 20-30 cm. But like all living creatures in this detachment, there are exceptions - these are those that do not see anything at all in daylight - these are cave spiders, there are also those whose vision can be compared with human - these are spiders -horses, their visibility is 360 degrees.



Spiders rarely have only two eyes. Basically, they have four, six, eight or even twelve eyes. Most spiders have eight pairs of eyes arranged in two transverse rows. There are also spiders that have only four pairs of eyes. The front eyes are called the main or medial. They are always dark in color. But the rest of the pair of eyes, the so-called secondary ones, have a brilliant color, and sometimes it seems that the spider has small mirrors. There are also spiders that have several pairs of eyes enlarged at once. So, in jumping spiders, 4 pairs of eyes are enlarged at once, and in spiders of the Dinops class, only two main eyes are enlarged.







An interesting fact: the spider sees its prey only with its main, front eyes. And with the rest of his eyes he cannot examine objects, but they allow him to see all those movements that occur behind, from the side and even above him. In the same jumping spiders, the eyes are able to distinguish the volume of objects, and from behind, he can see movement at a distance of about 25 centimeters.

Yes, I read a lot about spiders and their vision. But the information is sometimes contradictory. There are sources where they say that there are a maximum of 12 eyes, but there are as in a joke, and in which row. and write that two in eight rows. But the most reliable source says two to eight. So here are some clear pics. These are ogre spiders.





It's impossible to say for sure. It depends on the species to which the animal belongs. The average number is eight, but maybe only two, and some (cave species) do not see at all, but the maximum number is 12.

Spiders come in many varieties, and the number of eyes often depends on the size of the spider itself. The smallest number of eyes, two. Maximum amount twelve eyes. Well, basically the spider has eight eyes, of which two are the main eyes.

The science to which this question relates is called arachnology. Only in the area that the union once occupied, almost three thousand varieties of spiders were recorded. The body of a spider consists of two main parts: the cephalothorax and the abdomen. The eyes, about which the question itself is asked, are located on the front side, but their number is different. We rarely see the usual two eyes in spiders, common number eyes are six or eight. The spider brain is located in the center of the cephalothorax and occupies one third of the volume in size. But the most interesting way of hunting spiders and the properties of the web, which is used in hunting. Spider web is one of the most durable materials and science is working on ways to obtain such material artificially. The first attempts are successful.

For illustration, I chose the cutest face of a spider with 8 eyes.