How many eyes does a spider have? Features of arachnid vision: how many eyes does a scorpion have?

Did you know?It is the compound eyes that are responsible for the perception of color in insects.

Not all types of spiders have facets. It is believed that these rudiments were left to spiders by their ancestors - chelicerates, which had a faceted eye structure. Such organs are also capable of detecting and reflecting light. In the structure of the lateral auxiliary organs of perception, the layer of nerve cells is much closer to the light flux than the light-sensitive cells. This creates blind spots where the optic nerve attaches, but at the expense large quantity organs, this deficiency does not create inconvenience.

What is the power of their vision?

The ability to distinguish between the strength and direction of light allows the spider to track the direction of movement of its prey. This is especially important for those who weave webs.

Important!The movement of objects is recorded by the side eyes, then the spider turns to the target and can examine it in close-up with the help of the main ones. Without lateral additional organs of vision, he will not be able to hunt.

The advantages of spider vision can also be called the following:

• better picture detail than a person;
• ability to see close-up;
• spiders see objects close to them better than objects at a distance of more than 10 cm;
• ability to see in the ultraviolet spectrum;
• ability to perceive polarized light;
• the ability to follow prey in any direction around you;
• eyes help to move quickly in the grass;
• the spider does not miss when jumping for prey, which means it can very accurately determine the distance.

Peculiarities

A large number of eyes allows the spider to see almost around itself. In addition to them, the spider has sensitive hairs on its legs, with which it “hears movement,” complementing the visual picture of the world.

Important!Brazilian banana spider- the most aggressive of the hunting species. Its poison is fatal to humans, and this hunter attacks any moving object.

Features of spider vision are:

• number of organs;
• each eye sees a separate picture, but for the spider it combines into one whole;
• different structures of the main and additional organs.

So, knowing the spider’s habitat and its species, we can draw conclusions about how many eyes it has and how it can see. Without such information, our understanding of arachnids will be far from complete.

The main phobia of many people is the fear of spiders. But these defenseless creatures do not cause any harm to humanity, and occasionally they can attack in defense. Only a few species in the world are capable of causing harm to humans.

Variety of spiders

As for species, there are about 40 thousand of these representatives of the arachnid class. And each of them is unique. And this is not the limit, since each species has its own subspecies, and the number of all arachnids can exceed a six-digit number.

Sensory organs

The spider's main sensory organ is its eyes. Depending on the species, the spider has its own pair of eyes, ranging from one to eight. Basically, many species have eight pupils, but there are also those that feel great with a pair of eyes, like common insects. As an example, the tarantula spider has four pairs, the cross spider has the same number, and the tarantula also does not differ in the number of eyes. Oddly enough, spiders have very excellent vision and can compete with their sharpness even with humans. The exception is those species that spend their entire lives in the dark; they do not need to have good eyesight. They are more guided by their paws, which have very sensitive hairs. This small detail is very important for the spider, since these hairs replace them with:

• ears (with the help of them they are even able to hear the direction of the wind, not to mention any sound);
• tongue (spiders don’t care how tasty the food is, they care whether it’s edible or not, and it’s the hairs that perform this function);
• nose (the sense of smell also lies on the feet).

After conducting many experiments, scientists came to the conclusion that some types of spiders are able to distinguish colors, which is not given even to dogs. The experiment consisted of the fact that the spider was asked to choose one fly between two areas of illumination: green and red, which was accompanied by electric shock. In repeated situations, the predator chose the fly under the green light.
Each individual has both main and lateral eyes. Each pair of them has a viewing circle of approximately 40%. Some types of spiders (for example, tarantulas) have a viewing angle of 360 degrees. If the spider noticed the prey with its side eyes, then before attacking, it will turn towards it with its main gaze.
As they say, “there are no eyes in the back of the head,” but this is by no means about our main characters. It doesn’t matter whether a spider has two, eight or sixteen eyes, in any case it will remain the same fearless, brave and courageous predator on Earth.

Most people on the planet are disgusted and wary of spiders, and some even fall into a panic stupor when they see them. In any case, these mysterious creatures always arouse keen interest, especially since some features of spiders have not yet been studied.

Representatives of arachnids are often mistakenly called insects, but in fact they are not. Spiders belong to ancient class arthropods, since they have 4 pairs of legs, and insects have only 3. The head of the spider merges into a single whole with the body, it contains eyes, the size of which corresponds to the size of the arthropod itself.

How many eyes does a spider have?

It is worth noting that the vision of arachnids is completely different. Cave spiders, for example, are completely blind, and many have vision that is almost no different from ours; they even recognize colors. Spiders also see ultraviolet light, which is impossible to see with our vision.

The number of eyes varies among all representatives of arthropods. But Most spiders have 6–8 eyes, distributed on the head in 2 rows. Only 2 eyes are primary, the rest are additional.

Unlike the main dark eyes, the additional ones are shiny, since in them the light is reflected from the inner shell. These eyes perform mainly protective functions that detect movement, thus helping the spider to avoid danger in time or quickly notice approaching prey. With such a powerful arsenal, the spider has a view of up to 30 centimeters, although it does not distinguish objects by size and shape.

Not long ago, researchers studying interesting view jumping spiders, another feature of the auxiliary eyes was discovered. During experiments with painting different eyes, it was possible to find out that the additional eyes closest to the main ones distinguish not only movement, but through them the spider can distinguish certain details. It turns out that the front lateral eyes have the main function of protection, since with them the spider can see a moving danger, and not just recognize the movement.

In general, the visual capabilities of arachnids are quite large and extensive. With all his eyes, he can see more than just in front of him. Thanks to the additional lateral ones, this interesting arthropod creature recreates a picture of everything that surrounds it from the side, behind and even above it. All the spider's eyes are a single integral observation system that allows its owner to survive in dangerous world and hunt successfully.

Video on the topic

How spiders see:

Amazing spiders - jumping spider:

The number of eyes depends on the location and method of hunting of the spider. Maximum 2 rows of 4 pieces for a total of 8.

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

Most spiders have 8 gases, which usually form 2 rows. It is worth considering that the main eyes do not have a mirror, that is, an internal, reflective shell. The lateral eyes have a mirror, but are always devoid of muscles.

Despite this, among 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 jumping spiders, on the contrary, see almost the same as a person, even though they can distinguish colors.

From 2 to 12 eyes various types spiders The most common spiders have 8 eyes. But with so many eyes, spiders cannot boast good eyesight, they can see the victim at best at a distance of 20-30 cm. But like all living creatures in this order there are exceptions - these are those that do not see anything at all in daylight - these are cave spiders, there are also those with vision which can be compared to humans are jumping spiders, 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 eyes. They are always dark in color. But the remaining pair of eyes, the so-called side ones, have a shiny 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, while 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 his other eyes he cannot examine objects, but they allow him to see all the movements that occur behind, to the side and even above him. The eyes of the same jumping spiders are able to distinguish the volume of objects, and from behind they 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 claim that there are a maximum of 12 eyes, and there are, like in a joke, and in which row. and they write that there are two in eight rows. But the most reliable source says from two to eight. So here are clear photos. These are ogre spiders.





It's impossible to say for sure. This depends on the species to which the alepod belongs. The average number is eight, but there may be 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 is two. Maximum quantity twelve eyes. Well, the spider basically has eight eyes, of which two are the main eyes.

The science to which this question relates is called arachnology. In the area once occupied by the union alone, almost three thousand species of spiders have been recorded. The spider's body consists of two main parts: the cephalothorax and abdomen. The eyes, about which the question itself is asked, are located on the front side, but their number is different. It is very rare to see the usual two eyes in spiders; the usual number of eyes is six or eight. The spider's brain is located in the center of the cephalothorax and occupies one third of the volume in size. But the most interesting is the way spiders hunt and the properties of the web that is used for hunting. The spider's web is one of the most durable materials and science is working on ways to produce such material artificially. The first attempts are successful.

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

Ecology

The eight-eyed jumping spider's field of vision is nearly 360 degrees, according to new research. Scientists have found that these “all-seeing spiders” can see humans perfectly and can also watch videos of nature.

This study attempted to describe how each of the spider's 8 eyes works. 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 spider, try to avoid people, and jumping spiders often look completely fearless, says the author of the study Elizabeth Jakob.“I doubt they'll confuse large objects like people with prey, but they're definitely interested in whether you're in danger.”

“If you start pulling a thread close to a spider, it is more likely to attack it, just like cats do when they attack a moving rope.”, added Jacob, a professor at the University of Massachusetts and a researcher in organismal and evolutionary biology.

She said there is a lot of misinformation on the Internet that the bite of these spiders is supposedly quite dangerous to humans. These creatures rarely bite a person, but even if this happens, you will get away with a slight scare 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 number of other tests to better understand how the visual system of these creatures works. Some spiders only have 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, said Jacob. – These eyes have a very unusual structure. They have large fixed lenses and a tiny boomerang-shaped retina that provides 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 back side a long moving tube inside the spider's head. The spider can move these tubes in order to scan everything around it. One of the researchers said that it looks like a spider is looking at its surroundings with a flashlight.

The remaining three pairs of eyes are called the minor or secondary eyes. They also have excellent vision and can distinguish movements well. Of these, one pair is directed forward and to the sides. Another pair is very tiny and also looks to the sides. Last pair located on the sides and back of the spider's head.

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

“If a spider stares at you, you can be sure it will be a jumping spider.”, said Jacob. These spiders react to their reflection in the mirror and can even watch videos of insects.

If you show spiders a video of a moving cricket, it will attack the screen. IN wildlife 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.

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