How a chameleon mechanism changes color. How does a chameleon change color? Paint chameleon "marshmallow". basic colors: fuchsia, lime, gold, yellow, gray, purple

The study involved male Madagascar panther chameleon (Furcifer pardalis), which can change color from blue-green to bright red and back in a few minutes. It is known that color change is associated with the work of special skin cells - chromatophores, redistributing pigments of four colors. Pigments reflect visible light in a narrow spectral range, but now scientists have found that iridophores, cells that do not absorb light, but reflect it, are much more important for chameleons.

The skin of chameleons was carefully studied using an electron microscope and found two layers of iridophores in it, with the top layer containing guanine nanocrystals organized in a clearly structured lattice. The grating pitch (the distance between the crystals) plays a key role in the color change - when it increases, the maximum wavelength of the reflected light shifts to the long-wavelength (red) region, and when it decreases, it shifts to the short-wavelength (blue) region. By changing the grid spacing by stretching or shortening the layer of iridophores, chameleons adjust the color to the environment.

Chameleons also have a second, deeper layer of iridophores, with a large lattice pitch of nanocrystals. The reflection maximum of this layer is in the infrared region of the spectrum. Presumably, this layer in chameleons is an important protection mechanism against overheating in hot conditions. Scientists suggest that a similar mechanism can be used to create new artificial materials that can change color.

Chameleons are one of the most unusual animals on Earth: they communicate by changing color, they kill the victim with lightning speed by shooting their tongue, and they live in places that are not easy to get to and which, unfortunately, will soon change beyond recognition due to human activities.

There is hardly an animal that can compete with a chameleon in the number of anatomical curiosities. These lizards have a tongue longer than their body, and with its help they are able to get their own food in a split second with one “shot” - to catch and kill some insect. Chameleons have excellent eyesight, their telescopic eyes can rotate independently of each other. Terrible “horns” protrude directly above the eyes, and the fingers have become like claws and serve to firmly grip the branches on which these lizards spend their whole lives. But among all the variety of bright features, there is one that distinguishes chameleons from other lizards - this is the ability to change color. The widespread belief that chameleons take on the color of the surface they are on is actually not entirely true. Of course, in some situations, the ability to mimic comes in handy, but basically chameleons resort to color changes to communicate with each other and with the outside world. By changing color, these lizards indicate their state: readiness for mating, threat to the enemy or stress. “Chameleons have long attracted the attention of researchers, but despite this, not all of their mysteries have been solved,” says Christopher Anderson, an expert on these lizards from Brown University in Providence. “We are still trying to figure out in detail how they work – how they shoot with their tongue while hunting and how they change color.”

About 40 percent of the more than 200 species of chameleons known to science inhabit Madagascar, almost all the rest live on the territory of continental Africa. With the help of DNA tests, it was possible to isolate several new species, although in appearance their representatives practically did not differ from those known before. More than 20 percent of the species have been identified in the last 15 years. Unfortunately, the future of these amazing creatures in nature is far from rosy. In November last year, the International Union for Conservation of Nature (IUCN) Red List included more than half of the chameleon species under the status of "threatened" or "close to vulnerable." Anderson is a member of the IUCN Chameleon Panel. Christopher studied in detail the hunting skills of his wards. Using a 3,000 fps camera, he captured a chameleon eating a cricket. In reality, everything happens in 0.56 seconds - in the recording, the hunt lasts 28 seconds, and with the help of the camera, the operation of the "trigger" of the lizard's tongue was disassembled in great detail.

Christian Ziegler The insect fell victim to a chameleon from the genus Calumma who decided to feast on it. Thanks to sharp eyesight, the lizard manages to direct the “shot” of its long tongue with a wet sucker at the tip with jewelry accuracy.

The hyoid bone of the chameleon is surrounded by elastic collagen tissue and is located in the annular "trigger" muscle. As soon as the lizard aims at the prey, it slightly sticks out its tongue, the trigger muscle compresses this bone, and the tongue, previously gathered in a tight fold, abruptly slides off it, straightening like a spring. The tip of the tongue is shaped like a sucker, and the victim sticks tightly to its wet surface. The tongue retracts and - the dish is on the table! Regarding color control mechanisms, then the work of geneticist and biophysicist Michel Milinkovich, published this year, turned the recent ideas of scientists upside down. For many years it was believed that the change in color of a chameleon occurs due to the spread of pigments along special processes of skin cells. Michel argues that this assumption is not convincing, because in nature there are many green individuals whose skin lacks green pigments. Milinkovic and colleagues from the University of Geneva found another layer of cells under the pigment cells, which contain nanocrystals arranged in a triangular lattice. It turned out that under pressure and exposure to chemical compounds, these crystals become manageable: when the distance between them changes, the color reflected by the skin also changes. With an increase in the gap between the "chameleon" crystals, the gamma shifts from the blue part of the spectrum to the green and further - up to the red. Nick Henn, an amateur breeder from Pennsylvania, had his first chameleon when he was seven years old. In twenty years, Henn's collection has grown to two hundred individuals who live in his basement in Reading.

Cages placed in a row are filled with plants, on which lizards climb with pleasure. At the bottom there is a decent layer of sand so that the females can lay their eggs. Humidity and light are adjusted to recreate the natural environment for the animals. Correctly arranging the cages is a more difficult task than seating the delegations of warring countries at the UN assembly. Animals once again should not cause aggression in each other, so Henn placed the females so that they did not see the males, and the males so that neither females nor warlike rivals fell into their field of view. Amber, a young panther chameleon, belongs to a species that inhabits the Ambilobe region in northern Madagascar. Its body is decorated with red and green stripes, on the sides of the lizard bordered in light blue. When Henn, having opened the cage, began to push Amber with a long stick, the chameleon began to “wind up”. It was easy to notice - the red stripes suddenly filled up and became noticeably brighter.

The widespread belief that chameleons take on the color of the surface they are on is actually not entirely true.

Nick put Amber in the next cage, where Bolt, the blue-striped panther chameleon, the largest in Henn's collection, was in charge. Bolt's reaction to the intruder was not long in coming: as soon as Nick opened the cage, the owner moved forward a few centimeters, and his green stripes turned bright yellow, and his eye sockets, throat and spikes on his back turned from green to orange-red. Amber also blushed a little, but the further, the more he was inferior in the “battle of colors” to the enemy, who literally spewed out the entire palette. And this is not enough for Bolt: getting closer, he opened his mouth, showing a bright yellow mucous membrane. Henn sends Amber home. “If left to chance, Bolt will start to shove and even bite Amber until he turns brown, the way chameleons throw the white flag in a duel,” says Henn. A 2014 study showed that these lizards have evolved the ability to take on a dull brown “obedience color” due to their slowness – it does not allow them to flee from the winner in a fight.

Photo: Coracoid outgrowths adorn the muzzle of Parson's chameleon - one of the largest species. By these outgrowths, lizards recognize "their own", they are also suitable as a formidable weapon in a duel for a female. Author: Christian Ziegler">

Beak-shaped outgrowths adorn the muzzle of Parson's chameleon - one of the largest species. By these outgrowths, lizards recognize "their own", they are also suitable as a formidable weapon in a duel for a female.

Photo: Beak-shaped outgrowths adorn the muzzle of a long-nosed chameleon. By these outgrowths, lizards recognize "their own", they are also suitable as a formidable weapon in a duel for a female. Author: Christian Ziegler">

Beak-shaped outgrowths adorn the muzzle of a long-nosed chameleon. By these outgrowths, lizards recognize "their own", they are also suitable as a formidable weapon in a duel for a female.

Photo: Two male panther chameleons have just completed a fight for a female. It is not difficult to determine the winner: it shimmers in the sun. His opponent is in mourning. Author: Christian Ziegler">

Two male panther chameleons have just completed a fight for a female. It is not difficult to determine the winner: it shimmers in the sun. His opponent is in mourning.

Some types of chameleons, although they change color, do not do it clearly enough to intimidate the enemy. Then other methods come to the rescue - lizards compress the body, and then straighten the ribs at the joints in order to push the spine up and “grow” due to this. Another trick to make you look more imposing is to curl your long ponytail tightly into a ball and use your tongue muscles to puff out your throat. Turning, after all these metamorphoses, sideways to the enemy, the chameleon seems much larger. One of Henn's favorites - a lizard named Katy Perry (that's the name of the American pop star. - Approx. Ed.) - has taken on a pink-red hue, signaling to its relatives that it is ready to mate. Her neighbor, named Pinat, is also pink, but with dark stripes on her body, which means that she is already bearing offspring. If Cathy comes across a male who can impress her with his bright colors and spectacular mating dance, she may well agree to prolong his lineage. If the same male meets on the way of Pinat, it will immediately darken all over, and bright spots will appear against this background. For a particularly dull boyfriend, the lizard will open its mouth menacingly, begin to hiss and try to bite him. Both male and female chameleons are polygamous (mating with multiple partners). Most species lay eggs, which hatch into young, and in some, children are born alive in transparent sacs that resemble cocoons. Chameleons do not bother raising babies, so they are left to their own devices from the first days of life. Since these animals spend most of their time in trees, in order to hide from prying eyes, it is enough for them to cower and topple over on the underside of a branch. And once on the ground, lizards, at the sight of a predator, try to pretend to be one of the leaves, of which there are so many around.

Christian Ziegler The life cycle of the Labora chameleon lasts about a year. Some chameleon species can live up to ten years in captivity. In the natural environment, they do not live even half of this period.

But chameleons cannot cope with the main enemy- Human agricultural activity ruthlessly destroys their habitual habitat. 9 species listed in the IUCN Red List are on the verge of extinction, 37 are endangered, 20 are vulnerable and another 35 are close to the status of vulnerable. Biologist Crystal Tolly, like Christopher Anderson, is on the IUCN Chameleon Expert Group. Since 2006, in South Africa, Mozambique, Tanzania and the Democratic Republic of the Congo, Tolly's team of scientists has discovered 11 new chameleon species. Cristal is from Massachusetts and has been studying lizards for 15 years under the auspices of the National African Institute for Biological Diversity in Cape Town. “When genetic analysis confirms that the individual you found is a representative of a new species, the feelings are simply overwhelmed,” Tolly says enthusiastically. - Not like when you write an article that no one will read later. Here it is a completely different matter - your discovery becomes part of scientific knowledge for centuries! Sighing, Krystal continues, “But as soon as the euphoria subsides a little, the terrible reality again comes to the fore. A picture of industrial deforestation rises before our eyes. In the branches of trees falling to the ground, my tiny pets try to find shelter. Sometimes I think it would be better for them to remain unknown to science. After all, if a person does not stop, very soon they will all die out.

What are your first associations with the word chameleon? I think most people, when answering this question, will converge in the options "color change" and "shoots the tongue." It is the ability to quickly change the color and pattern of the skin that the chameleon owes its fame among people!

Contrary to legend, a chameleon does not disguise itself as an environment by changing color. They change color depending on temperature, light and mood. This is a unique ability of the body, which is not possessed by many reptiles, insects and fish.

We noticed this feature a long time ago, even in antiquity, but many centuries passed until we understood how this happens. Scientists (P. Baer, ​​Brücke, Krukenberg) helped to unravel why the chameleon changes its color. Under a microscope, they managed to find out the nature of such a phenomenon.

So, why does a chameleon manage to change its color pattern so quickly? What is this secret?

It's all about the amazing pigment cells - chromatophores! Chromatophores, which in Greek means “carrying paint”, really have a complex mechanism of work and are closely related to the nervous system of a chameleon. These cells contain colored substances in the cytoplasm - pigments, thereby causing the color of the cover of chameleons. Among the main types of pigment cells, the following can be distinguished: melanocytes and melanophores, containing in organelles - melanosomes - various modifications of melanin (from yellow to almost black); xanthophores containing carotenoids, flavins and pteridins (from yellow to red), localized in organelles - pterinosomes - or in the form of droplets in the cytoplasm; iridocytes, or guanophores, containing crystals of guanidine, sometimes causing even a brilliant silver or golden color.

In order not to go deep into the description of cellular physiology, we will briefly describe the very process of the work of these cells. Chromatophores are located in the outer - fibrous and deeper layer of the skin of a chameleon, they are branched cells with grains of dark brown, black, reddish and yellow pigment in them.

In some chromatophores, there are many such grains, while in others there are few. In those places where there are more such cells, the color is brighter, and vice versa, respectively. But it's not just the amount of pigment. It is also important how it is located in the cage! The pigment can be scattered throughout the chromatophore, located in all its branches, or can be collected in one pile in the middle of the cell. Pigment grains are not attached to a permanent place, they can move along the chromatophore.

When the processes of chromatophores contract, the pigment grains are concentrated in the center of the cells and the skin looks whitish or yellow. When the dark pigment is concentrated in the branches of the chromatophore, the skin acquires a dark, almost black color. The appearance of different shades is caused by a combination of pigments from both layers. Green tones additionally arise as a result of the refraction of rays in the surface layer, which contains many guanidine crystals that strongly refract light. As a result, the color can quickly change from whitish and orange, through yellow and green to purple, dark brown and black, and these changes can capture both the entire body and its individual parts and be accompanied by the appearance and disappearance of various kinds of stripes and spots. Moreover, the chromatophores themselves can then sink into the depths of the skin - and then the skin turns pale, then approach its surface - and the skin becomes more contrast and bright.

All of the above changes in color occur under the influence of factors and stimuli that can be divided into two main groups: physiological factors (temperature, lighting, humidity, hunger, dehydration, pain) and emotional stimuli (fear or aggression when meeting a male or female chameleon or other animal).

A vivid example of these processes is the rapid color changes in male chameleons during the breeding season and during fights, when they try to turn their brightly colored body sides towards each other. As if demonstrating his superiority over his opponent.

I want to note the special influence of light on the camele's camouflage system. Scientists have found that there is a close relationship between the vision of a chameleon and its ability to change color. The visual system - this is where the signal chain is tied that transmits commands to the cells. In the course of research, it was found that the ability to change color is lost when the optic nerve is damaged. This means that light through the eyes acts on the nervous system and only through it on the chromatophores. Nerves run from the brain to the chromatophores. It is through them that commands are received to change the shape and location of the chromatophores in the layers of the skin.

In the course of research and experiments, the following paradoxical facts and patterns were revealed:

• When stimulated by visual impressions or during electrical stimulation of the central segment of the optic nerve, a darkening was noticed first of some parts, and then of the whole body.
• When the eye apparatus is removed, the corresponding half of the chameleon's body brightens.
• Electrical stimulation of the spinal cord causes enlightenment, and its removal causes darkening.
• When anesthetized with ether, also during sleep, and when dying, the animal brightens, acquiring light gentle tones, and when anesthetized by the action of chloroform, it darkens.

To explain these sometimes contradictory data, scientists adopted the hypothesis that there are two kinds of centers in the central nervous system of a chameleon: volitional and automatic.

Automatic centers maintain a certain tone of the color-changing system, and when irritated cause skin lightening, but these centers are dependent on volitional centers, which have an overwhelming effect on them and, consequently, cause the opposite effect, i.e., darkening. The nerves that transmit commands from the central nervous system to the chromatophores are located together with the motor nerves, and irritation of these latter causes skin lightening, while the weakening of the peripheral endings during poisoning with curare causes, on the contrary, darkening.

Thus, the excitation of the automatic centers and the nerves coming from them is accompanied by enlightenment in the chameleon, which is the result of the contractile activity of the protoplasm of the chromatophores, because the shape of the cell itself does not change. Arbitrary color change is possible, of course, provided that the brain is intact and disappears when the hemispheres, cerebellum, and other parts are removed. (P. Baer, ​​Brucke, Krukenberg).

Such a complex mechanism determines the color behavior of the chameleon that surprises us all! As I said earlier, other representatives of the living world also have such mimicry - stick insects, flounder, etc. But another intriguing feature of this reptile, which no one else has, is its language, which can instantly overtake and capture the victim of a chameleon! But more on that next time!

Exotic, peculiar, mysterious, supernatural ... This is how a chameleon can be characterized. He lives on the same planet as us, but looks like he came from outer space. Either a small dinosaur, or an alien. Otherwise, you can’t say about a chameleon ...Everyone has probably heard about these reptiles, butChameleons are best known for their unique ability to change skin color.

Chameleons have always aroused people's interest. Back in 48 BC. e. The chameleon was described by Aristotle noting that the color changes when it puffs up. And the ancient Roman scientist Pliny mistakenly associated the change in color solely with the background. In the 17th century, the German scientist Wormius explained the play of colors by the "sufferings and experiences" of the chameleon. Perhaps Wormius flattered the animal somewhat, calling its simple mental activity "experiences", but it turned out that he was closest to the truth.

What causes a change in skin color in a chameleon?

People tend to associate the chameleon with cunning and camouflage, believing that the reptile changes skin color to camouflage itself with its surroundings and objects. You will be disappointed, but this is nothing more than a myth. Their ability to change color is of a completely different nature. First of all, the ability to change color is a kind of communication. In this way, a chameleon communicates with its own kind. At its best, the color of the reptile appears when it meets another male. When this happens, they inflate the larynx and increase in size, as if inflated, and they can only inflate one side. Their color becomes much brighter. This is a kind of competition between two "gentlemen". Most often, a larger chameleon is perceived as dominant, and sometimes they pounce on each other with their mouths wide open. They fight until one of them retreats. When meeting with a female, the color will be the same, but the chameleon will not swell in the presence of a lady.

Thus, animals change colors when they want to be noticed, declaring the boundaries of their territory to other males, or, conversely, attracting brides. Of course, they can hide perfectly among the foliage, but usually, when a reptile changes color, it tries to stand out.

The color of the chameleon also changes depending on the state of his body. Changes in temperature, lighting and humidity, adverse conditions of detention, illness, hunger, dehydration, anger, fear, stress - all these factors also affect the color of the animal's skin. If the chameleon is under stress, it will be darker tones. In a word, a change in the color of a chameleon is a signal that something has happened that falls outside the scope of “normality” in the understanding of the animal.

Important: chameleons need to be protected from stress in every possible way. You should not bully the chameleon, show him other animals, often transplant to other places. Stress will be expressed not only in a change in color, but also in the refusal of food. In general, chameleons are not stress-resistant animals. Remember that the worst thing for reptiles is stress. Stress can end badly. Frequent deaths.

Watching a chameleon for a long time, you will learn to understand what your pet wants to express, changing color. And if the color of a chameleon suddenly coincides with the background surrounding it, then this is an accident, and nothing more.

How does a chameleon change color? Mechanism of color change

Zoologists have found that the chameleon is able to change color due to the special structure of the skin. In the outer and deeper layer of the skin of a reptile there are light-reflecting cells - chromatophores. They contain grains of black, red, yellow and dark brown pigments. When the processes of chromatoforms contract, the grains of pigments are distributed in their center, and the skin of the animal acquires a whitish or yellow color. If the dark pigment is concentrated in the outer layer, then the skin becomes dark in color. By combining pigments, various color shades appear. Thanks to this mechanism, the color "palette" of the reptile is very saturated.

The color of a chameleon can instantly change from light to purple, then to black and dark brown. The color changes both throughout the body and in its individual areas, accompanied by the appearance or disappearance of stripes or spots of various colors.

Green is the main color for chameleons. There are also yellow, gray and brown animals.

Chameleon colors

There is an opinion that the descendants of dinosaurs can be painted in any color, but this is not so. Chameleons of different species can change the color palette in a fairly wide range, but only within the limits reserved for this particular species. Under the influence of the above factors, the reptile is able to change colors and acquire new shades, but within its own color range. So, for example, in just a second, a male from green can turn orange or red. These same chameleons, falling asleep, turn pale yellow, pink or red. Or, take, for example, the Yemeni chameleon. Green when calm, when scared or angry, the Yemeni chameleon can turn black with yellow and green spots.

It is easy to guess that when keeping a chameleon at home, he has no particular reason to change skin color. You will not intentionally frighten the ward or keep him in unfavorable conditions. Therefore, you should not count on the fact that your home dinosaur will constantly shimmer in different colors, like a New Year's garland.

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Chameleon is an inhabitant of sultry Africa, who gained fame thanks to the unique ability to change skin color. This small lizard, only 30 cm long, can transform itself, becoming black, pink, green, blue, red, yellow. Many scientists have conducted various studies to find out how the chameleon changes color, and what it is connected with. It was assumed that in this way he disguises himself under the background surrounding him. But this turned out to be an incorrect assumption.

This lizard is unique in itself. She looks like a dragon, often changes skin color, sits for hours on the branches of trees, waiting for the victim, which she captures with her long tongue. Her eyes live a separate life, turning in different directions. The chameleon changes color thanks to special cells - chromatophores. His skin is transparent, which is why cells containing pigment of different colors are so clearly visible.

For a long time, researchers could not understand how a chameleon changes color, and why this happens. It was assumed that he needed this for disguise. After all, having painted, for example, in a lizard, it can disguise itself in foliage, hiding from predators and waiting for its victims. Indeed, in the course of evolution, many chameleons have learned to acquire the color and pattern of their enemy - for example, birds or snakes.

Modern research has shown that the process of how a chameleon changes color depends entirely on its condition. Skin color varies from mood changes - reactions such as fear or joy. It may even depend on the air temperature. In Africa, many chameleons get in the morning to attract, but brighten in the afternoon so that it is not so hot. They use variegated colors in mating games, in order to attract a representative of the opposite side.

Chromatophores in chameleons are located in the deep layers of the skin and are directly dependent on the nervous system. In the upper layer are cells containing red and yellow pigments. Next is guanine, which reproduces the blue color very accurately. Beneath it are melanophores responsible for black and yellow pigments and containing melanin. The way the pigment granules are arranged in the cell completely affects the color. The chameleon is a very interesting animal. After all, the pigments in its cells move very quickly, changing color. If they are concentrated in the center of the cell, then it will remain transparent, and if they are evenly distributed over it, then they will be painted in an intense color.

Nerve endings connect chromatophores to the brain, from where commands for change come. The way a chameleon changes color can be compared to a palette in which colors, mixed up, create completely new shades. Due to its ability to change skin color, this lizard has gained immense popularity. Today, other things that shimmer in different shades or change them are called chameleons.

Although it seems that by changing color, the lizard wants to disguise itself, this is not so. She doesn't care about the background at all. Skin color is influenced by mood, emotions experienced, air temperature, but not by the environment. Therefore, the opinion that when a chameleon is on it, black and white cells will appear on it, is fundamentally wrong.