How a chameleon changes color and why, interesting reptile facts. Why does a chameleon change color? How exactly and with what help these lizards change color Why does a chameleon change color
Chameleons are one of the most unusual creatures that inhabit the planet. These reptiles attract attention primarily with their original ability to change color. Why do chameleons change color? In what cases do they resort to such metamorphoses? How do chameleons change color? We will consider the answers in our material, and also present some interesting facts about these amazing animals.
Mechanism of color change
Before telling why the chameleon changes color, I would like to say a few words about what makes this ability possible. The original function is due to the specific structure of animal skin tissues. Almost its entire surface is covered with special cells called chromatophores. The latter contain color pigments. Dyes are presented in the form of microscopic mobile grains.
Chromatophore cells can expand and contract. The result is a mixture of color pigments in individual combinations. If the grains are concentrated in the center of the cell, it acquires a light shade. When the pigments move to the periphery, dark colors are formed.
The deep and superficial layers of the skin contain different quantity chromatophore with separate combinations of dyes. This, in fact, explains the widest range of colors to which the chameleon changes color. Why do such animals resort to such unusual metamorphoses? We will talk about this further.
Why does a chameleon change its color?
Each of us is familiar with the statement that such reptiles change color in order to camouflage against the background of the surrounding area, trying to become invisible to predators. However, as the results of special studies show, this is nothing more than a delusion. In practice, such animals are not able to become monochrome on a white canvas. The same goes for the black background. In such situations, the shade of the body of the lizard will still remain somewhat contrasting.
So why does a chameleon actually change color? Scientists have found that such metamorphoses can occur under the influence of a number of emotional and physiological factors. First of all, it is worth noting the effect on the body of an animal of a certain temperature, lighting, humidity. Chameleons can change the shade with dehydration, pain, hunger, fear, aggression towards the enemy, the desire to attract the attention of the female.
Why do chameleons change skin color? The researchers found that a significant role here is played by what objects the animal's gaze is directed at. According to the results of experiments, when the optic nerve of a lizard is damaged, the ability to color metamorphoses is completely lost. This is due to the fact that the transformation of shades occurs only with a certain chain of actions. Getting on the retina of the eye of a chameleon, the light affects the nervous system. Signals are transmitted to the brain, and then to the chromatophores. Exposure of an animal to light of a certain intensity leads to a change in skin tone in a particular spectrum. The same thing happens if you irritate the body of a reptile with weak charges of electric current.
So we found out why the chameleon changes color. Contrary to popular belief, these lizards are not experts in camouflage. The color change serves other purposes.
What shades can the body of chameleons acquire?
More than 160 species of lizards that belong to the presented genus live on the planet. Most of them can only change color from green to brown. However, some reptiles have learned to convert body tones into the widest spectrum, ranging from white, yellow, orange to purple, pink, black. It is noteworthy that the color of chameleons does not change instantly. It usually takes up to a minute. After all, chromatophore cells take some time to contract and expand.
Chameleon vision
If we talk about interesting facts about these animals, special attention deserves extraordinary vision. Chameleons are able to rotate their eyes at an angle of 360 degrees, covering any surrounding objects. Moreover, the visual organs can rotate independently of each other. When necessary, the eyes focus on individual objects on both sides of the body. Focusing of vision in one direction occurs during the hunting of a chameleon. Thus, the lizard gets the opportunity to notice potential prey at a distance of more than 10 meters.
Hearing
As you can see, with the eyesight of such reptiles everything is in order. However, what about the perception of the sounds of the surrounding world? With hearing, such lizards were less fortunate. Like other reptiles, such as snakes, chameleons lack a middle ear. For this reason, they do not recognize most sounds. However, it cannot be argued that these lizards are deaf. In fact, their hearing is limited to a frequency range between 200 and 600 hertz.
Food
An interesting fact is that chameleons have an extremely long ballistic tongue. In most species, its dimensions exceed the parameters of the body. At the end of the tongue there is a so-called trapping sucker. During the search for food, the chameleon takes a fixed position in ambush. The rotation of the eyes in different directions allows the lizard to notice the insect. At the moment of attack, the chameleon rapidly throws out a ballistic tongue in the direction of the victim. The process of capturing and pulling prey into the mouth takes a fraction of a second.
The diet of chameleons is made up of butterflies, beetles, grasshoppers and crickets. The largest representatives of the genus of lizards are able to hunt birds and rodents. During periods of food scarcity, chameleons may consume small fruits and tree leaves.
Dimensions
An amazing fact is that the body parameters of lizards that belong to this genus vary considerably. The smallest chameleons on the planet are representatives of the species Brookesia micra. Adults can only grow up to 15 millimeters. As for the largest chameleons, these are the lizards of the species Furcifer oustaleti. Their maximum dimensions are about 70 centimeters.
Most people associate the word "chameleon" with the ability to change the color of the body. Actually, this skill made him stand out among other lizards and made him so popular.
Contrary to popular belief, the chameleon changes color not only to camouflage the environment. A number of other factors can also be distinguished: physiological (humidity and temperature, lighting) and emotional (aggression, fear mating season).
Many centuries have passed until scientists managed to solve the riddle of the chameleon, find out and study the nature of its ability.
Examining the skin of a lizard under a microscope, biologists have identified special pigment cells - chromatophores. They are located on the surface of the skin in two layers, can stretch, contract and have a complex mechanism of work, closely related to the nervous system.
The chromatophores contain grains of pigments of different colors (dark brown, reddish, yellow and black). When cells contract, the skin turns blue, and when stretched, first green and then yellow. If both layers of chromatophore contract simultaneously, the lower layer of white cells without pigments opens and the skin of the lizard appears pale.
Red color gives the skin a separate group of cells that can become lighter or darker depending on the location of melanin granules in them, the same pigment that in humans is responsible for the color of the skin, hair and iris.
Some believe that chameleons are able to take on any color or ornament when disguised, but this is not entirely true. A chameleon will not turn black and white in a cage if it lies on a chessboard. Possible color combinations and skin brightness for each separate species different, but always varies within a limited range.
To people watching chameleons, it may seem that these reptiles change color deliberately, "fitting" themselves to the color. environment. In this case, one would have to admit that chameleons have self-consciousness and an abstract, which is not expected from.
Mechanism of color change
The color change of males during the mating season becomes especially bright and unpredictable. This is not only a way to attract the attention of females, but also a threat addressed to rivals.
Such patterns of color change in chameleons suggest that color variations are controlled by the nervous system. The mechanisms of nervous regulation of the activity of chromatophores are not fully understood, but they play a certain role: if one eye is removed from a chameleon, the corresponding half of the body loses its ability to change color.
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- Why does a chameleon change color
Fish, insects, and reptiles can also disguise themselves by changing their color. One of the most famous lizards that can radically change the color of their body in a given situation is the chameleon.
Instruction
Chameleons are the inhabitants of the sultry continent called Africa. They are now common in South India and Southern Europe, as well as in Madagascar, Hawaii and Sri Lanka. Chameleon is unique! Not only does he have the incredible ability to change the color of his skin, but also his eyes, covered with fused eyelids, live their own. own life, turning in different directions, independently of each other. In addition, these lizards can spend hours on the branches of trees, waiting for their prey. As soon as one or another insect enters the field of view of the chameleon, he immediately, without hesitation, grabs it with his long and sticky tongue.
This reptile is widely known for its unique ability to miraculously change the color of its skin. It is curious that a lizard up to 30 cm long can skillfully disguise itself, becoming either red, then black, then blue, then yellow. Scientists, doing research on chameleons, tried to find out how these lizards change the color of their skin. Initially, it was assumed that chameleons simply like to adapt to the background surrounding them, considering it their duty. This assumption turned out to be incorrect.
According to modern research, chameleons change the color of their skin depending on their condition: the mood of the animal can affect the color change, it can be a reaction to fear or joy, it can also depend on the ambient temperature. Zoologists have found that the color of your body changes thanks to special cells - chromatophores. The fact is that the skin of this lizard is quite transparent, therefore, containing pigments of different colors, they are well traced.
Grains of chromatophores contain grains of several pigments at once: red, yellow, black and dark brown. If the segments of these cells begin to shrink, then there is a redistribution of pigments, the concentration of which increases sharply. In this case, the skin of the reptile becomes light (for example, yellowish or white). If one of the dark pigments is reduced, then the skin of the chameleon becomes dark. It is curious that such a reduction occurs on different levels, which allows you to bring combinations of certain pigments to a completely different shades.
It takes no more than two seconds to change the skin color of a lizard! For a long time the researchers assumed that chameleons change color only for camouflage: for example, by painting in green color, the lizard can hide in the grass or in the foliage. However, this assumption turned out to be only half true. The fact is that chameleons change their color not only for disguise, but also for their own personal purposes. For example, some chameleons that live in sultry Africa turn black in the morning. This allows them to attract the rays of the sun. During the day, they become light, so as not to suffer from the heat. These lizards use a variety of variegated colors in their marriage games to attract a partner. It has been scientifically proven that these animals do not pay attention to the background around them at all. It is curious that in the process of evolution, some species of chameleons generally learned to copy the color of their own - birds and snakes.
Chameleons are amazing animals. Their roots go far into antiquity, they lived in the time of the dinosaurs. These animals have gained popularity due to amazing ability- change skin color.
Instruction
Chameleons - inhabitants of the savannas, deserts, rainforest and steppes. They mostly live in trees and less often on the ground. Chameleons have the ability to change skin color to a wide variety of shades: pink, green, black, yellow. The special structure of the skin allows chameleons to change color. In the deep layer of the skin there are special branched cells - chromatophores. They are reflective and contain grains of pigments of different colors: yellow, red, black, brown. Chromatophores are also present in reptiles, fish, and amphibians. Cells have a complex mechanism of work associated with the nervous system. The cells of the upper layer contain red and yellow pigment, further goes layer guanine is a colorless crystalline substance, melanophores containing a black pigment are located even deeper. Depending on the incoming signal nervous system the distribution of pigment granules occurs, they mix, forming new colors.
The chameleon changes color depending on the environment, when experiencing feelings of hunger, fear, aggression. Temperature, humidity, light also determine the color of the animal. Most often, the skin color harmonizes well with the surroundings, with the background of the habitat, to disguise the chameleon. Another reason for color change is communication with their relatives. During the period, the skin color becomes bright to attract the female, but aggression is accompanied by a dark color. If two chameleons do not share the territory, then they begin to compete with each other. The first stage of the competition for a place in the sun is to color the skin. The male who will be brighter than his relative is confident.
Desert dwellers use their peculiarity to absorb sunlight. In the morning, the color is black to absorb as much heat as possible, and in the afternoon they become light gray to reflect Sun rays. The color can also change only in certain areas, then multi-colored stripes or spots cover the body of the chameleon. It is a mistake to think that a chameleon can take on absolutely all colors and patterns. It changes its color in the range laid down in the physiology of the animal. Chameleon owners love to experiment with them. If you put a chameleon on a chessboard, then it will not be in a black and white box.
note
The pigment granules can move very quickly, instantly changing the color of the chameleon's skin.
Some varieties of chameleons take on the color of their opponents (snakes, birds), which are dangerous.
Amazing animals - chameleons. With its ability to different situations change color they attracted the attention of scientists and ordinary people. There is a widespread belief that a chameleon changes its color depending on the background where it is located. But this is far from true.
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 gained the greatest fame due to their unique ability 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 color play by the “suffering 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 disguise, believing that the reptile changes skin color while masquerading as surrounding area and items. 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 at its best the color of the reptile appears when meeting with 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, unfavourable conditions content, 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 long time behind the chameleon, you will learn to understand what your pet wants to express by 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 special structure skin covers. 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 different types can change the color palette in a fairly wide range, but only within the limits allotted 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 colors. 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 at rest, when frightened or angry, yemeni chameleon may 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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Chameleons famous for being able to almost instantly change their color and seem to dissolve in the vegetation thanks to high-tech photonic crystals on the surface of their colorless skin cells, the refractive properties of which they can control.
For a long time, researchers wondered how a chameleon - in general, a nondescript and slow animal - succeeds so well.
Research done with males Madagascar panther chameleon(Furcifer pardalis) showed that in the process of meeting and communicating with females and other males, they change color from blue-green and green to bright red in just a few minutes.
Scientists provoked male chameleons to "duel" with each other and measured the color saturation using a spectrometer, which made it possible to record radiation not only in the visible, but also in the ultraviolet part of the spectrum.
The use of such a device showed the ability of chameleons to "color" also in colors invisible to the human eye.
Photo 1. Chameleons change color not only for masking
According to the results of the experiment, no particular relationship was found between the range of colors used and the habitat of chameleons.
The greatest scatter of coloration was observed in species with the most pronounced social behavior(in this case, the competition of two males), and not in species living in places with large quantity multicolored objects (grass, tree trunks, ).
Coloring chameleons that use maximum amount colors, turned out to be the most noticeable not only for their relatives, but also for, which contradicts the theory of color change only for masking.
However, predators often fail to attack brightly colored individuals, because they the slightest sign dangers are able to “dissolve” against the background of the environment in a few milliseconds.
Further studies have shown that the change in color is associated with special cells within the skin - chromatophores that redistribute grains of pigments of four colors.
These pigments absorb visible light at all wavelengths except for a specific one (red, for example).
Iridophores and xanthophores
Recently, Michel Milinkovitch of the University of Geneva found that it is even more important for chameleons iridophores- cells that do not absorb light, but transform the geometric structure of the skin surface, causing it to bend or reflect certain waves.
M. Milinkovich and his colleagues studied the skin of chameleons using transmission electron microscopy and found two layers of iridophores there.
The top layer was covered with guanine nanocrystals laid out in the form of a clearly structured lattice.
Photo 2. The surface of the skin of chameleons is dotted with special cells - iridophores
The distances between individual crystals in the lattice play a key role in color change: when males are in an excited state, the spacing increases.
The greater the distance, the stronger the reflection of light with a longer wavelength (red).
As the crystals approach each other, blue light begins to be reflected.
Then the chameleons are helped already xanthophores(yellow pigment cells): they make Blue colour green, and red - orange or yellow.
Milinkovic also discovered a second level of skin with iridophores arranged in a more chaotic way. They reflect light very well in the near infrared range.
In the hot and humid environments where chameleons live, these crystals are an important protection mechanism against overheating. This structure of the skin, apparently, is unique.
However, only chameleons masterfully use not only skin pigments, but also photonic nanocrystals, which allow them to control light with extreme precision.
How chameleons can help science
Now researchers are considering how the information they have obtained can be applied in practice, for example, in the development of new means and methods of camouflage. And something has already come up.
So, scientists from the University of California at Berkeley have created an ultra-thin material that can change color at the nanoscale, like the skin of a chameleon, depending on tension, bending or pressure.
Majority color natural materials(as well as paints, fabrics) depends on their chemical composition.
Photo 4. The study of chameleons helps to develop nanotechnology
When White light hits the surface of these materials, a certain wavelength of light is absorbed, and the rest is reflected back into the surrounding space.
Because of this, we perceive certain colors. A change in color thus requires a change in the chemical composition of the material.
The invention of the Americans takes a different approach to creating color.
The material is made using the so-called structural coloring. That is, the color of the surface (absorbed and reflected waves) determines the structure of the material.
This is not a new phenomenon - nature thus creates iridescent overflows of feathers, butterfly wings or beetle exoskeletons.
As early as 300 years ago, he suggested that some structural staining methods could be used in industrial and commercial production.
Chameleon faux leather
Here's how it works artificial leather chameleon.
A silicon film, which is 1000 times thinner than a human (about 120 nm), is attached to a layer of silicone, and then tiny (less than a wavelength of light) fins are applied to it.
The silicon layer is so flexible that it can be compared to skin, and it can be attached to almost any surface.
Variable distance between corrugated ribs, or micro-corrugations, allows you to get different colors.
In addition, the material has a high ability. It reflects up to 83% of the incident light, so that in fact the artificial skin is as bright as the skin of a real chameleon.
Photo 5. Chameleons are unsurpassed masters of disguise
The material produces pure colors ranging from green to yellow, orange and red. And also new material turned out to be much lighter and easier than it turned out before.
This is the first time anyone has been able to make a flexible structure like chameleon skin that can change color simply by bending.
If you have a surface with certain structures arranged in such a way as to interact with certain wavelengths of light, you can change its color, affecting both its properties and dimensions.
The developers believe that the silicon-based material can be used in the manufacture of energy-saving color displays, various camouflage materials and coatings.
And they can also be used to visually display structural wear and tear on buildings, bridges, wings and other important structures (when a crack appears, the tension of the material changes slightly, which means that even minor cracks will become more visible to the human eye).
The researchers have also been able to create a fabric that can change color depending on how it is folded.
The semiconductor silicon became the basis for this material.
In the smallest cuts on its surface, scientists also inserted silicone particles 120 nm wide, which are able to reflect waves of different spectra and, accordingly, be painted in different colors- green, yellow, red or orange.
The color that the fabric will be dyed depends on how it is bent or folded, and it changes instantly.
Well, in broad sense we are talking about creating materials that will completely change the face of our world.
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