How a chameleon changes color. How a chameleon changes color and why, interesting facts about the reptile

How does a chameleon change color?

Probably everyone has ever heard about a chameleon, and more than once wondered how a chameleon changes color. Chameleons are very amazing animals, whose roots go back to ancient times. The first chameleons lived 100 million years ago, at the same time as dinosaurs.

How a chameleon changes color

Chameleons are best known for their ability to change skin color. But not many people know how this process happens. The change in color of a chameleon is associated with the structure of its skin. In the deeper outer fibrous layer of the skin there are special branched cells called chromatophores. Chromatophores are light-reflecting cells that are present in reptiles, fish, amphibians, and cephalopods, which contain grains of pigments of different colors:

• black
• red
• yellow
• dark brown

When the processes of these cells contract, the grains of pigments are distributed in the center of these same cells, and at the same time the chameleon’s skin acquires a whitish or even yellow color. If dark pigment is concentrated in the outer layer, the skin becomes dark in color. And the combination of pigments leads to the appearance of all kinds of color shades. For example, green color appears when light rays are refracted in the surface layers of the skin containing guanine crystals. A chameleon's color can change quickly. From light, through yellow or green to purple, then all the way to black and dark brown. Color changes occur not only on the entire body of the chameleon, but also in individual areas, which are accompanied by the appearance or disappearance of various stripes and spots of different colors.

Why does a chameleon change color?

Why does a chameleon change color? Changes in the color of the chameleon’s body occur both under the influence of external stimuli - temperature, humidity and light, and as a result of thirst, hunger, irritation, fear, etc. Most often, the color of the chameleon is in harmony with the surrounding background, the area in which it is located, the most camouflaging the animal. The chameleon also uses changes in its color to communicate with other chameleons. For a more visual representation of the color change of a chameleon, you can see for yourself how the chameleon changes color; a video of this action is posted on the Internet in the public domain.

Changes color for camouflage. This is not entirely true. If you plant a chameleon on the ground, it will not become as black as the ground at that very second (and the next too), and on a snow-white sheet it will not become white. Chameleons change skin color under the influence of physiological(lighting, hunger, illness, air temperature, etc.) and emotional-volitional factors. Color change is possible only if the brain and eye apparatus are intact. The color of the entire body or its individual parts may change; the change may occur in spots or stripes. The same goes for color saturation.

What is the mechanism for changing skin color in chameleons? In these animals, in the fibrous and deeper skin there are branched cells - chromatophores, which contain Various types pigments (colored substances) in the form of grains. Have no grains permanent place and can move freely throughout the chromatophore; in particular, they can be concentrated in the center of the cell or located at its ends. In addition, the number of pigments in chromatophores is not the same: some have more, others have less. The grains can also move up and down. In addition, the chromatophores themselves can rise to the surface of the skin and make its color more intense or, conversely, move away from the surface and make the color paler.

Panther chameleon (Furcifer pardalis)

The main mechanism that moves the pigments in chromatophores is the nervous system. From the central nervous system to each chromatophore there is a nerve that transmits certain signals, causing pigments and chromatophores to move. The eyes play an important role in changing skin color. Scientists have found that Without eyes, chameleons lose the ability to change skin color. Therefore, they suggested that light is the main stimulus that sends signals through the eyes nervous system chameleon. Also, based on experiments, experts suggested that in the central nervous system there are two centers responsible for color changes: volitional and automatic.

A few examples:

The concentration of grains in the center of the chromatophore as a result of contraction of its processes makes the skin light (white, yellow, white-yellow),
- dark pigment concentrated in the chromatophore processes, giving a dark to black color,
- green color is the result of refraction sun rays in the cells of the superficial layer of the skin, rich in guanidines,
- removal of the optic nerve, for example, from the left eye makes the entire left half of the chameleon’s body white,
- during mating season chameleons are able to change their color and color saturation in a split second,
- during anesthesia, the skin of chameleons darkens to black, and when sick or dead, it lightens to almost white.

Exotic, peculiar, mysterious, supernatural... This is how you can describe a chameleon. He lives on the same planet as us, but looks as if he came from outer space. Either a small dinosaur or an alien. There’s no other way to say about a chameleon...Everyone has probably heard about these reptiles, butchameleons gained 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 inflates. And the ancient Roman scientist Pliny mistakenly associated the change in color solely with the background. In the 17th century, the German scientist Vormius explained the color play by the “suffering and experiences” of the chameleon. Perhaps Vormius somewhat flattered the animal by calling its simple mental activity “experiences,” but it turned out that he was closest to the truth.

What causes chameleon skin color to change?

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, the chameleon communicates with its own kind. IN at its best The reptile's color 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 significantly brighter. This is a kind of competition between two “gentlemen”. Most often, the larger chameleon is perceived as dominant, and sometimes they attack each other with open mouths. They fight until one of them retreats. When meeting 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 well among the foliage, but usually when a reptile changes color, it tries to stand out.

The color of a chameleon also changes depending on the state of its body. Changes in temperature, lighting and humidity, unfavourable conditions maintenance, illness, hunger, dehydration, anger, fear, stress - all these factors also affect the color of the animal’s skin. If a chameleon is stressed, it will appear darker in color. 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 must be protected from stress in every possible way. You should not bully the chameleon, show it other animals, or often move it 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. Stressful state could end badly. Fatalities are common.

Watching long time as a chameleon, you will learn to understand what your pet wants to express by changing color. And if the color of a chameleon suddenly matches 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 thanks to special structure skin. In the outer and deeper layer of reptile skin there are light-reflecting cells - chromatophores. They contain grains of pigments of black, red, yellow and dark brown. When the chromatoform processes contract, the pigment grains are distributed in their center, and the animal’s skin acquires a whitish or yellow color. If the dark pigment is concentrated in the outer layer, then skin covering takes on a dark color. When pigments are combined, a variety of color shades appear. Thanks to this mechanism, the color “palette” of the reptile turns out to be very rich.

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

The main color for chameleons is green. Yellow, gray and brown animals are also found.

Chameleon colors

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

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

In contact with

To protect themselves, many animals change color to adapt to their environment. Previously, there was an opinion that the chameleon varies its color scheme precisely for this reason. But the unusual reptile turned out to be not as simple as previously thought. A chameleon does not change color to scare off predators or blend in with its surroundings, as scientists recently discovered. Why does a chameleon change color? This is how he interacts with other individuals of his species, transmitting information, a scientific group from the University of Arizona determined.

How does a chameleon change color?
The coloring of male chameleons becomes much more intense when they compete with each other for territory or the attention of a female, showing aggression. Surprisingly, males that display brighter colors and quickly change the color scheme on their heads usually win the fight. During confrontation, chameleons display rich yellow, orange, green and turquoise tones. With the help of eye-catching color signals and sudden changes appearance the chameleon emphasizes its superiority, and the “rainbow” fight rarely ends in physical contact. If sparring does occur, it lasts 5-15 seconds, no more.

Taking as a “guinea pig” the Yemeni chameleon of the species Chameleon caluptratus (distribution area – Arabian Peninsula: territory Saudi Arabia and Yemen), known for his aggressive behavior, scientists attached 28 sensors to his body and tracked the size, brightness and speed of change of color spots. During the experiment, the scientific team discovered that when in a calm state, the chameleon changes color from brown to green with yellow hues, but at the same time retains its own unique color, different from its other relatives.

Interesting to know! There are about 160 species of chameleons in total. 75 species of endemic chameleons, of which three varieties are close to extinction, live in Madagascar. The latest species found is the Belalanda chameleon, which scientists say is one of the rarest reptiles in the world.

Interesting to know! The smallest chameleon in the world belongs to the deciduous chameleons - endemic to Madagascar of the genus Brookesia Brookesia minima - the size of an adult is about 1.5 cm. This miniature chameleon cannot change its color - it always retains a brown tint with a slight green tint. Scientists have hypothesized that the small size of the chameleon is a unique way of adapting to environment for the purpose of extending life cycle. The largest chameleon in the world is Furcifer oustaleti with a body size of up to 70 cm, including the tail - about 1.5 m. The most unusual of the chameleons is the Rwenzori Chameleon, a three-horned reptile from Uganda.

How a chameleon changes color: new research
In addition to brown, red and yellow pigments, chameleons, like other reptiles, have so-called structured shades: colors that are formed without the participation of natural skin pigmentation, but thanks to physical phenomenon optical interference. Iridophore cells consist of microscopic crystals (nano-crystals), alternating with layers of cytoplasm, so light waves of a certain length are selectively reflected by the surface of the chameleon's skin, which leads to the formation of a bright spotted color and a change in the color of the animal.

Interesting to know! The length of the chameleon's tongue and tail is almost 2 times the longitudinal size of the body. The reptile's sticky tongue is organized as a catching organ, thickening towards the end - the chameleon throws it out in a split second. The tail, along with the paws, participates in the movement of the animal - the chameleon wraps it around the branches. The reptile's eyes move inconsistently, providing a 360-degree view. The chameleon is widespread in tropical forests India, Sri Lanka and Madagascar, the desert part of Africa, introduced to America.

Chameleons famous for the fact that they can almost instantly change their color and seem to dissolve among 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 were at a loss, wondering how the chameleon - in general, an inconspicuous and slow animal - manages to do so well.

Studies conducted with males Madagascar panther chameleon(Furcifer pardalis), have shown 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 into a “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 has shown the ability of chameleons to “paint” also in colors invisible to the human eye.

Photo 1. Chameleons change color not only for camouflage

According to the results of the experiment, no particular relationship was found between the range of colors used and the habitat characteristics of chameleons.

The greatest dispersion of color colors was observed in species with the most pronounced social behavior(in this case, competition between two males), and not in species living in places with big amount multi-colored objects (grass, tree trunks,).

Coloring chameleons that use maximum amount flowers, turned out to be the most noticeable not only for their relatives, but also for, which contradicts the theory of color change only for camouflage.

However, predators often fail to attack brightly colored individuals, since at the slightest sign of danger they are able to “dissolve” against the background of the environment in a few milliseconds.

Further research showed that the change in color is associated with special cells inside the skin, chromatophores, which redistribute the pigment grains of the four colors.

These pigments absorb visible light at all wavelengths except a certain one (red, for example).

Iridophores and xanthophores

Recently, Michel Milinkovitch from the University of Geneva found out that for chameleons it is even more important 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. Milinkovic 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, arranged in 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 the color change: when the males are in an excited state, the interval increases.

The greater the distance, the more light is reflected from longer waves (red).

As the crystals come closer together, blue light begins to reflect.

Then the chameleons are helped xanthophores(yellow pigment cells): they make Blue colour green, and red - orange or yellow.

Milinkovic also discovered a second level of skin with iridophores located in a more chaotic manner. They reflect light very well in the near-infrared range.

In hot and humid environment Where chameleons live, these crystals are an important mechanism for protecting against overheating. This skin structure is apparently 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 thinking about how the information they obtained can be applied in practice, for example, in developing new means and methods of camouflage. And we have already come up with something.

Thus, scientists from the University of California at Berkeley have created an ultra-thin material that can change color at the nanoscale, like chameleon skin, depending on tension, bending or pressure.

The color of most natural materials (as well as paints and fabrics) depends on their chemical composition.

Photo 4. Studying chameleons helps develop nanotechnology

When white light hits the surface of these materials, certain wavelengths of light are absorbed while others are reflected back into the surrounding space.

Thanks to this, we perceive certain colors. A change in color thus requires a change in the chemical composition of the material.

The American invention takes a different approach to creating color.

The material is made using so-called structural painting. That is, the color of the surface (absorbed and reflected waves) is determined by the structure of the material.

This is not a new phenomenon - nature thus creates the rainbow tints of feathers, butterfly wings or beetle exoskeletons.

Even 300 years ago, he suggested that some structural dyeing methods could be used in industrial and commercial production.

Faux chameleon skin

Here's how it works faux leather chameleon.

A silicon film, which is 1000 times thinner than a human film (about 120 nm), is attached to a layer of silicone, and then tiny (smaller than the wavelength of light) ridges 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.

The variable distance between the corrugated ribs, or microcorrugations, allows you to obtain different colors.

In addition, the material has high ability. It reflects up to 83% of the incident light, so in fact the artificial leather is as bright as the skin of a real chameleon.

Photo 5. Chameleons - consummate masters camouflage

The material produces pure colors ranging from green to yellow, orange and red. And also new material turned out to be much easier and easier than it turned out before.

This is the first time that anyone has succeeded in making a flexible chameleon-like structure that can change color simply by bending it.

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.

They can also be used to visually display structural deterioration in 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 were also able to create fabric that can change color depending on how it is folded.

The basis for this material was the semiconductor silicone.

Scientists also inserted silicone particles 120 nm wide into the smallest cuts on its surface, which are capable of reflecting waves of different spectrums and, accordingly, being colored in different colors- green, yellow, red or orange.

The color the fabric turns depends on how it is folded or folded, and it changes instantly.

Well, in a broad sense we're talking about about creating materials that will completely change the face of our world.

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