Which chameleon changes color better? Why does a chameleon change color?

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 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 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, unfavorable 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 processes of the chromatoforms contract, the pigment grains 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 skin 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 color scheme

There is an opinion that the descendants of dinosaurs can be any color they want, 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 intentionally 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 different colors like a New Year's garland.

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

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

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

Instructions

Chameleons are inhabitants of the sultry continent called Africa. Currently, they are 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 life, turning to different sides, independently of each other. In addition, these lizards can stay on tree branches for hours, waiting for their prey. As soon as one or another insect comes into the chameleon’s field of vision, he immediately, without hesitation, grabs it with his long and sticky tongue.

This reptile is widely known unique ability a miraculous way to change the color of your skin. It is curious that a lizard up to 30 cm long can skillfully camouflage itself, turning red, black, blue, or yellow. Scientists studying chameleons tried to figure out how these lizards change the color of their skin. Initially, it was assumed that chameleons simply love to adapt to the background around them, considering this 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 change of color can be affected by the animal’s mood, it can be a reaction to fear or joy, it can also depend on the ambient temperature. Zoologists have found that the color of its body changes thanks to special cells - chromatophores. The fact is that the skin of this lizard is quite transparent, and therefore contains pigments different colors, are well traced.

Chromatophore grains contain grains of several pigments at once: red, yellow, black and dark brown. If the segments of these cells begin to shrink, then a redistribution of pigments occurs, the concentration of which increases sharply. In this case, the reptile's skin becomes light (for example, yellowish or white). If one of the dark pigments is reduced, the chameleon’s skin becomes dark. It is interesting that such a reduction occurs at different levels, which makes it possible to bring combinations of certain pigments to completely different shades.

To change the color of a lizard's skin you need to spend no more than two seconds! For a long time researchers assumed that chameleons change color only for camouflage: for example, turning green, the lizard can hide in the grass or foliage. However, this assumption turned out to be only half true. The fact is that chameleons change their color not only for camouflage, but also for their own personal purposes. For example, some chameleons living in hot 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 mating games in order to attract a partner. It has been scientifically proven that these animals do not pay attention to the background around them. It is curious that in the process of evolution, some types of chameleons generally learned to copy the color of their own birds and snakes.

Chameleons belong to the class of reptiles and appearance very similar to lizards. The natural color of a chameleon's skin is greenish-brown, beige, and at the same time resembles the color of tree bark and leaves. And this helps them camouflage themselves in their habitats - in trees, where they spend a significant part of their lives.

Almost from childhood, we all know the statement that these reptiles change color, camouflaging themselves with the color of the surrounding area, depending on the natural background, and thus escaping from predators. (By the way, there is an assumption that a chameleon can change color not at all for protection from enemies, but for communicative purposes - to “communicate” with representatives of its own species).

It is this ability that is considered the most characteristic of this species of reptiles. However, scientists have found that such a statement is nothing more than a legend. If chameleons had the ability to instantly “repaint” themselves to match the color of the area, they would turn white on a white blanket or black on a pile of coal.

How does a chameleon change colors?

It was found that the change in color occurs as a result of changes in temperature, lighting and even... the mood of the creature. And special cells called chromatophores are “to blame” for this. This Greek word literally means “color-bearing” (chroma - color, paint and phoros - carrier).

Related materials:

Why are lightning bolts different colors?

Chromatophores are located both in the superficial (fibrous) and deeper layers of the chameleon’s skin and have a branched structure. The mechanism of operation of these pigment cells is quite complex. It is directly related to work nervous system reptiles. The cytoplasm of the chromatophores contains pigments that determine the color of the chameleon's skin. They are black, yellow, reddish, dark brown.

Pigment grains are not fixed in one place, but have the ability to move throughout the cell, sometimes concentrating in the center, sometimes “creeping” to its ends. The number of these pigment grains in the chromatophores is also not the same: in one cell there are more of them, in another there are very few. Consequently, the coloring of the chameleon will be uneven because of this.

And the chromatophore cells themselves are quite mobile: they can rise closer to the surface of the skin or, conversely, go deeper. It is clear that the intensity of the color will depend on this.

When the chromatophore processes contract, pigment grains collect in the center of the cells, and the skin becomes whitish or yellow. And when grains of dark pigment collect in the branches of the cell, the skin becomes dark, and may even turn black. Various shades are obtained by combining pigment grains of both layers - superficial and deep.

Related materials:

Why is snow white?

The nature of the appearance of green tones is interesting: this occurs due to the refraction of rays in the outer layer, which contains many light-refracting crystals. Because of this, the color of a chameleon can quickly change: from light - through various bright types of orange, green, purple - to black. Moreover, it can change both along the entire length of the reptile’s body, and in individual stripes and spots.

Reasons for a chameleon's color change

Scientists Brücke, P. Baer and Krukenberg also found that the reasons for the change in color of these reptiles can be both physiological and emotional in nature. The former include, in addition to those mentioned above, temperature, lighting, high humidity, as well as dehydration, hunger and pain; to the second - a feeling of fear, a state of aggression towards the enemy or during an unwanted meeting.

What are your first associations with the word chameleon? I think most people, when answering this question, will agree on the options “change in color” and “shoots with 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 legends, the chameleon does not disguise itself as environment change of color. They change color depending on temperature, light and mood. This is a unique ability of the body that not many reptiles, insects and fish possess.

This feature was noticed a long time ago, back in ancient times, but many centuries passed before they understood how this happens. Research by scientists (P. Baer, ​​Brücke, Krukenberg) helped to unravel why the chameleon changes its color. Under a microscope, they were able to find out the nature of this phenomenon.

So why is it possible for a chameleon to change its color pattern so quickly? What is this secret?

It's all about amazing pigment cells - chromatophores! Chromatophores, which from Greek means “paint-bearing”, really have a complex mechanism of operation and are closely related to the nervous system of the chameleon. These cells contain colored substances in the cytoplasm - pigments, thereby determining the color of the chameleon's cover. Among the main types of pigment cells, the following can be distinguished: melanocytes and melanophores, containing in their organelles - melanosomes - various modifications of melanin (from yellow to almost black); xanthophores containing carotenoids, flavins and pteridines (yellow to red), localized in organelles - pterinosomes - or in the form of droplets in the cytoplasm; iridocytes, or guanophores, containing guanidine crystals, 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 process of operation of these cells. Chromatophores are located in the outer - fibrous and deeper layer of the chameleon's skin; they are branched cells containing grains of dark brown, black, reddish and yellow pigment.

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, accordingly, vice versa. 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 permanent place, they can move around the chromatophore.

When the chromatophore processes contract, pigment grains are concentrated in the center of the cells and the skin appears 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 containing many guanidine crystals that strongly refract light. As a result, color can quickly change from whitish and orange, through yellow and green to purple, dark brown and black, and these changes can affect both the entire body and its individual parts and are accompanied by the appearance and disappearance various kinds stripes and spots. Moreover, the chromatophores themselves can either sink deep into the skin - and then the skin turns pale, or approach its surface - and the skin becomes more contrasting and brighter.

All of the above-described changes in color occur under the influence of factors and stimuli, which 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 striking 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 sides of the body towards each other. As if demonstrating his superiority over his opponent.

I would like to note the special influence of light on the chameleon’s camouflage system. Scientists have found that there is a close relationship between a chameleon's vision and its ability to change color. The visual system is where the signal chain that transmits commands to cells is established. Research has revealed that the ability to change color is lost when the optic nerve is damaged. This means that light acts through the eyes on the nervous system and only through it on the chromatophores. Nerves go from the brain to the chromatophores. It is through them that commands are sent to change the shape and location of chromatophores in the layers of the skin.

During the research and experiments, the following paradoxical facts and patterns were revealed:

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

To explain these sometimes contradictory data, scientists accepted the hypothesis that the central nervous system of the chameleon contains two types of centers: volitional and automatic.

Automatic centers support famous tone color-changing system, and when irritated they cause skin lightening, but these centers are dependent on the volitional centers, which have a suppressive effect on them and, therefore, 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 clearing of the skin, while weakening of the peripheral endings due to poisoning with curare causes, on the contrary, darkening.

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

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