How do chameleons change its color?

Question

how not why

Answer 1

The chameleon has several cell layers beneath its transparent skin. These layers are the source of the chameleon's colour change. Some of the layers contain pigments, while others just reflect light to create new colours.

A popular misconception is that chameleons change color to match their environment. This isn't true. Light, temperature, and emotional state commonly bring about a chameleon's change in color.  

Answer 2

There is a wide spread opinion that the chameleon changes its color according to its environment, turning itself invisible to its predators.

An individual able to shift its behavior in accordance with different persons is compared to a chameleon. But is that so?

Science does not confirm this idea at all.

Actually, the chameleon is constantly changing its color. Chameleons possess in chromatophores (cells that give skin's color) two types of pigments: one black (melanin) and another one, of various colors. Chromatophores retire or display their ramifications, changing this way their color.

Their movements are under the control of nerves or hormones (adrenaline secreted by the adrenal gland and hormones of the hypophysis). These colors respond perfectly to the needs of their arboreal life: 130 species of chameleons out of 156 live in trees. Colors displayed by the chameleons vary from gray to whitish, black, vivid green, green-yellow, olive or blue.

Adding to their natural colors their ability to stay still for minutes and their wagging and extremely slow movements (unusual for a lizard) that makes their laterally flattened bodies to look like a leaf or twig shaken by wind, we now understand why they may be inconspicuous for their predators.

Of course, they afford these slow movements, due to their hunting technique, based on their tongue, which is the longest in the world compared to the body length. The tongue is launched and put back in a fraction of second (0.04 s the launch (!), 0.5 s the put back).

The sticky tongue can catch from insects to even small birds in the largest species, than can be 70 cm (two feet) long. This effective hunting technique is also practiced by some newt species from Americas. The chameleon does change its color, but mostly for

Chameleons are solitary and extremely territorial, rejecting even the company of other chameleons. If two chameleons meet face to face, they do all they can to impress each other, displaying menacing postures (wagging, jaw clacking, whistling, swelling of the body and the gizzard) and ? menacing colors! The defeated one will adopt a pale-gray color and will leave the territory.

In fact, if a chameleon is attacked by a predator, its color turns reddish with brown and yellow stripes, as their predators (snakes, mammals) do not distinguish colors well.

Color also signals changes in light and temperature in the environment. In the morning, after a fresh night, the chameleons will warm in the sun, flattening their flanks, which turn black.

If a leaf is put on the back of a chameleon and removed after a period, it will leave a color mark on its back, following its shape, due to the shifts in light and temperature. And the chameleons are not the only lizards than can change color: some iguanas, even called false chameleons, can do it exactly in the same manner.

As chameleons are somehow related to iguanas, it is plausible that the changing color ability developed in a remote ancestor, during the dinosaur era. Thus, being a chameleon won't hide your real feelings. There are in fact some other species that DO copy their environment, using chromatophores, like octopuses or many flatfishes, like flounders.

Answer 3

http://en.wikipedia.org/wiki/Chameleon#C...

Answer 4

The transparent skin of a chameleon has four layers which work together to produce various colors. The outside layer has two kinds of color cells, yellow and red. Just inside this layer are two more layers that reflect light: one blue and the other white. The innermost layer — important and complicated — contains pigment granules (melanophore cells).

The melanophores have a dark brown pigment called melanin, the same substance that colors human skin brown or black. The main body of each melanophore sits like a brooding octopus beneath the reflecting layers and sends tentacle-like arms up through the other layers.

The color cells alter size, which changes the amounts of red, yellow, and dark brown in the skin and this, in turn, alters skin color. The reflecting layers modify these effects. Where the skin has a blue layer under yellow cells, the blue reflects through the yellow and changes it to green. Where the blue layer is missing, white shines though and enhances the yellow and red above.

The skin brightens when the cells pull the dark melanin from their tentacle-like arms into their bodies. The skin darkens when the cells spread the dark pigment through their arms into the upper layers of the skin. The brownish black color then obscures the white layer, darkening the skin like a black cloud darkens the land.

That's how the chameleon changes color. It knows what color to change to just as we do when we turn red with embarrassment.

http://www.wonderquest.com/Chameleons.ht...