THE chameleons they are reptiles belonging to the family Chamaeleonidae With unique characteristics: the twisted tail, the rotating eyes, the very long tongue to catch the insects and the color of the changing skin. It is in the common imagination to think that the chameleons, from the Greek “Chamai” And “Leon” -” Lion of earth “, change color For camouflage from predators in dangerous situations but reality is different. Their natural coloring green – brown It is the one that acts as a mimicry and allows it to hide from the enemies, while the ability to change the pigmentation is mainly used for social behaviorscommunicate it emotional state (excitement, relaxation or fear) or for adjust the body temperature. For example to attract females, males show colors such as the redThe blue and the bright green and in moments of aggression, they show yellow And orange. This ability is made possible by the arrangement in the space of specials crystals of Guanina present in skin cells (iridophausts), as reported by a 2015 scientific article published on Nature Communications From Jérémie Teyssier and collaborators.
Because the chameleons change color
The chameleons populate the tree -lined forests and the spots of vegetation of the savannas and other natural environments, their natural coloring is often a shade between the green and the browna color that allows these animals of camouflage And confuse with the foliage and the cortex of the trees, thus protecting them from the sight of the predators. For these reptiles, without natural “weapons” such as poison, claws or sharp teeth, it is essential not to be identified by the enemies in their habitats. In light of these considerations therefore, the chameleons do not need to change color to camouflage themselves but they do it to take social behaviors or for biological mechanisms. “Earth lions” can become orange, red, blue or yellow And it is not entirely clear whether they are able to adapt to any color present in the environment, probably only to a small number of shades. The change of coloring takes place mainly for the following reasons:
- Performances: males use lively colors to attract females, such as red, blue and bright green.
- Competitive behavior: show bright colors and rapid color changes to report aggression to rivals, such as yellow and orange. Females ready to lay eggs take dark shades and behave aggressively to discourage males, becoming brown.
- Humor: The color seems to reflect also the emotional state of the chameleon, black indicates stress or fear. Large colors, however, can be sported during sleep, while more soft green shades generally indicate that the chameleon is happy and rest.
- Thermoregulation: it is estimated that chameleons change color to adjust the body temperature, becoming darker to absorb more light and heat when it is cold (black) and clearer when they warm up to the sun. Like lizards, chameleons are animals eco -meal or “in cold blood” and are unable to regulate their internal temperature.
The capacity of the chameleons is so iconic that it has inspired the term “chameleontic“Used in our speeches to define a changing person in behaviors and opinions.
How do chameleons do color
The study “Photon Crystals Active Color Change in Chameleons “Causes” Conducted by Jérémie Teyssier and published in Nature Camunications has proved to be a turning point for understanding the ways in which chameleons change color. Initially, it was thought that the capacity of the chameleons of changing color was due to the action of dermal chromatophorescells capable of changing the coloring of the skin through the dispersion or aggregation of organels (melanosomes) loaded with melanin.
The researchers revealed a more complex mechanism at the base, involving another type of cell, the iridophausts he is Guanina crystals inside them. These cells are arranged in two layersone more superficial and the other deeper. The crystals, also present in fish scales, have the ability to reflect different shades of lightas if they were mirrors, depending on theirs spatial arrangement which, in situations of stress or relaxation, is different. When the various crystals are closer to each other, they reflect wavelengths around blue (relaxation), when they are more distant they reflect wavelengths that paint the animal of bright colors such as red or yellow (excitement).
The deeper layer of iridophyrs is more disorganized and mainly reflects wavelengths corresponding to the infrared and direct and indirect solar radiation, suggesting their role in the thermal regulation of the animal.
