Chameleons don’t only change color in order to hide, they often do it to regulate their temperature or to communicate with other chameleons. Chameleons are cold blooded, and can’t produce their own body heat, they rely on external sources for heat. A chameleon will change its color to be darker when its cold in order to absorb more heat, and then go lighter when it warms up in order to reflect the sun’s light. Chameleons also change their color to communicate with other chameleons, either for mating or for territory.
Scientists believe that they now know how chameleons change their color so easily. Before they thought that it was done through pigments in their skin similar to how octopi or squid, with a cell called chromatopheres. Instead researchers have discovered what they believe to be the real way that chameleons change color, they use a layer of nanocrystals in a special layer of their skin called iridopheres.
These iridopheres are crystals held in the skin, and are held together at different tightness for different colors. The scientist working out of the University of Geneva worked with the panther chameleon. They discovered that these chameleons have two layers of the iridophore cells. The first and top layer of the iridophere is used for their color changing. The different organization of these cells in the skin allow for the different colors the chameleon can show. When the chameleon is calm the cells are in a dense network and reflects blue wavelengths, giving the chameleon its blue color. At this time the chameleon can also appear to be green because of the yellow pigments called xanthophores in the lizard’s skin, which when mixed with the blue wave lengths makes them appear green. When it is excited the cells are loosened, which allows the other colors like yellow and red to be shown. These cells are mostly found in the males, because males of many species out in the wild tend to be brighter and flashier in order to attract mates. Females tend to be duller in color, and have less of the upper layer of iridophere cells.
The second layer of the iridophere is filled with larger and less organized crystals. This layer is helpful for the lizard’s internal heating. The crystals in this layer being good at much of the infrared light, helping the chameleon avoid over heating in hot and dry locations. These two layers of the iridophere allows the chameleon to have the best of both worlds, it allows them to quickly change their color while being able to maintain a constant body temperature.
This discovery is an important one for the scientific community. While it may seem like an unimportant discovery it could actually be a very interesting advancement for new technologies.
Posted by: Madison Boone (A)