Why Chameleons Change Colours?

Why Chameleons Change Colours?

PROF WAQAR HUSSAIN

               Chameleon are specialized clade of lizards that has 600 species, many has distinctive magical property of change of colour of their skin. Chameleons are famous for their quick color-changing abilities for three main reasons; first, to regulate their body temperatures; second, for social signaling and third, for camouflage.

             

 Heat regulation: Since chameleons can’t generate their own body heat so they change the color of their skin in a way to maintain optimum body temperature.  Chameleons in cold weather become dark to absorb more heat, whereas in hotter times, turn into lighter grey colour to reflect most of the sun’s heat.

             

Social Signaling: Chameleons’ changes colour to communicate their feeling. Males become bright to signal their dominance and turn dark in aggressive mood.  Males show lighter, multicoloured patterns when courting females.

Females can let males know if they are willing to mate by changing the color of their skin.

              Camouflage: Some species adjust their colors for camouflage in accordance with the vision of the specific predator species (bird or snake) by which they are being threatened.

                Chameleons are domesticated so Owners should know their colour language to get to their inner feeling.

 How chameleon changes their colours?

             The outermost layer of the chameleon’s skin is transparent. Beneath this are three 

more layers of skins which contain specialized cells called chromatophores. The chromatophores at each layer are filled with sacs of different kinds of pigment.

         Chromatophore cells in the first and upper layer are called xanthophores(yellow pigment) and erythrophores(red pigment).

         Chromatophores cells in second and middle layer are called iridophores or guanophores; these contain guanine appearing blue or white.

       Chromatophores cells in the third and the deepest layer called melanophores; contain melanin, the dark brown pigment.

           These pigments are packed in tiny sacs within the cells.  When a chameleon experiences changes in body temperature or mood, its nervous system tells specific chromatophores to expand or contract.

For instance, an excited chameleon might turn red by fully expanding all his erythrophores, blocking out the other colors beneath them

         With these layers of cells, some chameleons are capable of producing a dazzling array of reds, orange, pinks, yellows, blues, greens, purple, black and browns. These bold statements won’t help them blend into the background, but they will allow them to get their message across to other chameleons loud and clear.