Every day we are surrounded by the beauty of colours in nature. Nature is indeed a bag full of surprises as it never fails to capture my attention. Every life that exists on Earth has been designed intricately and ingeniously.
All creatures have different structures, adaptabilities, colours etc. Chameleons are one such unique creature that exists in nature. They are a type of lizard and can commonly be found in lonely parks or in wood lands. These chameleons have a special ability of changing their skin colour. Generally, lizards adapted to dessert areas lack this ability to change colour..
So what is responsible for this colour change?
There is a myth that chameleons change their colour only to save themselves from predators. But it is not the only reason for its colour change. Chameleons change their colour to indicate a variation in their mood. Colour change is a visual signal, signal indicating mood, aggression, mating behaviour and to mark their territory. The skin of every animal contains cells which are made up pigments or coloured substances. These substances lend colour to the skin. If you look at the skin of chameleons closely, you will notice that they have multiple layers.
Generally the top most layer of its skin is transparent. Underneath the first layer there are three more layers present which contain specialised cells called chromatophores. These cells enable the colour change process in chameleons. The following representation below is how the layers of skin are arranged in a chameleon.
The first layer beneath the transparent skin contains pigment cells. The different types of pigments that are present are as follows:
Xanthophores – which are yellow in colour;The first layer beneath the transparent skin contains pigment cells. The different types of pigments that are present are as follows:
- Erythrophores – which are red in colour;
- Guanine – which are blue in colour;
- Melanophores – which are brown in colour.
All these cells are accountable for controlling colour change in these animals. Melanophores have small narrow tubes called tentacles. These tentacles will move up through other layers. The nervous stimulations in chameleon raise the melanin granules.
Just below the layer of Xanthophores and Erythrophores, a type of cells called iridophores is present. This layer contains an organized array of transparent, nano-sized crystals that reflect specific wavelengths of light. The reflected light is perceived as colour. The latest research on colour-changing in chameleons reveals that they change their colour by adjusting the spacing between these nano-crystals, which causes different wavelengths of light to be reflected. These nano-cyrstals along with the pigments in the chameleon skin contribute to the overall colour of the skin.
Some believe that temperature and mood of the chameleon is responsible for colour change. Suppose if chameleon is in peaceful mood it produces a pale yellow skin colour. If the colour is red then it means it is in an aggressive mood. Most chameleons can change colours between brown and green and vice versa. Few of them can even create a type of patterns with these different colours. On the other side there are certain chameleons which cannot show colours like pink, purple, blue and black and many more.
Researchers are still investigating the function and the need of colour change in chameleons, but more recent research shows that the chameleons change colour to communicate with each other during social interactions.
Chameleons have many more unique features, other than changing their colour. Some of them are:-
- They have longer tongue. As long as 2 times its body length.
- They have powerful eyesight.
- They have feet with 5 toes, grouped into two. This enables it to perfectly adapt climbing.
- Chameleons don’t have ear drums. Though it is not completely deaf, they have bad hearing sense.
So next time you get to see a chameleon, observe all these features. Look for its colour and guess its state of mind.