Today I watched an epic documentary about reptiles & amphibians.
While watching said documentary, absorbing all the glorious David Attenborough narrations, all of the unbelievably epic shots and marvelling at a whole bunch of cold-blooded creatures, I saw the panther chameleon.
Edging along a branch through the Madagascan forest, I was captivated. It’s pincer-like hands gripped around the branch as it crawled along, it’s individually rotating eyes looking 360° around itself. It looked so perfectly adapted to its environment, I was in awe.
And then I realised.
Chameleons are colourful.
My blog is about colours.
I can write all about chameleons!
I’m sure this will surprise you all when I say I’ve never really known a lot about chameleons or any sort of reptile for that matter, so we’ll be starting with the basics.
- A chameleon is a type of lizard, part of the suborder Iguania
- With 171 different chameleon species, the majority of them are found in Madagascar
- The largest chameleons are over half a metre long (69.5cm)
- The smallest chameleons can be only 16mm
- The chameleon will continuously grow throughout it’s life
- Chameleons eat insects and birds with an absolutely crazy tongue that can shoot out twice as far as its body length
- They are 1 of only a small number of animals that can change the colour of their skin
Now this is where it gets interesting. It’s a common assumption that chameleons can just change their colour to match their surroundings. Scientists believed they changed colour in the same way that octopus or squid do by adjusting pigments in their skin cells to alter colours.
However, it doesn’t work quite like that.
Chameleons change the colour of their skin in response to their emotions or environmental factors like light or temperature. More recent research has discovered they do it by changing the actual structure of their uppermost layer of skin cells called iridophores.
These iridophores contain nano-crystals (made up of guanine, one of the key components of DNA) which will determine the colour of Chameleons skin.
When these nano-crystals are all close together, the chameleon is in a relaxed state. Because of this closeness, only small wavelengths such as blue or green are reflected from the cells and that is the colour we see the chameleon as. (To read about different wavelengths of colours click here).
When a chameleon gets amped up, say if a rival comes along, the chameleon will stretch his skin. This spreads these nano-crystals apart from each other and will consequently reflect colours of longer wavelengths such as yellow, orange and red.
Beneath this fascinating upper layer of cells is another, thicker layer of skin cells. Scientists believe it is this secondary layer of cells which help to maintain the temperature of the chameleon as the cells found here reflect near-infrared sunlight.
However, all this cool skin cell stuff going on, only really happens in male chameleons. Female and babies are generally dull colours as they don’t need to be competing with rival chameleons therefore their upper layer of iridophores is greatly reduced in comparison.
To conclude one of my favourite blogs to write so far, chameleons are pretty amazing creatures. For more interesting info on chameleons check out these resources:
- Life, Reptiles and Amphibians (BBC)
- Bradford, A. (2015, June 3). Chameleon facts. Retrieved from http://www.livescience.com/51061-chameleon.html
- Geggel, L. (2015, March 10). Chameleons’ color-changing secret revealed. Retrieved from http://www.livescience.com/50096-chameleons-color-change.html
- Service, R. F. (2015, March 10). The secret to chameleon color change: tiny crystals. Retrieved from http://www.sciencemag.org/news/2015/03/secret-chameleon-color-change-tiny-crystals
- Vitt, L. (2015, May 20). Chameleon. Retrieved from https://www.britannica.com/animal/chameleon-reptile