PHYSICS, NO BIO - Secret of chameleons' colour change is out

Geneva PTI





Light-reflecting cells in the skin provide chameleons their uncanny colour-changing abilties that help them attract mates and ward off predators, scientists have found. Unlike other animals that change col our, such as the squid and octopus, cha meleons do not modify their hues by accumulating or dispersing pigments within their skin cells, the researchers found.Instead, the lizards rely on structural changes that affect how light reflects off their skin. Researchers found that chameleons have two superposed thick layers of iridophore cells -iridescent cells that have pigment and reflect light.
The iridophore cells contain nanocrystals of different sizes, shapes and organi zations, key to the chameleons' dramatic colour shifts, the researchers said. The chameleons change the structural arrangement of the cells by relaxing or exciting the skin, which leads to a change in colour. The study is published in the journal Nature Communications.