Image from Wikimedia Commons
This week, the most highly anticipated movie of the year is being released, The Avengers: Age of Ultron. The intense action and gifted screenwriters are sure to get people excited, as they satisfy their superhero cravings. The mesmerizing shocks of thunder, to the advanced technology of iron man. Their array abilities are sure to leave many moviegoers drooling, as they wished they were the heroes fighting on screen. However, what if I told you there was a creature that is real, and has a super power of its own, that rivals the valiant figures onscreen? You would be shocked, as much like the super heroes, these chordates are also able to utilize their arsenal for vast situations. The chameleons are able to distort and change their skin pigments for protection, social situations, and environmental conditions.
Through two special skin layers that lay on top of each other on the epidermis, chameleons are able to change their pigmentation. They do this by manipulating light emissions, most commonly the sun. They are able to accomplish this feat, as the superimposed layers called iridophores containing nanocrystals reflect light at various wavelengths. Mainly composed of guanine, the lattices in these nanocrystals are able to shape shift in various sizes. The longer the lattices are, the longer the wavelength. That’s why in the relaxed state chameleons are green, while excited (shorter lattices) they are yellow, red, and orange. They are able to utilize this technique with the many thousands of nanocrystals on their epidermis to produce many combinations of pigments that help them blend in. This is especially important as the main predators of chameleons are birds and snakes. These two species both have well developed eyes and for the snakes heat sensing tongues. This makes it especially important for chameleons to camouflage in their environment to avoid the keen senses of the bird and snake.
Besides protection, color changes are a good indication of social signaling amongst fellow chameleons. The degree or spectrum of colors displays their physical conditions and more importantly their intentions to others. For instance darker colors means anger and this is often used as a deterrent for other chameleons. In contrast, males flaunt lighter patterns to court females. They also used multicolored streaks and designs in the hopes this draws them in as well. Interestingly in some species, such as Smith’s dwarf chameleon, they change their color variation in accordance to the vision spectrum of their predators. Thus they are able to go undetected, even if their camouflage appears to be vibrant; those bright colors may not appear so in other species’ field of vision. It is also worth noting that these color contrast aren’t universal amongst chameleon, but rather basic guidelines that follow the premise of most of them.
Chameleons wouldn’t be super animals if they could not overcome their environment. This can be seen in desert dwelling chameleons, as they change in order to aid themselves in thermoregulation. This can be observed in the early mornings when it’s cool. They usually have a coat of black, as it helps absorb the few rays of light that make it past the clouds. However later through the day as the clouds disappear, they retract their black pigment and it becomes light grey. This ultimately reflects the sun and desert dwelling chameleons usually lay under rocks during the day, therefore they are able to keep a cool body temperature. This new way of thermoregulation is extremely important as the hot desert heat without these ways to lower the temperature are dangerous to chameleons as they are exothermic. In another words they are cold blooded animals, so the excruciating heat are potent to chameleons.