Miraculously providing simple explanations for things that are , in reality , EXTREMELY COMPLICATED !
Miraculously providing simple explanations for things that are , in reality , EXTREMELY COMPLICATED !
Why do reptiles SHED THEIR SKIN ? What can go wrong , and how can we help ?
As the first true land animals , reptiles needed to develop a skin that not only provided a barrier to injury and infection , but also that prevented excessive loss of water and protection from the sun ’ s damaging radiation . The solution lay in extensive use of keratins and waxes in the outer layers of the skin , or epidermis , together with the pigment melanin , which offers some defence against uv rays . Keratins are tough proteins which are also integral components of mammalian hair , along with feathers , nails , claws and beaks ! Reptile scales , which are extensions of the epidermis , are also highly keratinized , and afford additional protection whilst also minimizing friction .
In fact , the skin of reptiles is quite similar to that of mammals , which also contains large amounts of keratin , with two important differences . Mammals possess sweat glands and hair ; both of which are crucial for temperature regulation and an endothermic ( or warm-blooded ) lifestyle . Incidentally , because reptiles don ’ t have hair follicles , they don ’ t get ‘ pimples ’, which means that any noticeable lump or bump under the skin should be treated seriously .
The harsh terrestrial environment also causes substantial wear and tear on skin , which must also permit the animal to grow , so some mechanism of repair and replacement is essential . All land animals regularly replace their skin – it ’ s just that there are two very different strategies employed . In mammals , the deepest layer of the epidermis continuously produces new cells , which differentiate as they move up through the skin , until they are eventually worn away and exfoliated from the surface . A similar model is used by crocodiles and turtles , so although all these animals ‘ shed ’ the outer layer of their skin , this is an uninterrupted process and is not often noticeable . Snakes and lizards take a very different approach , which involves periodically shedding the entire outer epidermis ; this is replaced during a phase of active cell division . In between times , the skin is essentially in an inactive ‘ resting ’ phase . The advantage of this method is that it allows for different layers or types of skin cells to be produced , which confers better protection . It also helps to remove parasites . The disadvantage is that the animals are vulnerable around this time . Lizards often shed in patches , while snakes commonly discard their outer skin in a single piece . Insects , spiders and crustaceans also shed their skins in a similar manner , also called sloughing ,
Image by Yupa Watchanakit .