What are keeled scales?

Some reptiles, such as lizards and snakes, have keeled scales. 

Keeled scales are not smooth. Keeled scales have a ridge down the centre, making them rough. 

If a snake or reptile has keeled scales, they are usually the dorsal (back) scales. The reason for having keeled scales is not cleary understood, but it might be so that they can hide. Keeled scales are not as shiny as smooth scales, so they do not shine in the sunlight, enabling the reptile to hide.  

Examples of snakes that have keeled scalses include the European Adder (Vipera berus berus), the Puff Adder (Bitis arietans), the Speckled Green Snake (Philothamnus punctatus), and the Nose-Horned Viper (Vipera ammodytes ammodytes).

Photographer: Martina Nicolls

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM