Why do snakes have scales and not fur or hair?

Introduction

Snakes are fascinating creatures that come in a wide range of sizes and colors. One distinguishing feature of snakes is their scaly skin. Unlike most other animals, snakes do not have fur or hair. Instead, their skin is covered in scales. But why is this the case? What is the function of snake scales, and how did they evolve?

What are scales?

Scales are flat, rigid structures that cover the skin of snakes. They are made of keratin, the same protein that makes up hair, nails, and hooves in other animals. Scales are arranged in overlapping rows, which gives snake skin its distinctive texture. Unlike fur or hair, which grow continuously, scales do not grow once they have formed. Instead, snakes shed their entire outer layer of skin periodically, in a process called ecdysis.

The function of scales in snakes

Scales serve several important functions in snakes. First and foremost, they provide protection. The scales help to prevent injury from predators, prey, and the environment. They also help to reduce friction when snakes move through their environment. Additionally, scales provide a barrier against water loss and infection.

Scales vs. fur and hair

While most animals have fur or hair, snakes evolved to have scales instead. This is likely due to the unique challenges faced by snakes. Snakes move through a variety of environments, from rocky deserts to dense forests. Scales provide a more durable and protective covering than fur or hair would. Additionally, snakes do not need insulation to regulate their body temperature in the same way that mammals do.

Evolution of scales in snakes

The evolution of scales in snakes is not fully understood, but scientists believe that scales may have evolved from the protective plates found in the skin of some early reptiles. Over time, these plates became more flexible and lighter, eventually evolving into the scales we see in modern snakes.

Scales as protection

One of the most important functions of scales is protection. The overlapping rows of scales provide a tough, durable barrier that helps to prevent injury from predators and prey. Some snakes have especially thick scales, such as the armadillo girdled lizard, which has scales that are fused together to form a protective armor.

Scales and thermoregulation

While mammals use fur or hair to regulate their body temperature, snakes use their scales. Scales are not very good at retaining heat, which is why snakes are often found basking in the sun. By absorbing heat from their environment, snakes can regulate their body temperature without using energy. When they get too hot, they simply move into the shade or into a cooler area.

Shedding of scales

Snakes shed their skin periodically, in a process called ecdysis. This allows them to grow and replace old, damaged scales. Shedding is triggered by a hormone called ecdysteroid, which causes the outer layer of skin to separate from the underlying layers. The snake then rubs against rough surfaces to help remove the old skin.

Diversity of snake scales

There is a wide diversity of scales among different species of snakes. Some snakes, such as the ball python, have smooth, shiny scales. Others, like the rattlesnake, have rough, keeled scales that help them grip surfaces. Some snakes have scales that are brightly colored or patterned, while others have scales that blend in with their environment.

Conclusion

In conclusion, the scales on a snake’s skin serve important functions, such as protection and thermoregulation. While most animals have fur or hair, snakes evolved to have scales instead. The evolution of scales is believed to have originated from the protective plates found in the skin of early reptiles. The diversity of scales among different species of snakes is a testament to the adaptability and versatility of these fascinating creatures.