Difference Between Limbless Amphibians and Snakes

The key difference between limbless amphibians and snakes depends on their external appearance. Limbless amphibians do not possess any scales on their skin, and their eyes are covered. On the other hand, snakes possess significantly visible scales on their skin, and their eyes are exposed.

Both limbless amphibians and snakes possess superficial similarities including their body shape, size and mode of locomotion. Hence, it is important to identify specific differences between snakes and limbless amphibians since limbless amphibians more often get misidentified as snakes. It is a general fact that most people are afraid of snakes. Therefore, they tend to kill them once spotted. Due to misidentifications, limbless amphibians which are entirely harmless to humans also become victims.

CONTENTS

1. Overview and Key Difference
2. What are Limbless Amphibians
3. What are Snakes
4. Similarities Between Limbless Amphibians and Snakes
5. Side by Side Comparison – Limbless Amphibians vs Snakes in Tabular Form
6. Summary

What are Limbless Amphibians?

Legless amphibians or Caecilians are dark coloured limbless organisms with yellow stripes on the ventral side of their bodies. These organisms belong to the order Gymnophiona that comprises over 180 species identified so far. Caecilians are distributed in the tropics of South and Southeast Asia, Africa, and South America.

Structurally, they vary from the size of a small worm up to a size of more than 150cm long. Also, they possess moist and smooth skins. Furthermore, calcite scales are present beneath their skin, but no scales are present as in the snakes. Caecilian skin appears segmented since it contains annuli; i.e., ring-shaped circles. These organisms mainly live in damp or wet soil environments and also in aquatic habitats. Furthermore, terrestrial caecilians lay eggs or give birth to young while aquatic caecilians give birth to larvae.

Caecilians are mostly fossorial organisms with the presence of a strong skull. Using that, they make tunnels and move through the soil. Moreover, caecilians respire through the lungs, skin and oral cavity. As an adaptation for the fossorial lifestyle, a skin layer covers the caecilian eyes. Consequently, their eyes are functionless. Caecilians possess needle-like teeth to feed on insects, small snakes, worms and frogs etc. However, the information present on Caecilians feeding and digestion is minimal.

What are Snakes?

Snakes are limbless reptiles that belong to the order Squamata and class Reptilia under phylum Chordata. Hence, they are a taxonomically diverse group of organisms with 2900 species identified. Though snakes are limbless, rudimentary limbs are present in pythons. Thus, this fact suggests that the pythons were the first to evolve as snakes. Anatomically, snakes possess a body length which ranges from 10cm up to a length of 8 meters. Scales present on the skin covers their entire body. Their appearance (colour and pattern) of scales vary among species. Therefore, scales become the primary criterion for identifying different species of snakes.

They possess a good sense of vision, and they respire only through the lungs. Snakes live in both aquatic and terrestrial environments. Most of the snakes are non-venomous. However, some species of snakes are venomous. They inject the venom to paralyse the pray and feed on it. Venomous snakes have the ability to kill any type of living organisms. Non-venomous snakes use different techniques for predation. Nevertheless, both these types of snakes swallow their prey without chewing.

Furthermore, snakes have the ability to survive under different environmental conditions. For instance, during the scarcity of water, snakes absorb water in their preys’ body. Moreover, uric acid is their main excretory product which preserves the water content within their bodies.

What are the Similarities Between Limbless Amphibians and Snakes?

• Both limbless Amphibians and Snakes contain cylindrical body types.
• Both types are limbless
• Also, both possess a moist, soft skin
• In both types, the modes of locomotion are gliding and swimming.

What is the Difference Between Limbless Amphibians and Snakes?

Limbless amphibians and snakes look similar since they are limbless organisms. But they belong to two different groups of animals. Limbless amphibians do not have scales on their skin while snakes have. Therefore, this is the key difference between limbless amphibians and snakes. Furthermore, limbless amphibians eyes remain closed while snakes eyes remain open. Thus, it is another difference between limbless amphibians and snakes.

The following infographic representation illustrates more information on the difference between limbless amphibians and snakes.

Summary – Limbless Amphibians vs Snakes

Due to superficial similarities, limbless amphibians are often get misidentified as snakes. But through closer observations, these two types of organisms could be identified separately. Presence of scales on the skin of snakes is the main criterion of differentiating. Other than that, physiologically different characteristics enable us to distinguish these two types of organisms. Unlikely some species of snakes, limbless amphibians are completely harmless to humans.  This is the difference between limbless amphibians and snakes.

Reference:

1.Daniel Cressey “Limbless Amphibian Family Discovered in India.” Nature News, Nature Publishing Group. Available here  
2.Wallach, Van, and James A. Peters. “Snake.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 1 Nov. 2018. Available here  

Image Courtesy:

1.”Dermophis mexicanus”By Franco Andreone (CC BY-SA 2.5) via Commons Wikimedia
2.”2082037″ by susannp4 (CC0) via pixabay