Difference between Amphibians and Reptiles

Amphibians and reptiles are the two classes of animals. The branch of zoology which deals with the study of the amphibians and reptiles is known as Herptology, and the person who keeps these animals is known as Herpers. Amphibians and reptiles both belong to the same phylum and subphylum.

Amphibians live on both terrestrial and aquatic environment so regarded to have dual lives. They spend half of their life on land and half on the water and have porous skin which requires moisture. Reptile is the group of animals that live on land, have a scaly skin, breathe through lungs and lay eggs. Flaky skin of reptiles prevents them from the harsh environment of the earth. The fundamental difference between amphibians and reptiles lies in their life cycle and physical appearance.

Animals of these two groups have many similar characteristics. In earlier times, there was no such different zoological classification because of similarities. Amphibians and reptiles have been kept in the same phylum and subphylum because of being ectothermic (cold-blooded) and usage of camouflage for protection from predators.

It was found that reptiles transitioned from amphibians million years ago because of environment change and other evolutionary processes. Amphibians are also said to be the link between the fish and the terrestrial reptiles, the first animal who migrated from sea to land. Seymour is the organism known for the link having skull properties like amphibians and skeleton of reptiles.

Comparison Chart

What are Amphibians?

Amphibians spend dual life, their larval stage in water and adulthood stage on land. These are the type of ectothermic vertebrates found in marine water, freshwater, land etc. They can maintain their body temperature according to the atmosphere.

Amphibians exhibit external fertilization in which male sperm and female egg are fused in water, and the newly born organism survive in water until their larval stage. The remaining life is then spent on the land. The eggs are covered with a smooth gel-like substance. Because of this reason, amphibians are also known as oviparous. The life cycle of the amphibians undergoes the process of changes; metamorphosis and body develop into an adult.

Amphibians use both gills and lungs for respiration. They use gills while breathing in water and use lungs for breathing on land. The skin of amphibians is porous, sticky and slippery. They use camouflage which means they have the ability to change skin colour according to the change in environment.

Amphibians do not have sharp teeth and nails like other animals but secrete toxins which are highly poisonous for killing the predator insects for protection. Amphibians have webbed feet and short limbs which aid them in jumping and swimming.

Types

There are three main types of amphibians; newts and salamanders (urodeles), frogs and toads (anurans) and caecilians. A common misconception is that snails are also amphibians because of their presence on land and water. But the fact is there are two distinct categories of the snail. Snails are not amphibians.

What are Reptiles?

Reptiles are also ectothermic vertebrates. They live only on the terrestrial environment. Reptiles do not go under the process of metamorphosis. They lay eggs on land and use lungs for respiration. The skin of reptiles is scaly and hard composed of keratinous skin. The type of skin is not permeable to water. This type of skin helps them in living terrestrial harsh environment and saline environment. There are almost 9000 species of the reptiles found till yet.

Reptiles show internal fertilization and incubate their eggs. They dig the gravel, sand, dirt and lay eggs there to maintain the temperature of the eggs. Reptiles have four limbs which are helpful for them in running and swimming. Snakes are an exception as they do not have limbs and they crawl.

Types

There are four classes of reptiles; crocodilian, Squamata, testudinal and Rhynchocephalia. In Crocodilia group, crocodiles and alligators are present. In Squamata group, lizard, snakes and similar creatures are included. All turtles are included in the testudines group. The Rhynchocephalia group has only two species.

Key Differences between Amphibians and Reptiles

1. Amphibians spend half of their lives on land and half in water whereas reptiles live on land.
2. Amphibians spend their larval stage in water and adulthood on land whereas reptiles live on land except a few.
3. Amphibians show external fertilization, whereas reptiles show internal fertilization.
4. Amphibians can breathe through gills as well as through lungs whereas reptiles can breathe only through the lungs.
5. Amphibians have the limitation of visualization up to narrow bands of the colour spectrum, whereas reptiles have a varied range of colour spectrum and can visualize different colours.
6. Amphibians have three-chambered heart whereas reptiles have three-chambered heart, but the ventricle is further divided through a spectrum.
7. Amphibians lay their eggs in the water which are covered with soft shell whereas reptiles lay their eggs in the land which are covered with hard protective shells.
8. Amphibians have remarkably smooth, sticky, moist and highly porous skin whereas reptiles have dry, hard and scaly skin.
9. Amphibians secrete toxins from the skin which provide them protection whereas reptiles have hard scaly skin for protection.
10. Amphibians have webbed feet which help in swimming and jumping whereas reptiles have four limbs which help in running and swimming.

Key Similarities

1. Both amphibians and reptiles belong to same phylum “chordate” and subphylum “vertebrata”
2. Both amphibians and reptiles are ectothermic or cold-blooded as they maintain their body temperature according to the external environment.
3. Both use skin alteration for protection and thermoregulation for the maintenance of body temperature.
4. Both are mostly omnivores.
5. Both have an opening “cloaca” which acts as a common opening for the intestinal, genital and urinary outlet.

Conclusion

In conclusion, both amphibians are reptiles are types of cold-blooded vertebrates with some different characteristics.