A to Z of Nature | Amphibians - Learn From Nature

What makes amphibians different?

Amphibians, like any animal group, have unique traits that are unique to their classification. If you aren’t sure if the animal is an amphibian, check out this list of amphibians characteristics.

External egg fertilization. When it comes to reproduction, amphibians don’t require mating before they release clear eggs with a jelly-like texture. Instead, their eggs are fertilized after. During metamorphosis, amphibians develop fair beyond this state.
Grows 4 legs as an adult. While there are a few exceptions, the majority of amphibians have four legs. Scientists believe that their evolution from the lobe-finned fish is likely why they still require a wet environment.
Cold-blooded. Like reptiles and fish, the amphibian is cold-blooded, which means that it matches its internal temperature to the temperatures around it. In doing so, these animals prevent their environment from damaging their body. Find out all the differences that separate amphibians vs. reptiles here!
Carnivorous appetite. The average frog or salamander may not indulge in large game, but every amphibian is a carnivore. Anything that they can swallow will become their dinner if it is small enough. Some species of toads will even eat mice.
Primitive lungs. Due to the evolution that occurs with every amphibian during metamorphosis, their lungs change as well. They must function as gills while the animal is still underwater, but they allow the animal to breathe through the skin directly as adults.
Lives on water and land. When amphibians are born, they will start their life in the water. However, their natural evolution leads them to live primarily on land. Whether in water or on land, these animals must have a moist environment.
Vertebrates. Every single amphibian, regardless of its small beginnings, has a backbone. This backbone begins as cartilage, changing as the rest of the organs go through a metamorphosis as well.
Like any animal class, there are a few amphibians that don’t quite fit the mold. For instance, though many amphibians develop four legs to walk around on land, there are a few that don’t – caecilians, sirens, and amphiumas. Any caecilian species have more than this simple exception. Along with their lack of legs, these amphibians also have no underwater stage in their life and will release live young during reproduction, rather than expel unfertilized eggs. They can be viviparous, growing their young inside eggs in the body (like pregnancy).

There are THREE types of amphibians :

Anura: Also called Salientia, this group primarily includes toads and frogs, making them one of the most significant orders of the class.
Apoda: As the least familiar of orders, this group of amphibians primarily covers caecilians, which live in the ground and streams.
Urodela: These amphibians include newts and salamanders with tails and a long yet thin body. They also have fewer bones in the skull.

A few links – amphibians groups & websites ….