Amphibians are animals which are able to both live on land and in water. They are cold-blooded vertebrates (animals with backbones) and include over 6000 species. Amphibians begin their lives in the water using their gills and tails to survive and navigate. Eventually, they start to develop lungs and limbs which allow them to move onto land.
There are three orders of amphibians, these are; Anura (Frogs and Toads), Caudata (Salamanders and Newts), and Gymnophiona (Caecilians). An order refers to a group of animals which are related. The order which has the most types of species is the Anura (Frogs and Toads), in this order, there are over 5900 species.
Amphibians can be found all over the world, on every continent except for Antarctica. They are freshwater animals which means that they aren’t usually found in saltwater.
Lifecycle
The life cycle of an amphibian starts in the water where a female lays eggs which are then externally fertilized. The majority of amphibian eggs are surrounded by clear jelly and they are usually laid in clusters or singly. The eggs then hatch into tadpoles which are able to breathe under water using their gills. The tadpoles move around in the water using their tails, and they feed on vegetation that they find in the water.
The tadpoles eventually go through a process known as ‘metamorphosis’. During this process, the tadpoles start to grow limbs and go through other physical changes which allow them to survive on land. For example, they grow lungs.
What Do They Eat?
The majority of amphibians will eat any live food that they are able to catch and swallow in one go. This includes things like insects, snails, worms, and slugs. These things make up the main part of an amphibians diet.
Larger amphibians will even eat mice and other large prey. Some amphibians will actively hunt down their food so they can eat it, while other amphibians will wait for the prey to come to them.
Amphibians Can Breathe Through Their Skin
Amphibians are able to breathe through their skin; this is known as ‘cutaneous respiration’. This type of respiration can take place on land and in water. This respiration process takes place due to capillaries which are near the skin, these capillaries allows gas to be exchanged between the air/water and the amphibians blood.
Defenses
Amphibians are the prey of many different other animals. So they need to have defenses which allow them to survive and not be eaten. The main defense that amphibians have is their skin. Their skin tastes really bad and is often toxic, which puts off predators from eating them. Most amphibians secrete poison from their skin as well to ward off predators.
Very toxic amphibians are also brightly coloured which warms predators that their prey could be toxic and that it should be avoided.
Amphibians are also able to camouflage themselves to blend in with their environment to avoid being detected by predators. For example, amphibians which are brown in colour will be able to blend in with the mud and dirt which is everywhere.
