Amphibians are a class of animals like reptiles mammals and, birds. They live the first part of their lives in the water and the last part on the land. When they hatch from their eggs, amphibians have gills so they can breathe in the water. They also have fins to help them swim, just like fish. Later, their bodies change, growing legs and lungs enabling them to live on the land. The word "amphibian" means two-lives, one in the water and one on land. Like fish and reptiles, amphibians and cold-blooded. This means their bodies don't automatically regulate their temperature. They must cool off and warm up by using their surroundings.
Most amphibians hatch from eggs. After they hatch, their bodies are still in the larvae stage. In this stage they are very fish like. They have gills to breath under water and fins to swim with. As they grow older, their bodies undergo changes called metamorphosis. They can grow lungs to breathe air and limbs for walking on the ground. The transformation isn't the same in all amphibians, but they all go through some sort of metamorphosis.
There are three main types of amphibians frogs, salamanders and caecilians.
- Frogs - Frogs are amphibians of the order anura. They generally have a short body, webbed fingers and toes, bulging eyes, and no tail. Frogs are good jumpers with long powerful legs. Toads are a type of frog. Two species of frogs are the American bullfrog and the poison dart frog.
- Salamanders - Salamanders look a bit like lizards. They have skinny bodies, short legs, and long tails. Salamanders can re-grow lost limbs and other body parts. They like wet, moist areas like wetlands. A newt is a type of salamander.
- Caecilians - Caecilians are amphibians that don't have legs or arms. They look a lot like snakes or worms. Some of them can be long and reach lengths of over 4 feet. They have a strong skull and a pointed nose to help them burrow through dirt and mud.
The Frog lIfe cycle
A great example of metamorphosis in living beings is the frog life cycle, a frog undergoes many stages to reach adulthood. These are:
1. The frog is born as an egg
2. After hatching the frog is a tadpole with a tail and gills
3. It becomes a tadpole with two legs
4. A tadpole with four legs and a long tail
5. A froglet with a short tail
6. A a full grown frog
1. The frog is born as an egg
2. After hatching the frog is a tadpole with a tail and gills
3. It becomes a tadpole with two legs
4. A tadpole with four legs and a long tail
5. A froglet with a short tail
6. A a full grown frog