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Amphibians are one of the classes of chordates. The word amphibian means both sides of life. This is because the amphibian begins its life in the water and then finishes it mainly on land. The change of an animal in its appearance from baby to adult is called metamorphosis. An amphibian goes through metamorphosis as it grows from a baby to an adult.
The amphibian, because it must be moist, sometimes hides out in the summer as if hibernating. This is called estivation. It also buries itself in the mud during the winter and hibernates to prevent it from freezing as it is cold blooded.
Common amphibians include frogs, toads and salamanders. They are, on the whole, quite small vertebrates.
System
Type
|
Amphibians
System
|
Muscular-Skeletal |
An amphibian has an inner skeleton with a backbone. It has webbed feet, but no claws. They have attached limbs at the shoulders and hips. With the frog and toad, the front legs are shorter and weaker and the rear legs much stronger for leaping. |
Digestion | An amphibian takes in food through the mouth. The frog has a long tongue that it whips out and grabs insects with. It has a digestive system with stomach, intestines. |
Nervous | An amphibian has a brain and nervous system. It has two eyes, with a third extra protective eyelid for when it is on land. |
Circulation | A amphibian is cold blooded so its body temperature is the same as its surrounding environment. |
Respiration | A amphibian takes in oxygen through the skin. It then goes through the bloodstream directly. On land the amphibian uses lungs. |
Reproduction | A amphibian reproduces sexually. The eggs are fertilized outside of the mother's body. The mother lays the eggs which are in a jellylike layer. The father immediately comes by and fertilizes them. The frog's eggs are black and white. The young frog is called a tadpole and it hangs on to plants. |
Excretion | A amphibian has a thin skin that is moist. |
Symmetry | A amphibian has bilateral symmetry. |
Coloration | A amphibian is green, yellow, brown |