Previous knowledge: in the 1st lesson students learnt the main feautres of vertebrate animals.
2. Vertebrate animals: amphibians
Students watch this video that contains the main characteristics of Amphibians
Hello everybody! Today we’re going to look at a truly amazing group of vertebrates... When they’re born they usually live in water... but when they grow up and become adults they spend most of their time on land. We present - the Amphibians! All amphibians have some common characteristics that you should know about so you can recognize and differentiate them. Amphibians have thin, bare skin, with no hairs and scales to protect them. Most have four legs and a membrane between their toes that allows them to move much better in the water. Amphibians are oviparous, but they don’t incubate their eggs after laying them... they abandon them and don’t care for their young. Not very good parents, huh? When they hatch, they’re small larvae and live in water. Slowly... very slowly... their bodies go through a process called metamorphosis. During this process, the body of the amphibian... changes... their front and rear legs, their limbs, grow... and their heads and their bodies develop, so they finally look like their parents. In the early stages of their lives... amphibians breathe through gills, but when they grow up and become adults... they breathe with their lungs. The problem is, their lungs are very small, and cannot get all the oxygen they need to live. But nature is very clever... and has solved this problem by allowing them to breathe and get the oxygen they need... through their skin. That’s why they need to be near water - to keep their skin wet. In the early stages of their life, some amphibians are herbivores, but when they grow up... most become carnivores. So they need to hunt... Some have a long, sticky tongue they shoot out to capture prey. Aren’t amphibians fascinating? And also a bit strange?! So let’s remember the most important characteristics... Amphibians are vertebrates; they’re oviparous; in the early stages of their life they live in water as larvae, but slowly they change until they look just like their parents. This process of change is called metamorphosis. Amphibians are carnivores, so they have to hunt to eat; they have thin, smooth skin, and breathe through their skin and with their lungs. Amphibians are so interesting, aren’t they? Goodbye for now everyone, and don’t forget to subscribe to Happy Learning!
Students read the following text about amphibians.
What makes and amphibian?
Amphibians are animals that live part of their lives in water and part on land. They usually have soft, moist skin that is protected by a slippery layer of mucus. They also tend to live in moist places or near water to keep their bodies from drying out. There are three main groups of amphibians: caecilians; salamanders, newts, and mudpuppies; and frogs and toads.
Are vertebrates (which means they have a backbone or spine)
Are ectothermic. Also known as “cold-blooded,” ectothermic animals cannot regulate their own body heat, so they depend on warmth from sunlight to become warm and active. If they get too hot, they have to find shade or a burrow to help them cool down.
Breathe through their skin.
Go through metamorphosis. Young amphibians hatch from eggs, but do not look like their parents. As they develop, their body shape changes.
Now you are ready to work on the following activities where you will have to put your knowledge about amphibians in action.