Amphibians are vertebrates that live in water as larvae and on land as adults. They have moist skin without scales or claws. There are three types of amphibians: salamanders, frogs and toads, and caecilians. Amphibians evolved to live partially on land by developing stronger bones, lungs, and breathing tubes. They can breathe through their skin but some live on land for more available food. Amphibians have external fertilization and undergo metamorphosis from embryo to adult. Frogs jump while toads prefer land. Salamanders and newts have different skin textures. Axolotls never develop lungs while caecilians resemble worms and live underground.

1. Amphibians

2. What are Amphibians?Amphibians are vertebrates that, with some exceptions, live underwater as larva and on land as adultsAmphibians have moist skin that contain mucous glands, and lack scales and clawsOnly three types of amphibians remain on earth today (salamanders, frogs and toads, and caecilians)

3. Amphibian EvolutionIn order to adapt to living partially on land, amphibians had to adapt and evolveAmong these changes, bones in the hips and limbs had to strengthen to protect the internal organsMore importantly, amphibians had to develop strong lungs and breathing tubes to breathe the air on land

4. BreathingAmphibians are able to breathe through their skin, so they can live their entire life underwater if they choose toHowever, some amphibians prefer living on land to look for more available food

5. HearingAmphibians have sensitive hearing. They have Tympanic membranes on the side of their head, which are pretty much exposed ears that help them sense sound and motion in the water

6. reproductionAmphibian eggs are externally fertilizedThey are laid underwater, otherwise they will dry up and perish

7. MaturationMost amphibians just grow into adults. Frogs and Salamanders go through a more dramatic change as they grow from embryos into adults

8. Types of amphibiansFrogs have long legs and make lengthy jumps. They prefer living a life both on land and underwater

9. Types of amphibians (continued)Toads have stocky bodies and prefer a life more adept to land. While toads, like most amphibians, prefer moist places to live in, there are some types of toads that have adapted to life in deserts

10. Types of amphibians (continued)Salamanders and Newts look and act alike. About their only difference is in their skin. Salamanders and smooth and feel almost slimy. Newts have bumpier skin. They both live in damp and moist environments

11. Types of amphibians (continued)Axolotls are Salamanders that can not live on land. They never develop strong lungs to live on land like average Salamanders. They breathe using their feather-like gills

12. Types of amphibians (continued)Caecilians are strange amphibians that resemble worms or snakesCaecilians are legless, have fish-like scales, and eat small invertebratesThey burrow underground in moist soil or live underwater

13. Types of amphibians (continued)Some amphibians are deadly. Brightly colored amphibians like this Poison Arrow Frog warn you that they are not good to eat and will harm you if you touch themTake it as a warning sign when you see brightly colored amphibians or insects, it pretty much means, “Back off!”

14. Amphibians in popular media