Ask a Naturalist: What is an amphibian?
November 24, 2020
Written by Sara Tabatabai
Simply put, an amphibian is an ectotherm (cold-blooded animal) comprising frogs, toads, salamanders and newts. Some believe that amphibians are invertebrates, animals lacking a backbone, when really, they do! Frogs, toads, salamanders, and newts all have a skeleton and are thus vertebrates (animals with a backbone).
Fun Fact!: The word amphibian come from an Ancient Greek word “amphíbios” meaning “both kinds of life”. This refers to their incredible life cycle where the first part of their life is in water and the second part on land.
All amphibians start their life in water. Eggs are laid in water where they hatch and begin their journey as a tadpole. Frog and toad tadpoles look nearly identical and can be difficult to identify species until they reach young adulthood. Salamander and newt tadpoles, on the other hand, look quite different than their amphibian cousins. Amphibians undergo an incredible metamorphic change that allows them to transition from living in water to living on land. As the tadpoles eat and grow, their back legs are the first to develop. Soon after, their front legs grow. As they continue through their life cycle, they develop lungs to replace their gills in order to prepare them for life on land. If the tadpole is a frog or toad, they eventually lose their tails!
Now an adult, amphibians live the remainder of their life on land. It is important for many species to live in damp habitats to keep their skin moist which supports breathing and absorbing water through their skin. That’s why it’s important that we refrain from picking up amphibians to prevent them from absorbing anything off our hands (like hand sanitizer) that could be toxic to them. Once it is time to reproduce, amphibians will return to water to lay their eggs and continue the cycle!
Check out this in-depth video (or click the image below) of the development of a Wood frog from egg to adult!
Also watch this video (or click the image below) all about amphibians. It's especially perfect for the kids!
Use recyclable materials to create this amazing frog life cycle craft!
Explore the difference between the scaly skin of a reptile and the slimy, porous skin of an amphibian using two hard boiled eggs! Learn who would be more affected by pollution and think about ways you can help protect aquatic habitats! Check out the activity here!