Frogs and toads; newts and salamanders; and caecilians make up the group known as amphibians. Amphibians are ectothermic, which means their body temperature changes with their environment. Animals that are ectothermic are often referred to as being ‘cold-blooded’, although this is not a very accurate or helpful expression.
Water plays an important part in the lives of amphibians. Amphibians breathe and take in water through their skin. Keeping moist allows the exchange of oxygen and carbon dioxide between the amphibian and its environment to continue. Most amphibians also require water to mate and to lay and fertilise their eggs.
Other amphibians, called ‘direct developers’, lay their eggs in a jelly-like mass that does not need to be in water. They emerge from the mass as fully-formed amphibians. Even more amazing, is the Gastric Brooding Frog that carried around its eggs in its stomach. Eventually the frogs emerged from the mother’s stomach fully formed. Sadly, Gastric Brooding Frogs, which were found in Australia, are now believed to be extinct.
Amphibians around the world are threatened by climate change, habitat destruction and a disease called Chytrid fungus which have led to worldwide extinctions. Zoos and other conservation organisations are looking for a way to save amphibians.
Find out what Perth Zoo is doing to help or look under the Conservation and Research section of this website.
What is the difference between a frog and a toad?
There are more than 4,500 known species of frogs and toads in the world. There is very little difference between frogs and toads. Frogs tend to have smoother skin than toads and their lives are more closely tied to water. Toads, however, live mostly on land and have warty skin.
What are caecilians?
Very little is known about these worm-like amphibians. So far 124 species have been discovered. They are limbless and have very sharp teeth. They have shiny skin which is ringed and has skin folds called annuli. Some caecilians live underground, while others live underwater. Those that live underwater have a fin and a tail they use for swimming.
Click on the amphibians below to learn more about those on display at Perth Zoo.