Amphibians species are one of Canada’s vulnerable ecosystem inhabitant and amphibians should be protected to insure their conservation. Canada is home for 42 species of amphibians which populations are declining in Canada. Amphibians are unfortunately an ecological indicator and in the last decades they suffered a dramatic population decline all around the world. 37% of Canada’s amphibian species have declined to the point that they are now designated as endangered, threatened, or species necessitating special concern.
Amphibians species are members of the class Amphibia, a group of vertebrates that include toads, frogs, newts, Spadefoots, Mudpuppies and salamanders. In Canada the amphibians species are composed of 2 orders the Anura ( frogs and toads ), Caudata ( Salamanders and newts ).
Most Canadian amphibians species lay their eggs in water and the newborn goes through a metamorphosis from a juvenile water breathing phase to an adult air breathing phase, but some retain the juvenile water breathing form all their live. The Amphibian skin is permeable to water and contains glands which keep the skin from drying out. Most amphibians species are able to exchange gasses with the water or air via their skin.
Due to their vulnerabilities to predator all amphibians have developed poison glands as a defence mechanism, although toxicity varies by species. The skin colour of amphibians is due to pigment cells called chromatophores. Bright colours usually indicate an exceptionally toxic poison.
There are currently about 4600 species of amphibians in the world, 42 species of amphibians can be found in Canada. They fall into two major groups, the Caudata (mudpuppies, salamanders, and newts) and the Anura (frogs and toads).