Five Fun Amphibian Facts – Amphibian Week

7 May 2024

Giant salamanders

The largest amphibians in the world are to be found in China. The Chinese giant salamander (Andrias davidianus) lives in the lakes and mountain streams of central China’s Yangtze river basin and is, unfortunately, considered critically endangered. In 2007, one salamander kept at a farm was measured at 1.8 metres long and weighed 59 kilograms. Average adult salamanders weigh around 25 kilograms and measure just over a metre long – larger than many breeds of small and medium dogs!

Neotenous axolotls

Amphibians, usually, begin their lives as aquatic animals in a larval stage that cannot survive out of water (often called tadpoles). To reach adulthood, they go through metamorphosis, lose their gills and begin to live on land.  The axolotl (Ambystoma maxicanum), however, is a species of salamander that reaches adulthood without passing through metamorphosis – keeping its gills and living in water throughout life. This is because they lack the ability to produce thyroxine, crucial in metamorphosis. This process of retaining juvenile features into adulthood is known as neoteny.

Harmless frogs

In nature, aposematism is the name given to the way animals advertise their unpalatability to potential predators – such as the way wild poison dart frogs advertise their toxicity through by their bright coloured skin. However, despite some of these frogs being some of the most toxic animals on the planet, their toxicity is due to their wild diet (often ants). This means that, although it may seem dangerous to an outsider, dart frogs kept in captivity, without a wild diet, are completely harmless.

Worm-like caecilians

Probably the most unrecognised of the three amphibian groups (alongside frogs and salamanders) are caecilians. These limbless, worm-like animals live in soil or streambeds in areas of Central and South America, Asia and Africa. Whereas the smaller species resemble worms, the larger species – such as the Thompson’s caecilian of Columbia (Caecilia thompsoni) – resemble snakes. Their very sparse fossil record means little is currently known of their evolutionary history.

True toads

Frogs and toads may be confused as two different groups of amphibians – whereas ‘toads’ are actually a family within the order Anura (frogs). True toads come from the frog family known as Bufonidae, of which there are close to 600 species. Luckily, we are not misnaming the common toad found in UK, as this common or European toad is indeed a true toad, with the species name Bufo bufo. It’s distribution stretches from Siberia to North Africa – a truly adaptable amphibian.