World's weirdest amphibians

A Chinese giant salamander, the world's largest amphibian, which can reach lengths of up to 1.8m. Their flesh is considered a delicacy in Asia, and their large size makes them easy and lucrative prey Photograph: International Cooperation Network for Giant Salamander Conservation

A Sagalla caecilian. Caecilians are a lesser known group of amphibians that have no limbs and only a very short tail. They are found primarily in tropical regions Photograph: John Measey/Zoological Society of London

A purple frog. This purple-pigmented frog that lives in India was only discovered in 2003 because it spends most of the year buried up to 4m underground Photograph: Sathyabhama Das Biju/Zoological Society of London

Heleophryne rosei - Table mountain ghost frog
Also known as Rose’s ghost frog, this rare species is only found on Table Mountain in Cape Town, where it lives in streams and moist, forested gorges Photograph: Vincent Carruthers

An olm is blind salamander with transparent skin that lives underground, hunts for its prey by smell and electrosensitivity and can survive without food for 10 years Photograph: Arne Hodalic/ZSL

Lungless salamanders of Mexico are a highly endangered species that do not have lungs but instead breathe through their skin and mouth lining Photograph: Jonathan Campbell/Zoological Society of London

Malagasy rainbow frog - a highly-decorated frog that inflates itself when under threat and can climb vertical rock surfaces Photograph: George Sunter/Zoological Society of London

Rhinoderma darwinii - Darwin frog
This is a photograph of Darwin’s frog – a close releative of the Chile Darwin’s frog, which has not been photographed alive and has not been officially seen since 1978 Photograph: Jaime Bosch/Zoological Society of London

A Betic midwife toad. These toads evolved from all others over 150m years ago – the males carry the fertilised eggs wrapped around their hind legs Photograph: Jaime Bosch/Zoological Society of London

Gardiner's Seychelles frog is perhaps the world’s smallest, with adults growing up to just 11mm in length – the size of a drawing pin Photograph: Naomi Dook/Zoological Society of London