What do a blind salamander that can go without food for a decade, a frog so small that it fits on a drawing pin and another that lives only in the human burial grounds have in common?
The answer is that, as well as being among the weirdest amphibians on the planet, they are some of the most endangered, yet they have been ignored by conservationists and the public. London Zoo's new list of 10 of the world's most unique and threatened amphibians is part of a project to pinpoint the most unusual species on the growing list of imperilled animals and plants.
The Edge (evolutionarily distinct and globally endangered) scheme is highlighting the plight of amphibians which, because of their slimy image, struggle to attract the level of support that more "cuddly" endangered species get. Helen Meredith, who heads the amphibian section of Edge at the Zoological Society of London, said: "These amphibians are among the most remarkable and unusual species on the planet and yet an alarming 85 per cent of the top 100 are receiving little or no conservation attention and will become extinct if action is not taken.
"These animals may not be cute and cuddly but, hopefully, their weird looks and bizarre behaviours will inspire people to support their conservation. Tragically, amphibians tend to be the overlooked members of the animal kingdom."
Amphibians are the world's most endangered animals with a third of species classified as threatened by the World Conservation Union, which overseas the Red List. A quarter of mammals are threatened and one in eight bird species.
Its latest assessment warned that the number of species on the brink of dying out has risen by 180 since 2006 to 41,415. Of the 10 amphibians selected by the zoo, five are critically endangered – the highest level of alert. Another, the Chile Darwin's frog, whose male protects its young by carrying them in its mouth, has not been seen since 1978 and may be extinct.
The danger to the amphibians is increased by the spread of the chytrid fungus, which is killing frogs and toads worldwide and may be spread by people. The fungus blocks skin pores of infected animals, slowly suffocating them.
The project will begin by funding a resident scientist for each of the Edge species who will monitor and investigate their condition. The species have been selected not just for how endangered they are, but for how genetically unusual they are.
The olm is a blind, subterranean member of the salamander family which hunts for its prey by smell and electrosensitivity and can go a decade between meals. it is found only in a 2,000 sq km area of the Balkans. Six of the Edge species are frogs or toads, including the Gardiner's Seychelles frog the world's smallest with adults growing to just 11mm, and the ghost frogs of South Africa, which include one sub-species that is found only in the traditional human burial grounds close to Table Mountain near Cape Town.
Ten endangered oddities
A limbless amphibian with sensory tentacles on the sides of its head. It can be found only in the Sagalla Hills in Kenya. Critically endangered.
A purple-pigmented frog from India that was only discovered in 2003 because it spends most of the year buried up to 4m underground. Endangered.
One sub-species is found only in the traditional human burial grounds of Skeleton Gorge in Table Mountain. Critically endangered.
A blind salamander with transparent skin that lives underground in the Balkans. It hunts for its prey by smell and electrosensitivity and can survive without food for 10 years. Vulnerable.
Chinese giant salamander
This salamander can grow to up to 1.8m in length and has evolved independently from all other amphibians on the planet. Its numbers have has declined by 80 per cent since the 1960s, and it is now critically endangered.
A highly endangered salamander that does not have lungs but instead breathes through its skin and mouth lining. Critically endangered.
Malagasy rainbow frog
A highly decorated frog that inflates itself when under threat and can climb vertical rock surfaces. Subject of a captive breeding programme at London Zoo. Critically endangered.
Chile Darwin's frog
A frog whose males protect the young in their mouths. This species has not been officially seen since around 1980 and may now be extinct. Endangered.
Betic midwife toad
Spanish toads that evolved from all others over 150million years ago. The males carry the fertilised eggs wrapped around their hind legs. Vulnerable.
Gardiner's Seychelles frog
Perhaps the world's smallest frog, with adults growing up to just 11mm in length. Vulnerable.