©Arne Hodauc/Network for Giant Salamnader Conservation
Olm (left) a blind salamander and Chinese giant salamander (right) that can grow up to 1.8m in length

They could all merit a place in a gallery of Nature's strangest creatures. But apart from their strange looks and shapes they have one thing in common - they are all in danger of extinction.

Amphibians as a rule are not cute and cuddly which puts them way down the pecking order of species that need to be saved.

But they are a key indicator species and if they start to decline it is a clear warning that the environment is in trouble.

The Zoological Society of London (ZSL) has drawn up a list of some of the world's most extraordinary creatures threatened with extinction.

They found 85 per cent of the top 100 of the 'world's weirdest and most endangered creatures' are receiving little conservation attention and will disappear if no action is taken.

They include exotically-named species such as the Lungless salamander and the Betic midwife toad.

All amphibian species were assessed according to how Evolutionarily Distinct and Globally Endangered they are and as a result ZSL has launched an amphibians conservation and fundraising initiative which it has called EDGE.

The amphibians are those with few close relatives and are highly distinct genetically. They are also critically endangered and desperately in need of immediate action to save them.

By mathematically combining a measure of each species' unique evolutionary history with its threat of extinction, the scientists were able to give species an EDGE value and rank them accordingly.

Helen Meredith, EDGE Amphibians coordinator, said: "These animals may not be cute and cuddly, but hopefully their weird looks and bizarre behaviours will inspire people to support their conservation"

©George Sunter/Naomi Dook
Malagasy rainbow frog (left) inflates itself when under threat and Gardiner's Seychelles frog (right)

ZSL has identified and is starting work to protect 10 of the most unusual and threatened EDGE amphibian species this year. They include:

*Chinese giant salamander (salamander that can grow up to 1.8m in length and evolved independently from all other amphibians over 100m years before Tyrannosaurus rex)

*Sagalla caecilian (limbless amphibian with sensory tentacles on the sides of its head)

*Purple frog (purple-pigmented frog that was only discovered in 2003 because it spends most of the year buried up to 4m underground)

*Ghost frogs of South Africa (one species is found only in the traditional human burial grounds of Skeleton Gorge in Table Mountain, South Africa)

*Olm (blind salamander with transparent skin that lives underground, hunts for its prey by smell and electrosensitivity and can survive without food for 10 years)

*Lungless salamanders of Mexico (highly endangered salamanders that do not have lungs but instead breathe through their skin and mouth lining)

*Malagasy rainbow frog (highly-decorated frog that inflates itself when under threat and can climb vertical rock surfaces)

*Chile Darwin's frog (a frog where fathers protect the young in their mouths, this species has not been officially seen since around 1980 and may now be extinct)

*Betic midwife toad (toads that evolved from all others over 150m years ago - the males carry the fertilised eggs wrapped around their hind legs)

Gardiner's Seychelles frog (perhaps the world's smallest frog, with adults growing up to just 11mm in length - the size of a drawing pin)

Dr Jonathan Baillie, head of the EDGE programme, said: "Tragically, amphibians tend to be the overlooked members of the animal kingdom, even though one in every three amphibian species is currently threatened with extinction, a far higher proportion than that of bird or mammal species.

"These species are the "canaries in the coalmine" - they are highly sensitive to factors such as climate change and pollution, which lead to extinction, and are a stark warning of things to come.

"If we lose them, other species will inevitably follow. The EDGE programme strives to protect the world's forgotten species and ensure that the weirdest species survive the current extinction crisis and astound future generations with their extraordinary uniqueness."

Further information about the EDGE programme can be found at www.zsl.org/edge.