A tiny snail found in only one lake in the UK has been dubbed as precious as an Egyptian artefact as conservationists bid to save it.

Several British zoos are setting up so-called ark populations of the glutinous snail, one of Europe's rarest species, using creatures bred in a back garden in Ceredigion.

"Beguiled by their cuteness," conservationist Ian Hughes has made it his "life-defining" mission to protect the threatened mollusc, which was once widespread in UK waters.