A 'MUTANT' snail, the only one of its kind ever found in Wales, has been discovered in a Pembrokeshire garden.

The snail, named John, was picked off a plant in a St Nicholas by a shellshocked gardener, wowed by the whirls of its shell which have grown upwards into a cone shape.

There is nothing unusual about John's breed, it (snails are hermaphrodites) is a banded snail, Cepaea nemoralis, one of the most common breeds of snail in Europe.

However John's shell is a natural phenomenon thought to occur in between one in 10,000 and one in 100,000, where the whirls of the shell have grown loosely coiled into a pointy ,unicorn horn shaped, shell.

The causes of this natural phenomenon, called scalariform, are still being researched but are thought to include early injury or mite infestation, heritable genetic changes or possibly foreign grains in the shell, similar to pearl formation.

While others have been discovered in Ireland and Lancashire, this scalariform mutant is the only one on record to have ever been found in Wales.

John is now a guest of Ben Rowson, Senior Curator of Invertebrate Biodiversity (Terrestrial Mollusca) at the National Museum of Wales.

"It's very, very rare for the shape of the shell to be changed like this," he said. "I was really excited when I heard about the discovery and thought it would be wonderful to get it for the museum to show to people.

"The museum has the second biggest snail shell collection in the UK with more than a million shells, but we'd never had a shell scalariform and in 20 years of looking around Britain and Ireland I have never found a scalariform Cepaea."

Getting John to Cardiff was not, however, plain sailing (or snailing). The phenomenal snail escaped from its box and fled back into the wilds of St Nicholas. Remarkably it came back and was found days later feasting on a hollyhock.

Ben agreed to provide John with expert care for the rest of its life (expected to be around another two years) and the snail is currently resident in his kitchen, feasting on carrots, sprouts and cucumbers.

When john shuffles off this mortal coil its shell will into the museum's collection and a sample of DNA will be preserved in the hope that in future research may be able to offer some explanation as to why its shell has grown in this way.

Until then John will live in Cardiff where its fame is spiralling; it has already had a photoshoot for Mollusc World magazine and will be shown to the Conchological Society of Great Britain and Ireland at its next meeting.