So imagine the surprise 47-year-old mum of two Emma Young, of Alexandria, had when she carried out her washing and almost tripped over an exotic yellow-bellied slider turtle.

Emma said: “It was slap in the middle of the patio with its head and legs all tucked inside its shell."

The former Oxfordshire estate agent has worked on the front desk at Loch Lomond Sea Life Centre since 2006 and is used to seeing exotic marine life on a daily basis.

She added: “I must confess I had no idea what this one was at first though, I thought it was a tortoise.” Emma’s daughter 14-year-old Kirsty wanted to keep it, but realising it would need a huge tank Emma instead contacted Sea Life curator Mark Hind, who agreed she could take it into work.

“We’ve posted a picture on Facebook and if anyone is desperate to retrieve their lost pet we will be thrilled to see them reunited,” she said.

Mark Hind suspects the slider, thought to be female, is more likely to have been deliberately abandoned.

“The species is one of several that were imported in their thousands to meet a demand for pets spawned by the Teenage Ninja Turtle craze,” he said.

“Fans purchased these cute baby turtles without really considering how big they grow and how much care and feeding they need.

“Consequently lots of them have ended up being dumped in ponds and rivers. Fortunately they can’t breed successfully in our climate, but they are voracious predators and can wreak havoc among native marine life.” The most common species in their range in Florida and Virginia, yellow-belied sliders can live to 30-years-old and even longer in captivity.

If nobody comes forward to claim her, the unusual garden visitor will be transferred to the Scottish Sea Life Sanctuary in Oban, where there is a special ‘Turtle Shelter’ housing several other refugee turtles and terrapins.

Emma’s home is separated by a road and rail line from the River Leven, but she wonders if perhaps that’s where it came from.

“The good news is that she doesn’t appear any the worse for her adventure,” she added.