Low temperatures in ponds and waterways has meant a rise in the number of ‘Peter Pan’ tadpoles across Suffolk.

Experts and amphibian groups say they have seen an increase in the phenomenon, which means tadpoles do not change into frogs or newts – instead remaining in a state of extended childhood.

Examples have been known to reach up to 12cm in length, with reports of Suffolk tadpoles with heads as big as 2p coins.

John Baker of the Suffolk Amphibian and Reptile Group, said the phenomena is more common with newts but said he had noticed an increase this year.

He added: “I have spent quite a long time working on large natural ponds that tend to be colder, but they also turn up in garden ponds as well. It’s a consequence of last year being a cool summer and this year we are going in the same direction – a late spring and fairly cool summer.

“The newts I’m finding are certainly tadpoles that were produced last year. In a good year they would have turned into newtlets by the end of the summer/early autumn and leave the water.”

Mr Baker said other large tadpoles found in the county were likely to be a year old and may have overwintered from 2012 and added that common frogs are currently about three weeks behind in their growth cycles.

Peter Pan tadpoles, despite their name, can eventually catch up. Mr Baker said: “They will grow up, if they spend the winter as tadpoles they generally turn into young newts or frogs – just a bit bigger than normal ones.

“But they should reach sexual maturity normally. In the case of newts, they can reach sexual maturity in a tadpole form – so you get something that looks like a newt but it has gills on it.”

Sarah Colnet, who works for Suffolk Wildlife Trust, found a giant tadpole while clearing out an overgrown pond at her home in Athelington, near Stradbroke.

She said: “It was pretty big, it’s head was about the size of a 2p coin, which when you consider what tadpoles normally look like, it’s this sort of big, mutant big. They are really chunky, really fat. They are really strange. It’s because they haven’t got the food and the right temperature to develop further.”

Mr Baker asked anyone finding a Peter Pan tadpole to get in touch via www.sarg.org.uk