Two of the rarest breed of turtle on the planet have been born at a Bristol zoo.

The duo of tiny Bourret’s Vietnamese box turtles hatched at Bristol Zoo Gardens after 12 weeks in an incubator with the temperature set at 26C.

The hatchlings are currently the size of a small matchbox but could live to be 50 years old.

The Vietnamese box turtles got their name because they have hinged plates on the bottom of their shells which allow them to seal their shells front and back like a box to protect them from predators.

The temperature of the incubator is likely to determine the gender of the turtles, however, it is years before zookeepers can be certain.

The new arrivals at Bristol Zoo

Bristol Zoo is the only zoo in the UK which breeds the critically endangered species and the new arrivals brings the number of Bourret’s Vietnamese box turles born at the Clifton attraction to 10.

The breed originates from mid-Vietnam and is so endangered because they are hunted for both food and medicinal use.

They are one of three similar species of box turtles in Vietnam, the others are found in the north and south.

Tim Skelton, curator of reptiles and amphibians at Bristol Zoo, said: “Some species of box turtle are worth their own weight in gold on the black market”

“They are critically endangered which means they are in imminent danger of extinction if nothing improves in their wild status.”

The hatchlings compared to the new pound coin

The zoo is working closely with the Turtle Conservation Centre in Cuc Phuong national park in Vietnam, providing funding, medication and advice about turtle husbandry

The new turtles are being fed on snails, worms and fruit and are being cared for in an air-conditioned room where they will remain until they are big enough to join the Zoo’s other turtles.

Tim Skelton added: “At the very least we are preventing these turtles from becoming extinct. We have a duty to breed them and in time possibly release them in the wild. We want to do more to improve their future.”