The tree snails have produced 15 young
The last-known colony of a species of tree snail decimated by 'cannibal snails' has been entrusted to Bristol Zoo.
The centimetre-long Partula faba snails, which are extinct in the wild, hail from Raiatea in French Polynesia.
The zoo hopes to save the species, which is also threatened by invasive plants in its native habitat.
Its climate-controlled room is the only place in the world where the snails, which number 88, can be found.
The group has produced 15 young, with the smallest only 2mm long.
The zoo has added to its own colony of Partula faba with snails given to it by Durrell Wildlife Trust and Imperial College London. The last delivery of snails was taken by the zoo in February.
A spokesman said it was a "significant boost" in the fight to save the species.
Rare snails bred at Bristol Zoo
Keeper Grier Ewins said: "Tree snails are incredibly endangered, with Partula faba being one of the most endangered of them all - they really are on the edge of survival."
Invasive snails that were introduced to the French Polynesian islands in the 1970s decimated the tree snails.
Between the mid 1970s and mid 1990s, an estimated 80% of tree snail species were lost.
Loss of habitat, due to aggressively spreading plants such as the South American velvet tree, is also affecting wildlife on the islands.