Prague Zoo Is Once Again Breeding The Snail-Eating Northern Caiman Lizard

Strong jaws equipped with short, tile-like "molars" act as a nutcracker. Photo Petr Hamerník, Prague Zoo

Reptile curator Petr Velenský said, “I’d liken it to polishing up the family silver. In August, it will be exactly thirty years since we started keeping northern caiman lizards. Back then, it was a creature known more from textbooks and museums, there was little information about its life or even photographs. When we successfully bred them in 1998 and published the breeding methodology in our professional magazine Gazella, it was the first time the species had been bred in captivity and documented, a real sensation. Our hatchlings went to India, for instance, as part of an exchange for gharials.”

However, until recently there was only one old female left at Prague Zoo. The keepers have to peel the shells from the snails and feed them directly into her mouth. In order not to interrupt the continuity of breeding, it was necessary to obtain young, unrelated individuals.

Caiman lizards use their tongues to deftly flip their slippery morsels several times around the mouth to separate out the sharp fragments of crushed shell, which are then spat out. Photo Petr Hamerník, Prague Zoo

Prague Zoo obtained the five young caiman lizards - three males and two females hatched last July - from colleagues at Zoo Basel in Switzerland. The remaining female, who is now enjoying a peaceful dotage in the zoo’s rear facilities, has been replaced by this young, vital group in the massive exhibition in the Terrarium. It is here that people can observe their bizarre diet.

Describing it Velenský said, “Almost without exception, northern caiman lizards seek out gastropods with shells. They are usually fed every other day with garden snails that are farmed for human consumption. They will eat up to five snails per sitting, which we thaw out and warm up for them, whole of course. The caiman lizards then break the shells to the accompaniment of loud cracking and munching as they turn the morsel in their mouths, remove fragments of shell with their tongues and prepare the slippery body for swallowing.”

The massive orange head and large black eyes give the northern caiman lizard an attractive appearance. Its wide, dark tongue is also quite captivating. Photo Petr Hamerník, Prague Zoo

Northern caiman lizards belong to the Teiidae lizards and despite their common name, they have little in common with caimans, except for a number of horned, raised scales along the dorsal of the back and also their preference for water. In the water they seek food as well as shelter from predators. This species inhabits the Amazon forests of South America. Due to their secretive way of life, there is still relatively little known about them, making it difficult to estimate the extent and status of the wild population.

The group of year-old lizards in the Terrarium in the lower part of Prague Zoo are now about 60 cm in length, however, as adults they can be up to twice that length and weigh around four kilograms. Photo Petr Hamerník, Prague Zoo