A new addition to Prague Zoo: the Lake Titicaca Water Frog

Photo: Petr Hamerník, Prague Zoo

We have two dozen two-year-olds who are ten centimetres in body length and twenty centimetres when stretched out. Simply by looking at them, it’s already obvious that the comparison of large grown up frogs to a crumpled rag floating in water is quite justified. These frogs, which never leave the aquatic environment, have large creases on the sides of the body, on the back and on the hind legs. Because of this loose skin, the Titicaca Water Frog is sometimes jokingly referred to as the Titicaca Scrotum Frog.

There is a good reason for this “surplus” of skin. Lake Titicaca is 3,812 metres above sea level, so it contains relatively little oxygen. Since the water frog breathes through its highly permeable skin, it must use the largest surface area it can in this environment. Thus, the skin folds work in basically the same way as gills.

Half a century ago, Jacques-Yves Cousteau introduced the Lake Titicaca Water Frog to the world. His film, Legend of Lake Titicaca (1969), contains fascinating footage of water frogs teeming on the shores and in the depths of the lake. At the time Cousteau’s divers recorded individuals up to half a metre long (with their legs extended) and weighing close to a kilogram. The total number of water frogs was estimated at one billion!

Nobody’s going to make a similar film today. Even as Cousteau was filming, the ecological balance of Lake Titicaca had been fundamentally disturbed by the artificial introduction of the rainbow trout. Later, pollution and other negative factors were added. As a result, water frog numbers have fallen to a fraction of what they originally were. Today it is a critically endangered species. (This does not prevent local residents from using it as an aphrodisiac and medicine. They blend the meat with carrots and other ingredients to make a special greenish cocktail.)

Denver Zoo, together with other collaborating organizations, is endeavouring to help the water frog. For the first time in the Northern Hemisphere, they managed to get this unique species to reproduce. It is a great honour for us to be able to accept some of this brood at Prague Zoo. Of course, we will also try to contribute to the survival of the Lake Titicaca Water Frog – but, unfortunately, without the conservation of Lake Titicaca, in the long run, it will all be in vain.