What's in a name?
Also known as African clawed frogs, platannas have powerful back legs and sharp claws on three of their toes. Most of the names for the common platanna reference its admittedly weird hands. Its scientific name is Xenopus laevis, which roughly translates from Greek to “smooth strange-foot”.
“Platanna”, the most commonly used name in South Africa, is Afrikaans and comes from the old Middle Dutch “plat-hander” – meaning “flat-handed”. Internationally, it also carries the name African clawed frog or claw-toed frog, again emphasising its unique feet (more about their toes below).
They hold prey in their mouths and tear it with an overhead “kick” by their back legs.
Where do they live?
Platannas are found throughout the swamps, wetlands, ponds, lakes, and slow-flowing rivers of Sub-Saharan Africa. Because they are so adaptable, platannas that have escaped as pets or laboratory animals have been inadvertently introduced to other parts of the world as an invasive species, including North America, the UK and China.
These frogs are almost completely aquatic and only ever leave the water if forced by drought or other significant disturbances. In cases of drought, they will bury themselves in mud and wait for up to a year for rains to return. But, they can also use their powerful hind legs to cover large distances on land quickly and have been known to travel over 2km to find alternative bodies of water to live in.
What do they eat?
Platannas aren’t your stereotypical frog. They don’t have tongues to catch insects, nor do they have teeth to enjoy any particularly specialised diet. Instead, these carnivores rely on their hands, feet, and enormous mouths to feed!
Platannas are not fussy, they will prey on small fish, tadpoles, crustaceans, insects, worms, and any carrion they find – they will even eat their smaller neighbouring platannas! When they spot prey, they lie motionless, and when their prey gets too close, they will quickly use their front hands to grab food and shovel it into their open mouths.
Platannas’ back legs aren’t just for swimming – the three last toes on each foot have sharp claws that are used to rip up large prey or pieces of food into smaller, bite-sized pieces.
Platannas have terrible eyesight. Unlike most frogs, which use their eyes to find prey, platannas rely on their sense of smell and specialised organs (lateral lines) to detect vibrations and pressure changes. Some Aquarium fans might remember that lateral lines are an organ that fish have too.
As tadpoles, platannas are filter feeders that consume microscopic plankton and algae. Because microscopic organisms are the first part of the ecosystems that recover after droughts, platanna tadpoles can feed in waters where adults can’t… which means the tadpoles can serve as a food source for the adults until larger prey appears.
Interesting fact...
In the 1930s, it was discovered that a female common platanna would spawn if injected with the urine of a pregnant woman (the hormone chorionic gonadotropin being the active ingredient). In the 1940s and ‘50s, this was the only available pregnancy test, and many hospitals around the world kept and bred platannas to perform such tests.
