The baby fish are only two centimetres long and have been whizzing around their new home in Vienna’s Haus des Meeres.
Piranhas are a freshwater fish that usually inhabit South American rivers, and are renowned for their sharp teeth and powerful jaws.
However, contrary to what many people think they are not a brutal killer, but a timid fish that hunts in a large school to protect itself from predators.
They also make good parents – removing plants to dig pits to lay their eggs in and then constantly swimming around the nest to guard them.
The newly hatched fish feed on plankton, and move on to smaller fish once they are large enough.
The piranhas are on the second floor of the Haus des Meeres aquarium – which is located in a former anti-aircraft gun tower in Vienna’s Esterhazypark.