According to Ananova Czech newspaper Blesk reports that South American piranhas have been released by an unknown prankster into an East Bohemian water known as Rosnicky pond.
Local angler Martin Konecny said: “I was not the first to catch this fish in the Rosnicky pond. Piranhas appeared on the fishing hooks of three people before me.”
He added that he first knew there was something wrong when he saw bloody bite marks on the carp that inhabit the pond.
Jiri Moravec, an expert from the Czech National Museum, said: “Piranhas appear from time to time in Bohemia. Most of the time, however, they are put into our waters by aquarists who don’t know what they’re supposed to do with this fish when it grows up in their aquariums.” 
Fishy Facts
The piranha (also known as the caribe) is a ferocious, schooling, fresh-water fish. It is native to warm lowland streams and lakes in South America, east of the Andes Mountains. Piranhas have been introduced to other places, including Northern Brazil, Hawaii, and parts of Central and North America. There are many species of piranha; they belong to the genera Pygocentrus and Serrasalmus. They reproduce by laying eggs.
Piranhas range in colour from yellow to steel-grey to bluish to partly red to almost black. They range from 6ins to 2 feet (15-60 cm) long. Piranhas have a bulldog-like face with a very large lower jaw and many razor-sharp teeth. The teeth are replaceable; when one is broken off, a new one grows in its place.
Piranhas are opportunistic carnivores (flesh-eaters). They eat aquatic and land animals that are in the water. Some of the prey includes fish, molluscs, crustaceans, insects, birds, lizards, amphibians, rodents, and carrion (dead meat). These fish are diurnal (most active during the day).
Many animals prey upon piranhas (especially young piranhas), including other piranhas, caimans, water snakes, turtles, birds, otters, and people (piranhas taste good).
Piranhas are attracted to frantic splashing , like that of an injured animal.
Piranhas are drawn to blood. An open wound on an animal or human will bring piranhas in large numbers.
In Brazil farmers who are forced to take there cattle across water to get to grazing areas lose an average of one animal per crossing to piranhas. It has been said that some sacrifice a weak or injured animal to insure the safety of the heard.
