Two piranhas have been caught in the Evros River along the border between Greece and Turkey. On July 31 a Turkish
fisherman caught an 18-inch piranha in the river, which started the
mystery. Then this week a 
Red-Bellied Piranha (Photo by Cliff/Creative Commons via Wikimedia)Greek fisherman caught a 9-inch piranha while
rod-fishing on the river using sweet corn as bait -- deepening the
mystery.
The fish, known for their sharp teeth and voracious appetites, are native to the Amazon River in South America. The Evros River is a major point of entry for illegal immigrants from Asia coming into Europe. It is not yet known how these South American immigrants made it to a river in southern Europe. However, it is likely that someone had the fish in an aquarium and emptied it into the river.
Any remaining piranhas are unlikely to have a great impact on the other species. Piranhas are used to a much warmer climate and are unlikely to survive long in the Evros.
Sources: Rianovsti, Ekathimarini
