Pacu fish suddenly appeared in Russia

The pacu fish, the close relative of the dangerous carnivorous piranhas, suddenly appeared in the western city of Kaliningrad (Russia), on the Baltic Sea.

>>>Warning fish species 'bite testicles'

According to the Moscow Times, leading sources from Interfax, their appearance makes local people and environmental experts extremely worried.

The fish pacu appears in Russia.(Photo: Getty)

Where to find the pacu fish in the Baltic Sea.(Photo: Getty)

The main pacu fish appears in South America, called "Testicle-Eating Fish" by Russian media, "Fish eat testicles" . This fish has a monstrous characteristic of eating swimmers' testicles in the waters where it lives, mistaken for their favorite nuts.

A resident of Kaliningrad happened to find it and gave it to marine biologists.

An adult fish pacu can grow up to 90cm and weigh up to 25kg. It usually eats nuts, leaves, underwater vegetation and snails.

Pacu fish originated in the Amazon basin, then appeared in Papua New Guinea in the 1990s. It used to make 2 fishermen in the Pacific Ocean die of blood loss after being bitten off the testicles.