Forget about Piranha's,  there's a more dangerous species of fish towards man and it has been found in Illinois Lake Lou Yeager.  This type of fish is called a Pacu and it eats testicles, well ok maybe not testicles but nuts.  

The Pacu is a toothy fish that can weigh more than 50 pounds.  It's teeth aren't sharp spiked teeth but more like human teeth. Pacu's normally eat nuts aquatic vegetation and snails.  They really pose no threat to humans.

People of New Guinea might think different about Pacu's.  According to the Metro, In 2011 a Pacu fish known to locals as ball cutter was caught after two fishermen died from blood loss because a fish bit off their testicles.

 

Authorities have announced that the Pacu fish were probably dumped in the water by someone which is illegal to do and they will not survive the winter.