Pacu fish

Pacu fish, cousins to the piranha and known as "frugivores," have human-like teeth that can crack nuts and fruits. Pacu and piranha – both native from South – have similar teeth, although the difference is jaw alignments; piranha have pointed, razor-sharp teeth in a pronounced underbite, whereas pacu have squarer, straighter teeth in a less severe underbite. Pacu, a safer alternative to meat-eating piranhas, is a popular aquarium fish world-wide.