What is the Red-bellied piranha and where can you catch it: Amazon Lord. Often feared because of its seemingly aggressive and frenzied attacks, the red-bellied piranha (Pygocentrus nattereri) has a reputation as a voracious predator, with razor-sharp teeth and an insatiable appetite. Although it is extremely variable in appearance, the red-bellied piranha takes its name from the characteristic red belly, which is often a deeper, more intense red in the male piranha, while the rest of the body is usually grey, with silver flecked scales, sometimes appearing creamy-brown on the sides. Blackish spots are often apparent behind the gills, and the anal fin is usually black at the base, while the pectoral and pelvic fins vary from red to orange. The red-bellied piranha also has a dark grey head that is orange-red below, and silvery, red-flecked eyes. Read more on this beast….