The Pygocentrus Ternetzi is a very unique Piranha.  They are only found in the lower South America Region from Paraguay to Argentina.  There is much debate to this species, some experts say that Pygo.Ternetzi should be classified as its own species due to their beautiful yellow coloration, while others say that Pygo.Ternetzi is indeed the same as Pygocentrus Natteri (red belly piranha) and their yellow color is due to their locality. 

The Pygo. Ternetzi can be housed with all the other Piranhas in the Pygocentrus family, Caribe, Super reds, Piraya, and Redbellies.  They like a PH of 6.0 and a temperature of 78 degrees.  They are not picky eaters and will eat anything that is offered to them.  Not much is known of the reproduction of Pygo. Ternetzi but many experts agree they breed just like Pygo Natteri.

Food:
Ternetzi can be taught to eat almost everything meaty, ranging from feeders (goldfish, rosy reds, minnows, tetras, basically anything small enough), frozen fish (smelt, cod, catfish, salmon, tuna fish etc.), shrimps, krill, mussels, squid, insects and even small mammals (pinkies, mice....), reptiles and amphibians. Some owners have 'learned' their piranha's to eat food items such as dog- and catfood, cheese, fish flakes and pellets, and even seeds vegetables (such as cucumber), and fruit. Other make their own food cubes by blending different ingredients, ranging from pellets and food supplements designed for aquarium fish, to vegetables and meat, mix it with gelatine, and freeze it.
Redbellies, like other Pygocentrus-species, catch living prey by active chase. They will charge a group of fish, snapping at anything they can get a hold of and will chase individual prey until caught. This can take quite some time, because they are fast swimmers, but can sustain high speeds for only short bursts.
They also sometimes practice the ambush method, but usually only get a fin or mouth full of scales rather than the whole fish.