Did you mean "latin name" or "scientific name"?Pygocentrus Nattereri
Many people here call Red Bellys either natts or reds. When someone refers to pygos, they are talking about the classification of pygocentrus, i.e., nattereri, caribe, and piraya. We should have our piranha information section up shortly but I recommend visiting OPEFE to find out this info. A link can be found in the Links and Articles.