If you have any pictures I can try to identify them for you.

If you have more then one then they are of the Pygocentrus family.

When the crocs were small, and we feed them, the piranhas used to come up from behind the crocs, and take the food out of their mouths.

Im jealous. That is Pygocentrus Caribe

I really want some to put with my Pygocentrus Nattereri (red bellied piranha)