Your fish is a Red Belly 100%. Pygocentrus Nattereri. They are illegal in a few states, unless much has changed in the last few years since I stopped breeding them. I haven't kept up on it. Traded in the last of my big Red's for some of the marine fish I have now. Piranhas cannot overwinter in most of the U.S. They are skittish fish, and do not swarm, or attack like in the movies. I had tanks full of large piranhas and never worried about being bitten. My Queen Trigger, on the other had, is a much more aggressive fish than a piranha. If you want a swarming effect, you need to have a large group of small piranhas. The big ones eat a large amount of food every few day, then basically just sit around waiting to be fed in a few days. If you want a more aggressive piranha, you would be better of with some Cariba or old Spilo's, or a single Sanchezi, Rhom or Manueli. Here's a video of mine that for some reason has over 70,000 views. It was a short clip to show an importer out east how many babies were in the next hatch. My last tank of piranhas that now houses triggers and angels. There were a bunch of Cariba's, a few Red Bellies, and a Sanchezi that you can see on the right.