Some who have kept various speicies of Piranhas will tell you that these Piranhas are more aggressive than the Black Piranhas
1.Caribe Piranha
2.Altuvie Piranha
3.Brandti Piranha - a very nice and rare piranha
4. Elongatus
5. Irritant
Read this site in which they will mention various species of aggresive piranhas::
http://www.aquascapeonline.com/store...?idCategory=22