After doing alot of research (p-fury and other pages) yesterday to confirm what species of piranha I have, I am pretty sure I have a red belly (natt). But just to be 100 %positive what are the main differences between a red belly and the caribe? Cuz I have seen some that are kinda close in appearance. I asking mainly because of tank size. I do have to say this site is THEE BEST for all you could ever want to know about your P's. Rock on guys!!