Red Belly Piranha or Black Piranha

[h1n1]

When you say aggressive do you mean to other fish or people around their tank ect?
I used to keep 3 red bellies in a 55 and they would destroy any other fish put in their tank.
They were however scared to death whenever someone walked past the tank or when you put your hand in the tank to do water changes ect.
The opposite of that was a Red Devil i had for about 10 years.
He was about 14" and he would bang the glass and "attack" anyone walking past his tank (including my german shepherds) And when doing water changes on his tank it was not a matter of IF you were going to get bit it was a question of HOW MANY TIMES am I going to get bit THIS TIME. lol
hope this helps
Eric

well it depends pn the individual rhom but my rhom is a finger chacer and always cruses the intire tank acting like hes boss but if u put ur hand in he just sitts there and if u go to touch him he freaks out and runc away but 1 time he tryed to bite my gravel vac but he only did that 1 time. but he tears up any fish i put inthere, hes never botheres my snails tho

 

[ADeter5]

Yea. I have got a 10" Red Devil that I completely had to pull away from even my bigger Cichlids. I had 3 10" Manganuse in there with him that he would always try to attack.. He's now safely in a 220 with a Red Tailed Cat. Haha