They have bad attitudes, and grow to a manageable 8-10"...They are not unlike any other guapote and I think they prefer harder water than most sa/ca...Nandopsis tetracanthus.....
They can be pretty nasty.You could probably keep a couple convicts with one in a 55.It's hard to say if You could keep anything with Him for sure cause individuals vary.You can usually tell the sex by color pattern.
Here is a couple pics of my male at 2" when i first got him