I am currently testing a 10" aimara with three 6" brycon, there is occational chasing, most of the time it is fine. There have been few deep teeth marks appear on the brycon though. One adverse affects is that the aimara has given up taking dead food. Might be eyeing up the brycons. It maybe 'Hoplias psychology' that along with curupira if kept with fish that don't present a territorial threat and are too large to eat there won't be a problem. Still goes for algae magnets and hoses though.
Based on previous expearence I would not add two Hoplias together, especially if one was an aimara. as said I did have to pull out my intermedius (which I now think is lacedae). My curupira does go for my fowleri cat, I guess it's another ground dweller and this is in a 8x3 tank. It has crossed my mind to try removing the cat an the curupira and put the larger aimara 18" in there with the now very large brycons and ATF. I think if I try that it will need to be a couple of days watching just incase. I don't trust the large aimara. Still thinking about it. I would be gutted to loose the ATF. it is too large now to go in any other tank.
