One of the best pet fish ever. I got mine as a sickly pet store fish with ich. He was 1.5" big when I got him. He is over a year old and 8". He likes to eat plants but is not too bad. Not plant tank friendly. These fish are one of my all time fav. They are out going and really easy to care for. They get along with many many different kinds of fish. But can eat small tetras. But are not big time hunters. They play nice with other cichlids of many sizes from rams to oscars. They are not aggressive semi aggressive would be a better term. There are exception. I have head of some nasty severum. But for the most part they are really tame and laid back. Best fish I ever owned.
Like the comment posted above, I have never seen really aggressive behavior from these fish. Though these fish are predators, as long as you do not put anything in your tank with them that will fit into their mouth you will probably never have a problem. I usually only consider a fish aggressive if they attack fish their size (or occasionally even bigger), because this is not a feeding response. I have kept them in tanks with other cichlids (including oscars) and in community tanks with semi-aggressive fish and never had a problem with aggressive behavior. In fact, when grouped with other fish known to be aggressive I have seen severums which could not get enough food because oscars, Jack Dempsy's and whatnot were always first at the feeding trough. I prefer to keep these fish in a species tank or with semi-aggressive fish, but I do usually have a few of these in my smaller South American tank. I feed mine cichlid pellets and shrimp pellets, and they tend to do just fine. I have three small ones (1 1/2") right now, and will probably add a few more in the next several months so I can try to breed them. If anyone on this forum has any breeding tips for this species, please PM me.