My Oscar "Fugly" in my avatar is selectively aggressive. Jaguars of any size are dead. Dominates other oscars. Fine with parrots and centrals for the most part. But when she wants something dead, it will be dead.
i think its a red texas cichlid the rio grand ones. i have one 3in in a 90g. along with a green terror 5in and jd 7in and a few others. and the texas is always fighting over space.! once in a while they get along
Ive kept just about every SA/CA cichlid over the years. Most aggressive i have had was a 15" Male Dovii. The only thing that kept him in check was a 15" female jaguar cichlid. But im sure it was a only a matter of time untill the dovii out grew the Jaguar and he would have dominated her. I have kept Umbii as well but nevr had them get to adult size to comment on thier behavior.
Only going off personal experience but oscars are puffs!! I had 2 10" each got whooped within an inch of their life at the same time by a 5" green terror.
My midas on the other hand is just brutal ive watched him as he's grown kill everything in his tank including his female. Earned himself the name 'Bully' and gets my vote
I believe different blood lines also of the managuese has something to do with it. My male in the 125 by himself since I have kept many fish over my years this guy is brutal. My other breeding jags were tame compared to this monster. He has killed three large females and when he was 3 inches decided to murder every fish the first night I got him. He was a return to my local PFS for same reason. He killed three texas cichlids twice the size of him and large pleco. He doesnt eat them just kills them. I cant stick my hand in his tank and if I take the lid off he splashes me constantly. Everything in the tank is out and he beats up the filter constantly. Serious I need to catch a full size warmouth and record his brutal attack. He doesnt chase he rams them full tilt against the glass pinning them against a corner and pressing until no life. I watched him do it to a female jag and before I could get her out he already did internal damages that she died from within hours.
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