My 6-WC-Yucao Orinos, all raised together with no other fish since babies are doing the same thing.
The largest most colorful fish is torturing the 4 other fish. I am very sure its a male. All 6 fish are very close in size around 4.5 - 5.0 inches.
The largest fish chases the other 4, every where in the 90-G-tank, they crash into the filter pipes hide in the fake plants, hide behind the filter in-takes.
He will not bother 1 fish though, this other fish goes were it wants. He will swim back to it, give it a few nudges, maybe an open mouth but not attack it. This other fish is not afraid of it and does what it wants.
I swear this is paring behavior, but I am not 100% sure because I have never had a single pair of ANY TYPE of cichlid in my life. I have kept my share of aggressive large cichlids, but ALWAYS in single fish setups, so I have never had to deal with fighting or paring behavior.
It looks like if I remove the other 4, and just keep these 2-fish everthing would be fine.
The newest problem is he now attacks as soon as the lights come on for feeding time. He is so mean now, he will eat a pellet, then chase the others away from the rest of the food, so I am now having problems getting everone to eat, and wasting food.
All the fake silk plants I added have not helped at all. I removed them for a few days, then put them back. Now I am removing them again. The fake plants make it harder for me to vac all the poop from the bare bottom, since there doing nothing to help the fighting issues, and even though they look nice, I am removing them again today for good. Going back to a completly bare-tank.
I am losing my mind with these guys, I am at the point were all I do is feed, change there water, turn off the lights and leave the room. I'm thinking of quitting them, and either getting back into Jaguar cichlids, (a boring but stable single-fish-setup) or maybe trying my luck with a single baby Jardini-Arrowana (never had an arrow before).
Uhh, disgusted

and going crazy..