I have two Convicts. In a tank with 2 Platies, 3 Zebra Danio, 5 Tiger Barbs, 1 Tricolor (Bala), 1 Red Tailed Black Shark, 2 large Tinfoil Barbs and 2 Rainbow Cichlids all living peacefully in a 175 L Aquarium. Now I don't think these Convicts are wussies, but they have never hurt or showed any signs of aggression to any other fish. They are both females and are somewhat young. They are really great fish...
I don't think these fish are not at all aggressive, unless you compare them to Tetras or other peaceful type of fish. My Convicts, two females and one male, are the weakest of my fish. The african Cichlids I have, both types are zebrasare much more aggressive. Even my Pacu punks the Convicts. These are peaceful fish that like to be watched and even touched lightly and played with.
I had 2 pink and 2 black convicts in the same tank initially. The 2 pink ones paired up and I decided to move the black ones to another tank. The remaining pink ones started cleaning up a pot I gave them and I saw eggs a few days later. Strangely, these two pink convicts are both female (I later found out because both have orange bellies). True enough the eggs didn't hatch and turned white and were gone (probably eaten) after a few days. One female started beating and chasing the other female all the time. I then introduced a pink male and he immediately paired up with the aggressive female. I saw eggs a few days later but the female started to beat her male and the other female and forced both into the far corner. I decided to remove the 2 and only leave the female in the tank. There are fry everywhere now and she's taking really good care of them, digging them out if they're stuck under the gravel etc. Only problem is she seems to lose interest in food and only swims all over the tank finding babies that aren't with the group and bringing them back to the group.
The 570 L tank I have has very few fish in it. That is, until this morning. I was checking my smaller breeder tanks and exclaiming about the baby fish when my son said I had babies in the large tank too. Sure enough, I had a cloud of tiny convict babies. I only have two black convicts, two jewel cichlids, and two other cichlids all about the same 8 cm size. I added the black convicts about three weeks ago and have enjoyed watching them move in. First they took over one corner of the tank and now they moved the jewels out of their established area and moved in there. Now they have tons of little ones and move them around every so often. I was hoping I could get a few to survive, but after reading other stories on this page that shouldn't be a problem.
I have had a number of disasters with delicate, expensive fish. Then someone recommended some convicts to me and I was very keen. They are not only cheap but are beautiful to look at. At first I was worried about getting them because I had read in books that after breeding the male would "torture" or kill its mate but I still went ahead with it and bought 1 male and 2 females. There was a bit of fin nibbling but nothing life threatening. I was successful in breeding and ended up with 9 extra cichlids. After a while the male did eat about 5 babies. To whoever is starting an aquarium, I highly recommend this fish!
I was watching my community tank which included 2 convicts. The male was near the bottom of the tank, not far from the back. A cloud (like a genie out of a bottle) appeared behind him which, on closer inspection, became about 50 fry. OK, no problem I thought. Mummy and Daddy (which I had called Ronnie and Reggie after the Cray twins) then went quite insane, attacking the other fish in the tank. The next day 9 fish had been killed and the rest were bruised and battered. I had to rush out and buy a new tank for my poor fish, or what was left of them. I got on the net to find out more about these fish. The strangest thing that I read was that they were like guard dogs, very nasty, but they knew and trusted the person who fed them. I also keep piranhas so my next step was to test the convicts. I put my hand in the water in the tank. They looked at me. OK, next I moved my hand slowly towards the male who was babysitting. He just waited. I put my finger next to him, with all the fry swimming around my hand and he came and rubbed the side of his body on my finger. I love convicts. I have never met a fish with so much character.