I just added the convicts, Oscar, and electric yellow that's been with the Oscar from juvenile. All of the fish seem to be minding their own and for the most the sharks swim casually about together and once in a while I will see them playing chase, but it lasts a few seconds then they are back to normal. The only thing that's got me concerned is the Oscar and the way he just sits in the corner of this 75 gal tank and it appears as though hes always gasping for air, but the new tank is well aerated. He grew up in a 10 gal with the elec yellow and the Oscar is about 8" and the elec yellow is about 5-6". Maybe the Oscar is traumatized from living in the small tank and only able to move frontwards and backwards. Looked like turning around was too much work and now he's got all this room to work with and can't comprehend or grasp the concept...???