I have owned rainbow cichlids, jewel cichlids, firemouths, convicts and keyholes. You'd think a convict or a jewel would be the most aggressive but no. I have a fully grown male rainbow cichlid that acts like a pirhana. I have been bitten by that fish about a half dozen times and he's TRIED to bite me literally 5 times that much. He forced me to re-home another male rainbow or he'd have killed him. He forced me to get another tank so that I could keep my female convict alive and until recently, I had to keep him alone otherwise he'd destroy all of my fish. I keep reading that rainbows are semi-aggressive and yet this one rainbow is far more aggressive than anything else I have owned. I'm quite jumpy when I put my hand in the tank to clean the glass or vacuum the gravel because he WILL attack me. Anyone else had this with rainbows?