Singularly females seem to be more accepting of other new world tankmates at least it's been that way at my house - the male 100% intolernate of an other large new world cichlid. He will relentlessly hunt them down til' death. A pair in my experience can live in a 75 til they breed - then the female becomes his target hence divider. Currently in a 125 my pair make nests 3 ft long - they require lotsa room - the more room the better the chance of tankmates. I've seen video on this site w/ RT pairs and - plecos,bichirs,cats, hooks, silver dollars,and Dat's- "note" none of these are other cichlids.