Nice pick-up, sorry I can't help you with the sexing. As far as comm.'ing them mine was a complete puppy dog with anything non-cichlid. Got along fine with small grow-outs that were cichlids such as Lyonsi, Pearsei and Bocourti. However as the Bocourti started getting some size on him the Zon turned, relentless beating on the Bocourti. The Zon was 11 inches and the Bocourti had just hit 6 inches. I also had problem comm.ing my Zon with a GT. My Gt was about 8 inches and used to subject the Zon to what I thought was harmless chasing. Never even tore a fin on the Zon. The GT finally wound up killing the Zon one night. I was shocked cause the Zon was destroyed by the morning. At the time the Zon was 12 inches and the GT had just reached 10 inches. Still all fish are individuals so you might be okay. Just keep an eye on them cause you never know.