depends on the fish. some will say yes, some will say no. its probably not a good idea to try though, they each have their own requirements, but its possible
just curious. my dad has frontosa and electric yellows and i have my kenyis and want peacocks, but we love the jack dempsys too... he wants to start trying to breed the electric blues...
How long have the frontosa and yellows been together? They require a completely different diet. The frontosa is a meat eater and the labs are algae grazers.
+1again, there is always exception to the rule! I am a big believer in introducing everyone as juveniles, or at least at the same time.