Datnoids aren't cichlids and as such one can't assume that juts keeping a group under ideal conditions will yield breeding. Take into consideration that Dats are probably solitary ambush predators, then take into consideration that if that's true they probably only seek each other out during the breeding season. If that is the case then keeping them in a group may actually cause a stressful situation which they maybe capable of living in but may never be comfortable enough to breed in. These are things that are the unknowns that everyone is speaking about. When you look at aquarium fish the ones that aren't usually captive bred are usually large predators ATF, Payara, and maybe Datnoids fit in that niche as well. Perhaps seasonal congregating and migrating of the sexes is just one of many environmental cues that we are having trouble reproducing for Dats. Again this is just conjecture on my part as others have already said there are a lot of factors we're unaware of concerning Dats.
