I dont know for sure, but i suspect that they have been spawned, and given the increasing success of barramundi cod (pocadot groupers), flowery cod etc for the aquaculture market i imagine they wouldnt be that hard but relatively worthless.
I suspect that if you were to breed them it wouldnt be with 5 fish, perhaps 50 is more in order, dominance seems to play a role in maintaining small groups of this fish.
Christian