I could see maybe an accidental breeding happening in the wild.  I think that's how most fish hybrids occur in the wild.  I don't see them mating purposely.  Even in mammals it is hard to get two different species to breed.  Many are manmade so to speak.  Others are made by some very wierd means.  There was a breeding of an african leopard with an african lion once.  When the female was in heat the drugged her heavilly, and let a male leopard into the cage with her.  He willingly mated with her, but it was hard to tell if she was willing since she was drugged and probably trippin hard.  LOL.  So in my mind they wouldn't mate of their own free will, but if you just happened to have a mating pair of both species in the tank together and they just happened to be breeding at the same time, then I am almost %100 positive that you would get an accidental hybridization.   Good Luck!!
				
			
	
	

