I won't really know but honestly I'm not expecting to get many fry seeing as how my last attempt at raising a spawn was such a total failure. I'll be happy with 10 or so fry.
I'm still not certain that I'll mix the fry but if I do I'll just have to guess at who the parents are. I won't be asking much money for them anyways so taking the extra time to keep them separate is not a big priority for me right now. I do know that I'll be keeping the melanos (if I get any) for myself because that is what I really want to work on. I'll probably keep at least 1 pair per spawn.