I have a 50 g tank. We had only 1 fish remaining an albino red tail. We wanted to get it going again so we got a couple platys, 2 Molly's and a new pleco. The Molly's died and the platys survived. A day after the mollys died I noticed 8 fry in the tank. I don't know who the parents are, the mollys or the platys. How can I tell? My tank has a lot of hiding spaces and not a lot of fish just the red tail, pleco and 2 platys. Do the fry have a better then average chance with this group?