Yes, thats sort of what I was getting at in that last post, thats exactly how fertile fh are made. However that doesn't mean that just any two paraneetropolus species are interfertile. Like many of the Amphilophus are. The thing with Amp's is they are all so closely related, most of them belonging to the same complex within the genus. Paraneetropolus not so much, most have genetically diverged from each other way more than Amphilophus. I also believe that syns are one of the worst of the lot for this, I read an article a long time ago (wish I could find it again, I've been trying to find that page again for something like 5 years...) It stated that hybrid syns didn't start to show fertility 'til the strain was 75% syn, and even then only in very small numbers, best fertility in hybrid syns was shown at percentages above 75% purity. The article did not discuss what would happen if you used paraneetropolus that were closely related to syn for the cross. I firmly believe using P. melanurus would produce fertile male young if crossed to a syn, and if it didn't at 50%, it would for sure at 65%
Also consider this. Say you have a 65% pure, fertile hybrid of whatever breed, cross him to yet another breed, cross his daughter back to him, and you'll have fertile males. The fertile, mostly pure part of the strain is acting as the "controlling interest" if you will. It may not be 65% pure anymore, but the genes from...umm, lets say texas for example, will be strong enough to carry the fertility in the strain. This is how a true master creates a fh, bit by bit adding traits. You'd have to do sooooo many lines of each cross to prevent inbreeding depression.
p.s. getting 2 male, 4 female pink fene's this Saturday, I have a few fish I'm considering pairing them to. A female bp, I also have male and female belize syns the same size as the pink fene's, I can't wait!
p.p.s. also getting some carpintis the same size as my syns and fene's, that should spice things up a bit too.
