Regarding the split fin, – the remarks I made would really go for any fault which may have a genetic cause, – whether its one or the other doesnt really matter. If its a genetic fault, (which theres a chance it is if the fish is born with it) – then I think theres a risk it may give it on to offspring, and in that case I actually think its a pity to breed it.
So it doesnt really matter if its one or the other.
Regarding the ‘blue line’ problem. Well, many, or most of the fish you buy in shops is without location, – I f.ex. have p.parvulus – bought in a shop, – and without a doubt parvulus. There are also slight differences in this species after where they come from, but I dont know where mine come from. They still belong to one of the most beatiful species in my opinion 🙂
And the blue line – I understand your problem, but still I think excatly the blue line (s) are so beatiful and different from other species, and it has not been so much around in the last years I think, so to have it and help us hold on to this particular sp.species is really valuable.