The strange young female 1) has an incomplete anal fin; we know of no Parosphromenus with such a fin as normal. This certainly is a congenital defect; 2) the spot on the dorsal is very likely such a defect, too; we do not know this from any other P. pahuensis.
The paleness of the body seems to be a reaction to the courtship behaviour of the male. But it is not yet grown enough to finally decide.
Such congenital defects could be inherited to parts of the offspring, or could be lost in them. Without genetical investigation of the individual this is impossible to decide. Adult pahuensis look very similar in both sexes; the females normally look a little more dull than the males. I had a wildcaught pair from Hiroyuki Kishi that always made it difficult to decide: who is who? I could decide it, but the female showed in principle the same body and fin colouring as the male. And since filaments are missing too, this was really a problem. Therefore: wait and see how the colouring of the fish develops when she becomes bigger.
If the fish originates from Bernd’s stock (and there is no reason to mistrust him or suppose that there has been an involuntary interchange; that has never happened to him, he is very sensible in that respect), then we can suppose it’s pahuensis female.
There are two possible ways of dealing with the problem: a) wait and see. However, if the offspring seems to look normal, this is no proof that the genetical defect was restricted to this individual alone. The defect could be recessive and not openly repeated. b) Begin anew with new fish that do not show this defects. This is surely the better solution. However, if you go this path, it would be better to change both partners if the male came from Bernd’s stock too. If not, you should only change the female for one of a different heredity line.
Maybe, this is too strong a position. Then you should go the first path, but be very cautious in dealing with the offspring. In any case, Bernd’s pahuensis stock need to be supervised closely. The most probable explanation is, however, that this are single phenomena occuring in one idividual only. This always can happen. If there are no signs of more defects in other individual of that stock, tehre may be a problem nevertheless. But you could do nothing against it and live with the results. If these defects appear more often in Bernd`s stock, then one should not use it any further for propagation of the species.
It’s interesting that we come across such phenomena rather rarely. P. quindecim, for instance, has been propagated from one original stock only until the present day, and it never showed (openly) congenital defects. But that maybe different with different species and stocks. We do know nothing about the health of the stocks that reach our aquaria. But the longer they have been treated inadequately since being caught out of their natural habitats (and the trade treats such fish badly for weeks and months, in Asia already, in Europe afterwards) the fish may bear the consequences without revealing them in their open appearance.