I'm still very unsure about calling that a nourissati. It is much chunkier and shorter bodied then any nourissati I have ever seen pictured or in person. Also most nourissati tend to show one main black blotch on there side with very light to now barring as adults. The one you pictured showed very strong barring.
Plus the Growouts that you posted on the ACA site look nothing like the adult you pictured here. So either what is normally seen in the hobby sold as nourissati is not the right fish or your fish is not. This still does not explain how your fry from the pictured fish look completely different and several of them even from the same spawn seem to have different traits. This is why I feel they are probably a mix.
I'm definately interested to see if this ever gets sorted out. Some misteries go unsolved though

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