The cow patterned 'marbled' fenestratus of today is different from the original and naturally occurring 'marbled' fenestrata from and endemic to Lago Catamaco. Those from Catamaco generally hold the marbled pattern short(ish) term and eventually turn all pink or white at maturity with minor patches of color but nothing at all like the captive strain we see today.
The marbled fene like the one on the OP were developed on the early 2000s in Australia and were originally sold to a single distributor in Thailand long before making way to North America. The line started from a male Catamaco marbled/pink fish and was bred with a 'normal' female of unknown provenance (though we(TUIC) had sent thousands of Rio Antiqua population fenestrata overseas during this time so that is certainly a possibility).
Story(from 2009) from the original distributer in Thailand, whom was the first and only at the time to receive & distribute them from the source breeder in Australia: "he used to breed normal fenestratus, and sell them to his LFS which is my workplace... out of a batch of normal fry he noticed a single one with a small white patch on its belly, kind of like a scar looking wound, which is what he originally thought, when he noticed it was an absence of colour, he grew that fry up, and paired it to a normal female who, when they bred, produced 50% marbled and 50% possible 'splits' it was also possible that it was a sex linked gene and the pied/marbled fenestratus were all girls, but he has since had two marbled pair up and successfully raise fry"
Now here we are in late 2024, close to 25yrs +/- since the fish was initially developed so it is absolutely not unreasonable to consider they are NOW hybrids. Why? well how many Vieja hybrids exist just here on mfk forums alone.. now factor in the entire globe and of course the fact that they are heavily produced these days in Indonesia and are available from most trans-shippers relatively often.
I've physically witnessed 'marbled fenestrata' juveniles from Indo with heavy maculicauda (black belt) patterns.
What do 'I' think of this fish? As if that matters. But, I think they look pretty darn cool. That said, TUIC is not known for offering known hybrid cichlids. Ever in our 29 yr history. Very far and few times in that same 29 yrs have we offered even man-made lines. We have(i.e. electric blue acaras, red spotted gold severums etc)and still do but not very often and usually they are 'box fillers' to complete an order/import.
I have offered the Catamaco population many, many, many times as Wild, F1 & F2 stock. Sadly though in recent years the demand for THAT fish has declined in way of the man made line. So much so that I eventually(in 2022) sent my f1 breeding stock to Asia on wholesale as they no longer warranted the space in my facility. With I no longer having them and COTA also no longer around you(the hobby) will all have to rely on hobbyist home bred stock and trust the sellers. fyi: Buyer beware of anyone selling them as wild or F1.