You'd be surprised how often these pop up (even in wild fish), the offspring just don't usually make it long enough to get noticed.
I would agree on how often these pop up, if we were talking about aquarium strains of fish. Lots of things can surface when aquarium strains of fish are being bred, but in the case of aquarium strains, such as the piebald fenestratus bred in AU, there's no telling what the genetic make up was of the original breeders. Especially in AU where importing WC cichlids is not only very costly, but next to impossible for the average hobbyist. You can only import fish from countries approved by AQIS & you need to have a registered compliant quarantine room.
I recall a number of years ago where a breeder in AU had magically come up with some Malawi L. caeruleus (common yellow labs) that had no black in the fins - a solid yellow lab. They were an obvious hybrid, and already quite a common hybrid cross here in NA, but in his mind he was 100% certain the the fish were pure. After some serious pounding by a few individuals, myself included, the parents turned out to be an aquarium strain purchased at the LFS, just like the guy with the marbled fenes. Yeah sure, ok.
Or how about how all of the albino African cichlid strains that magically surfaced yrs ago, all within a few years of each other? Decades of producing millions of offspring in ponds in South Florida and not a single albino morph, then all of the sudden albinos of every genus & species suddenly pops up out of nowhere. Hmmmmm. All hybrids, some obvious, some not, but openly referred to as such by the commercial breeders in FL producing them, but in the hands of a hobbyists those 2, 3 or 6 albinos that surfaced in a spawn of "normal" parents that were created from 'pure' stock & were now being offered up for sale as though they had stumbled onto the holey grail of fish. Right. In every single case these fish were eventually traced back to aquarium strains.
Interestingly enough Ruck Fules piebald bifa was also purchased at a LFS, according to that link one which none other than Don Conkel was known to supply. Coinkydink? Hmmmmm. Maybe.
I'm not pointing any fingers at anyone, chain of command from the collectors at the lake/river to the exporter to the importers stateside isn't always 100% fool proof either. I have seen & heard some pretty wonky things taking place at the collection/export end of things over the years, and all an importer really has to go by is what they are being told by the exporter.
I agree with Matt;
That two random, wild fish would have this extremely unusual mutation seems to be pretty unlikely...
That, or if what Jamie states is true we should have been seeing this piebald gene expressing itself in a lot of other random zonatum breedings, which so far no one has.
