He breeds them separately but grows out batches of fry from various lineages in the same tank. I have gotten a female Rio claro from him in a shipment of HRPs before. I'm suspecting that something similar happened somewhere down the line when he went to pull holdbacks for broodstock. Could probably get the genome of these fish sequenced to compare them to the genomes of actual nicaraguan siquia.I would suspect there has been a mix up somewhere. This has been ongoing since nigrofasciata has been in the hobby. Before there was any complete study and analysis most hobbyists unintentionally cross bred them.
To raise closely related species together usually doesn't end with pure as there is always the little guy sneaking in to fertilize the eggs.