Agree with snork6, we can advise further when we have the data. But in the interim, I can answer your question about platy and swordtail breeding.
The scientific nomenclature (naming) of species is a clue to much about the species. The platy and swordtail species are all in one genus, Xiphophorus; this name is derived from the Greek xipho (sword) and phorus (bearer), an obvious reference to the sword-like tail of the male swordtails. There are 28 distinct species in the genus Xiphophorus native to areas of Belize, Guatemala, Honduras and (primarily) Mexico. Most aquarium fish have been developed from three species, Xiphophorus hellerii (green swordtail), X. maculatus (southern platyfish) and X. variatus (variable platyfish).
Xiphophorus hellerii, the green swordtail, is the type species of this genus; ”type species” of a genus refers to the species that has all the physiological characteristics which separate it from all species in other genera. Today, the type species is usually the first species bearing the characteristics to be described by science. All species subsequently included within the genus will share all these characteristics.
Because the species are in the same genus, they will cross-breed. This is how the many colour varieties of swordtail have been artificially bred.
Byron.
