Swordtail Question

[henningc]

I've been in the hobby for many years but never seriously messed around with Swordtails that much. Several months ago I got a group of semi-adult Painted Swords to breed for a summer project. They are Pumpkin Orange and Balck. They have dropped several batches of fry and each batch gets larger which is normal. Just by chance, one female is in a tank away from the others with a few other fish and she has dropped fry as she was pre-hit when I got her. Apparently, the breeder I got her from was doing a little genetics science project with this line of Swordtails. The odd female looks just like her sisters only she drops painted, koi and now black & white fry. The first drop produced one really nice koi female along with painted fry. The next drop a greater percentage, say 20% koi and the rest painted. The third drop produced about 20% ,5% black and white and the rest painted.

My question is does anyone know the genetics behind this occurance? I'm thinking I might go out an obtain a few Koi and Black and White Swrodtails and segragate the color varieties. That will be costly as it may total $60-$70 if not more. I really don't want to cross them to each other as there is a good chance the gene pattrens are unstable at this point. If anyone has ideas or know more about this I'm looking for answers.--Thanks