Beginner breeder needs some information...


Dear VPI,

I'm considering starting a breeding project for ball pythons--I find the entire idea of it very appealing.  Unfortunately I'm still not sure about the way everything works as far as morphs.  What I want to know is if I crossed a 100% het-piebald male with a normal female, is it as simple as a 50/50 chance of getting piebald offspring?  If not please explain.  Thank you very much. Elijah

Dear Elijah,

This is an over-simplified explanation, but a good way to think about most of the characters of color and pattern that are being bred. For each aspect of color or pattern, an animal has two homologous genes that control the trait.

In this example, piebald and normal are different versions of the same trait.

The piebald father has two homologous genes for the trait of "piebaldism". The normal mother has two homologous genes for the trait of "normal." Since each has two matching homologous genes, they are both said to be "homozygous" for their trait--the male is "homozygous for piebald" and the female is "homozygous for normal".

When a piebald is bred to a normal, each baby randomly receives one of the two genes from the father and one of the two from the mother. For this particular trait and this homologous gene, the baby has to receive one piebald gene from the father, and one normal gene from the mother.

So every baby from this cross will have one piebald gene and one normal gene. These are homologous genes, but this condition of have different homologous genes is called "heterozygous". The babies, all of them, will be het-piebalds. Each will carry the piebald gene. But in this case, since the effects of the single piebald gene are overwhelmed by the effects of the normal gene, the babies will all look normal. When this is the result, it is said that piebald is a recessive trait.

Hope this helps. If you want to breed ball pythons, you should buy our book from our website at There is a while chapter on breeding, a chapter on eggs and hatching and a chapter on genetics where all of this is explained and illustrated.  Good luck,    DGB