Now this is where ball pythons become particularly interesting. Ball pythons started
out as your standard normal wild type, typified with black and brown patterning.
But now there are literally hundreds of different morphs out there that have been
found in the wild (Base Morphs) and that breeders have used to design new morphs
(Designer Morphs). In order to understand how ball pythons genetics work you must
understand some of the basic terminology.
As you discover more about these amazing animals you will come across the terms ‘Base
Morph’ and ‘Designer Morph’. It is useful to gain an understanding of these terms
in order to help you differentiate between morph ‘families’
Base Morphs - These are morphs that have been found in the wild and brought into
breeders collections. Examples would be Albinos, Axanthics, Pastels, Spiders. Base
morphs generally carry one morph gene and still occur in the wild although they are
not very common. Perhaps a few dozen are found each year in the wild for every 20-30,000
normal ball pythons found.
Designer Morphs - These are morphs that have been ‘designed’ by breeders, these would
not occur in the wild because the odds of two base morphs gene holders coming into
contact in the wild are astronomical. By combining two or more ‘base’ morphs one
can create new and brilliant looking animals..
E.g. - By breeding a Pastel to a Spider you can design a Bumblebee. The Bumblebee
is a blend of both the Spider and the Pastel gene.
When dealing with Ball Python morphs you will notice the phrases ‘Normal’, ‘Recessive’,
‘Incomplete-Dominant (Co-Dominant)’, and Dominant’ being used, within these gene
types you will also come across the terms ‘heterozygous (Het)’ and ‘homozygous’.
These are referring to the gene types of that particular morph. It is important for
those interested in breeding ball python morphs to be familiar with what these gene
types are and how they work.
On a very basic level , genes work in pairs, and what gene is on each side of this
pair will determine how the ball python will look.
Before we explain each gene type, here is a list of the most common morphs. These
are all Base morphs, as designer morphs are all a blend of different gene types
which would just confuse matters for us at this stage.
When you breed a Recessive gene ball (eg.Albino) to a Normal ball, the Albino will
pass the Albino gene on and this will sit on one side of the gene-pair in each baby
snake, the other side of this pair will have a Normal gene inherited from the Normal
parent. All the babies will look normal but they all carry the Albino gene, we call
these ball pythons heterozygous (het). This is because recessive genes are almost
a ‘hidden’ gene, and in order to see a visible albino there needs to be the albino
gene on each side of the gene-pair,
Here is a system called the Punnet Square, we use the Square to determine the outcome
of breeding genetics.
First up we will demonstrate breeding an Albino to a Normal. We will show the Albino
as ‘aa’, ‘a’ being the recessive albino gene, there are two ‘a’s because a visible(homozygous)
Albino has the two Albino gene’s, one on each side of its gene-pair. The Normal is
shown as ‘NN’, two Normal genes.
So you can see that by breeding an Albino (aa) to a normal (NN), you will produce
babies that are Normal (N) looking but carry the albino gene (a), aka Het Albinos
Now, let’s see what happens if you breed a Het Albino (Na) to a Het Albino (Na),
So, it looks like you will get one Normal (NN), two Het Albinos (Na) and one Albino
(aa) from breeding a Het Albino to a Het Albino. This is out of a theoretical 4 egg
clutch. The problem that shows now is that the Het Albino’s (Na) and the Normals
(NN), are both Normal looking, so in this case we refer to the Het Albinos (Na)
as 66% Possible Het Albinos, as two thirds of the normal looking babies should be
OK, so what happens if you breed a Het Albino (Na) to a Normal (NN), or an Albino
(aa) to a Het Albino (Na) ? Lets have a look at the Punnet Squares for these two
Het Albino (Na) to Normal (NN)
Albino (aa) to a Het Albino (Na)
The Het Albino to Normal Breeding should produce two Normal (NN) and two Het Albinos
(Na), but again you would not know visually which carry the Albino gene as they would
all look Normal., so we refer to these four snakes as 50% Possible Het Albinos, meaning
that, theoretically, half the clutch carry the Albino gene.
The Albino (aa) to Het Albino (Na), is actually a great breeding. From a four egg
clutch you should get two Albinos (aa) and two Het Albino (Na). The great thing here
is that there is no guesswork as to which normal looking babies carry the Albino
gene, They all do! Thanks to the Albino (aa) parent, they ensure that every baby
hatched carry the Albino gene.
So, to summarise briefly, recessive genes are only visible (homozygous) when both
sides of the gene pair carry the recessive gene. If the gene-pair only carries one
albino gene then the animal will carry the recessive gene but will look normal (heterozygous).
When dealing with dominant (dom) or incomplete dominant (co-dom) things are a lot
more simple. Lets have a look at these next.
This is what you can expect the visual forms of a recessive gene ball python to look
We have used the Axanthic as our example.
Heterozygous for Axanthic (Het). Looks normal but carries the Axanthic gene on one
side of its gene-pair.
Homozygous for Axanthic. Homozygous carries the recessive gene on both sides of the
gene-pair. This allows the Axanthic gene to show itself as the black and white animal.
Co-Dominant (incomplete dominant) genes are genes that show themselves if only one
side of the gene-pair carries the gene, examples are Pastels and Mojaves. These genes
are dominant over normal genes unlike recessive genes which are submissive to normal
genes. These can also be called Heterozygous’ as the animal carries the co-dom gene
and the Normal gene on its gene-pair.
So if a co-dominant gene shows itself visually if one side of the gene-pair carries
the gene, then what happens when both sides of the gene-pair carry the co-dom gene?
Well we then get what call the ‘Super’ form of that particular gene. In the case
of a Pastel gene we get the ‘Super Pastel’, and with the Mojave gene we get the ‘Super
Mojave’. We can also refer to these as being the ‘Homozyguos’ form as both sides
of the gene-pair carry the gene. The Supers can either be an enhanced version of
the animal (Super Pastel), or a completely different looking animal (Super Mojave)
Lets have a look at how the Punnett Square operates with Co-Dom genes. We will use
the Pastel gene as the example, this will be expressed as Np*, the ‘p*’ indicates
that the gene is Pastel Co-Dom, any result in the Punnett Square that has this ‘p*’
will tell us the animal is the visual Pastel form.
First up is the breeding between a Pastel (Np*) and a Normal (NN) ball python
So in this theoretical four egg clutch we would get two Normal (NN) babies and two
Pastel (Np*). The good thing about working with Co-Dom genes is that any normal looking
babies are just that, normal. They do not carry the Co-Dom gene, so there is not
guesswork involved as when dealing with recessive genes.
Let’s have a look now if we breed a Pastel (Np*) to a Pastel (Np*)
Out of this 4 egg clutch we should get one Normal (NN), two Pastels (Np*) and one
Super Pastel (p*p*). That is a pretty good looking clutch. The Super Pastel (p*p*)
has the pastel gene on both sides of its gene-pair, giving us the ‘homozygous’ or
‘super’ form of the animal.
Now the great thing about the ‘Super’ form of a co-dom gene is that, when bred, all
of the babies will inherit the co-dom gene, so all will have the co-dom gene in its
visual form. Supers are excellent to have in any breeding collection as they are
Lets see how it works when we breed a Super-Pastel (p*p*) to a Normal (NN)
Great stuff! So you can see that all the babies in the clutch will inherit the Pastel,
so all will be the visual Pastel, no normals in sight! This is great clutch.
Finally lets quickly see what happens if you then breed the Super Pastel (p*p*) to
a Pastel (Np*), and a Super Pastel (p*p*) to a Super Pastel (p*p*).
Super Pastel (p*p*) to Pastel (Np*)
From this clutch we should get two Super Pastels (p*p*) and two Pastels (np*)
Super Pastel (p*p*) to Super Pastel (p*p*)
What a super clutch! All Super Pastels!
To summarise then. Co-Dom genes always express themselves visually if the co-dom
gene is on one side of the gene-pair. If the co-dom gene is on both sides of the
gene-pair then we get the Super form of the animal which is either an enhanced visual
version (Super Pastel) or a completely different looking animal (Super Mojave).
This is what you can expect the visual forms of a Co-Dom gene ball python to look
We have used the Mojave as our example.
This is the heterozygous form of the Mojave. The Super Mojave below is the homozygous
Lets have a look at the Pastel Co-Dom gene.
Above is the heterozygous Pastel, below is the homozygous Super Pastel
You will notice that the Super Pastel is a more intense version on the Pastel.
The Super Mojave is totally different looking to the Mojave. This is because when
the two Mojave gene are on each side of the gene-pair it is how they react with each
We can only tell what a Super will look like once we produce one through breeding.
Image from www.thepaintedpython.com
Image from www.only88.jp
Dominant genes work in the same manner as Co-Dom genes but they do not produce a
visible ‘Super’ form of the animal. Examples of dominant genes are Spiders and Pinstripes.
When looking at breeding dominant genes, you can have a look at the Punnet Squares
above. Dominant genes work the same as Co-Dom, just remember that there is no visible
Ah-hah! So if what happens if the dominant gene end up on both sides of the gene-pair?
Easy, the animal will look the same as if there was one dominant gene on the gene-pair,
but, when this animal is bred, all the babies will inherit the dominant gene. This
is the same principle as the Co-Dom ‘Super’ , but without the extra fancy looking
ball python, instead of calling this animal a ‘Super’ it more commonly referred to
as the Homozygous form.
This does raise an issue in ball python breeding. If breeding a Spider to a Spider
does not produce a visible ‘Super’ Spider, then how do you know if any babies carry
the Dom gene on both sides of the gene-pair? The only way would be to raise the Spider
babies and then breed them to normal ball pythons, if all the babies that hatch are
Spiders then there is a good chance that the parent was a dual dominant gene holder,
or a Homozygous Spider.
It is thought Cleopatra wore ball pythons as wrist bands, hence the name ‘Royal (regius)’