The punnett square below shows the results of crossing a Double Co-Dominant ( Pastel + Spider ) Bumblebee Spider Ball Python het Albino ( Pp'Ss'Aa ) to a Pastel het Albino & Anerythristic ( Pp'RrAa ). The outcome of such a cross would produce 12 different looking snakes as detailed below, some of them are also heterozygous for recessive traits.

Normals x 6 ( 9.37% ), Spiders x 6 ( 9.37% ), Pastels x 12 ( 18.75% ), Bumblebee x 12 ( 18.75% ), Albino x 2 ( 3.12% ), Albino Killer Bees? x 2 ( 3.12% ) , Super Pastels x 6 ( 9.37% ), Albino Pastels? x 4 (6.25% ), Albino Bumblebee? x 4 (6.25% ), Killer Bees x 6 ( 9.37% ) , Albino Super Pastel? x 2 ( 3.12% ), Albino Spider x 2 ( 3.12% )

Co Dominant

... A Co Dominant gene is one that is able to have an effect on the animal in it's heterozygous state. In other words it needs only one lowercase letter to have an effect. Co Dominant = Visible Heterozygous. When we write a Co Dominant gene in a Punnett Square we follow the lowercase letter with a ( ' ) also known as a prime. When two lowercase Co Dominant genes are present it further has an effect on the animals appearance and these snakes are known as " Supers " ( h'h' )

The Process of making the above punnett square:

Firstly we determine the genetics of the adult snakes in this case we were using a Female Bumblebee Spider Ball Python heterozygous for Albino and a Male Pastel het for Albino & Anerythristic.

So how do we write this up in the punnet square?

I use the letter P to represent the pastel but it can be any letter of the alphabet you choose, a S for Spider and an A for Albino. Because we know the Pastel gene to be Co Dominant we write it as Pp', pretty much the same as if we were writing the genotype for a heterozygous snake as an example het for Albino would be written as (Aa) but because the Pastel is a Co Dominant animal we put a ( ' ) after the lower case letter in this case p to show that it is a Co Dominant gene. So now we have our first two letters of the genetic make up of the snake Pp', the spider gene is also a Co Dominant gene so would be written as Ss', this now gives us the two co dominant genotypes Pp'Ss' the Albino gene is a simple recessive gene and because this snake is het for this trait then it is written as Aa. Therefore the genotype for the female is Pp'Ss'Aa.

The Male is a Pastel so as above his first set of genes are Pp' he is also het for Albino again as above Aa but is also het for Anerythristic which I use the letter R to represent so as with the Albino this is a simple recessive gene so is written as Rr, put all these together and you have Pp'RrAa

Using the Female genes as an example we need to calculate all possible combinations to insert into the top of the punnet square the top row in pink in this example. Pp'Ss'Aa would break down into 8 possible combinations we calculate these by taking one copy of each gene Starting with The Capital P we then look at the Spider gene and take the capital S then the Het for Albino and take the capital A we then have PSA which goes into the first row column two. There are other combinations available using the capital P so we look along and take the capital S spider gene again but this time we take the lowercase albino gene a, PSa insert this into row one, column three. Still stopping with the capital P of the Pastel we now use the s' of the spider gene and the capital A of the Albino which gives us Ps'A, insert this into the first row, fourth column, The last possible combination for the capital P is Ps'a which is inserted into the first row, fifth column, we now start calculating with the lowercase p' gene, looking across we can use the capital S of the Spider gene and the capital A of the Albino gene giving us p'SA, we keep going like this until all possible combinations are exhausted.

The males genes are calculated in exactly the same way but they are inseted into the first column highlighted in blue in the example below. Your Punnett square should look similar to the one below when you have finished.

We now start putting the combination of the male gene and the female gene into the appropiate squares.
Take the first letter of the male column 1 row 2 which is a capital P and put it in Row 2 Column 2, then take the first letter of the female in this example a Capital P and also put that into Row 2 Column 2, back to the male and take the second gene the capital R also put this into Row 2 Column 2 then the females second letter and so on, continue filling in the table working along the rows until all the table is filled in.

How we determine the offspring using the punnett square:

We look at each cell in the table in turn as these represent a possible hatchling, If we look at Row 2 Column 2 then we see that the code for this hatchling is made up of all Capitals this tells us that it is Normal looking, in the example at the top of the page we also see other combinations that are classed as normal ( highlighted in Yellow ) in cell Row 2 Column 3 we have PPRSAa this snake would also appear normal because it has no lowercase letters paired, it only has one lowercase ( a ) telling us that this hatchling would be normal looking but carries the gene for Albino. Using this logic then Row 5 Column 2 PPrSAa would also be normal, it would be also be het for Anerythristic determined by the lowercase ( r ) and het for Albino again determined by the lowercase ( a ).

So why isn't Row 2 Column 6 ( Pp'RSAA ) a normal it doesn't have any paired genes? Because the p' is a co dominant gene we know this by the ( ' ) that follows the lowercase letter, we also know that Co Dominant genes only need one instance to have an effect on the hatchling ( visibly heterozygous ), so this example would be a Pastel. Or another example would be (PPRs'AA ) Row 2 Column 4 this combination of genes tells us that it would be a Spider donated by the s' and the absence of any other Co Dominant genes or paired recessive genes.

A hatchling that has paired Co Dominant genes is a Super, as an example in our punnet square at Row 6 Column 6 ( p'p'RSAA )this combination of genes donates a Super Pastel, another examples of Super Pastels in the punnett square are ( p'p'rSAa ) this hatchling although looking like a Super Pastel also carries the genes for Anerythristic ( r ) and Albino ( a ) determined by the single lowercase letters.

The Bumblebee hatchlings are the ones that are double Co Dominant, they have the p' and the s' gene in there makeup, look at the examples highlighted in bright green in the punnett square.  Row 2 Column 7 ( Pp'Rs'AA ) the hatchling of Row 3 Column 7 ( Pp'Rs'Aa ) is also a Bumblebee but is also het for Albino.

Killer Bees are double Co Dominant but they are Super Pastels and Spider combined ( p'p'Rs'AA ), the p'p' tells us it's a Super Pastel and the single instance of the s' Spider,  other Killer Bees in the punnet square are het for either Albino, Anerythristic or both. Again we know this by the single instance of the lowercase recessive gene.

All the Albino morphs are determined by the presence of two lowercase a's ( aa ).

There are 12 possible morphs that can be created, as the average clutch size of a Ball Python is 6 it would not be possible to produce all morphs in a single clutch and as some morphs have more chance of occuring, the likelihood of producing half of the known mutations is further unlikely. Looking at the given percentage for each morph in our punnet square, it would seem probable that at least a Bumblebee and Pastel would occur within a clutch, we have a 12 in 64 chance of producing one of these morphs, this means that for every 64 eggs that are laid 12 have a chance of being either a Bumblebee or Pastel. Some mutations such as the Albino Super Pastel that have only a 2 in 64 chance of being produced may never be produced through this kind of cross, but then again lady luck may be shinning down on you and you might produce an Albino Killer Bee in your first clutch.

Predicting the outcome of crossing mutations can be fun, but remember that it only shows what it likely to be produced and is not a guarantee of what actually will occur in a given clutch.