Cold Blooded Eye Candy

Super Snakes, Super Confusing

Using the BEL complex in ball pythons, Kassandra breaks down what a "super" morph is using basic genetics terminology and a little common sense.


Super confusing
If you spend any amount of time around the morph reptile hobby, you’ll hear terms like co-dom, super and het tossed about.  For the most part, these terms have served their purpose, although they are often confusing, and in some cases, just plain wrong.

Let’s start at the beginning, because that is where it all starts going wrong.

You do not have to understand what DNA is or what it is made of or how it “works” to wrap your head around genetic inheritance.  The ball python genome has not yet been mapped.  All that we know of ball python color and pattern morphology has been learned by observing the results of breeding trials, just as Gregor Mendel did with his peas centuries ago.  

All you need to know is that the gene that encodes any trait consists of a pair of alleles inherited from the parents - one allele from the father, and one from the mother. 

In python breeding, we do not use the word allele enough.  If you don’t understand what an allele is, you will never be able to understand how they can affect your breeding projects.  An allele is any mutant that “fits” into one of the pairs of a gene for a specific trait.  All alleles are genes, but not all genes are alleles.  

Clown, for example, has two known alleles that may exist at the “clown” locus.-

1.     The “mutant” Clown allele

2.     The normal (wild type) allele

Things get a little more complicated when you consider the Mojave locus, because numerous alleles have been found to exist in this “complex”

1.     Mojave

2.     Lesser/butter
3.     Phantom/Mystic
4.     Mocha
5.     Russo
6.     Special

The most important thing to remember when encountering a gene with multiple alleles is that any one animal can have a maximum of TWO of each of those.  Imagine a game of musical chairs, where there are many players (alleles), but only two empty seats left (the gene pair of a specific locus).  For example-  You can breed a lesser mojave BEL to an Invisiball, but you could never create a Mystic Mojave Russo because there are only two “empty seats” at each locus.


* BEL= Blue Eyed Leucistic or "Blue Eyed Lucy"

Regardless of which allele combination we are talking about, one thing is true-ALL of the combinations  in the chart above are Supers.  A “Super” is an animal that cannot produce a normal.  However, a Super is NOT necessarily homozygous for a trait.

The term “het” is short for heterozygous .   Heterozygous animals have different alleles present at a given locus. Homozygous animals have a pair of the SAME alleles at a given locus. 

So how is the industry getting this wrong? 

First, the implication is that the term “het” is only applicable to recessive traits, such as albino or piebald - genes that look normal unless there are two copies present at a gene locus.  A het albino would have one albino allele, and one “normal” allele at the gene locus for the albino trait.  A homozygous albino would have two albino alleles, one from each parent. 

An incomplete dominant trait, such as pastel - can also exist in heterozygous and homozygous forms.  Colloquially, we refer to a homozygous pastel as a Super Pastel.  In this case, the animal is indeed both a super (cannot produce a normal looking snake) and homozygous (has two copies of the same allele at one locus)

In the case of a gene locus with a multiple allele “complex”, like the Mojave chart above, it is possible for a “super” to exist, but for the animal to actually be heterozygous for two different traits.  Remember- het simply means the alleles at the locus are
NOT THE SAME.  A “Karma’ blue eyed lucy is het for both Mojave and Phantom.  Because those two mutations are complimentary alleles, they can “mate up” and form a new “Super”.  The resulting blue eye luecistic (BEL)

How do we know these are all different alleles and not just different names for the same thing?  Well, in some cases we don’t - lesser and butter, for example.  All evidence suggests lesser and butter are two lines of the same trait.   They look virtually identical to each other in heterozygous and homozygous form and they combine with other traits to produce identical results. 

However, in most cases, the homozygous forms differ, even if only slightly.  A homozygous Mojave, for example, is a BEL with a purple-grey head, while a homozygous Butter is completely white.  A latte is white with a yellow dorsal stripe, while a crystal is a white snake with a multi-tonal yellow & purple-grey pattern.

It is also true that some of the combinations produce indistinguishable plain blue-eyed white leucistics, but the “component” alleles are all easily distinguished from one another - a Lesser is different from a Russo, though they make a BEL in both their combination and homozygous super forms. 

Looking at it from yet another angle, Purple passion (a Mojave x Phantom Super) and the homozygous Phantom look very much alike.  However, when bred to normal, the Purple passion will produce mojaves and phantoms, where the homozygous phantom will produce only phantoms.

Hope y'all are finding these blog post interesting and informative.  Next time I'll talk about recessive traits with multiple allele combinations.  Happy

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