The Lampro Blog: Genetics
Hi everyone, I’m planning on doing future blogs on different kingsnake morphs, so I thought I should start off with a quick explanation of genetics. Explaining everything in detail can be very confusing to the beginner, including myself, so I want to make this as simple as possible. A lot of the morph names come from Brian Hubb’s book, “Common Kingsnakes”.
One thing I need to mention is every phenotype found in the wild, like a black & white banded or brown & white banded, are considered morphs. In this article, I will simplify it by calling the “wild types” normal.
In simple terms, a snake is born with two genes, one from each parent. These genes are responsible for the pattern and color of the snake. The genes responsible for normal (wild type) patterns, are always dominant. Genes that are responsible for genetic mutations, such as Albinos and Newport’s, are either co-dominant or recessive. These genetic mutations are also known as morphs. With Cal Kings, there are many different morphs. Here is a small list of morphs and the type of genes they carry:
Recessive
Albino
Melanistic
Hypomelanistic
Whittier
Striped Mud
Co-Dominate
Newport
Long Beach hypermelanistic
Striped
Blotched Mud
First I will explain how a co-dominant gene works. Say for instance you breed a normal Cal King (dominant gene)…
….to a Newport (co-dominant gene)
You can expect to get around 2 or 3 Newport’s in a clutch of 10. The rest will be completely normal and not carry any type of Newport gene in them. 20 or 30 percent of the clutch being Newport is just an average number. You can get more than 50% Newport’s in a clutch and its always possible to get all Newport’s or no Newport’s, but that is rare. I once hatched 2 Newport’s out of 3 eggs.
That’s how the co-dominant gene works with locality animals. You can often get very different results when breeding kings from two different areas. For example, my friend, Rich Morgan, bred a San Diego striped king to a banded king from Los Angeles and got mostly aberrant young. This does not happen if you breed a banded to a striped king from the same population, otherwise aberrant patterns would be very common in nature.
In Southern CA, most aberrant patterns of Cal kings are the result of the striped and banded patterns being expressed at the same time on the same snake. I don’t know exactly why this happens, but it only happens in areas where there are both banded and striped kingsnakes. However, there is one area in Kern Co. where there are no striped kings and aberrant’s have been found. Those aberrant’s are probably better described as partially aberrant, but there is a noticeable difference when compared to a normal banded pattern. In Northern CA, the aberrant pattern is the norm for the Central Valley Black Belly kingsnakes. A fully-striped pattern up there would be considered aberrant.
Now we come to the recessive gene, which is a bit more complicated than a co-dominant gene. When breeding a normal Cal king (dominant gene) to an albino (recessive gene)….
Albino CA Kingsnake
….we get 100% heterozygous (het for short) offspring. These offspring are het for the albino gene, which means they carry the albino gene in them from one parent and the normal gene from the other parent. Because the normal gene is dominant over the recessive gene, they all look normal. To get albinos, both parents must carry the albino gene, so you must either breed these hets together, or breed on back to the albino parent. With those two breedings, het to het and het to albino parent, you will see different results in the percentage of albinos in a clutch. You will get a higher percentage of albinos if you breed a het back to the albino parent, than you will if you breed two hets together. An average, breeding het to het will result in 25% albino, 25% normal, and 50% het for albino offspring. When breeding a het to the albino parent, you get 50% albino and 50% het for albino. Again those are just averages and anything can happen in a clutch. I’ve heard of two albino Cal kings being bred together for years and always producing albinos, until one year a normal pops out of a clutch of albinos. That is rare and most of the time results are predictable.
The chart bellow explains multiple recessive breedings and their results. No. 1 represents a normal Cal king on the left (the two dark boxes symbolize the two normal dominate genes that snake carries), and an albino on the right. Again, the two white boxes symbolize the two recessive genes that albino carries. All the offspring (hets) carry one gene from each parent. Because the normal gene is dominant over the recessive gene, they all look normal, but are het for albino. The rest of it should be easy to figure out now.
Multiple recessive and co-dominant genes can be combined and expressed at the same time. The result would be a morph you most likely wouldn’t see in the wild. A snake that is expressing two different genes at the same time is called a double homozygote. These double homozygote’s then become their own morph and have their own names. One example is the Blotched Mud Morph, which has rarely been found in Southern CA. This morph is expressing both the Newport and Long Beach hypermelanistic genes. Because both genes are co-dominant, a double homozygote can be produced in the first generation. There is a 1 in 4 chance of this happening, which means, on average, 25% of the clutch could be double homozygote’s.
The “Blotched Mud” morph is a double homozygote (Newport X Long Beach hypermelanistic).
Its a little different when creating a double homozygote with recessive genes. For this example, I will use a lavender albino and a hypermelanistic morph. These are both single recessive traits. Don’t confuse the L.B. hypermelanistic with this one. They are two completely different morphs. Also, a lavender albino is different than a regular albino.
Hypermelanistic (Recessive)
Lavender Albino (Recessive)
If you breed a lavender albino to a hypermelnistic, all the babies will look normal but will be het for both genes. These babies are called double hets. They look normal, but carry both genes. If you breed these double hets together, the results are variable. Among a clutch from double het to double het breeding, you will or can get:
Lavender albinos
Lavender albinos het for hypermlanism
Hypermelanistic
Hypermelanistic het for Lavender albino
Double hets
Het for Lavender albino
Het for hypermelanism
Normal het for nothing
Double homozygote (lavender albino X hypermelanistic)
Because you can’t tell the normal (het for nothing) babies from the double hets and single hets, all the normal babies are considered “possible hets”. Only through test breeding, can you find out what genes they carry, if any.
There’s only a 1 in 16 chance of producing a double homozygote. If your female is only laying 7 eggs per clutch, it may take two to three clutches to produce the double homo. This double homo (lavender albino X hypermelanistic) has been named Purple Passion.
Juvenile Purple Passion
The Lampro Blog is dedicated to all things Lampropeltis, both captive and field related, with multiple contributors.
Ross Padilla is a field herper and keeper of 20 years who has a particular interest in the California Kingsnake and it’s various morphs. Check out Ross’s website, “Southern California Kingsnakes.” He can be contacted at padillaross13@yahoo.com
