The term Red Coastal Carpet Python has been around since the early 2000’s. This term is used to describe animals that, as neonates, are hatched with a red coloration or red tones on their background color. Some animals look albino or hypo as hatchlings, having little black with reddish eyes. A few people have tried to tease out this trait, but no one has achieved concrete results. I am one of those lucky few that have had the opportunity to work with this trait. Ever since I saw my first “red” coastal I knew I had to work with this trait. In this article I am going to go over my observations, breeding efforts, future projects and try to finally answer some of the common questions regarding this color form of coastals.
There are a few red lines around these days, but the most recognized, without a doubt, are the animals descending from Madame Blue Berry (MBB). This was an animal that was owned by Will Leary. She had a unique look with a very pixelated head pattern and grey/blue tones. One of his most famous pairings was with a jaguar called Benjamin. These two produced some unique looking animals, with high red coloration staying longer in development and a reduction in black. Giving them the nickname “red hypos.” Around the same time, a new morph was showing up, the Caramel. This phenotype as hatchlings looks a lot like reds but it’s mode of inheritance was easily figured out to be incomplete-dominant. As they age, Caramels gain yellow tones and black flecking with super Caramels gaining little black. The rise of the Caramel put the reds in the back burner for most while others dropped the project completely. Why was the red such a tricky phenotype to figure out? Animals that showed no red as babies could potentially throw red babies. Animals that were red when bred together didn’t produce any “supers” and sometimes you had no red babies in the same clutch even if both parents were reds. The inheritance looked like it was a mix bag, acting randomly and not in a simple Mendelian way.
In the late 2000’s I was fortunate enough to acquire a MBB line red from Will Leary’s stock. A local buddy, David Poppy, sold this animal to me and I named him Roku. Roku blew me away and I knew right there that I wanted to work with these regardless of its mode of inheritance. My goal was to simply produce the best looking reds and make a “better” normal. If along the way I figured out what’s going on with them, great, but that wasn’t my initial goal. I searched for the best complementary female for him. I wanted to produce what is called an outcross, meaning you cross out the line to an unrelated animal to bring new genetics or to diversify it. I wanted a female with little black and that wasn’t carrying any red genes. This will be useful later on when I try to tease out its inheritance. I ended up settling on a Lemke line female I named Azula. Lemke/VPI/MPenn animals tend to lack a lot of their black which was exactly what I was looking for.
My first successful clutch was in 2012. When the babies hatched, they were a mixed bag. Some had reddish brown tones, others didn’t express any red at all and yet there were a few that had higher expressions of the trait. The simplest way to describe it was a curve from no red to middle “grade” and high expression reds. I selected my holdbacks, sat back, and watched them grow. As they grew my holdback animals started to color up, gaining redder coloring and losing the black that was on the edge of the pattern. This black didn’t totally disappear but faded away and sometimes created a “shadow.” Giving them a ghostly appearance.
For my second clutch, I paired one of my female holdbacks named Katniss with a red jaguar named Culruin. Culruin was bred by Erin Buhaly using siblings that came from Will Leary’s MBB line. This clutch yielded all red animals of different levels of expression and all except for one were jaguars. This made the reds pop more since the jaguar morph is also a color enhancing gene. This clutch didn’t really tell me a lot about the mode of inheritance, but the resulting animals were trophy red jaguars. So, what next? The next steps in teasing out the mode of inheritance was to perform a backcross (crossing my holdback back to her red father) and another outcross using Culruin. With these two pairings I will have a clear picture finally of how it’s being passed on.
My third clutch in regard to testing the mode of inheritance yielded the results that I was expecting. I paired Culruin with Azula and the results were again a mixed bag of animals ranging from high red expressors, to medium, to no red. A nice curve going from no red to a high concentration. This clutch was a decent size (17 eggs) giving me a big sample size. If Culruin was a “super” the red should’ve been inherited dominantly and all animals should have been red. If it was incomplete-dominant a clear 50-50 split would have been observed. But what we saw was a “dilution” in the phenotype giving us animals with different levels of red pigment. Now for the backcross, this was the most important of the “test crosses.” If there was a super involved, it should appear in this clutch but again the results showed a mixed bag of reds. This time, the ones that expressed the reds were nicer and had higher levels of expression which I was expecting since I am bringing together two related animals of high quality and expression. However, there were some clear non-reds in the clutch with not even a hint of red showing up.
So, now that we have years of clutch data and I have seen how babies develop; what does this say about the mode of inheritance? There is a line of coastals that have been following the same mode of inheritance that mirror my results beautifully, the tiger coastal, which has been proven to be polygenetic. After all this time, I can confidently say that the red trait is also polygenetic in nature.
To better understand what a polygenetic trait is, let’s think about height in humans. Height in humans is a polygenetic trait meaning there is more than one gene that controls height. I can have two parents that are over six feet tall but when they produce kids, it doesn’t mean they will automatically make giant babies or be as tall as they are. Yes, there’s a higher chance of this happening; however, when genes are mixed together they are allocated randomly. Offspring can be shorter than the parents, average height, or taller depending on what genes are passed on.
In the case of the reds, people like myself have been trying to take those genes and concentrate them as much as possible, this will make the results less variable. Because the amount of variation within the genes of that animal is less, the results tend to be more consistent. This is why lineage history is important. If I want to have consistent results and less variation, knowing the history of the animals will make the results a bit more predictable.
I am happy with the current state and look of the reds I have been producing. I will continue line breeding and see how much the gene can be “improved” but there might be a point where the look of the animal will level out. Now that I have my base phenotype, the possibilities are endless. I want to focus on breeding my reds into axanthics and also creating a red stripe unrelated to the red tigers. My goal was always to create the best looking “base” coastal to give people a solid starting point on their projects. My customers will have the benefit of working with a line that has been selected for at least three generations ensuring that their results will always be stunning animals. In conclusion I hope this article has helped shed some light on MBB red coastals. Even though this line of coastal carpets has been in the hobby for over 10 years we are only starting to scratch the surface on its potential.
