By Billy Hunt
When I discovered carpet pythons back in 2006, the one animal that drew me to them, was the infamous 50% Irian Jaya Jaguar “Bullwinkle”. At that time, I had no idea what “50% I.J.J.” meant. Carpet pythons can be a confusing group for a new keeper to try to learn. There are several subspecies and color morphs so when you add the percentage aspect to the equation, you have a recipe for a confused keeper. I know I was. The first question I had when I saw Bullwinkle’s description was, “What does 50% mean?” As I dug deeper, I started seeing animals like SOB (75% irian jaya jaguar) and Riddler (75% jungle jaguar). These animals were 75% or 88% animals. At this point I knew I had to learn these percentages.
The first thing a new carpet keeper needs to learn are the subspecies. A lot of people think that a carpet python is a carpet python. As with most reptiles, it’s not always that simple. When I first started with carpets, the main three that were available in the USA were Irian Jayas or “Papuan carpets” (Morelia spilota harrisoni), Jungles (Morelia spilota cheynei), and Coastals (Morelia spilota mcdowelli). Since then, more subspecies have become readily available. To keep things simple, we will focus on these three (Ijs, Jungles, & Coastals) for this article.
The second thing that we must keep track of, is which morph comes from which subspecies. Jaguars come from coastals, granites from irian jayas, and zebras from jungles, to name a few. Therefore, it’s important to keep track of lineage in carpet pythons. The breeder/keeper should know if what they have is a pure example of a subspecies or if they are starting with a cross. At first glance, this can be a lot for someone new to try to keep track of, that isn’t familiar with carpets. But it comes with time.
The first example I will use is a 50% Irian Jaya Jaguar or IJJ. To get that animal, you would have to breed a pure irian jaya carpet to a pure coastal jaguar carpet. With a pairing like this, odds are, 50% of the clutch will appear to be normal and 50% of the clutch will show the jaguar gene. All of the offspring (the normals and jaguars) will be 50% irian jaya and 50% coastal (host to the jaguar gene). So, the visual jaguars being 50% irian jaya blood, makes them 50% Irian Jaya Jaguars. The normals are also 50% irian jaya/50% coastals, but don’t express the jaguar gene.
Now we can take the 50% irian jaya jaguar and breed it back to a pure irian jaya to create 75% irian jaya jaguars. How we get these percentages is, we take the 50% irian jaya blood from the jaguar and add it to the 100% irian jaya and then divide it by two. With this, 50 plus 100 equals 150. 150 divided by 2 is 75, which gives us the 75% that the animals will be. This also means that the normals from this pairing would also be 75% irian jaya and 25% coastal. If we breed one of the 75% IJJ to one of the 75% normals, you will produce animals that are still 75% irian jaya and 25% coastal.
You can continue this type of breeding until you get into the high percentages like 88%, 94%, etc. This plays a part as well in knowing how long it took for that animal to be produced. A 50% animal is most likely a first-generation animal. Then the 75% animals were the second generation. 88% animals were three generations in and so on, as you reach the higher percentages. That is also why you will most likely see a higher price tag on a higher percentage animal because it took multiple generations for the breeder to get that 88% animal as opposed to the 50% animal. This percentage concept can be applied to any crossing of subspecies or hybrids. It was seen a lot with diamond jungle crosses that we use to see a lot about a decade or so ago.
The most important part of doing this is to start with pure examples of whatever you are crossing or know what your animals are to begin with. Percentages are also being used to show how outcrossed an animal is as well. This is seen a lot in granite carpet pythons since that particular gene is known to have inbreeding depression if you don’t outcross. Outcrossing is something that should be considered for any recessive mutation. It only helps that long-term viability of those recessive projects. Especially with irian jaya or Papuan carpets that are still imported as wild caught or farm bred animals.
We still have a huge opportunity to outcross the irian jaya mutations. Another place you can see the percentages being used is in bredli, more specifically hypo bredli. A hypo bredli bred to a non-hypo bredli will yield 50% hypo blood animals. This helps because then you know exactly how much hypo blood is in your animals. We can apply this to many species, carpets are a lot more likely to be crossed as far as subspecies go. This is a good way to keep track of what you have.
As a breeder myself, I can’t stress this enough. Represent your animals correctly when you can, and get as much information as you can. The percentage practice was used a lot more in the past and has fallen to the wayside over the past 5-10 years. If we have the ability to know and use genetic percentages to better identify our animals, we need to share this knowledge with one another. We as keepers should document our breeding lines to further our hobby and enhance community.
