Type: Incomplete Dominant
First Produced By: Paul Harris
First Produced In: 2010s
Last Updated: 2021-12-14
Do you have any suggestions or corrections for this article?
Click here to contribute feedback
Hypomelanistic Carpet Pythons, also known as “Hypos“, belong to the newest Carpet Python morphs available to us outside of Australia. This co-dominant trait occurred in Coastal Carpet Pythons, Morelia spilota mcdowelli. Melanism is the opposite of albinism and means that affected animals will develop more black pigments. The prefix “Hypo-“ stands for an underdevelopment or a deficiency of a substance for example. So, Hypomelanistic describes the lack of black pigments in these Capet Pythons. 
I started working with a pair of suspected hypomelanistic carpet pythons about 5 years ago, the animals were interesting and I decided that it would be worth the time to try to prove if it was indeed reproducible. With any potentially new mutation it is imperative to carry out well planned test pairings in order to quantify exactly what, if anything, it is. How, or if, it is heritable and lastly whether it is something already in the hobby or something truly new. Two years ago I began a series of test breedings to answer all of these questions and it is only now after this year’s breeding results that I can answer those questions with the necessary data to back them up. The results are that the new gene is incomplete dominant in inheritance.
The second questions is more complicated (is it something truly new), the answer to that is also yes. The area of biggest concern was that the putative new morph may be related to the very well established Caramel morph. To determine the answer I bred the “hypomelanistic” male to a proven female super caramel Jaguar, this ensured that all babies would be heterozygous for Caramel and half in theory would also have the new gene. This is exactly what happened. The entire clutch was held back to observe how they developed and it became very clear which animals inherited the new gene within the first several shed cycles. The combination examples were simply outstanding.
The next phase was to determine if these mutations were allelic (compatible). When the combo males were 18 months old they were test bred to 4 females, females specifically chosen because they would NOT produce red babies on their own. The results proved the new morph was not allelic with caramel at all, which came as a bit of a surprise. I was hoping it would be entirely separate but had mentally prepared for that to not be the case. In these clutches the presence of ANY normal offspring would prove that the Hypo/Caramel males were not Hetero-allelic Homozygotes. In fact there were Normal, wild type hatchlings in all of the test clutches. This proves beyond doubt that the new morph is entirely distinct from Caramel, and much more extreme in appearance.
To date I have not hatched a super form, the female from the original pair laid her first, very small clutch only this season. That clutch did not contain an obvious homozygous animal however the odds were easily missed on such a small clutch. I am very confident that a homozygous expression will be produced soon however. To date there are absolutely no dominant mutations known in Pythons and there is no reason at all to believe that this will prove the exception. 
Hypos show lots of red and orange colors as babies and have significantly less dark scales compared to normals as adults. Especially when combined with other morphs like Jaguars or Caramels, the results are stunning!
Hypo Centrilian, Hypo Coastal
No known related traits