I’d like to talk about one of my favorite ball python morphs, the banana gene. It is an incomplete dominant trait first produced by NERD in 2003. Incomplete dominant means an animal only needs one copy of the gene for it to express itself, however a “super” (homozygous) form exists when both parents pass the gene on to their offspring.

An adult and baby banana ball python. As you can see, they are bright yellow with black spots as adults, looking very much like a banana. They have white bellies. This is a different gene from albinism, and they have normal eyes. Here’s a wild type for comparison:

One thing that is very unique to the banana gene is it is sex linked (the only ball python morph that does this, not sure about other animals). Female bananas will produce equal split of male and female, banana and wild type. However in males, it is linked to how the sire inherited the gene. If he inherited it from his father’s side, he is a “male maker” and almost all of the bananas he produces will be male. The sex split and morph split are the same (50/50), but almost all the males will have the gene and almost all the females will be wild type. Same if he inherited the gene from his mother, just reversed (this is a “female maker”). A common myth/misunderstanding is that this holds true all the time, it does not. A male maker can still produce female banana ball pythons, and male wild types. Same for female makers, in the other direction. Roughly 3% of snakes produced from male bananas will be one of these instead of the “expected” outcome.

These are both super bananas if you wanted to see what they look like ^^