I know I did a complete breakdown definitive post on this earlier this year or last year but I'll be damned if I can find it using KS's sub-par search engine. So here I go again but this time in response to Gregg's query.

With the axanthics/anerys, are the hogs actually either of those???

I believe they are, and I believe they are Axanthic and not Anerythristic as some people keep labeling them as I'll explain shortly.

By genetic definition, Axanthics should produce no yellow coloration... With anerys, by definition, there is no red coloration produced...

This is pretty much true about how both of these terms are generally defined, unfortunately there are very few resources accurately defining the differences between the two. What we are left to do is look up the terms that are oppositely related such as Erythrism for Anerythrism and Xanthism for Axanthism.

Erythrism, as defined by Wikipedia and other sources is "...an unusual reddish pigmentation of an animal's body...". Anerythrism is just the opposite, so we are left to infer that Anerythristic animals lack red pigmentation. However, yellow pigmentation still exists and is often visible in phenotypic Anerythristic animals as well mixed phenotypic animals such as Snows in Corn Snakes. The 3 or 4 Snow Corns I've had over the last 16 years have always had some amount of yellow pigmentation generally seen on the neck but also other parts of the body as well.

Xanthism is defined as "...animals whose colouration is unusually yellow through an excess of yellow pigment, or possibly a loss of darker pigments that allows yellow pigment to be unusually dominant. It is often associated with the lack of usual red pigmentation and its replacement with yellow.". So, if Axanthism is the opposite, we are left to infer that yellow pigmentation is lost but that red pigmentation can also be reduced or absent as well.

With all of that said, Axanthism seems to fit what we have in the hognose world as I have never see any amount of yellow at all in any of the Axanthics in my collection nor in anybody else's. On top of that, I've never see any yellow pop up in the Snows either which is usually evident with Corns as they mature, but I can only go by what I've seen in the means of pictures of what BHB has and Vin Russo considering their Snows are a couple of years old now.

From what we see in the hogs, they do not produce either coloration which is obvious when looking at the belly where there should be orange patterning...

I disagree with this again based on the fact that Axanthism can exclude both red and yellow pigmentation from happening. The bellies of my 2 Axanthics, of which I've acquired in 2007 as babies have gone through several different color changes as far as lightening or darkening up during different growth spurts, but neither have ever exhibited any ventral coloration other white and black.

I think things are much more complex than what the current definitions can define as Troy points out...

I definitely believe this to be true with some of the morphs out there such as the Anaconda/Supercondas who seem to have linked genes of solid colored bellies when of normal coloration but are then lost when mixed with color morphs such as Albinos, PPA's and Axanthics (as so far observed) by going back to checkered bellies. Also the Red Extreme Albinos are a complex polygenic trait as well as all of the other linebred traits. But I think that the primary color morphs such as Albinos, Tpos Albino/Hypos, PPA's, Axanthics are fairly simple Recessive traits and aren't prone to too much variation in the general definitions of how their genes work. Even Toffees I don't consider 100% simple Recessive due to the "paradoxing" feature that is not understood. Personally I think the "paradoxing" with the Toffees is either a linked gene type of trait or that the Toffee gene is a faulty/leaky gene that is attributing to the amount of melanin that is being released. Of course that is all hypothesis based on things I've read about how some other genes/traits work. But I digress...
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Troy Rexroth
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