"I think of hypomelanism in different terms than it usually gets used. I consider it a 'general' reduction in pigmentation!"

I am not so sure I agree with that. Hypomelanism simply means Reduced melanin which is only one of the pigments we are discussing. If the reduction in pigmentation that you speak of includes melanin, then yes it is a hypo, If the reduction in picmentation does not involve melanin, then it is not a Hypo. Melanin is the key word. There are specimens (anerys for example) with reduced pigmentation that still possess normal amounts of melanin. These would not be Hypomelanistic. They would be "Hypopigmented" or more specifically anerytheristic. Again Melanin is the key word here. It is a hypo as long as the reduction in pigment involves melanin. If other pigments are also reduced along with it then it may be able to have other terms applied to it as well, but is is still safely refered to as a hypo.

Hypomelanism is a very broad, and often confusing, term covering everything from animals with simple recessive genetic mutations such as leucism, albinism, and amelanism to animals that are on the lighter end of the spectrum of what is considered to be normal for them. However, when most people think of a “hypo” they are usually thinking of something that falls somewhere in between these two extremes.

Most people in the hobby consider a “hypo” to have reduced amounts of melanin to a lesser extreme than that of the amelanistics, albinos, and Leucistics but to more of an extreme than that of a light specimen that still falls within the range of what is expected for that type. In addition, many people do not consider something to be a “true hypo” unless there is some reproducible genetic marker that is responsible for causing the melanin reduction. Weather that genetic marker is co-dominant or a simple recessive trait, usually depends on the species being discussed. I should also mention that the notion that hypomelanisn has to be a genetically reproducable trait is only a perception by many hobbyists; it is not part of the actual definition of hypomelanism.

There is one other thing to consider when deciding if a specimen is a hypo or not. The term Hypomelanism refers to an specimen that displays reduced amounts of melanin, possessing smaller amounts than would the norm for that population, be it species, subspecies, or local. So, when determining whether a certain specimen is hypomelanistic one must compare it to a sample population, and the size or type of that sample population can often be the factor that determines if that specimen is going to be considered a hypo or not.

For example, a Hogg Island Boa Constrictor is often considered a naturally occurring hypo, and this is true, if you are looking at Boa Constrictors in general as a species. However, it is not true if you are just looking at the island(s) where they occur, as that is their “normal” coloration for these Boas in that specific area.
-----
James Wilson
Pacific Coast Herpetological
www.pacificcoastherpetological.com

[ Reply To This Message ] [ Subscribe to this Thread ] [ Show Entire Thread ]