to VRHD

VRHD Overview

What’s in a Name?

Coming up with an appropriate name for this snake was troublesome. Hypomelanistic Durango Mountain Pine Snake is certainly a mouthful. Just contemplating the act of saying it makes one weary. Also, a unique designation is needed to keep from confusing this particular hypo with other potential hypos and, to cover all bases, all future hypos. So, to avoid the embarrassment of some cutesy appellation concocted after one too many gin and tonics, we are going to take the chicken’s way out and call these animals — VR Hypo Deppei, and even better and shorter, VRHD. If you are really lazy you can just call them VDs . . . though blurting out at the next expo that you want some VD could raise a few eyebrows.

Enter the VRHD

Our group of deppei originated from the Los Mimbres collecting locality in the state of Durango, Mexico nearly 30 years ago. We were fortunate to have begun our deppei journey with several bloodlines. This gave us a broad array of genetic variation from the beginning. The emergence of the VRHD gene(s) came relatively late in the history of our work with the species. It was most likely lurking in the background as a recessive trait from the beginning and a lucky roll of the dice resulted in the fortuitous pairing of animals heterozygous for the VRHD type hypomelanism.

The casual way that the term “hypomelanism” is bantered around when discussing coloration in animals (reptiles in particular) can be confusing. Sometimes the term "hypomelanism" is invoked when pattern elements normally composed of dark pigment are greatly reduced in size or are missing altogether. An example being the severely reduced or missing black rings on certain line bred strains of tri-colored kingsnakes. In other situations, the term hypomelanism is used when the melanin on an otherwise normally colored animal is sill present but in a watered down or dilute form. The dilution often occurs to such an extent that normal pattern elements appear dramatically lighter and often more colorful as the masking effect of melanin is reduced. Colors on such animals generally appear both substantially brighter and more saturated. To make things a bit more confusing there are actually three types of melanin: eumelanin, pheomelanin and neuromelanin. Neuromelanin is found only in nerve cells and doesn't impact coloration. Recent research indicates that both eumelanin and pheomelanin are responsible for reptile pigmentation. Of the more common eumelanin there are two types—brown eumelanin and black eumelanin. For simplicity's sake we will corral all the various melanins under the catchall, "melanin."

Enter the VRHD and both the aforementioned examples of hypomelanism occur at the same time, often on the same animal. The coalescing of the two types of hypomelanism on one animal seems a strange and unusual occurrence. On areas of the snake where the dilute melanin scenario is at work the dilution can appear complete or nearly complete, similar to albinism. Normally black or dark pigmented pattern elements such as the primary blotches are often rendered as a light, clear, fleshy pinkish lavender. True black on the VRHDs is either missing altogether or is restricted to a fine edging around the dilute saddles - a beautiful filigree of black. This effect alone is stunning. The background area, which serves as a foil for the primary blotches and other pattern elements, is wildly variable in color and saturation but can be divided into three basic color groupings which are summarized as follows:

Summer Phase

We coined the term "Summer Phase" to describe all of the VRHD with background coloration composed in large part by various shades of yellow. Viewing animals from this grouping reminds one of extravagant warmth and brilliant, clear sunshine. The yellow background on Summer Phase animals varies from a warm, pastel yellow to a blinding, saturated lemon yellow. The normal deppei penchant for variation applies here and the results are striking.

Winter Phase

VRHD with the background area composed mainly of various shades of white have been designated as “Winter Phase.” The white background against which the other pattern elements are laid calls to mind stark fields of snow and ice illuminated by a bloodless winter sun. The white background on these animals varies from a clear, luminous ivory to a brilliant snow white. The cool, frosty appearance of these animals seems directly at odds with their Summer Phase brethren.

Summer and Winter Black

As mentioned before, some Summer and Winter phase VRHDs sport some very limited black. It exists as a delicate, filigree or tracery, one scale or less in width around some dorsal pattern elements. This black filigree, when present, is usually restricted to the anterior third of the snake. This is usually a deep, inky pigment with no dilution on younger animals but on older/larger animals it often appears as a medium to dark purple/blue. This rather delicate detailing lends a sophisticated polish to an already devastatingly beautiful animal.

VRHD Pattern

As stated earlier, normal Las Mimbres deppei can be quite variable in pattern. The genes responsible for the hypomelanism in the VRHD are evidently linked to genes that control pattern variability as well. This situation is not too unusual as pattern abnormalities are known to sometimes accompany hypomelanism in other reptiles. However, the VRHD take pattern variation to an all-time high. In fact, from what we have seen early on, VRHD seem to possess genetic "sets" or "families" of  pattern variation. This project is still very much in its infancy and we are still on a journey of discovery with the pattern types. A few of the more common pattern types are described here with the list being nowhere near complete:

As the name implies, this is the pattern "family" that the normal pattern variations fall within. Typically, normally patterned VRHD have pattern variations on a theme of pronounced, wide dorsal blotches often with some striping present laterally on the anterior  1/3 of the snake. The background is generally clear of pattern but often contains scales with darker pigmentation along the "ridge" of the scales.


Animals belonging to the striped group have longitudinal, mid-dorsal striping that can occur as a stand-alone pattern or in different combinations with other pattern types. The striping is usually composed of a single line of background color. The stripe is often bordered on each side by darker pigment that is sometimes but not always reflective of what would normally be the blotch color. Black filigree may or may not be present. Striping can be continuous or interrupted with starts and stops. When incomplete, the striping somehow manages to integrate very tastefully with the other pattern types. The width of the striping varies between three to six scales wide.


As the name implies, pattern elements can seem to "disappear" into the background color. Unlike “vanishing” patterned kingsnakes, the pattern elements of the VRHD actually tend to vanish with age and in some areas, disappear altogether into the background. There is no set area on the snake where this happens but it seems to generally occur most often on the forward 2/3 of the body. Tail patterning seems mostly unaffected though some heavy intrusion of background color can be seen.


A very unexpected pattern type, even for deppei. There seems to be significant variability within this pattern type. The spots are generally round and symmetrical with regard to each other and are placed along the dorsal apex of the spine. They can vary wildly in diameter between specimens exhibiting the trait. The diameter of the spots varies between three and eight scales wide.  The spotted pattern type seems to "clear the decks" of other pattern types in the immediate areas where the spots occur. However, blocks of the spotted pattern can be combined with other pattern elements as one moves down the length of the snake.


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