This week at Living Gems Reptiles, we are taking a break from our regular updates to discuss an unusual topic: sudden color fade in the Brazilian Rainbow Boa. A little understood -- and less discussed -- part of keeping this gorgeous subspecies, this phenomenon is an intriguing possibility of which any current or potential owner should be aware.
Background
While Brazilians are known for changing color as they mature -- it is commonly said that babies can move one or two levels up or down the “quality scale” as they grow -- that is a gradual and ongoing process, often taking 18 to 30 months to fully occur.
Sometimes, however, a Brazilian changes color very unexpectedly and quickly. When this happens, the animal’s color almost seems to undergo a “fade” effect, often over the course of less than one shed.
There seem to two very separate and distinct forms of this phenomenon.
In the first, a Brazilian will lose *all* of its color, in effect completely “browning out” from its prior orange or red. By way of illustration, following is a picture of Stone, a then four-year-old male (he is the animal in the background; before he faded at age two and a half, he was the same color as the animal in the foreground):
The above picture is courtesy of Daniel (used by permission); Living Gems has not yet experienced this type of fade directly.
In the second form, the animal will lose only *part* of its color, leaving a fascinating patchwork of vibrant and whitish areas. By way of illustration, here is a picture set of our own Hills, an (estimated) four-and-half-year-old male with firecracker-level orange color. The set was taken in the context of his pairing with Alexandrite, the female in the photos, and spans a period of three months.
February
March
April
May
As you can see, the fade hit very suddenly between March and April, a period of less than one shed. Up until May, I had thought it a temporary condition brought on by breeding stress, one which would disappear after a break, a meal, and a shed. It did not, leaving Hills with a novel new look.
Analysis
While I had heard of the first type of color fade, the second was new to me. Having spoken to many of the top Brazilian breeders since that date, here is what we have been able to determine:
One, while uncommon, color fades are not as rare as they might seem. Of the nine top breeders I spoke with directly, eight had personally witnessed this phenomenon. Their experience ranged from single animals to multiple occurrences. (One of the eight had experienced the first fade type only, and the ninth never answered directly.) In addition to their own experiences, several were able to relate stories of other breeders and customers who had experienced fades. Based on this data, I suspect the phenomenon is publicly underreported -- and understandably so, as it would be very easy to scare away customers who did not understand the nature of this change.
Two, this does *not* seem to be a disease, affliction, or in any way health-related. With only one single exception, all animals that experienced a color fade were reported to be and remain in good health, continuing to eat, grow, poop, and breed exactly as they had before the change. Animals they were housed in the same collection, room, or even cage have been completely unaffected, even over the course of years. I was also told of several cases where the animals were maintained as front-line breeders even after a change, and continued to produce normal offspring. In other words, the color fade is cosmetic and affects the specific animal only.
Three, while a last-minute example proves this can affect a snake of any age, the reported incidents seem to affect *mostly* adults that are exposed to a breeding environment. In every reported case except that one, the animal was two and a half years or older (in other words, sexually mature), and either actively breeding or housed in a situation where they could sense and react to the opposite gender during breeding season.
So, if not a disease, exactly what is this?
The best collective guess, based on all these conversations -- including one with a breeder friend who was kind enough to have his geneticist colleague sit in -- is that the color fade phenomenon is probably controlled by a family of genes, and thus “non-calculably inheritable” (in other words, only one or two animals in each litter may eventually express it). In addition, it may have breeding hormones as a major trigger. By way of full disclosure, alternative theories included moisture-triggered (which I suspect coincides with breeding conditions, as many people raise humidity during breeding season), fecal burns (which is possible, but I’m pretty sure is inaccurate in Hills’ case), and some type of vitamin/mineral deficiency that interfered with the ability to synthesize color (possible, but even this would have a genetic underpinning, or many more Brazilians would fade).
Questions and Answers
This theory leads directly to two additional questions: how prevalent are these genes in the Brazilian market, and what do you do if one of your animals experiences a color fade?
I don’t think anyone can answer the first question. These genes are absolutely “out there” in the public market, as evidenced by the reported cases. But no one knows just how common they are, both because the change is unusual and not always reported. This is compounded by the fact that very few breeders know the genetics of their animals back more than one or two generations, so these genes can remain “hidden” in otherwise beautiful breeders.
For the second question, I would urge anyone who experiences a color fade to let the source breeder know. That tips them off to the fact that one of their animals carries this gene set, and they can then factor that into future breeding decisions.
While I cannot speak for other breeders, in Living Gems’ case, after much deliberation, we plan to continue breeding Hills. We have two solid reasons for this.
One, animals with color as intense as Hills are rare. We’ve moved on every pick of that quality we’ve seen over the past year, and have seen only two. We believe we have the appropriate female stock to develop that color while separating out the fade genes for use elsewhere.
Two, the color fade gene set seems to be poorly understood or researched. We are not aware of a single instance in which offspring have been tracked and reported on to gain more understanding -- which is a shame, because like all unusual genes, this set has the potential to be a strong plus in the right project. If an entire litter could be followed and reported on, it would collect some very useful data for the Brazilian community as a whole. We will work with our customers to collect and share that data.
As a final note, to reassure those customers pursuing Hill’s amazing color but not the fade genes, we are willing to extend a guarantee: if any customer who purchases these offspring experiences a fade and is *unhappy* with the result, we will give that individual a discount on a future baby. (Remember, this is anticipated to occur in only one or two animals per litter. We will probably tie this guarantee to the original purchaser and a set period of years, just to avoid age-related issues. As was pointed out by the geneticist, this change can happen naturally to older animals.)
Thoughts? Comments? We welcome your input!
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