The Sterling Story

On June 5, 2010, a litter of 15 BCI was born to a '06' pastel female bred by a very colorful '06' male.  While the parents are both attractive boas, there is nothing about their appearance or known lineage to suggest anything genetically unusual about them.  They were bred to produce pastels, with the hope that the minor tail stripe on each might be magnified.  That didn't happen.

When I discovered that the female had given birth, I looked in the cage and saw what at first was an unrecognizable sight.  Several of the babies looked smooth grey, without any discernible saddles on their backs. Upon closer examination, I found that 5 of the 15 babies were completely devoid of saddles, side medallions, head markings, and belly markings.  They have a distinct color difference on their tops, compared to their sides, and the tops of their tails are very dark, with snow white bottoms.  To put it plainly, these babies are patternless. 

They are in all other regards normal, active, boas.  They are of comparable size to their littermates.  They show no behavioral abnormalities.  

I initially suspected that this is a simple recessive genetic mutation. Subsequent breeding trials support this conclusion:

I have twice bred het x het (4 different Boas) producing roughly 25% visual Sterlings in each litter. 

I have twice bred Sterling x het (3 different animals) and produced roughly 50% Sterlings in each litter. 

I have bred a Sterling to an unrelated super-hypo and produced no Sterlings (all hypo het Sterlings). 

And on June 1, 2014, a Sterling x Sterling breeding has produced a full litter of Sterlings. 

According to the Merriam-Webster Dictionary, when "sterling" is used as an adjective, one of the meanings is "conforming to the highest standard." And these patternless boas, unlike many others that get called "patternless," really have no pattern. 

Most other so-called patternless boas have reduced patterns, or at least have a few saddles or side medallions. These do not.

So, "Sterling Patternless Boas" conform to the highest standard of patternlessness.