Posted by:
JKruse
at Thu May 13 14:15:28 2010 [ Email Message ] [ Show All Posts by JKruse ]
Although I do not understand, nor does anyone else, the increase of melanin over time it's something that has been naturally-selected for....whether it be evolutionary anomaly in response to a high-elevation population, we can only speculate. But here is a response I gave to Rainer (Bluerosy) from down below indicating these are NOT the typical "high-black" variant of Sierra zonata:
"Rainer, i do indeed have localities of and know of Sierra snakes from additional localities that are naturally selected for higher black crossover. Indeed I know there is not just one specific location that this phenomena occurs.....there is great research being done out west that encompasses this very subject and will likely be published in the next few years. Wish i could say more but can't. But this Sierra variation have patterns that are stationary/constant and DO NOT CHANGE over the course of time.
These Sierra snakes I'm showing are different in that it is not about selecting for higher amounts of black......females generally hatch "anery" (no one knows why there seems to be a sex-linked phenomena going on with this phenotype) and then undergo (much like gaegeae) a GRADUAL ontogenetic CHANGE whereby the melanin completely suffuses (except for the ice-white bands). So a baby that has the lavender body rings, after about a year, will no longer have (save for a few scales possibly here and there) any color left. The few scales that may show through are lavender, NOT red.
The Sierra snakes that are "high-black" hatch out with the bright red lateral slivers and KEEP THEIR PATTERN over time...it's UNCHANGED.
What's even more interesting is that the tri-colored males do not have normal skin color under the scales, but rather their skin is black despite being a tri-colored snake. I can not explain what is going on, much like the few others that are working with this really unusual natural variation of Sierra zonata. But what i do know is that there are not the typical high-black variation you're thinking of. They are indeed different."
It's anyone's guess, but it's a very unique variant.....almost the same effect of what black milks go through however the white bands remain unaffected. Just plum weird.
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Jerry Kruse
www.zonatas.com
And God said, "Let there be zonata subspecies for all to ponder..."
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here's one explanation for melanin...... - JKruse, Thu May 13 14:15:28 2010