I hate to keep bothering Don, especially when there's so many smart folks here. If I asked him all the questions I really wanted to, he might run away screaming. 
You bring up another question that's been bugging me: howintheheck does a snake have hypomelanism and amelanism at the same time?? Yes, I do understand genetics -- it's just that it seems to be a contradiction in terms. If you're producing NO melanin, then it would seem to be irrelevant whether you also have a gene for SOME melanin. I don't understand why you would see any effect from the hypo gene at all. Tis a puzzlement!
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0.1 Peruvian rainbow boa (Amaru)
0.3 Honduran milksnakes (Chicchan, Chanir, Hari)
0.0.3 corns (Cetto, Tolosa, TBA)
1,000,000.1,000,000 other critters