Most web sights and people say that true silverbacks come from Bolivia but some very reputable people and web sights say they come from South Brazil. For example this link.
http://www.boa-constrictors.com/com/Amarali/usfehlinfo.html
I have a so called Bolivian Silverback Amarali from the Joe Terry blood line yet at http://www.boa-constrictors.com/com/Amarali/Brazil/amarali-silverbacks.html
It looks nothing like a Bolivian Amarali but looks near Identical to a South Brazilian Amarali from the Sao Paolo region. And any one have any breeding advice? This is my favorite snake in my collection. Info seems to contradict. I'm confused.