Boa is a monotypic genus, meaning there is only one species of Boa, that is CONSTRICTOR when we refer to redtails or common boas or short-tailed boas those are all sub-species; c. constrictor, c. imperator, c. amarali.. et-al.
Many other types of snakes are referred to as Boas because they are placed taxonomically in the large group of related snakes that also includes the Boa C. ssp.. Examples of these would be the Rainbow boas (Epicrates) or the Madagascar boas (Acrantophis or Sanzinia), even the rubber boas of the US (Charina)..
If you want to know more about the Boa constrictor ssp. Here's a good place to start....
A quick intro to the Boa Constrictor....
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Gus
A. Rentfro
RioBravoReptiles.com
www.riobravoreptiles.com
"Quality is not an accident. Perfectly healthy animals are a minimum requirement.. everything else is just salesmanship" gus