Boa constrictor sigma

The Tres Marias Island boa.  This subspecies is under taxonomical debate and is not accepted in full be either the scientific or herpetological community.  There are no available records to show that this subspecies is in captivity either in the United States or abroad.  The islands are make up a small group roughly 100 km off the Pacific coast of Mexico.  Defined from 9 museum specimens.  Scale count variance and not appearance is the main support behind this subspecies.

With an absence of specimens in culture it is hard to be certain, but most feel that Sigma is an island form of Mexican B.c.imperator.

Taxonomic data: Smith 1943; scale count 77 dorsal rows; 253-260 ventrals; 55-66 subcaudal; average 35 saddles.

Compiled and written by Christopher Gilbert, © Gilbert Boas 2008-2017                                      Contact: