KARYOLOGY OF NORTH AMERICAN CROTALINE SNAKES (FAMILY VIPERIDAE) OF THE GENERA AGKISTRODON, SISTRURUS, AND CROTALUS

Abstract

The karyotypes of 10 species of crotaline snakes from three genera of the family Viperidae are described. All species were found to possess a diploid number of 36 with intergeneric differences involving at least two pairs of autosomes. More significant differences were found between the sex chromosomes with Agkistrodon piscivorous possessing a submetacentric W, A. contortrix possessing an acrocentric W, Sistrurus sp. possessing an acrocentric W, and all Crotalus sp. possessing a submetacentric or subtelocentric W. The chromosomal relationships of the genera are discussed in light of current thoughts on evolution in the Viperidae and chromosomal evolution in snakes.