Karyotypic Studies of two Species of South American Snakes (<i>Boa constrictor amaral</i><i>i</i> and <i>Bothrops jararac</i><i>a</i>)

Abstract

Karyotypic studies have been made of two species of South American snakes, <i>Boa constrictor amarali</i> and <i>Bothrops jararaca</i>. Both have 36 chromosomes; 16 macrochromosomes and 20 microchromosomes. While no morphological difference is discernible between the mitotic chromosome complements of the male and the female <i>Boa constrictor amarali</i>, a heteromorphic pair is evident in the female <i>jararaca</i>, in which the subterminal W is distinctly smaller than the mediocentric Z. Thus female heterogamety of the ZZ-ZW type is cytologically recognizable in <i>Bothrops jararaca</i>.