Micrurus tener, AND OTHER

Cole, Charles J., 2021, Karyotypes of Coralsnakes (Reptilia: Elapidae) from the Western Hemisphere, with Comments on Intraspecific Variation and Centric Fission of Chromosomes, American Museum Novitates 2021 (3972), pp. 1-8 : 5

COMPARISONS BETWEEN M. TENER AND OTHER SPECIES OF MICRURUS

Diploid chromosome numbers reported for species of Micrurus vary from 26–42, with some intraspecific variation in M. nigrocinctus and M. tener ( table 1). Interspecific variation in number of macrochromosomes ranges from 14–22 and variation in number of microchromosomes ranges from 10–20. Variation among the macrochromosomes apparently results largely from centric fissions of ancestral biarmed chromosomes into derived uniarmed or telocentric chromosomes, but there is no simple hypothesis that explains the variation in number of microchromosomes. In addition, there is a general geographic tendency in coralsnakes of the Western Hemisphere to have experienced an increase in the number of fissioned ancestral macrochromosomes trending from species occurring in northern temperate regions to species occurring in southern equatorial regions ( table 1). In the South American species M. iboboboca and M. lemniscatus all macrochromosomes are telocentric, except for one pair (subtelocentric; table 1) and there are changes additional to centric fissions.