Geographical variation of heterochromatin in Ctenomys flamarioni (Rodentia-Octodontidae) and its cytogenetic relationships with other species of the genus.

The first karyotype analysis of Ctenomys flamarioni, based on a sample of 46 specimens collected along the geographical range of this species, is reported. All specimens exhibited a diploid number of 48 but varied in autosomal arm number from a low of 50 to a high of 78. The amount of constitutive heterochromatin also varied with the species' geographical distribution. Comparison of G-band patterns showed a strong relationship between the karyotype of this species and those belonging to the Argentinian mendocinus group.