Despite its wide geographical distribution and habit specialization, Blarinomys breviceps is an understudied species. In this work, we analyzed for the first time the intrapopulation variation of the karyotype and cranial measurements of specimens collected in Minas Gerais state, Brazil. We described three new karyotypes with different diploid numbers due to the presence of B chromosomes (2n = 40, 2n = 41, and 2n = 42, with FN = 50), using conventional staining, GTG- and CBG-banding, Ag-NOR, and FISH with a telomeric probe. In addition, morphometric analyses based on twenty-two quantitative cranial characters showed absence of sexual dimorphism contributing to future studies of geographic variation of the species.

尽管其短地理分布和习惯的专门化，但Blaarinomys breviceps还是一个未被充分研究的物种。在这项工作中，我们首次分析了在巴西米纳斯吉拉斯州采集的标本的染色体核型内变异和颅骨测量结果。我们使用常规染色，GTG和CBG条带，Ag-NOR，描述了由于存在B染色体（2n = 40、2n = 41和2n = 42，FN = 50）而导致的具有不同二倍体数的三种新核型。 ，以及带有端粒探针的FISH。此外，基于22个定量颅骨特征的形态计量学分析表明，没有性二态性有助于对该物种地理变异的进一步研究。