A new karyotype for the genus Cavia from a southern island of Brazil (Rodentia - Caviidae)

intraspecific karyotype variation in mammal species is very common and often caused by centromeric fusion of acrocentric chromosomes. we describe here a new karyotype 2n = 62 (fn = 112) for the genus cavia from the moleques do sul islands, of the southern coast of brazil. we analyzed two male and four female karyotypes that had twenty-four biarmed pairs and six pairs of acrocentric chromosomes. the sexual pair consisted of a metacentric x-chromosome and a large acrocentric y. c-bands were found in the centromeric and pericentromeric regions of almost all chromosomes, except for some small biarmed and acrocentric ones. nucleolus organizer regions appeared in two biarmed chromosomes, and g-banding patterns were also seen.