<i>Oryzomys Flavescens</i>and<i>O. Delticola</i>Chromosomes (Rodentia, Cricetidae) from Uruguay and Argentina

Abstract

SUMMARYChromosomes were analyzed in fifty-four specimens of Oryzomys flavescens collected in one locality of Argentina and several regions of Uruguay. Forty-nine of the specimens from Argentina and Uruguay exhibited a diploid number 2n = 66, FN = 70, and the remainder five uruguayan and argentinian animals showed variations between 2n = 66, FN = 68 and 2n = 64, FN = 66. Oryzomys deificola, collected in several regions of Uruguay showed diploid numbers 2n = 60–62, FN = 80. Both sex chromosomes and autosomal polymorphisms are reported.