A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes Author Moreira, Camila Do Nascimento Author Ventura, Karen Author Percequillo, Alexandre Reis 0000-0001-9490-5457 cmoreirabio@gmail.com Author Yonenaga-Yassuda, Yatiyo text Zootaxa 2020 2020-11-06 4876 1 1 111 journal article 7983 10.11646/zootaxa.4876.1.1 4ee8b608-7c73-4980-9e86-3e3719e91c7f 1175-5326 4423612 190EC586-E14B-4AEF-A5EF-3DA401656159 Oligoryzomys delicatus Karyotype: 2n = 60 and FN = 72. Autosomal complement: seven metacentric and submetacentric pairs medium to small decreasing in size, and 22 acrocentric pairs (three large and the remaining small). Sex chromosomes: X, a medium acrocentric; Y, a small acrocentric ( Kiblisky 1969 , pp. 1339, Fig. 3 ). Another karyotype with a different diploid and fundamental number was reported by Gardner & Patton (1976) , 2n = 62 and FN = 74 or 76 (fundamental number comprises autosomal and sex chromosomes). Chromosome complement: five metacentric pairs (one large and four small), three subtelocentric pairs large to small decreasing in size, and 23 acrocentric pairs (one very large and the remaining small), the sex chromosome of this karyotype was unknown as only a female was examined. Baker et al . (1983) reported a diploid number of 60 and 64 for O. delicatus , and presented the G-banding for these karyotypes. These variation in diploid and fundamental number of O. delicatus occurs in different localities of Suriname and Venezuela ( Table 9 ). This karyotype was originally attributed to O. longicaudatus , variant 3, by Gardner & Patton (1976) , but Weksler & Bonvicino (2015b) assigned it to O. delicatus .