Oecomys trinitatis (Allen & Chapman, 1893)

Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis & Yonenaga-Yassuda, Yatiyo, 2020, A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes, Zootaxa 4876 (1), pp. 1-111 : 56

Oecomys trinitatis

Karyotype: 2n = 58 and FN = 96. Autosomal complement: 16 metacentric and submetacentric pairs large to small decreasing in size, four subtelocentric pairs large to medium decreasing in size, and eight acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large submetacentric (the largest chromosome of the complement); Y, a small acrocentric ( Patton et al. 2000, pp. 132, Fig. 91).

The karyotype of an undescribed species was reported by Patton et al. (2000, pp. 128, Fig. 88). Karyotype: 2n = 86 and FN = 98. Autosomal complement: seven small metacentric and submetacentric pairs, and 35 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large subtelocentric; Y, unknown as only females was analyzed.

Two additional karyotypes attributed to a presumptive new species of Oecomys , with 2n=54, FN=84 and 2n=54, FN=86, were presented by Gomes-Júnior et al. (2016; unpublished data from T. Lira) for populations from Amazonas, Brazil.

Based on our sampling efforts, we present three different karyotypes for the genus, mentioned here as Oecomys sp. 1, Oecomys sp. 2 and Oecomys sp. 3. The cytogenetic analyzes were performed for specimens collected in the Rio Japurá and Rio Içá, Amazonas state of Brazil ( Table 1 ).