Nephelomys maculiventer

Karyotype: 2n = 66 and FN = 112. Autosomal complement: 15 medium to small metacentric and submetacentric pairs, nine subtelocentric pairs (one large, four medium, and four small), and eight acrocentric pairs (one large, three medium, and four small). Sex chromosomes: X, a medium metacentric; Y, a small submetacentric (Gardner & Patton 1976, pp. 4, Fig. 1A).