Nucleolus Organizer Regions in Physalaemus Cuvieri (Anura, Leptodactylidae), with Evidence of a Unique Case of Ag-NOR Variability

Abstract

We studied ten specimens of Physalaemus cuvieri collected at different localities in Brazil using conventional staining and banding techniques. All specimens had 2n = 22. There were karyotypic variants: distinct patterns in the number and chromosome localization of Ag-NORs as well as in the corresponding secondary constrictions. Preliminary C-banding patterns obtained for specimens from two localities are also suggestive of karyotypic differentiation in P. cuvieri.