A new karyotype of Wiedomys pyrrhorhinus (Rodentia: Sigmodontinae) from Chapada Diamantina, northeastern Brazil

A new karyotype of Wiedomys pyrrhorhinus (Wied, 1821) is described, including G- and C-banding and Ag-NOR sites from specimens collected in the municipality of Morro do Chapéu, situated in the northern region of the Chapada Diamantina, state of Bahia. Karyological studies of W. pyrrhorhinus have shown a constant diploid number (2n) of 62 with two different numbers of autosomal arms (FNa): 86 and 90, respectively. The new karyotype revealed 2n = 62 and FNa = 104, being the higher autosomal number found so far for this genus. The X chromosome is a large acrocentric and the Y chromosome is a sma...