Mus (Nannomys) minutoides Smith, 1834

Denys, Christiane, Lalis, Aude, Lecompte, Émilie, Cornette, Raphaël, Moulin, Sibyle, Makundi, Rhodes H., Machang, Robert S., Volobouev, Vitaly & Aniskine, Vladimir M., 2011, A faunal survey in Kingu Pira (south Tanzania), with new karyotypes of several small mammals and the description of a new Murid species (Mammalia, Rodentia), Zoosystema 33 (1), pp. 5-47 : 31

Mus (Nannomys) minutoides Smith, 1834

Leggada minutoides Smith, 1834: 157 .

One individual was trapped by hand (out of any trap line) close to the village, two others in Lines C and D. They belong to a very small sized Mus species and show a brown back and white belly and a relatively long tail which places them into the M. minutoides or M. tenellus group in Kingdon’s (1974) key to east African Mus . The upper M1/ has a very elongated prelobe and the upper M3/ is very reduced. In order to get more morphological criteria of discrimination we have performed skull measurements on karyotyped series of both species and some morphological analysis. The three KP specimens fit well with the karyotyped M. minutoides specimens from Matthey for their sizes, except the HF length, which is smaller, and under the minimum value of the karyotyped sample. Skull dimensions fit well into the M. minutoides variability ( Table 13).

From a chromosomal point of view, pygmy mice have a strong variability in their diploid and fundamental numbers as described by Matthey (1970a, b), Aniskin et al. (1998), Veyrunes et al. (2004) and Kan Kouassi et al. (2008). A molecular analysis ( Verhuynes et al. 2005) has shown that the KP Mus (Nannomys) fits well within the M. minutoides group together with Guinean and South African specimens and this group diverges from M. musculoides ( Kan Kouassi et al. 2008) . The variation of diploid numbers observed here in KP results from Rb polymorphism often occurring in the species of the sub-genus Nannomys ( Veyrunes et al. 2004) ( Table 14, Fig. 17 ). By all karyotypic features these individuals belong to the “ minutoides ” group ( Table 14). In both M. minutoides and M. musculoides , lineages polymorphism would be found and a contact or a gap zone would occur between both species either in central or north Tanzania.

Figures

FIG. 17. — Standard karyotype of KP Mus minutoides Smith,1834 specimen (MNHN-CG2007-1061).