Pelomys fallax (Peters, 1852)

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 : 14-16

Pelomys fallax (Peters, 1852)

Mus (Pelomys) fallax Peters, 1852: 275 .

One relatively young individual was trapped in line D in herbs close to a waterhole. The skull displays grooved upper incisors, short nasal bones and a wide interorbital constriction, upper molars with large round cusps, which are relatively well aligned, and a large third upper molar, with one narrow posterior lobe that characterizes the genus. The only species recorded in Tanzania is Pelomys fallax . Comparisons with BMNH specimens of P. fallax from Uluguru Mountains ( Tanzania) showed a larger size of external parts and skulls ( Table 6). Comparison with the

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type specimen of P. fallax from near the Zambezi River, Caya District, Mozambique, shows some similarities in size and morphology with the KP specimen in that it has the tail equal in length to head and body. However, the KP specimen is smaller than all other measured specimens but it has larger molars compared to the Angolan specimen and fits better with the Tanzanian specimens and the holotype ( Table 7). All these results support the conclusions of Musser & Carleton (2005) that P. fallax may represent a species complex.

The karyotype of the studied male has 2n = 42 and FNa = 56 ( Fig. 6 ). As far as we know, the chromosome data are available for only one taxon of the genus, namely P. campanae Huet, 1888 ( Matthey 1963) which displays 2n = 48 and FNa = 52 and is very distinct from that of the KP specimen.

Figures

FIG. 6. — Standard karyotype of KP Pelomys fallax Peters, 1852 specimen (MNHN-CG2007-1247).