A new coccidian parasite of the genus Eimeria Schneider, 1875 is described from the subterranean African silvery mole-rat Heliophobius argenteocinereus Peters, 1846. Oocysts of Eimeria burdai sp. n. were subspherical to broadly ellipsoidal 17.8 (16-19) x 14.1 (12-15), with ashape index 1.2 (1.1-1.4). Oocyst wall was bilayered, smooth and colourless, approximately 1.0 thick. Outer layer was significantly thicker than inner one. A micropyle and oocyst residuum were absent. One or two ellipsoidal or spherical polar granules were present. Sporocysts were ellipsoidal, 10.8 (9-12) x 6.2 (5-8) with a shape index 1.7 (1.5-1.9). Sporocyst wall was single-layered, thin, smooth and colourless, with small Sticda body at the pointed end. In freshly sporulated oocysts, spherical sporocyst residuum was composed of small granules enclosed by a thin membrane. Sporozoites were elongate, lying length-wise in the long axis of the sporocyst, partially curled around each other, with single large refractile body located posteriorly. Faintly distinguishable nucleus was in the central part of the sporozoite. This eimerian represents the first coccidian species described from subterranean African silvery mole-rat (Rodentia: Bathyergidae).
Concentrations of lead (Pb), cadmium (Cd), copper (Cu) and zinc (Zn) were assessed in body tissues of a solitary subterranean rodent, the silvery mole-rat (Heliophobius argenteocinereus) from the African endemic family Bathyergidae. The mean concentrations of cooper and zinc in animals captured in Malawi were higher in liver compared to muscle (18.3 mg.kg-1 vs. 8.8 mg.kg-1 of dry weight for copper; 170.3 mg.kg-1 vs. 101.2 mg.kg-1 for zinc). No important differences were found in oncentration of heavy metals between animals captured in different habitats (grassland vs. cultivated crops) or between sexes. Very low concentrations of lead (0.41 mg.kg-1 in liver, 0.25 mg.kg-1 in muscle) and cadmium (0.09 mg.kg-1 in liver, 0.07 mg.kg-1 in muscle) indicate no health risk connected with local consumption of silvery mole-rats in the area under study.
Ethiopian rats (genus Stenocephalemys) represent a monophyletic group of Ethiopian endemic rodents that diverged in the Ethiopian Highlands during the Pleistocene. Because of the frequent occurrence of so-called reticulate evolution (i.e. repeated hybridization of partially diverged populations), their taxonomy has not been adequately resolved, despite the fact that they belong to the most abundant rodent genus in Ethiopia and are important as pests and carriers of pathogens (e.g. hantaviruses). Here we analysed material for 623 Stenocephalemys specimens using integrative taxonomy composed of genomic analyses (388 nuclear markers and complete mitogenomes), 2D-geometric morphometry of skulls and classical morphometry of external traits. The genus consists of six clearly defined gene pools (= species), characterized by specific morphology, ecology and distribution. Two of them, described here as new species, live in fragmented populations in Afroalpine habitats in the north-western part of the Ethiopian Highlands. We also showed that mitochondrial DNA is not applicable as a universal diagnostic tool for species discrimination in Stenocephalemys, because of multiple cases of mitochondrial introgression. This finding illustrates the utility of the genus as a suitable model for future studies of mito-nuclear coevolution along an elevational gradient.
The taxonomy and distribution of rodents in Zambia was comprehensively summarized in 1978 by W.F.H. Ansell in his excellent book Mammals of Zambia. Despite the fact that during the last three decades many new taxonomic revisions of African rodents were published and extensive new material collected, not much work has been done on Zambian rodents since the book publication. Here we summarize the current knowledge of one of the most speciose group of African rodents, the tribe Praomyini, in Zambia. We review available historical records and revise our recently collected material by sequencing the mitochondrial DNA gene of cytochrome b. The presence of eight species of Praomyini in Zambia is documented and the pattern of their geographical distribution is described and discussed. Two species, Praomys minor and Mastomys coucha, are reported for the first time from Zambia and Praomys cf. jacksoni probably represents a new undescribed species. On the other hand, the actual occurrence of Colomys goslingi, known in Zambia only from one historical record, is questionable. The results document the usefulness of the DNA barcoding approach for description of species diversity of taxonomically complicated groups with many cryptic species.