Fukomys ilariae, Gippoliti, Spartaco & Amori, Giovanni, 2011

Gippoliti, Spartaco & Amori, Giovanni, 2011, A new species of mole-rat (Rodentia, Bathyergidae) from the Horn of Africa, Zootaxa 2918, pp. 39-46 : 41

Fukomys ilariae sp. nov.

Somali striped mole-rat

Etymology. The species is dedicated to Miss Ilaria Alpi, an Italian journalist, who together with her cameraman Miran Hovratin, was assassinated in Mogadishu in 1994, while investigating trade in toxic cargoes between Italy and Somalia.

Type material. Holotype. Mounted skin ( MCZR 7016), 11.8 cm head and body length. No distinctive tail is apparent, but a very short peduncle seems to represent a vestigial tail, as reported for Heliophobius Peters, 1846 ( De Graaf, 1981) . Left side of the specimen is severely faded because of exposure to sunlight.

Type locality. The precise collecting locality of the type specimen is unknown because the label ( Fig. 1 ) indicates only Somalia. However, Somali specimens received by the museum were donations from the first Italian residents (military personnel and physicians) living in or near Mogadishu, and no Italian expedition to East Africa (including Eritrea, an older colony) is known to have deposited specimens to the Rome Museum. All the historical data in our possession, including the few catalogues published at the time that included Somali specimens ( Lepri, 1911; Masi, 1912) suggest that the mole-rat originated from the Lower Shebelle region in central-southern Somalia, practically the only region of Somalia occupied by Italians until the 1920s. The climate there is semi-arid, with a mean yearly rainfall of around 500 mm (480 mm: Mogadishu; 530 mm: Afgoye). An open shrub vegetation type —locally known as ‘boscaglia’— grows on the big Somali dunes, which are 20–30 km wide and extend parallel to the coast (Pignatti & Warfa, 1983).

Diagnosis. The description of the pelage coloration is based mainly on the right (unfaded) side of the specimen. Head shows a broad whitish midline that extends over the dorsal area, except on a small region over the neck ( Fig. 1 ). The whitish midline divides along the posterior dorsal area, forming a ‘swift tail’ 49.5 mm long. Rest of the body, including ventral area ( Fig. 1 ) and limbs, is Sienna hearth / burnt Sienna. No white patch is evident ventrally. Hairs are longer dorsally: c. 10 mm along the neck, 7.5 mm over the legs. The specimen shows reduced eyes covered with hairs. The absence of vibrissae on the head is probably caused by poor preservation of the skin.

Comparison with other bathyergid species and taxonomic assignment. In general, the skin is sparsely haired —instead of appearing velvety as in most Fukomys— as in some bathyergid species that are adapted to xeric habitats ( De Graaf, 1981). Digits show five concave nails ( Fig. 2 ). Hindlimb nails differ from those of other members of the genus Fukomys that show elongated and horizontally flattened ‘finger-nails’ ( Kingdon, 1974; pers. obs.). Anterior limbs appear more robust. The specimen belongs without doubt to a subterranean-adapted lineage. The shape of the nails excludes its belonging to the Chrysochloridae ( Kingdon, 1996) . Absence of pinnae and the habitat spectrum of the assumed capture site also led us to dismiss the genus Tachyoryctes (Spalacidae) , a mountain specialist ( Kingdon, 1996), although the latter genus is known to occur on the mountains of northern Somalia ( Funaioli, 1971; Agnelli et al., 1990). Absence of any trace of pinnae suggests that the specimen belongs to the family Bathyergidae (in accordance with the specimen label). It should be noted that at the time of its first taxonomic assignment, the skull was probably present. Owing to the absence of adaptation to burrowing of the forefeet claws, the new species should belong to the subfamily Georychinae Roberts, 1951 . Concerning the pelage pattern, the shape of the markings on the back is quite different from that found in other members of the family. The elaborate colour pattern of the skin is consistent with its assignment to the genus Cryptomys ‘ sensu lato’ ( Honeycutt et al., 1991), the only bathyergid genus showing a great variability in pelage coloration. We compared the colour pattern of our Somali specimen with those of other species of Fukomys found north of the equator, as described in the relevant literature. The westernmost species, F. zechi (Matschie, 1900) from Ghana, is described as “pale buffish or very light sepia-brown” in colour. Most individuals have a more or less developed white head-spot ( Rosevear, 1969). The Nigerian species, F. fo x i (Thomas, 1911) is described as “very deep sepia”, above and below. The only marking is a sharply defined pure white head spot, not found in all individuals ( Rosevear, 1969). A third species, F. ochraceocinereus (Heuglin, 1864) , is found from Cameroon to southern Sudan and northwestern Uganda ( Honeycutt et al., 1991). Fukomys ochraceocinereus oweni Setzer 1956 , from southern Sudan has blackish brown upper parts but it is a little paler below. The dorsal head spot, lips, chin, and line on mid-throat converge into a pure white spot on the breast ( Setzer, 1956). According to Delany (1975), mole-rats of southern Sudan, Uganda and eastern Democratic Republic of Congo, assigned to the taxon F. ochraceocinereus lechei (Thomas, 1895) , may have a patch of white fur on top of the head and a backwardly projected white stripe about 3 cm long, extending over the neck. As already stated, molecular data supported the split of Cryptomys Gray, 1864 in two genera, with Fukomys ( Kock et al., 2006) containing all the eastern, central and southern African taxa, except those of the Cryptomys hottentotus (Lesson, 1862) group, which is limited to the southern African subregion ( Faulkes et al., 2004; Ingram et al., 2004). On morphological and biogeographical grounds, we preliminarily assign the new species of mole-rat to the genus Fukomys .

Figures

FIGURE 1. Holotype of Fukomys ilariae sp. nov. (MCZR 7016): a) dorsal view; b) ventral view; c) right lateral view and the original label of the specimen.

FIGURE 2. Detail of a) anterior foot and b) posterior foot from the holotype of Fukomys ilariae sp. nov. (MCZR 7016).