Letheobia mbeerensis, Malonza, Patrick K., Bauer, Aaron M. & Ngwava, Jacob M., 2016

Malonza, Patrick K., Bauer, Aaron M. & Ngwava, Jacob M., 2016, A new species of Letheobia (Serpentes: Typhlopidae) from central Kenya, Zootaxa 4093 (1), pp. 143-150 : 145-146

Letheobia mbeerensis sp. nov.

Mbeere Gracile Blind-snake ( Figs. 2–4 )

Holotype. NMK S 2927, adult; Kenya, Embu County, Siakago-Mbeere (00o 35 ’S; 0 37o 38’E; 1221 m); collected on 29 April 2014, by a local farmer (name unknown). Live specimen given to Jacob M. Ngwava, curator at the Nairobi Snake Park, who forwarded it to Patrick K. Malonza at the Herpetology Section, National Museums of Kenya.

Description of the holotype. NMK S2927; Specimen in generally good condition. Snout rounded in dorsal profile, lateral profile bluntly rounded with an angular horizontal edge ventrally; rostral broad, ca. 0.6 head width at interocular level, truncated posteriorly; frontal very broad, crescentic, as wide as rostral and 1.5 times as broad as supraocular with relatively broad contact of nasals; supraocular broad, transverse, its lateral apex between nasal and ocular; nasal semidivided; nasal suture strongly bowed, arising from second supralabial and extending 3/4 of the distance to the rostral; nostril rounded, inferior; ocular similar in size to supraocular and half the size of preocular, ventrolateral apex between preocular and ocular [no subocular present]; eye barely visible as a tiny black dot in the anterior margin of preocular scale ( Fig. 2 ), preocular twice as large as ocular; 4 supralabials, third supralabial twice the size of first and second, fourth supralabial twice the size of third; supralabial imbrication pattern T-0 (no supralabial overlap of superior head shields; Wallach 1993). The absence of a subocular, is a difference between the new species and several other Letheobia . Again the scale pattern is very different from that of morphologically similar L. lumbriciformis . Body slender, total length/mid-body diameter ratio (L/D) ratio = 62.2; head slightly narrower than forebody; tail long (2.9% TL), ending in a rounded tip, lacking an apical spine; total length (TL) = 280.0 mm; Tail length (TAL) = 8.0 mm; mid-body diameter (MBD) = 4.5 mm; mid-body scale rows ( MSR) = 20; middorsals (MD) = 670; subcaudals (SC) = 20; dorsocaudals (DC) = 23.

Coloration. In preservative, red-brown on the head and fore body, posteriorly pale brown ( Fig. 3). In life pink, dorsal scales with a faint speckling of brown at distal margins ( Fig. 4 ).

Etymology. The specific epithet mbeerensis refers to the species’ greater type locality.

Diagnosis. The new species is assignable to the genus Letheobia on the basis of possessing the combination of characters:laterally rounded snout, gracile or worm-like body form, eyes not or barely visible, reduced to faint spots, and pinkish coloration (Pyron & Wallach 2014). Within Letheobia , L. mbeerensis may be distinguished by the following features: rostral broad, ocular shield reduced, 20 scale rows around the body along its entire length, 670 middorsal scales, tail long (for genus) 2.9% of total length, 20 subcaudal scales. The large number of subcaudal scales separates L. mbeerensis from all its congeners, among which L. lumbriciformis , with 17, has the next highest count. In addition, the new species is easily separated from several of its East African congeners by its lower number of midbody scale rows (20) versus 22 or more scale rows in L. gracilis (Sternfeld) (22–24), L. graueri (Sternfeld) (24), L. jubana Broadley & Wallach (24), L. largeni Broadley & Wallach (22), L. pallida Cope (22–24), L. pembana Broadley & Wallach (24), L. somalica (Boulenger) (24–30), L. sudanensis (Schmidt) (24– 27), L. swahilica Broadley & Wallach (22), and L. toritensis Broadley & Wallach (22–24). Several East African species formerly assigned to Letheobia (e.g., Broadley & Wallach 2007a) but now placed in Rhinotyphlops ( R. ataeniata , R. scorteccii (Gans & Laurent 1965) , R. unitaeniatus ; see Hedges et al (2014) may also be distinguished by their greater number of mid-body scale rows (23–26). Letheobia mbeerensis may also be distinguished from most of its East African congeners by its high number of middorsal scales (670) versus lower numbers in L. erythraea (Scortecci) (443–462), L. graueri (454–622), L. jubana (391–435), L. largeni (432), L. pallida (418– 429), L. pembana (353), L. swahilica (376–396), L. toritensis (427–487), and L. uluguruensis (Barbour & Loveridge) (379–416) as well as Rhinotyphlops ataeniata (443–531), R. scorteccii (311–405), and R. unitaeniata (467–586).

Letheobia mbeerensis is most similar to L. lumbriciformis , with which it shares similar body proportion (mean of 62.0 body diameters in total body length in L. lumbriciformis and 62.2 in the holotype of L. mbeerensis ). However L. lumbriciformis has 18 midbody scale rows (versus 20 in L. mbeerensis ). The new species may further be distinguished from L. lumbriciformis by having 670 middorsal scales (versus 465–607), a longer tail (2.9% of TL versus 1.3–1.7%; 20 versus 11–17 subcaudals), and eyes minute but visible (versus not visible).

Distribution, habitat and conservation status. The holotype of Letheobia mbeerensis was unearthed by a local farmer while tilling his farm. It is currently known only from its type locality in Siakago which lies within an area of high agricultural potential. This area is characterized by deciduous vegetation with most of the land now under cultivation. This is more than 500 km from the nearest records of the superficially similar L. lumbriciformis , at the Kenyan coast (Broadley & Wallach 2007a). It is unclear whether the species can tolerate human disturbance as is the case with some other blind snakes. Until such time as more information about the actual distributional range of this snake becomes available it must be considered Data Deficient, a status that applies to many typhlopids in general (Measey & Branch 2014).

Figures

FIGURE 2. Head scalation of Letheobia mbeerensis, holotype NMK-S 2927. A) Dorsal view, B) Ventral view C) Lateral view. The position of the eye is represented by a gray dot in the ocular shield. It is shown larger than actual size so that it is clearly visible on the diagram.

FIGURE 4. Life photo of Letheobia mbeerensis, holotype S 2927, showing unpatterned pinkish coloration. Photo by P. K. Malonza.