Leptotyphlops emini (Boulenger)

Published, First, 2007, A revision of the genus Leptotyphlops in northeastern Africa and southwestern Arabia (Serpentes: Leptotyphlopidae), Zootaxa 1408, pp. 1-78 : 34-35

Leptotyphlops emini (Boulenger) ( Plate 9 , Fig. 4)

Emin's worm snake

Glauconia emini Boulenger, 1890 , Ann. Mag. Nat. Hist. (6) 6: 91. Type locality Karagwe, Victoria Nyanza, Tanzania (ca. 01°S, 31°E, elevation above 1200 m), lectotype BMNH 1946.1.10.87 (formerly BMNH 1890.5.14.1), collected by E. Pasha; Boulenger, 1893: 64, pl. 3, fig. 8, 1915a: 198, 1915b: 617; Loveridge, 1924: 4.

Stenostoma emini — Tornier, 1896: 67.

Leptotyphlops emini — Loveridge, 1933: 223; Pitman, 1935: 50; Witte, 1941: 171; Meirte, 1992: 16, figs. 21, 23, 25; Hallerman & Rödel, 1995: 7; McDiarmid et al., 1999: 29; Spawls et al., 2002: 303 (part).

Leptotyphlops emini emini — Loveridge, 1941: 178 (part), 1942: 259 (part), 1957: 247 (part); Witte, 1953: 152 (part), fig. 36, 1962: 46; Broadley, 1971: 71 (part); Pitman, 1974: 66; Meirte, 1992: 16.

Leptotyphlops nigricans nigricans — Broadley & Watson, 1976: 490 (part, Nyamkolo); Hahn, 1978: 479, 1980: 23 (part); Broadley & Howell 1991: 22 (part); Hallerman & Rödel, 1995: 7.

Leptotyphlops conjunctus conjunctus — Broadley & Watson, 1976: 490 (part, Nyamkolo).

Diagnosis. A member of the Leptotyphlops nigricans species group. Differs from L. kafubi in its fused parietal bones, lower middorsal counts and having the nostril separated from the rostral by a longer suture.

Description. Body cylindrical, with head and neck broadened and flattened, the short tail tapers slightly before a small spine or blunt tail cone.

Snout rounded, rostral moderate (0.43–0.53 head width, mean = 0.46), truncated posteriorly, much wider than nasals and extending to a line connecting centre of eyes, a preoral groove present ventrally. Behind rostral, upper lip bordered by infranasal (nostril midway between rostral and supralabial along nasal suture), small anterior supralabial that reaches level of nostril with a width along lip 2.0–3.0 times that of infranasal, large ocular with eye central in upper half, and large posterior supralabial. Supraoculars pentagonal, slightly larger than the hexagonal frontal and postfrontal, which are slightly smaller than the interparietal and interoccipital (note that the postfrontal is fused wuith the interparietal in the lectotype). Parietals oblique, subequal to the fused occipitals, in contact with the posterior supralabial. Temporal single. No mental.

Body covered with 14 rows of smooth, imbricate, subequal scales. Reduction to 10 rows on the tail takes place lateral to the subtriangular cloacal shield. Total middorsals 198–244; subcaudals 20–32.

Total length/diameter ratio 38–74; total length/tail ratio 8.1–15.3.

Dorsum and venter uniformly dark brown to black, except upper lip, chin, and cloacal shield which are white.

Skull with fused parietal bones as in L. nigricans ( Plate 4 , Fig. 1A).

Size. Largest specimen (NMZB 14334 — Kyambura Game Reserve, Ankole, Uganda) 152 + 13 = 165 mm.

Habitat. Savanna.

Remarks. Glauconia emini was based on two syntypes, but BM 1946.1.10.86 was lost in the post on its way from London to Bulawayo, so BM 1946.1.10.87, the specimen illustrated by Boulenger (1893), is here nominated lectotype. It should be pointed out that this specimen is aberrant in having the postfrontal fused with the interparietal. Two additional specimens, BM 91.4.30.1 (A & B) from Nyamkolo on Lake Tanganyika, were assigned to G. emini by Boulenger in 1893, but the second of these has the frontal fused with the rostral, which led Broadley to tentatively assign it to L. conjunctus in 1976. We now consider this to be another aberrant L. emini , and this species was subsequently collected by Loveridge (1933) at Kitungulu, only 40 km north of Nyamkolo.

NMZB 14334 from Kyambura Game Reserve in southwest Uganda is unusual in having a very large rostral which is truncated posteriorly, together with the nasals, at the level of the eyes; in addition the enlarged anterior supralabial excludes the infranasal from the lip. A typical Leptotyphlops emini was taken at the same locality.

Distribution. Southern Sudan, south through western Uganda to western Tanzania and the extreme north of Zambia at the southern end of Lake Tanganyika, 650–1370 m ( Plate 5 ).

Localities. SUDAN. Loa MCZ 53450. UGANDA. Basaiba am Duki, Ruwenzori ( Tornier, 1896; Sternfeld, 1910) ZMB 13339; Bundibugyo MCZ 48036–37; Chamdura LIVM 1980.150.10; Kasenyi ZMUC/R. 52193; Kibulala LIVM 1962.106.57; Kitungulu MCZ 30063; Kyambura Game Reserve NMZB 14322, 14334; east of Lake Edward CAS-SU 21692; Mbarara LIVM 1962.168.24. TANZANIA. No locality ZMB 24960, 24968, 24970, 24972, 53615–16; Kapapa Game Controlled Area CAS 227770; Karagwe BMNH 1946.1.10.87 (lectotype); ZMB 21173; Michael’s Shamba, Mpande Dist. CAS 227778; Newala LIVM 1980.150.11. ZAMBIA. Nyamkolo BMNH 91.4.30.1A–1B.

Figures

PLATE 4. Figure 1. Dorsal views of the skulls of Leptotyphlops. A. Leptotyphlops nigricans (MCZ 21473) and B. Leptotyphlops kafubi (FMNH 56374), both after List (1966). KEY to bone abbreviations from List, 1966: Ax = axis, At = atlas, Eo = exoccipital, F = frontal, M = maxilla, N = nasal, P = parietal, Pf = prefrontal, Po = prootic, So = supraoccipital. C. Leptotyphlops cairi, after Abdeen et al. (1991). KEY to bone abbreviations from Abdeen et al., 1991: B.OC. = basioccipital; B.SP. = basisphenoid; C.T.C. = cartilaginouis trebacula cranii; EX.OC. = exoccipital; FR. = frontal; L.P.P.MX. = lateral process of maxilla; MX. = maxilla; NA. = nasal; OC.CO. = occipital condyle; P.MX. = premaxilla; P.OT. = prootic; P.VO. = prevomer; PA. = palatine; PR. = parietal; PR.FR. = prefrontal; PR.L.DG. = lateral downgrowth of parietal; PT. = pterygoid; S.OC. = supraoccipital. The lines represent 1 mm to scale. The stipple indicates thin transparent membrane. Figure 2. Dorsal views of the skulls of Leptotyphlops. A. Leptotyphlops nigroterminus sp. nov. (ZMB 51610); B. Leptotyphlops macrurus (BMNH 1957.1.10.26); C. Leptotyphlops boulengeri (MCZ 40087); D. Leptotyphlops reticulatus (BMNH 1954.1.12.77). E. Leptotyphlops longicaudus (NMZB-UM 29371); F. Leptotyphlops blanfordii (BMNH 1977.833); G. Leptotyphlops nursii (FMNH 66158). H. Leptotyphlops scutifrons merkeri (NMZB 8089). The lines represent 1 mm to scale. KEY: f = frontal; n = nasal; p = parietal; pp = postparietal; so = supraoccipital.

PLATE 5. Leptotyphlops. Distribution of the Leptotyphlops parkeri, L. reticulatus, L. longicaudus and L. nigricans species groups in northeastern Africa and southwestern Arabia.

PLATE 9. Figure 1. Leptotyphlops macrorhynchus. Dorsal and lateral views of the head of BMNH 1932.5.2.9 — Mouth of Kaliokwell River, Kenya. The line represents 1 mm to scale. Figure 2. Leptotyphlops pembae. Dorsal, lateral and ventral views of the head of BMNH 1947.1.1.43 — Kisiwani, Pemba Island, Tanzania. The line represents 1 mm to scale. Figure 3. Leptotyphlops macrops. Dorsal, lateral and ventral views of the head of the holotype, NMZB 11352 — Mkwaja Forests, Tanzania, after Broadley & Wallach (1996). The line represents 1 mm to scale. Figure 4. Leptotyphlops emini. Dorsal, lateral and ventral views of the head of CAS 227770 from Kapaka Game Control Area, Mpande District, Tanzania. The line represents 1 mm to scale.