Dasypeltis albigularis Tiutenko, Heller & Bates, 2026, sp. nov.

Abstract

Dasypeltis albigularis sp. nov. Figs 1 B, 2 A, 4, 8, 10, 11, 13 Common name. White-throated Egg-eater. Diagnosis. A medium-sized Dasypeltis (females approximately 90 cm in total length, males less than 60 cm). Dorsally usually uniformly dark-grey or blackish, seldom reddish-brown with faint dark streaks; or light yellow-brown with a dense and irregular pattern of small brown saddles and narrow brown bars on the flanks, and numerous small white markings. Interstitial skin light grey, sometimes bluish, especially in adults. Anterior infralabials, gulars, chin shields and 20–62 anterior ventral plates mostly white, other ventrals gradually transition to ash-grey. Dorsal scales arranged around midbody in 20–23 rows. Scales of the first row of dorsals on either side of the body very weakly keeld or smooth and much larger than other dorsal scales. Scales of the second row on either side of body weakly keeled. Other dorsal scales each with a moderate median keel and a pair of apical pits distally. Head with fine white spots and speckles. Supralabials 7, 3 rd and 4 th bordering orbit. Postocular single. Frontal shield pitted in only one row around edges. Inter-prefrontal sulcus moderately marked, not deep. Prefrontal scales longer and larger overall than internasals. Rostral shield visible from above head. Holotype. Ethiopia • ♀; approximately 2 km south of Welmel river bridge, south of Hawo village, Harenna Forest; 6°35'44"N, 39°35'43"E; alt. 1659 m; 28 May 2025; A. Tiutenko leg.; killed by local villagers on a road; ZSM 629/2025. Paratypes. (Six specimens) Ethiopia • 1 ♀; glade south of Hawo village, Harenna Forest; 6°31'26"N, 39°38'31"E; alt. 1608 m; 31 May 2025; A. Tiutenko leg.; ZSM 630/2025 • 1 juv.; Manyate village, Harenna Forest; 6°35'N, 39°35'E; alt. 1550 m; 28 Feb. – 2 Mar. 2026; A. Tiutenko leg.; hatched in captivity; ZSM 251/2026 • 1 juv.; same data as for preceding; ZSM 252/2026 • 1 juv.; same data as for preceding; ZSM 253/2026 • 1 juv.; same data as for preceding; ZSM 254/2026 • 1 juv.; same data as for preceding; ZSM 255/2026. Additional referred material. Ethiopia • 1 juv.; Manyate village, Harenna Forest; 6°35'N, 39°35'E; alt. 1550 m; 5 Mar. 2026; A. Tiutenko leg.; failed to hatch from an egg deposited in captivity; ZSM 256/2026. Live specimens: Ethiopia • 1 ♀; Manyate village, Harenna Forest; 6°29'07"N, 39°44'44"E; alt. 1554 m; 30 May 2019; A. Tiutenko leg.; ZSM 94/2019 • 1 ♂; Manyate village, Harenna Forest; 6°35'N, 39°35'E; alt. 1550 m; 26 May 2025; A. Tiutenko leg.; HFE 2025-002 (field number) • 1 ♂; same data as for preceding; HFE 2025-003 (field number) • 1 ♀; same data as for preceding; 2 June 2025; A. Tiutenko leg.; HFE 2025-050 (field number) • 1 ♀; south of Hawo village, Harenna Forest, in a glade in the forest while crossing a road after sunset; 6°31'34"N, 39°38'36"E; alt. 1663 m; 30 May 2025; A. Tiutenko leg.; HFE 2025-023 (field number) • 1 ♀; same data as for preceding; 31 May 2025; A. Tiutenko leg.; HFE 2025-031 (field number); • 1 ♂; south of Hawo village, Harenna Forest, in a glade in the forest while crossing a road after sunset; 6°31'26"N, 39°38'31"E; alt. 1608 m; 31 May 2025; A. Tiutenko leg.; HFE 2025-032 (field number); • 1 ♀; same data as for preceding; 31 May 2025; A. Tiutenko leg.; HFE 2025-33 (field number). Description of the holotype. ZSM 629/2025, adult female (Fig. 8). Body elongated, cylindrical. Dorsal scales on the body ovate and obtusely pointed, moderately unicarinate, those of the 3 rd to 5 th rows on either side reduced in size and obliquely positioned, with serrated keels; scales of the first row on either side are more-or-less rhomboid, very feebly carinate, and approximately one-and-a-half-times larger than those of the second row on either side which are of a similar shape but feebly carinate. Head small (HL 15.24 mm), HL / SVL 0.03 (head damaged posteriorly). SVL 508 mm, TL 74 mm, MDR 23, V 236, SC 52. Fourth and fifth ventral plates merged in the middle, plate 235 incomplete. Preoculars 1; postoculars 2; nasal scale divided between nostril and first supralabial. Temporals 1 + 2 + 3, scales of 2 nd and 3 rd transverse rows are keeled and equal in size and shape to dorsals. Supralabials 7, 3 rd and 4 th entering orbit; sixth supralabial the largest, approximately double the size of 3 rd and 4 th. Infralabials 7, 1 st to 3 rd in contact with the anterior chin shield, 4 th in contact with posterior chin shield. Colouration (soon after death): uniformly black above, ventrally uniformly black or ash-grey except for anterior infralabials, chin shields, gulars and anterior 31 ventral plates which are white or partly white. The first 21 plates are white medially and gradually merge into grey on the sides. Some white speckles are visible up to ventral plate 31. After over a year in ethanol, white parts now cream-yellow, otherwise colouration unchanged. Variation. There is minor variation in the scale counts of paratypes and additional referred material (Table 1). The juvenile female paratype ZSM 630/2025 (Fig. 10) has temporals arranged as 2 + 2 + 3. Temporals in the first two rows are, unlike in the holotype, smooth, elongate, and larger than the dorsals. In ZSM 255/2026, the 4 th to 6 th subcaudals are entire, and the posteriormost ventral plate is half the size of the preceding one; the white on the underside reaches the 20 th ventral plate. Plates 21 and 22 are moderately speckled with white, and plate 23 has only a few white spots. From plate 24 onwards, the ventrum is uniformly black. ZSM 251/2026 has particularly extensive white on the ventral surface: Ventral plates 1–62 are white, and white speckles are visible up to and including plate 82. All specimens of the new species had some aberrant ventrals and subcaudals. This is not known to occur with such regularity in other Dasypeltis species. The wild-caught specimens of D. albigularis sp. nov. had at least one such scale, whereas all hatchlings of the first clutch obtained in captivity had several (e. g. Fig. 12). The hatchlings of the second clutch produced by the same female had few or no such aberrations. It thus remains to be investigated whether abnormal ventral and subcaudal scales are usual for this species or are an occasional developmental artefact resulting from some individual condition of the parents or from environmental parameters of incubation. However, this phenomenon was not observed in D. atra hatched from eggs incubated under the same conditions. The female ZSM 94/2019 (Fig. 2) is currently the largest known specimen of this species, with a SVL of 80 cm and a TL of 12 cm. This snake hatched from an egg laid in 2018. Body size did not increase significantly after it reached the age of 2 years. Therefore, its current total length of 92 cm at the age of approximately 8 years is considered likely to be the maximum length for this species, although adult size in the wild is expected to be smaller. As noted above, this specimen has a small scale located between the nasal, prefrontal and internasal scales on either side of the head (Fig. 2 B). In addition, on the left side of the head, it has a scale between the nasal and the preocular that would normally be identified as a loreal (generally absent in Dasypeltis). HFE 2025-023 (Fig. 4), a young female, is pale brown with a dense pattern of dark brown markings consisting of small, mostly narrow and transversely slightly to distinctly enlarged saddles in the vertebral region, starting at the nape and extending to the tip of the tail, and somewhat narrow, often irregular bars of similar colour on the flanks. The saddles are sometimes blotch-like or in the form of two attached spots side by side or one in front of the other, and in parts, several such confluent spots form a zigzag dorsal stripe. Scales that constitute the saddles and lateral bars usually have dark brown edges. In the case of the bars, these darker edges are often confluent, resulting in undulating or slightly irregular dark streaks. Saddles and bars are mostly not confluent but occasionally form narrow bands across the back. The dorsum is also liberally decorated with small white markings (on the edges of dorsal scales), usually slightly elongated (anteroposteriorly); the largest of these are present between the saddles, but they occur all over the body, becoming less common and prominent on the tail. The pattern of dark markings is not visible in the exuvia. Bluish interstitial skin is most prominent posteriorly, such that the posterior half of the body has a bluish tint. As in black specimens of this species, the underside of the head and the anterior 25 ventral plates are white. The head is a combination of pale brown and grey (especially greyish on the sides), with scattered, small, dark brown or white spots; there is a conspicuous row of 4–5 white, dash-like markings medially on the back of the head; the eye is orange-brown with small dark markings, and the pupil is vertically elliptic. Underparts are mostly pale olive green with numerous scattered small white spots, but laterally the ventral plates are cream-brown, similar in colour to the first two rows of dorsals on either side. The edges of the scales of the latter two rows are, in parts, dark brown, forming a series of three broken stripes along the flanks. All other additional specimens are dorsally black and ventrally mostly dark grey. Infralabials, chin shields, gulars, and up to 25 anterior ventral plates are white. However, all specimens (not only those hatched in captivity but also wild-caught ones) have some malformed ventrals and subcaudals at different positions, where ventrals extend to half or less of the body width and undivided subcaudals are mixed with paired ones (e. g. Fig. 12). Comparisons with related species. Dasypeltis albigularis sp. nov., with a currently known maximum total length of 92 cm, is considerably smaller than its closest relatives – D. atra and D. gansi. For comparison, the largest known fem