Hebius modestus, commonly known as the modest keelback or Günther's keelback, is a species of natricine snake endemic to Asia.
Geographic range Confirmed range:
India: Meghalaya (Khasi Hills), Arunachal Pradesh China:Yunnan Province Myanmar: Kachin, Shan States
Disputed records: Historical reports from Vietnam, Cambodia, Laos, Thailand, and Guangdong/Guizhou (China) are questionable or misidentifications. It possibly occurs in Bhutan.
The type locality is Khasi Hills, India.
Description Adults may attain 60 cm (2 feet) in overall length; tail length 18 cm (7 inches).
Dorsum: Dark grayish-brown to olive brown, scattered with black spots or blotches. A dorsolateral series of ochre-yellow, orange-brown, or reddish-brown stripes (often reduced to elongate blotches) extends from the nape to the tail base on the 4th–7th dorsal scale rows. Postocular streak is absent.
Ventrally it may be yellowish with a , or yellowish in the middle and blackish on the sides, or almost entirely blackish.
Venter: Pale ochre-brown centrally, broadly edged with dark brown or blackish on the outer quarter of ventrals. Series of blackish spots on each side of the ventrals.
Head: Labial sutures black; short, broad, horizontal pale streaks on the neck sides before the dorsolateral stripe along with a streak on the nape, behind the parietal scales.
Scalation
Dorsal scales: 19-19-17 rows, weakly keeled at midbody and posteriorly; smooth on first dorsal scale row Ventrals: 143–163 in males, 154–168 in females Anal: Divided Subcaudals: 104–122, divided Supralabials: 8–9; 3rd–5th entering the eye Infralabials: 8–9 Anterior temporals: 1 or rarely 2; rectangular and elongate Preoculars: 1 (occasionally absent) Maxillary teeth: 27–30, with the last two moderately enlarged Boulenger, G.A. 1893. Catalogue of the Snakes in the British Museum (Natural History), Volume I., Containing the Families...Colubridæ Aglyphæ, Part. Trustees of the British Museum (Natural History). London. xiii + 448 pp. + Plates I.-XXVIII. (Tropidonotus modestus, p. 229 + Plate XIV., fig 3.)
Taxonomic history and diagnosis
Generic revisions
The species was initially placed in the genus Tropidonotus (Günther, 1875), later moved to Amphiesma (Malnate, 1960) but in 2014 it was transferred to Hebius by Guo et al. (2014) based on molecular and morphological data.
Differentiation from congeners H. modestus can be distinguished from similar species by:
Vs. Hebius venningi: Higher ventral counts (143–163 vs. 131–142), absence of postocular streak Vs. Hebius lacrima: Fewer ventrals (143–163 vs. 147), continuous vs. interrupted supralabial stripe Vs. Herpetoreas xenura: Fewer supralabials (8–9 vs. 9), continuous ventral blotches vs. discontinuous
Habitat In India this species is found in forests at altitudes of 600-1,500 m (approximately 2,000-5,000 feet).Das, I. 2002. A Photographic Guide to Snakes and Other Reptiles of India. Ralph Curtis Books. Sanibel Island, Florida. 144 pp. . (Amphiesma modesta [sic], p. 18.)
References
External links Amphiesma modestus at the Reptile Database
Further reading
Günther, A. 1875. Second Report on Collections of Indian Reptiles obtained by the British Museum. Proc. Zool. Soc. London 1875: 224–234. (Tropidonotus modestus, p. 232.)