Dendrelaphis biloreatus Wall, 1908

Biakzuala, Lal, Lalremsanga, Hmar Tlawmte, Tariang, Angshuman Das, Vabeiryureilai, Mathipi, Muansanga, Lal, Hrima, Vanlal, Kumar, Vikas, Kundu, Shantanu, Purkayastha, Jayaditya & Vogel, Gernot, 2022, Contributions to the taxonomic status and molecular phylogeny of Asian Bronzeback Snakes (Colubridae, Ahaetuliinae, Dendrelaphis Boulenger, 1890), from Mizoram State, Northeast India, Zoosystema 44 (7), pp. 177-196 : 182

Dendrelaphis biloreatus Wall, 1908

( Fig. 2A, B )

Dendrelaphis biloreatus Wall, 1908: 273 , figs 1-5. — Vogel & van Rooijen 2011b. — Wallach et al. 2014: 215.

Dendrophis gorei Wall, 1910: 829 .

Ahaetulla gorei – Smith 1943: 246.

Dendrelaphis gorei – Tian & Jiang 1986. — Dowling & Jenner 1988. — Das & Chaturvedi 1998. — Das 1996: 55.

TYPE MATERIAL. — Holotype. India • BMNH (no voucher number), a 690-700 mm specimen (native, June, 1907) (fide Wallach et al. 2014).

TYPE LOCALITY.— India, Sadiya on the Bramaputra 70 odd miles north-east of Dibrugarh ( Wall 1908), now Sadiya, Assam State, NE India, 27°50’N, 95°40’E, elevation 125 m a.s.l. ( Wallach et al. 2014).

MATERIAL EXAMINED. — India • 1 ♀; Mizoram, Kolasib District, Khuangpuilam ; 24°12’13”N, 92°41’10”E; 665 m a.s.l.; 7.X.2019; Jacob Lalhriatrenga leg.; GenBank: MT711167 , MT814708 , MT731341 , MT731342 ; MZMU1659 • 1♂; Mizoram, Aizawl District , MZU campus; 23°44’14”N, 92°39’47”E; 800 m a.s.l.; 6.VIII.2020; Michael Vanlalchhuana leg.; MZMU1812 • 1♂; Mizoram, Champhai District, Champhai Jail veng; 23°28’4”N, 93°19’0”E; 1420 m a.s.l.; 20.I.2021; Tbc. Lalpekthara leg.; MZMU2051 .

DIAGNOSIS (BASED ON NEW MATERIAL). — Specimens of D. biloreatus (N = 4) are diagnosed by the combination of: 1) brownish dorsum with a black stripe on each side of head extending up to the neck; 2) upper and lower lips and chin yellowish; 3) Ve 203 in females, 190-198 in male; 4) paired Sc 137-151 in males, 102 in damaged tail female; 5) divided As; 6) Ls 1-2; 7) PrO 1; 8) PoO 2; 9) Te 1+2, 2+2, 2+3; 10) 4th–5th SLE; 11) IF 10; 12) SL 8; 13) DSR 13:13:11; and 14) average RTaL 0.32 (0.26-0.36) in males, and 0.28 in the damaged tail female. The new materials from this study updated the known morphological characters as follows: upper limit of Ve 190-203 vs 192 ( Wall 1908) and 187-199 as D. gorei ( Smith 1943) ; lower limit of Sc 137-151 vs 147 ( Wall 1908) and 139-154 as D. gorei ( Smith 1943) ; Te 1+2, 2+2, 2+3 vs 1+1 ( Wall 1908; Smith 1943). In addition, we provide brief comparative morphological data between D. cyanochloris , D. proarchos , and D. biloreatus from other zoological collections, along with the new Dendrelaphis specimens collected from Mizoram State ( Table 1 ). See Appendix 1 for the detailed collection records, and Appendix 2 for the morphometry and scalation data of Dendrelaphis species collected from Mizoram State, India.

GEOGRAPHICAL DISTRIBUTION. —This species inhabits the Assam Valley with the adjoining Himalayan foothills, and northern parts of Myanmar near the border with Assam ( Vogel & van Rooijen 2011b). In this work, D. biloreatus is documented from four localities in Mizoram state at the elevation range of 443-1,420 m a.s.l. ( Fig. 5 ; Appendix 1)

Figures

FIG. 2. — A, Dendrelaphis biloreatus Wall, 1908 in life, showing anterior body and head from Kolasib, Mizoram, NE India. Inset: Dorso-lateral view of the head showing two loreal scales; B, juvenile Dendrelaphis biloreatus (MZMU1812) in life from MZU Campus, Mizoram, NE India, photographed by Tbc. Lalhruaitluangi. Inset: Antero-lateral view of the head showing single loreal scale, photographed by Romalsawma.

FIG. 5. — Elevation map showing the specimens location of Dendrelaphis proarchos Wall, 1909 (green shapes), Dendrelaphis biloreatus Wall, 1908 (yellow shapes), Dendrelaphis cyanochloris (Wall, 1921) (red shapes), Dendrelaphis cf. vogeli LSUHC 6768 (purple circle with dot), and Dendelaphis cf. ngansonensis CAS221428 (blue circle with dot) examined in this study. Confirmed populations of Dendrelaphis proarchos (green circles) and Dendrelaphis biloreatus (yellow triangles) are based on Vogel & van Rooijen (2011a, b).