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| Protobothrops flavirostris Grassby-Lewis, Brakels, Maury, Sitthivong, Frohlich, Pawangkhanant, Idiiatullina, Nguyen & Poyarkov, 2025 |
Abstract
We describe a new species of lance-headed pit viper from north-western Laos, based on morphological and molecular (6092 bp from cyt b, ND4, COI, 12S rRNA and 16S rRNA mitochondrial DNA genes and c-mos and RAG1 nuclear DNA genes) lines of evidence. Protobothrops flavirostris sp. nov. is easily distinguished from its congeners by the following combination of morphological characters: dorsal scales in 23–21–17 rows, all keeled; ventral scales 215; subcaudal scales 79, all paired; supralabials 7–8; infralabials 10; horn-like projections on supraoculars absent; head triangular with a typical lance-shaped pattern on its dorsal surface; three faint dark vertical stripes on the snout; head blackish-brown with rostral, nasals, preoculars, loreals and the two anterior supralabials, as well as the anterior parts of supraoculars yellow-orange; dorsal surfaces of body and tail brown or greyish-brown, dorsum with large dark reddish-brown cross-shaped blotches, edged in black, somewhat fused together forming an interrupted zigzag line and a row of large brown ventrolateral blotches on each side. The new species differs from the morphologically similar species Protobothrops kelomohy by a significant divergence in cytochrome b mitochondrial DNA gene sequences (p = 7.8%). The new species is currently known only from tropical limestone forest of Vientiane Province, north-western Laos (elevation 362 m a.s.l.). We suggest the new species be considered as Endangered (EN) following the IUCN’s Red List categories.
Key Words: Indochina, limestone, morphology, molecular phylogeny, Protobothrops flavirostris sp. nov., systematics, Vientiane Province
Family Viperidae Oppel, 1811
Subfamily Crotalinae Oppel, 1811
Genus Protobothrops Hoge & Romano-Hoge, 1983
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| The holotype of Protobothrops flavirostris sp. nov. in life in situ (NUOL 2024.89, adult female). photograph by R.J. Grassby-Lewis. |
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| The holotype of Protobothrops flavirostris sp. nov. in life (NUOL 2024.89, adult female) A general dorsal view B general ventral view C lateral view of the head, right side D lateral view of the head, left side E dorsal view of the head; F Ventral view of the head. photographs by R.J. Grassby-Lewis (A, B, D–F) and N. Maury (C). |
Protobothrops flavirostris sp. nov.
Diagnosis. The new species Protobothrops flavirostris sp. nov. differs from other members of the genus Protobothrops by the following combination of the morphological characters: dorsal scales in 23–21–17 rows, all keeled; ventral scales 215; subcaudal scales 79, all paired; supralabials 7–8; infralabials 10; horn-like projection on supraocular absent; head triangular with a typical lance-shaped pattern on dorsal surface; three faint dark vertical stripes on snout; head blackish-brown with rostral, nasals, preoculars, loreals and the two anterior supralabials, as well as the anterior parts of supraoculars yellow-orange; dorsal surfaces of body and tail brown or greyish-brown, dorsum with large dark reddish-brown cross-shaped blotches, edged with black, somewhat fused together forming an interrupted zigzag line; and a row of large brown ventrolateral blotches on each side.
Etymology. The specific name “flavirostris” is a Latin adjective in the nominative singular, masculine gender, derived from Latin words “flāvus” for “yellow” and “rostrum” for “snout” or “beak” and is given in reference to the characteristic yellowish colouration of the snout in the new species.
We suggest the following common names for the new species: “Vang Vieng lance-headed pit viper” (in English), “Ngu Phao Ka Ba Khor Kop” (“ງູເພົາກະບາຄໍກົບ”, in Lao) and “Laosskiy habu” (“Лаосский хабу”, in Russian). Furthermore, the new species is well-known to the Hmong people living in village communities around Vang Vieng and their local name for this species is “nan jaow ka,” which is roughly translated as “a snake that can open its mouth very wide” or “big-mouthed snake”.
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| Habitat of Protobothrops flavirostris sp. nov. Macrohabitat of the new species at the type locality, Vang Vieng District, Vientiane Province, Laos (A); uncollected adult snake (sex unknown) from Nang Oua Khiam Cave, Vang Vieng, Vientian, Laos in life in situ (B); uncollected adult snake (sex unknown) from Khan Kham Cave, Vang Vieng, Vientian, Laos in life in situ (C). photographs by P. Brakels (A); J. Wohlschiess (B); and P.L. Stenger (C). |
Rupert J. Grassby-Lewis, Peter Brakels, Nathanaël Maury, Saly Sitthivong, David Frohlich, Parinya Pawangkhanant, Sabira S. Idiiatullina, Tan Van Nguyen and Nikolay A. Poyarkov. 2025. A New endemic Karst-associated Species of Lance-headed Pit Viper (Squamata, Viperidae, Protobothrops) from Laos. Herpetozoa. 38: 43-60. DOI: doi.org/10.3897/herpetozoa.38.e146004
