diff --git a/data/03/AA/41/03AA411D72543C22FF59DFDBFE67F855.xml b/data/03/AA/41/03AA411D72543C22FF59DFDBFE67F855.xml new file mode 100644 index 00000000000..743cff17280 --- /dev/null +++ b/data/03/AA/41/03AA411D72543C22FF59DFDBFE67F855.xml @@ -0,0 +1,1908 @@ + + + +A new species of Lycodon Fitzinger, 1826 from the Northern part of the Truong Son Mountains, Central Vietnam (Reptilia, Squamata, Colubridae) + + + +Author + +Nguyen, Tan Van +Institute for Research and Training in Medicine, Biology and Pharmacy, Duy Tan University, Da Nang, 550000, Vietnam. & Institute for Research and Training in Medicine, Biology and Pharmacy, Duy Tan University, Da Nang 550000, Vietnam. + + + +Author + +Vogel, Gernot +Society for South East Asian Herpetology, Im Sand- 3, Heidelberg D- 69115, Germany. + +text + + +Zootaxa + + +2025 + +2025-01-20 + + +5570 + + +3 + + +484 +510 + + + + +https://doi.org/10.11646/zootaxa.5570.3.3 + +journal article +10.11646/zootaxa.5570.3.3 +1175-5326 +14745350 +2CE32D6B-6545-429E-801F-4BD5E58EBA24 + + + + + + + +Lycodon poyarkovi + +sp. nov. + + + + +( +Tables 1–2 +; +Figs. 4–6 +, +8–9 +; Appendix III) + + + + +Chresonymy +: + + + + + + +Lycodon paucifasciatus + +( +non + +Lycodon paucifasciatus +Rendahl + +in +Smith, 1943 +)— + + +Orlov +et al +. (2003: 217–240 + + +: in part); + + +Ziegler +et al +. (2004: 34 + + +, in part); + + +Nguyen +et al +. (2009: 320 + + +, in part); + + +Vogel +et al +. (2009: 131–182 + + +, in part); + + +Luu +et al +. (2013: 297 + + +, in part); + + +Poyarkov +et al +. (2023: 343 + + +, in part); + +Uetz +et al +. (2024 + +, page “ + +Lycodon paucifasciatus + +”, in part). + + + + + +Dinodon rosozonatum + +( +non + +Dinodon rosozonatum +Hu & Zhao, 1966 + +)— + + +Luo +et al +. 2010: 579–582 + + +, in part). + + + + + +Lycodon +cf. +rosozonatum + +— + + +Pham +et al +. (2019: 166) + + + + + + + +Dinodon rufozonatum + +( +non + +Lycodon rufo-zonatus +Cantor, 1842 + +)— + + +Ziegler +et al +. (2004: 34 + + +, in part); + + +Nguyen +et al +. (2009: 320 + + +, in part); + + +Luu +et al +. (2013: 97 + + +, in part). + + + + + +Diagnosis +. A new species of the genus + +Lycodon + +, characterized by: size medium-large, maximum total length up to +817 mm +; loreal usually not in contact with eye; dorsal scale rows 19–17(rarely 19)–15; 5–7 dorsal scale rows keeled at midbody; 221–228 ventrals; 83–92 subcaudals, paired; 8 supralabials with numbers 3–5 touching the eye; 1 preocular, 2 postoculars; temporals 2+3; anal plate undivided; dorsal crossbands narrow, with pinkish orange color, 24–33 crossbands on dorsum, 11–14 crossbands on tail, first crossband starting at VEN 10–15; head black, the plates conspicuously margined with pinkish-orange; venter reddish orange or cream; upper maxillary teeth: 6+3–4+2. + + + + + + +Holotype + +: +ZFMK 80661 +( +adult +female +) collected in +Phong Nha-Ke Bang National Park +, +Minh Hoa District +, +Quang Binh Province +, +Vietnam +( +Fig. 4 +). + + + + + +Paratypes +(n=3) + +: +DTU 616 +( +adult +female +) collected in +Dong Chau-Khe Nuoc Trong NR, Kim Thuy Commune +, +Le Thuy District +, +Quang Binh Province +, +Vietnam +( +16.976815°N +, +106.639777°E +; + +elevation +200 m +a.s.l. + +) by +T.Q. Phan +on + +01 May 2023 + + +; + +ZFMK 80662 +( +adult +male +; +Fig. 5 +) and +ZFMK 86452 +( +adult +female +) collected in +Phong Nha-Ke Bang NP +, +Quang Binh Province +, +Vietnam + +. + + + + + +Description of the +holotype + +( +Fig. 4 +). Body robust, slightly compressed laterally; tail comparatively long, thin and tapering; head elongate, longer than wide, flattened moderately distinct from the neck; snout elongate, flattened, projecting over the lower jaw; nostrils rather large, in dorsal-lateral position, round in shape; eye rather large with vertical pupil. + + +Body size +. SVL: +660 mm +, TaL: +157 mm +, TL +817 mm +, ratio TaL/TL: 0.192. + + +Body scalation +. Dorsal scale rows 19–17–15, the 7 upper rows feebly keeled at midbody; scales of the vertebral row slight enlarged; no apical pits; 228 ventrals; 88 subcaudals, all paired; anal plate undivided. + + +Head scalation +. Rostral heptagonal, wider than high, slightly visible from above; nasal single, elongated; nasal surrounded by the first two supralabials, rostral, internasal, and prefrontal; internasals two, curved, slightly wider than long, in contact with rostral anteriorly, nasal, and prefrontal; two prefrontals, large, subrectangular, prefrontal slightly shorter than frontal; prefrontals in contact with internasals, nasals, preoculars, and frontal; frontal rather small, pentagonal, tapering posteriorly, shorter than the distance from tip of snout to frontal; parietals longer than wide, in contact on approximately the length of frontal; 1/1 supraocular, distinctly wider than long, in contact with prefrontal; 1/1 loreal, contacting eye; 1/1 preocular, large, higher than wide, in broad contact with prefrontal; subocular absent; 2/2 postoculars; 2+3 temporals on both sides; 8/8 supralabials, first and second in contact with nasal, second and third in contact with loreal, third to fifth in contact with eye, seventh largest; infralabials 10/10, first pair in broad contact with each other, first to fifth in contact with anterior pair of chin shields; posterior chin shields equal to anterior ones in lenght, separated from each other by a pair of small scales. + + + +TABLE 1. Main measurements and meristic characters of the examined specimens of + +Lycodon poyarkovi + + +sp. nov. + +. +Notes +: N/a: not available; PNKB = Phong Nha-Ke Bang NP, Quang Binh Province, DCKNT = Dong Chau-Khe Nuoc Trong NR., Quang Binh Province, BHH = Bac Huong Hoa NR, Quang Tri Province. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+Previous taxonomy + +Proposed taxonomy + +Collection number + +Locality + +Status + +Sex + +SVL (mm) + +TaL (mm) + +TL (mm) + +TaL/TL + +VEN + +SC + +ASR + +MSR + +DSR +
+ +L. rufozonatus + + + +L. poyarkovi + + +sp. nov. + +ZFMK 80662PNKBParatypeM5361376730.2022192191915
+ +Lycodon +sp. + + +L. paucifasciatus + + + +L. poyarkovi + + +sp. nov. + + +L. poyarkovi + + +sp. nov. + +DTU 616 ZFMK 80661DCKNT PNKBParatype HolotypeF F675 660150+ 157N/a 817N/a 0.19221 228N/a 8819 1917 1715 15
+ +L. paucifasciatus + + + +L. poyarkovi + + +sp. nov. + +ZFMK 86452PNKBParatypeF6401557950.1922183191715
+ +Lycodon +sp. + + + +L. +cf. +poyarkovi + +ITB CZ4452BHHSFN/aN/aN/aN/a21482191715
+ + + +......continued below + + + + +TABLE 1. +(Continued) + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Collection numberSexBBTBFBBaBBVSLIL +PrO + +PoO + +Lo-E + +AT + +PT + +Source +
ZFMK 80662M2411151128/810/101/12/20/02/23/3This study
DTU 616F258+109.52.58/810/101/12/20/02/23/3This study
ZFMK 80661F331410828/810/101/12/21/12/23/3This study
ZFMK 86452F251113728/810/101/12/20/02/23/3This study
ITB CZ4452SF211015N/aN/a8/89/91/11/20/02/23/3 + +Nguyen +et al. +(2016) + +
+ + + +TABLE 2. +Comparison of morphological characters of + +Lycodon poyarkovi + + +sp. nov. + +with those of the + +L. paucifasciatus + +complex. Characters use are: (1) TaL/TL in males; (2) TaL/TL in females; (3) VEN in males; (4) VEN in females; (5) SC in males; (6) SC in females. Remark: Diagnostic differences from the new species are marked in bold. N/a: not available. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Species(1)(2)(3)(4)(5)(6)
+ +L. poyarkovi + +0.210.19221221–2289283–88
+sp. nov. +(n=1)(n=2)(n=1)(223.33±4.04, n=3)(n=1)(85.50±3.54, n=2)
+ +L. anakradaya + +0.190.19225 +232 +92 +91 +
(n=1)(n=1)(n=1) +(n=1) +(n=1) +(n=2) +
+ +L. cardamomensis + +0.20–0.21 (0.20±0.00, n=3)0.20 (n=2)215–222 (219.33±3.21, n=3)223–228 (225.50±3.54, n=2)87–93 (90.67±3.21, n=3) +91–92 (91.50±0.71 +, +n=2) +
+ +L. paucifasciatus + +0.19–0.230.21–0.22 +203–219 +22685–90 +92 +
(0.21±0.01, n=5)(0.21±0.01, n=2) +(213.00±6.60 +, +n=5) +(n=2)(88.00±2.00, n=2) +(n=2) +
+ +L. rosozonatus + +0.20 (n=1)0.19–0.20 (0.19±0.00, n=5)219–223 (221.00±2.31, n=4)221–224 (220.60±1.52, n=5)N/a80–85 (82.50±2.89, n=4)
+ +L. gibsonae + +0.20 (n=2)N/a223–226 (224.67±1.53, n=3)N/a91–92 (91.50±0.71, n=3)N/a
+ + +......continued below + + + +TABLE 2. +(Continued). Characters used are: (7) BB in males; (8) BB in females; (9) TB in males; (10) TB in females; (11) FB in males; (12) FB in females; (13) BaB in males. Remark: Diagnostic differences from the new species are marked in bold. N/a: not available. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Species(7)(8)(9)(10)(11)(12)(13)
+ +L. poyarkovi + + +sp. nov. + +24 (n=1)25–33 (27.67±4.62, n=3)11 (n=1)11–14 (12.50±2.12, n=2)15 (n=1)10–13 (11.00±1.73, n=3)11 (n=1)
+ +L. anakradaya + + +13 (n=1) + +12 (n=1) + +7 (n=1) + +5 (n=1) +N/aN/aN/a
+ +L. cardamomensis + + +12–13 (12.33±0.58 +, +n=3) + +13–14 (13.50±0.71 +, +n=2) + +6 (n=3) + +6 (n=2) + +20 (n=1) +N/a11 (n=1)
+ +L. paucifasciatus + + +10–17 + +10–11 + +5–8 + +5 + +17–24 + +19 + +8–10 +
+(13.60±2.70 +, +n=5) + +(10.50±0.71 +, +n=2) + +(6.80±1.30 +, +n=5) + +(n=2) + +(19.20±2.95 +, +n=5) + +(n=2) + +(8.80±0.84 +, +n=5) +
+ +L. rosozonatus + + +27–35 (31.20±3.03 +, +n=5) +28–30 (29.00±0.71, n=5)12 (n=1)11–13 (11.60±0.89, n=5) +8–12 (10.80±1.79 +, +n=5) +11–13 (11.60±0.89, n=5) +5–10 (7.80±2.17 +, +n=5) +
+ +L. gibsonae + + +17–18 (17.33±0.58 +, +n=3) +N/a +8–9 (8.67±0.58 +, +n=3) +N/a13–15 (14.33±1.15, n=3)N/a10–11 (10.50±0.50, n=3)
+ + +......continued on the next page + + + +TABLE 2. +(Continued). Characters used are: (14) BaB in females; (15) BV in males; (16) BV in females; (17) MSR. Remark: Diagnostic differences from the new species are marked in bold. N/a: not available. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Species(14)(15)(16)(17)Color of crossbandsDistributionsSources
+ +L. poyarkovi + + +sp. nov. + +7–9.5 (8.17±1.26, n=3)2 (n=1)2–2.5 (2.17±0.29, n=3)17–19 (17.5±1.00, n=3)pinkish orangeVietnam (north of Truong Son Mt.) +our data +
+ +L. anakradaya + +N/aN/aN/a17 (n=2)pinkish orangeVietnam (Langbian plt.) + +Nguyen +et al +. 2022a + +
+ +L. cardamomensis + +N/a +5 (n=1) +N/a17 (n=5)pinkish orange +Vietnam (Langbian plt.), Cambodia + +Do +et al +. 2017 + +; (Cardarmon Mt.), Thailand +our data +(southeastern) +
+ +L. paucifasciatus + + +11–14 + +3–3.5 + +4–5 +17pinkish orangeVietnam (Kom Tum-Gia Lai & +our data +
+(12.50±2.12 +, +n=2) + +(3.20±0.27 +, +n=5) + +(4.50±0.71 +, +n=2) +(n=7)Langbian plt.s)
+ +L. rosozonatus + +5–90.5–22–2.519pinkish orangeChina (endemic in Hainam Isl.) +our data +
(6.80±1.48, n=5)(1.70±0.67, n=5)(2.10±0.22, n=5)(n=10)
+ +L. gibsonae + +N/a +4.5–6 +N/a17pinkish orangeThailand (Sankamphaeng Mt. inVogel & David
+(5.00±0.87 +, +n=3) +(n=3)Khorat plt.)2019; our data
+ + + +FIGURE 4. + +Lycodon poyarkovi + + +sp. nov. + +in preservative, specimen ZFMK 80661 (holotype, female): General dorsal view (A); General ventral view (B); Lateral view of the head, right side (C); Lateral view of the head, left side (D); Dorsal view of the head (E); Ventral view of the head (F). Photos by G. Vogel. + + +Colouration in preservative: Dorsum blackish-brown with 33 light transversal cross bands on body and 14 on tail. Head black with distinct inverted V on the nape. Venter cream and getting distinctly darker towards the cloaca; ventral surface of tail blackish. + +Variation +(see +Tables 1–2 +and +Figs. 4–6 +for the details).The longest known specimen is 825+ mm long ( +paratype +, female; +SVL +675 mm +, TaL 150+ mm; +DTU 616 +). The longest known male is +673 mm +long ( +SVL +536 mm +, TaL +137 mm +; +ZFMK 80662 +); ratio TaL/TL: 0.19–0.20 (male: 0.20; females: 0.19). + + +Body scalation +. 19–17(rarely 19)–15 DSR; 221–228 VEN, without sexual dimorphism; 83–92 SC ( +92 in +male; +83–88 in +females). + + +Head scalation +. SL 8, IL 10; loreal rarely touching the orbit. + + + +FIGURE 5. + +Lycodon poyarkovi + + +sp. nov. + +in preservative, specimen ZFMK 80662 (paratype, male): General dorsal view (A); General ventral view (B); Lateral view of the head, right side (C); Lateral view of the head, left side (D); Dorsal view of the head (E); Ventral view of the head (F). Photos by G. Vogel. + + + +Dentition +(based ZFMK 80662 [ +paratype +] and ZFMK 86452 [ +paratype +]). Upper maxillary tooth formula: 6 anterior teeth, the last two much enlarged + a wide gap + 3–4 short teeth + a small gap, shorter than posterior teeth + two much enlarged teeth. + + +Main characters of pattern +. In life, the dorsum is blackish with 24–33 pinkish orange narrow crossbands on the body and 11–14 narrow crossbands on the tail. First light crossband starting between ventral scale 10–15, its length 7.0–11.5 ventral scales long at base, and 2.0–2.5 vertebral dorsal scales long. On the neck an inverted V shaped pink marking present. Venter cream or light beige-brown, uniform on the anterior quarter or third of the body, then getting progressively more intensely speckled with dark brown posteriorly; posterior part of the venter entirely obscured with dark brown; tail either entirely dark brown below or with irregular blotches corresponding to light crossbands ( +Figs. 4–6 +). + + + +FIGURE 6. +Photos in life of + +Lycodon poyarkovi + + +sp. nov. + +in Quang Binh, Vietnam—from Phong Nha-Ke Bang NP (A–E); from Dong Chau-Ke Nuoc Trong NR (F–H). Photos by: (A–B) reproduced from + +Vogel +et al. +(2009) + +; (C) T.N. Vu; (D) reproduced from + +Luo +et al. +(2010) + +; (E) L.P. Tran; (F) T.Q. Phan; (G–H) N.V. Ha. + + + +Hemipenis +( +in situ +). According to + +Vogel +et al +. 2009 + +, the hemipenis description is based on specimen ZFMK 80662 ( +paratype +). The organ is single, not forked, short, and massive. It reaches SC 7 or 9. It is densely covered with numerous spines on the distal 2/3, smooth and folded on its base and the first third. Proximal spines are much larger and wider than distal spines, decreasing progressively to become short but very dense on the distal half. The sulcus lips are very prominent and well developed throughout, densely covered with short spines on their outer side. + + +Comparisons: +Morphologically, + +Lycodon poyarkovi + + +sp. nov. + +is most closely resembles + +L +. +anakradaya + +, + +L +. +cardamomensis + +, + +L +. +paucifasciatus + +, + +L +. +rosozonatus + +, and + +L +. +gibsonae + +, because of the following characteristics: medium to large body (TL≥ +600 mm +); dorsal scales smooth or weakly keeled at midbody; 17–19 scales at midbody; body with red or pinkish crossbands on black or brown background; a pale inverted V on the nape (see +Figs. 1 +, +2 +, +7 +). Therefore, morphological comparisons with these five species appear to be the most pertinent. The main diagnostic characters separating + +Lycodon poyarkovi + + +sp. nov. + +from these five species are summarized in +Table 2 +and +Figs. 1–3 +, +7 +. + + + +FIGURE 7. +Photos in life of + +Lycodon paucifasciatus + +species complex and + +L. rufozonatus + +.— + +L. anakradaya + +in Khanh Vinh, Khanh Hoa, Vietnam (A);— + +L. cardamomensis + +in Cardamom Mt., Pursat, Cambodia (B); in Khao Wong NP, Rayong, Thailand (C); Song Hinh, Khanh Hoa, Vietnam (D)— + +L. paucifasciatus + +in Bach Ma NP, Phong Dien NR, Sao La NR, Thua ThienHue, Vietnam (E, F, G, respectively);— + +L. gibsonae + +in Khao Yai NP, Prachinburi, Thailand (H)— + +L. rosozonatus + +in Wuzhi Mt., Hainan, China (J)— + +L. rufozonatus + +in Chengdu, Sichuan, China (K); in Taiwan, China (L); Miyako, Okinawa, Yaeyama, Japan (M). Photos by: (A) reproduced from + +Nguyen +et al. +(2022a) + +; (B) J.C. Daltry; (C, H) P. Pawangkhanant; (D) reproduced from + +Do +et al. +(2017) + +; (E) L.C. Tran; (F) B.V. Nguyen; (G) N.A. Poyarkov; (J) G. Fan; (K, L, M) G. Vogel. + + + + +Lycodon poyarkovi + + +sp. nov. + +differs from + +L +. +anakradaya + +(inhabiting Southern +Vietnam +) by having: (1) slightly lower number of VEN in females (221–228 [avg. 223.33] vs. 232); (2) slightly lower number of SC in females (83–88 [avg. 85.50] vs. 91); (3) higher number of BB in both sexes ( +24 in +male, 25–33 [avg. 27.67] in females vs. +13 in +male, +12 in +female; (4) higher number of TB in both sexes ( +11 in +male, 11–14 [avg. 12.50] in females vs. +7 in +male, +5 in +female). + + + +Lycodon poyarkovi + + +sp. nov. + +differs from + +L +. +cardamomensis + +(inhabiting Southwest +Cambodia +and Southeastern +Thailand +) by having: (1) slightly lower number of SC in females (83–88 [avg. 85.50] vs. 91–92 [avg. 91.50]); (2) higher number of BB in both sexes ( +24 in +male, 25–33 [avg. 27.67] in females vs. 12–13 [avg. 12.33] in males, 13–14 [avg. 13.50] in females); (3) higher number of TB in both sexes ( +11 in +male, 11–14 [avg. 12.50] in females vs. +6 in +both sexes); (4) lower number of FB in male (15 vs. 20); (5) lower number of BV in males (2 vs. 5). + + + +Lycodon poyarkovi + + +sp. nov. + +differs from + +L +. +rosozonatus + +(endemic to +Hainan +Island +, +China +) by having: (1) usually lower number of MSR in both sexes (17 [rarely 19] vs. 19); (2) slightly lower number of +BB +in males (24 vs. 27–35 [avg. 31.20]); (3) higher number of FB in males (15 vs. 8–12 [avg. 10.80]); (4) slightly higher number of BaB in males (11 vs. 5–10 [avg. 7.80]). + + + +Lycodon poyarkovi + + +sp. nov. + +further differs from + +L +. +gibsonae + +(inhabiting +Khorat +Plateau, +Thailand +) by having: (1) higher number of BB in males (24 vs. 17–18 [avg. 17.33]; (2) higher number of TB in males (11 vs. 8–9 [avg. 8.67]); (3) lower number of BV in males (2 vs. 4.5–6 [avg. 5.00]); (4) lower max SVL in males ( +536 mm +vs. +906 mm +). + + +In particular, + +Lycodon poyarkovi + + +sp. nov. + +is distinguished from + +L +. +paucifasciatus + +by having: (1) higher number of VEN in males (221 vs. 203–219 [avg. 213.00]); (2) higher number of SC in females (83–88 [avg. 85.50] vs. 92); (3) higher number of BB in both sexes ( +24 in +male, 25–33 [avg. 27.67] in females vs. 10–17 [avg. 13.60] in males, 10–11 [avg. 10.50] in females); (4) higher number of TB in both sexes ( +11 in +male, 11–14 [avg. 12.50] in females vs. 5–8 [avg. 6.80] in males, +5 in +females); (5) lower number of FB in both sexes ( +15 in +male, 10–13 [avg. 11.00] in females vs. 17–24 [avg. 19.20] in males, +19 in +females); (6) slightly higher number of BaB in males (11 vs. 5–10 [avg. 7.80]) but in contrast of females (7–9.5 [avg. 8.17] vs. 11–14 [avg. 12.50]); (7) lower number of BV in both sexes [ +2 in +male, 2–2.5 [avg. 2.17] in females vs. 3–3.5 [avg. 3.20] in males, 4–5 [avg. 4.50] in females). + + +Lastly, + +Lycodon poyarkovi + + +sp. nov. + +was previously misidentified with + +L +. +rufozonatus + +or + +Dinodon +cf. +rufozonatum + +(see + +Ziegler +et al +. 2004 + +; + +Nguyen +et al +. 2009 + +). The new species can be distinguished from + +L +. +rufozonatus + +(data from Nguyen +et al. +in preparation) by having: (1) higher number of VEN in both sexes ( +221 in +male, 221–228 [avg. 223.33] in females vs. 198–216 [avg. 204.45] in males, 198–214 [avg. 199.75] in females); (2) higher number of SC in both sexes ( +92 in +male, 83–88 [avg. 85.50] in females vs. 62–83 [avg. 74.78] in males, 60–81 [avg. 68.67] in females); (3) lower number of BB in both sexes ( +24 in +male, 25–33 [avg. 27.67] in females vs. 45–78 [avg. 65.73] in males, 50–65 [avg. 58.50] in females); (4) lower number of TB in males (11 vs. 19–28 [avg. 22.20]); (5) dorsal crossbands pinkish (vs. rose red or grey). + + + + +Etymology: +We name the new species in honour of Dr. Nikolay A. Poyarkov, an Assistant Professor at the Lomonosov +Moscow State +University ( +Moscow +, +Russia +), in recognition of his contribution to the herpetology, especially on the Indo-Burma region including +Vietnam +. Futhermore, he was the first to note the distinction between the new species and the + +Lycodon paucifasciatus + +species complex group. We suggest the following common names for the new species: “Poyarkov’s Big-tooth Snake” (in English) and “ +Rắn khuyết Trường SƠn +” (in Vietnamese). + + +Natural history notes: +The new species + +L +. +poyarkovi + + +sp. nov. + +has a narrow distribution, seems to be quite uncommon due low encounter rates, is a nocturnal snake, usually observed crawling on the ground but also climbing quite well. It is observed in small puddles, edges of small and medium streams inhabiting montane forests at ca. +300–800 m +asl. In Phong Nha-Ke Bang NP, the one individual (uncollected, see +Fig. 6H +) was observed at night on the ground in a forest clearing or crawling through the roots of a fallen tree, lying at the edge of a small creek (see +Fig. 8A +). Colubrid species recorded in sympatry with the new species in Phong Nha-Ke Bang NP included: + +Ahaetulla prasina +(Boie) + +, + +Chrysopelea ornata +(Shaw) + +, + +Boiga bourreti +Tillack, Ziegler & Le + +, + +B +. +guangxiensis +Wen + +, + +B +. +multomaculata +(Boie) + +, + +B +. cf. +kraepelini +Stejneger + +, + +Coelognathus radiatus +(Boie) + +, + +Dendrelaphis ngansonensis +(Bourret) + +, + +Elaphe taeniura +(Cope) + +, + +Lycodon davisonii + +, + +L +. cf. +fasciatus + +, + +L +. +futsingensis + +, + +L +. +ruhstrati abditus + +, + +Liopeltis pallidonuchalis +Poyarkov, Nguyen & Vogel + +, + +Oligodon chinensis +(Günther) + +, + +O +. +cinereus +(Günther) + +, + +Oreocryptophis porphyraceus +(Cantor) + +, + +Ptyas multicincta +(Roux) + +, + +P +. +korros +(Schlegel) + +, + +P +. +mucosa +(Linnaeus) + +, + +Gonyosoma boulengeri +(Mocquard) + +, and + +G +. +coeruleum +Liu, Hou, Lwin, Wang & Rao + +( + +Ziegler +et al +. 2004 + +; + +Luu +et al +. 2013 + +; + +Poyarkov +et al +. 2019 + +; our data). In Dong Chau-Khe Nuoc Trong NR, the specimen DTU 616 was found while crawling on a dry tree branch near a stream about +1.5 m +above the ground (see +Fig. 8B +). Colubrid species recorded sympatry with the new species in Dong Chau-Khe Nuoc Trong NR included: + +Ahaetula prasina + +, + +Chrysopelea ornata + +, + +Boiga guangxiensis + +, + +B +. cf. +kraepelini + +, + +Dendrelaphis +cf. +pictus +(Gmelin) + +, + +Ptyas multicincta + +, + +Lycodon laoensis + +, + +L +. +futsingensis + +, + +L +. +ruhstrati abditus + +, + +Oligodon chinensis + +, + +Oreocryptophis porphyraceus + +, and + +Gonyosoma boulengeri + +( + +Pham +et al +. 2019 + +; our data). The diet of the new species is not known, though it likely consists of frogs and snakes ( + +Vogel +et al +. 2009 + +; our data). + + + + +FIGURE 8. +The macrohabitat of + +Lycodon poyarkovi + + +sp. nov. + +in Quang Binh, Vietnam –from Phong Nha-Ke Bang NP (A); from Dong Chau-Ke Nuoc Trong NR (B). Photos by: (A) L.P. Tran; (B) H.T. Bach. + + + + +Distribution +( +Fig. 9 +). The new species is to date known only from two localities in +Quang Binh Province +, +Vietnam +, namely: Phong Nha-Ke Bang NP in Minh Hoa District and Dong Chau-Ke Nuoc Trong NR in Le Thuy District, within the northern part of the Truong Son Mountain Range, which is isolated from the adjacent mountain massifs by lowland areas and is characterized by a high level of herpetofaunal endemism ( + +Poyarkov +et al +. 2021 + +, +2023 +). The new species is likely an endemic of this mountain region; further records from other mountain areas in the Bac Huong Hoa NR, +Quang Tri Province +of +Vietnam +(see discussion) as well as +Khammouan Province +of Central +Laos +are anticipated. + + + + \ No newline at end of file