Research Article |
Corresponding author: Truong Q. Nguyen ( nqt2@yahoo.com ) Corresponding author: Thomas Ziegler ( ziegler@koelnerzoo.de ) Academic editor: Robert Jadin
© 2019 Helen Y. Janssen, Cuong T. Pham, Hanh Thi Ngo, Minh Duc Le, Truong Q. Nguyen, Thomas Ziegler.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Janssen HY, Pham CT, Ngo HT, Le MD, Nguyen TQ, Ziegler T (2019) A new species of Lycodon Boie, 1826 (Serpentes, Colubridae) from northern Vietnam. ZooKeys 875: 1-29. https://doi.org/10.3897/zookeys.875.35933
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A new species of the genus Lycodon is described from Cao Bang Province, Vietnam, based on three individuals with distinct differences in morphology and molecular data. The new species is differentiated from its congeners by a combination of the following characters: dorsal scales in 17-17-15 rows, smooth throughout; supralabials usually eight (rarely nine); infralabials ten; one elongated loreal on each side, in contact with the eye; precloacal plate single; ventral scales 212–218 (plus one or two preventral scales); subcaudals 90 or 91; maxillary teeth 13 or 14; dorsal surface of body with 28 or 29 light body bands; dorsal surface of tail with 13 cream bands, forming a distinct blotch in the vertebral region. Based on phylogenetic analyses of mitochondrial cytochrome b sequence data, the new species is recovered as the sister species to a clade containing L. multizonatus and L. liuchengchaoi with strong support from the Bayesian analysis. The new species is at least 7.5% divergent from other species within this clade in uncorrected pairwise distance calculated using a fragment of more than 1000 bp of the mitochondrial cytochrome b. This discovery increases the number of Lycodon species known from Vietnam to 16.
Cao Bang Province, Lycodon pictus sp. nov., morphology, phylogeny, taxonomy
The genus Lycodon Boie, 1827 is one of the most diverse genera of colubrid snakes, with 61 currently recognised species (
Our recent field surveys in the Ha Lang and Trung Khanh districts, Cao Bang Province, northern Vietnam, revealed a snake population that was referable to the genus Lycodon based on the following characters: nostril enlarged; robustly arched upper maxillary bone with an inward curve in the anterior part; anterior and posterior maxillary teeth interrupted by a diastema; dorsal scales smooth or weakly keeled, in 17 rows anteriorly and at midbody, and posteriorly 15 rows (
The field surveys were led by TQN in October 2011 and from April to May 2012. The collected specimens were euthanised with ethyl-acetate, fixed in approximately 85% ethanol for 10 hours, and subsequently transferred to 70% ethanol for permanent storage. Liver tissue samples were preserved separately in 95% ethanol. The specimens were deposited in the collections of the Institute of Ecology and Biological Resources (IEBR), Hanoi, Vietnam and of the Zoologisches Forschungsmuseum Alexander Koenig (
Identification of sex was performed by dissection (inspection of gonads and presence of hemipenes). Maxillary teeth were counted by dissecting the right maxilla for teeth / sockets. Scalation and maxillary teeth number were examined with a binocular dissecting microscope. Measurements were taken following
Abbreviations of morphological characters are as follows:
SVL Snout-vent length (from tip of snout to vent);
TaL tail length;
TaL / TL ratio of tail length / total length;
TL total length;
DSR dorsal scale rows number at one head length posterior to the head – number of dorsal scale rows at midbody – number of dorsal scale rows at one head length anterior to the vent;
SL supralabials (counted on upper lips);
SL / orbit number of supralabials entering orbit;
IL infralabials (counted on lower lips);
Lor loreals;
Lor / eye loreal scale touching the eye (yes or no);
PreOc preoculars;
PostOc postoculars;
Atem number of anterior temporals;
PTem number of posterior temporals;
BodySc scalation of the body (keeled or smooth);
PreVen number of preventral scales;
Ven number of ventral scales;
SubC number of subcaudal scales;
Prec precloacal (or cloacal) plate (single or divided);
Teeth max number of maxillary teeth / alveoli.
Scale counts were taken following
Comparisons were mainly based on the data provided by
Representative taxa of the genus Lycodon were included in the study. Sequences of the species were downloaded from GenBank. Two samples of the population from Cao Bang Province (
DNA was extracted using DNeasy Blood and Tissue kit (Qiagen, Germany) following the manufacturer’s instructions. A fragment of the mitochondrial cytochrome b gene was amplified using the primer pair L14910 (5’–GACCTGTGATMTGAAAACCAYCGTTGT-3’) and H16064 (5’– CTTTGGTTTACAAGAACAATGCTTTA-3’;
PCR products were visualised using gel electrophoresis through a 2% low melting-point agarose gel stained with ethidium bromide. Successful amplifications were purified to eliminate PCR components using GeneJETTM PCR Purification kit (ThermoFisher Scientific, Lithuania). Purified PCR products were sent to FirstBase (Malaysia) for sequencing.
The obtained sequences were aligned in ClustalX 1.8.3 (
The final matrix consisted of 1011 bp aligned characters and the alignment contained no gaps. In total, 404 characters were found to be parsimony informative. MP analysis resulted in five most parsimonious trees having 1662 steps (CI = 0.41, RI = 0.72). Our tree topologies are very similar to those recovered by
IEBR 4166 (field number CB 2012.97), adult male, collected on 18 April 2012 by TQN et al. (altitude 701 m a.s.l.), Trung Khanh District, Cao Bang Province.
Lycodon pictus sp. nov. can be differentiated from its congeners by the following morphological characters: dorsal scales in 17–17–15 rows, all smooth; supralabials usually eight (rarely nine); infralabials ten; one elongated loreal on each side, in contact with the eye; precloacal plate single; ventral scales 212–218 (plus one or two preventral scales); subcaudals 90 or 91; a total length of 597+ mm in males and 543 mm in females; tail / total length ratio 0.211–0.215; maxillary teeth 13 or 14; dorsal surface of body with 28 or 29 light body bands; dorsal surface of tail with 13 cream bands forming a distinct blotch in the vertebral region; ventral surface of body and tail mostly cream with the dark body bands in part extending towards the venter, sometimes forming complete dark bands around the body.
Head elongate, moderately distinct from the neck, rather flattened, longer than wide, narrow anteriorly; nostril lateral, located in the middle of the nasal; eye large, pupils vertically elliptic; rostral triangular, much broader than high, hardly visible from above; nasal divided into two scales by a vertical ridge along posterior edge of nostril; two internasals, anteriorly rounded, slightly wider than high, bordered by two large, pentagonal prefrontals posteriorly; frontal single, enlarged, pentagonal to hexagonal, narrowed posteriorly; parietals longer than wide, in contact with each other medially, with upper anterior and posterior temporals, paraparietal laterally and four nuchal scales posteriorly; paraparietals elongated, anterior part widened; loreal 1/1, elongate, not entering orbit; supralabials 8/8, first and second in contact with nasal, third to fifth entering orbit, sixth largest; infralabials 10/10, first pair in broad contact with each other, first to fifth in contact with anterior pair of chin shields; anterior and posterior pairs of chin shields elongate, of the same size and shape, second pair not meeting in midline; preocular 1/1; postoculars 2/2, lowermost smaller, bordering anterior temporals; anterior temporals 2/2, posterior temporals 3/3, upper ones thinner than lower ones. Left maxilla arched, with an angular apex, distinctly bent inwards anteriorly. A total of 13 maxillary teeth or teeth alveola, with the following formula: five small anterior teeth, with the last two ones being somewhat enlarged + two strongly enlarged teeth, thick, and not much curved + a wide gap, somewhat wider than the length of the largest teeth + four small teeth + a small gap + two enlarged posterior teeth.
Body elongate, SVL 488 mm; TaL > 109 mm (tail tip lost); preventral 1, ventrals 212, from behind neck region distinctly notched laterally; subcaudals > 54 (tail tip lost), paired; precloacal plate single; DSR 17-17-15, all smooth; the vertebral scales not enlarged; DSR reduction from 17 to 15 at the position of ventral 150.
Head, neck, and dorsal surface of body brownish black; light body bands beginning after 1.5 times the head length behind the head, in total 29 transverse light bands on body and at least nine light bands on tail; the first four body bands yellowish cream, and distinctly widened towards the venter, increased in size posteriorly; a dark mottling in the vertebrate region more prominent posteriorly; the subsequent light body bands with two distinct indentations on each side, fused in the middle in the last third of the body. In dorsal view the light bands forming a distinct blotch in the vertebral region, with a dark centre and a lighter frame; laterally, the middle part of the light bands forming blotches, but wider and with an extended dark centre, fused laterally in the last third part of the body; the lower and widest part of the light body bands with a dark small blotch in the centre in the anterior part of body; the light bands on the tail with a blotch like pattern in the vertebral region, but less pronounced than that on body, and one light blotch at the lateral side of tail, widened towards the venter, with a dark centre; ventral surface of head and neck yellowish cream, belly cream and greyish cream in the last third part of body and on lower tail surface; the dark dorsal bands (28 on body and at least nine on tail) in part extending towards the venter (most prominent in the anterior five dark body bands), not forming complete dark bands around the body, but complete on the tail; lateral side of the head dark above and light below, with the lighter pattern beginning in the supralabial region; tip of lower jaw and infralabial region in part greyish; dorsal surface of the head and upper head sides a bit paler than the remaining head dorsum.
Hemipenes elongated, not fully everted, not turgid. Truncus without spines. Spine ornamentation starting at truncus region with somewhat enlarged, medium sized spines. Apex with microspines. Sulcus stretches in the middle to apex. Apex not fully everted, ending somewhat widened with an oblique opening, with microspines inside, pointing to the not fully everted condition of the outer genital organ.
In the juvenile
In the female
Sex, measurements (in mm), scalation data, and coloration pattern of Lycodon pictus sp. nov. For abbreviations see Materials and methods. Key: asterisk (*) lower Atem not touching PostOc; plus sign (+) tail tip lost.
Holotype IEBR 4166 | Paratype |
Paratype |
|
---|---|---|---|
Sex | male | female | juvenile |
TL | 597 | 543 | 237 |
SVL | 488 | 426 | 187 |
TaL | 109+ | 117 | 50 |
TaL/TL | – | 0.215 | 0.211 |
Teeth max | 13 | 13 | 14 |
SL | 8/8 | 8/8 | 9/8 |
SL/orbit | 3–5 | 3–5 | 4–6/3–5 |
IL | 10/10 | 10/10 | 10/10 |
PreOc | 1/1 | 1/1 | 1/1 |
PostOc | 2/2 | 2/2 | 2/2 |
Lor | 1/1 | 1/1 | 1/1 |
Atem | 2/2 | 2*/2 | 2/2* |
PTem | 3/3 | 3/3 | 3/3 |
DSR | 17-17-15 | 17-17-15 | 17-17-15 |
PreVen | 1 | 2 | 1 |
Ven | 212 | 216 | 218 |
Prec | single | single | single |
Subc | 54+ | 91 | 90 |
BodySc | smooth | smooth | smooth |
Dark bands on body | 28 | 29 | 28 |
Light bands on body | 29 | 29 | 28 |
Dark bands on tail | 9 | 13 | 13 |
Light bands on tail | 9+ | 13 | 13 |
Female
In our phylogenetic analysis, Lycodon pictus sp. nov. is most closely related to L. liuchengchaoi and L. multizonatus. From L. liuchengchaoi, the new species differs in terms of body scalation (all smooth in the new species vs. feebly keeled in several median rows in L. liuchengchaoi), head scalation (ten infralabials vs. 7–9) and dentition (13 or 14 maxillary teeth vs. 8 or 9). In addition, the new species differs from the latter in having 28 or 29 cream body bands (vs. 40 yellow rings on the body in L. liuchengchaoi) (
The new species differs from L. multizonatus by having more maxillary teeth (13 or 14 vs. 10 or 11 in L. multizonatus), more infralabials (10 vs. 8) and a single precloacal plate (vs. divided). In addition, the new species differs from the latter in terms of body scalation (minimum 212 ventrals and minimum 90 subcaudals vs. 190–195 ventrals and 68–75 subcaudals in L. multizonatus). Furthermore, L. pictus sp. nov. has fewer light body bands (28 or 29 vs. 55–73 in L. multizonatus) (
From its Vietnamese congeners, the new species can be differentiated as follows: Lycodon pictus sp. nov. differs from L. capucinus in having a single precloacal plate (vs. divided), a loreal touching the eye (vs. not in contact with the eye), in having more ventrals (minimum 212 vs. 182–211) and more subcaudals (90 or 91 vs. 59–74), and in terms of dorsal pattern (banded vs. reticulated) (
Lycodon pictus sp. nov. differs from L. cardamomensis in terms of dorsal scalation (17-17-15 smooth DSR vs. 19-17-15 weakly keeled DSR), in having a loreal in contact with the eye (vs. separated) and in having 28 or 29 light body bands (vs. 12-14 pinkish orange body bands) (
Lycodon pictus sp. nov. differs from L. davisonii in having 17 midbody dorsal scale rows (vs. 13 midbody dorsal scale rows), fewer ventral scales (maximum 218 vs. 235–265), more infralabials (10 vs. 8) and the absence of preocular (vs. present). In addition, the new species differs from the latter in having a different dorsal pattern (28 or 29 cream bands on body vs. 36 white rings on the body) (
Lycodon pictus sp. nov. differs from L. fasciatus in having smooth dorsal scales (vs. keeled) and more maxillary teeth (13 or 14 vs. 11). Additionally, the colour pattern of Lycodon pictus sp. nov. differs in being dark brownish black with light body bands turning into a marbling posteriorly, whereas L. fasciatus is black or purplish black above with yellowish cross-bars of irregular outline and has a dark median stippling (
Lycodon pictus sp. nov. differs from L. flavozonatus in terms of dorsal scalation (smooth vs. keeled), in having more subcaudals (90 or 91 vs. 80–88), the loreal in contact with the eye in Lycodon pictus sp. nov. (vs. separated in L. flavozonatus) and in coloration pattern (brownish black with 28 or 29 cream body bands and 9–13 light bands on the tail vs. black with 68 yellow body bands and 21 on the tail) (
Lycodon pictus sp. nov. differs from L. futsingensis in having more ventrals (minimum 212 vs. 193–208) and more subcaudals (minimum 90 vs. 72–87). Additionally, the loreal does not enter the orbit in L. futsingensis, whereas it enters the orbit in Lycodon pictus sp. nov. (
Lycodon pictus sp. nov. differs from L. laoensis in having a single precloacal plate (vs. divided), more ventral scales (minimum 212 vs. 163–192), more subcaudal scales (minimum 90 vs. 60–76), an elongated loreal scale in contact with the orbit (vs. separated) and cream body bands (vs. yellow) (
Lycodon pictus sp. nov. differs from L. meridionalis in having smooth dorsals (vs. feebly keeled in 10–12 median rows), a lower ventral scale count (maximum 218 vs. 227–240) and fewer subcaudals (maximum 91 vs. 96–106). In addition, the new species differs in having cream body bands (vs. yellow thin crossbars) (
Lycodon pictus sp. nov. differs from L. namdongensis in having more subcaudals (90 or 91 vs. 85) and the loreal in contact with the eye (vs. separated from the eye in L. namdongensis). The new species also differs in coloration pattern (brownish black with 28 or 29 light bands on the body vs. grey with 23 cream cross rings on the body in L. namdongensis), and in having irregular bands turning into a marbling posteriorly (vs. clearly demarcated cross bands on the body) (
Lycodon pictus sp. nov. differs from L. paucifasciatus in terms of dorsal scalation (17-17-15 smooth DSR vs. 19-(19-17)-15 DSR, the upper one or two plus vertebral row distinctly keeled) and fewer ventral scales (maximum 218 vs. 219–222). In addition, the new species has a loreal entering the eye (vs. separated) and 28 or 29 light body bands (vs. 14–25 beige or dirty cream body bands) (
Lycodon pictus sp. nov. differs from L. rosozonatus in having 17-17-15 smooth DSR (vs. 19-19- 15(17) keeled DSR), fewer ventral scales (maximum 218 vs. 221–234) and a loreal in contact with the eye (vs. separated). In addition, the new species has cream body bands (vs. pinkish red) (
Lycodon pictus sp. nov. differs from L. rufozonatus in having a loreal in contact with the eye (vs. separated), smooth dorsal scales (vs. feebly keeled in the posterior body part), and in coloration pattern (28 or 29 cream body bands vs. 44–52 light red body bands) (
Lycodon pictus sp. nov. differs from L. ruhstrati abditus in having smooth dorsals (vs. 7–8 dorsal scale (including vertebral) rows keeled), an elongated loreal in contact with the eye (vs. separated), and in having irregular bands turning into a marbling posteriorly (vs. clearly demarcated cross bands on the body) (
Lycodon pictus sp. nov. differs from L. septentrionalis by its smooth dorsal scales (vs. 7–9 median rows feebly keeled), 10 infralabials (vs. 7 or 8), and the loreal entering the orbit (vs. separated in L. septentrionalis). In addition, the new species differs in having cream irregular bands on a brown body (vs. white narrow bands on a black body forming complete annuli) (
Lycodon pictus sp. nov. differs from L. subcinctus in having 10 infralabials (vs. 8 or 9), one preocular (vs. preocular absent), smooth dorsal scales (vs. feebly keeled) and 28 or 29 cream bands on the body and 9–13 on the tail (vs. 9–15 bands on the body and none on the tail) (
Lycodon pictus sp. nov. differs from L. ophiophagus, a species from southern Thailand but with similar scalation, in having a loreal entering the eye (vs. separated) and in dorsal colour pattern (28 or 29 light bands on a brown body vs. 20 or 21 white bands on a dark body) as well as and in having irregular bands turning into a marbling posteriorly (vs. clearly demarcated cross bands on the body) (
For additional measurements, dentition, and scalation data see Tables
Lycodon pictus sp. nov. is currently known only from Ha Lang and Trung Khanh districts, Cao Bang Province, northern Vietnam (Fig.
The name of the species pictus means painted or decorated in Latin and refers to its unique dorsal colour pattern.
Lycodon pictus sp. nov. seems to be closely associated with karst environment. Specimens were found at night between 19:00 and 23:00, on forest paths or on the ground near cave entrances. The surrounding habitat was secondary karst forest, consisting of medium and small hardwood trees mixed with shrubs and vines. Air temperature was 23.4–29.6°C and humidity was 66–79%. Other reptiles were also found at the site, including Acanthosaura lepidogaster (Cuvier, 1829), Gekko adleri Nguyen, Wang, Yang, Lehmann, Le, Ziegler & Bonkowski, 2013, Goniurosaurus luii Grismer, Viets & Boyle, 1999, Lycodon futsingensis (Pope, 1928), and Protobothrops trungkhanhensis Orlov, Ryabov & Nguyen, 2009 (Fig.
Measurements (in mm), dentition, and scalation data of Lycodon species from Vietnam. Data taken from
Lycodon pictus sp. nov. | L. capucinus | L. cardamomensis | L. davisonii | L. fasciatus | L. flavozonatus | L. futsingensis | L. laoensis | |
---|---|---|---|---|---|---|---|---|
TL | 597 | 816 | 896 | 920 ♂ | 894 | 1440 ♂,1210 ♀ | 850 ♂ 773 ♀ | 470 |
Teeth max | 13 or 14 | 15 | 10–12 | 11 | 13 | 12–15 | ||
SL | 8 | 9 or 10 | 8 | 7 | 8 | 8 | 8 (7) | 9 or 10 |
SL/orbit | 3–5 | 3–5 | 3–5 | 3–4 | 3–5 | 3–5 | 3–5 (4–5; 2–4;4–6) | 3–5 |
IL | 10 | 9 or 10 | 10 | 8 | 9 (8, 10) | 10 | 10 (9, 11) | 10 |
PreOc | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 |
PostOc | 2 | 2 | 2 or 3 | 1 or 2 | 2 | 2 | 2 (3) | 2 (3) |
Lor | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Lor/eye | yes | no | no | yes | yes | no | no | no |
Atem | 2 | 2 | 2 | 1 or 2 | 2 | 2 | 2 (1) | 2 |
PTem | 3 | 3 | 2 or 3 | 2 | 2 | 2 or 3 | 3 (2) | 3 |
DSR | 17-17-15 | 17-17-15 | 19-17-15 | 13 | 17-17-15 | 17-17-15 | 17-17 (16)- 15 | 17-17-15 |
Ven | 212-218 | 182-211 | 215-228 | 233-265 | 182-225 | 211-221 ♂ 212-218 ♀ | 193-204 ♂, 198-208♀ | 163-192 |
Prec | single | divided | single | single | single | divided/ single | single | divided |
Subc | 90 or 91 | 59-74 | 87-93 | 90-108 | 65-94 | 81-88 ♂, 80-84 ♀ | 72-87 ♂, 78-85 ♀ | 60-76 |
BodySc | smooth | weakly keeled | weakly keeled | smooth | keeled | 7 rows feebly keeled at midbody | smooth | smooth |
Measurements (in mm), dentition, and scalation data of Lycodon species from Vietnam (continuation of Table
L. meridionalis | L. namdongensis | L. paucifasciatus | L. rosozonatus | L. rufozonatus | L. ruhstrati abditus | L. septentrionalis | L. subcinctus | |
---|---|---|---|---|---|---|---|---|
TL | 1139 | 723 | 763 | 1060 | 1234 | 964 | 1163 | 1000 |
Teeth max | 11 | 12 | 11 or 12 | 12 or 13 | 11–13 | 11–13 | 7 | 8–14 |
SL | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 |
SL/orbit | 3–5 | 3–5 | 3–5 | 3–5 | 3–5 | 3–5 | 3–5 (3–6) | |
IL | 10 | 10 | 10 | 10 (9) | 10 (9,11) | 7 or 8 | 8 or 9 | |
PreOc | 1 | 2/1 | 1 | 1 | 1 | 1 | 1 | 0 |
PostOc | 2 | 3 | 2 | 2 | 2 | 2 | 2 | 2 or 3 |
Lor | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Lor/eye | no | no | no | no | no | no | no | yes |
Atem | 2 | 2 | 2 | 2 | 2 | 2 (1) | 2 | 1 |
PTem | 3 | 2 | 3 | 3 | 3 | 3 (2) | 3 | 2 |
DSR | 17-17-15 | 17-17-15 | 19- (19-17)- 15 | 19-19- 15(17) | (19-17)-17-15 | 17-17-15 | 17-17-15 | 17-17-15 |
Ven | 227-240 | 218 | 219-222 | 221-234 | 184-225* | 197-229 | 202-224 | 192-230 |
Prec | divided | single | single | single | single | single | divided (rarely single) | |
Subc | 96-106 | 85 | 90-92 | 53-98 | 90-103 | 83-104 | 60-91 | |
BodySc | dorsals feebly keeled in 10-12 median rows, smooth in outer rows | smooth | upper 1 or 2 dorsal scale row(s) plus vertebral row distinctly keeled | weakly keeled | feebly keeled in the posterior body part | smooth (DSR 1-6), distinctly keeled (DSR 7-8 and vertebral row) | 7 or 9 median rows feebly keeled | feebly keeled |
Measurements (in mm), dentition and scalation data of Lycodon species from China, Laos and Cambodia. Data taken from
L. aulicus | L. banksi | L. davidi | L. gongshan | L. liuchengchaoi | L. multizonatus | L. synaptor | L. zoosvictoriae | |
---|---|---|---|---|---|---|---|---|
TL | 719 | 465 + | 389.5 | 963 ♂ | 676 | 505 | 487 | 520.7 |
Teeth max | 11 | 8 or 9 | 10 or 11 | 10 | 9 | |||
SL | 9 (8 or 10) | 8 | 8 | 8 | 7 or 8 | 8 (rarely 7) | 8 | 8 |
SL/orbit | 3–5 | 3–5 | 3–5 | 3–5 | 3–5 | 3–5 | 3–5 | 3–5/4–5 |
IL | 10 or 11 | 10 | 10 | 8 | 8 (7,9) | 8 (7) | 8 | 10 |
PreOc | 1 | 1 | 1 | 1 | 1 | 0 or 1 | 1 | 1 or 2 |
PostOc | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
Lor | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Lor/eye | no | yes | no | yes | yes | yes | no | no |
Atem | 2 | 2 | 2 | 2 | 1-3 | 2 (1) | 2 | 2 |
PTem | 3 | 3 | 2 or 3 | 2 or 3 | 1-3 | 3 (2) | 2 | 2 |
DSR | 17-17-15 | 17-17-15 | 17-17-15 | 17-17-15 | 17-17-15 | 17-17-15 | 15 or 17-17-15 | 17-17-15 |
Ven | 180-215 | 241 | 224 ♂ | 210–216 ♂, 215 ♀ | 190-228 | 190-195 | 201-203 ♀ | 213 ♀ |
Prec | divided | single | single | single | divided | divided | single | single |
Subc | 57-78 | 26 + | 99 ♂ | 95 or 96 ♂, 92 ♀ | 68-77 | 68-75 | 68 or 69 ♀ | 85 ♀ |
BodySc | smooth and glossy | smooth (six central DSR of posterior 1/3 feebly keeled) | middorsal scale rows slightly keeled, outermost rows entirely smooth | upper dorsal rows 6–12 and vertebral row keeled | feebly keeled in median rows | smooth | 6-7 upper rows and vertebral row feebly keeled | weakly keeled |
Measurements (in mm), dentition, and scalation data of Lycodon species from Thailand and Myanmar. Data taken from
L. albofuscus | L. butleri | L. effraenis | L. gibsonae | L. gracilis | L. jara | L. kundui | L. ophiophagus | L. subannulatus | L. zawi | |
---|---|---|---|---|---|---|---|---|---|---|
TL | 1480 | 876 | 700 | 906 | 533 | 535 ♂, 550 ♀ | 909 | 684 | 480 | |
Teeth max | 12 | 13 | 9 | 11-13 | 8 or 10 | 12 | ||||
SL | 8 | 8 or 9 | 9 | 8 | 8 | 8 or 9 | 7 | 8 | 7 | 8 or 9 |
SL/orbit | 3–5 | 3–5 | 3–5 | 3–4 and 3–5 | 3–4 | 3–5 | 3–4 | 3–5 | 3–4 | 3–5 |
IL | 9 or 10 | 10 or 11 | 10 | 10 | 8 | 9 or 10 | ||||
PreOc | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 1 | |
PostOc | 2 | 2 | 2-3 | 2 | 2 | 2 | 2 | 2 | 2 | 2 (1) |
Lor | 1 | 1 | 0 | 1 | 1 (united with lower PreOc) | 1 | 1 | 1 | 1 | 1 |
Lor/eye | no | yes | no Lor | yes | yes | no | no | no | yes | no |
Atem | 2 | 2 | 2 | 2 | 2 | 1 or 2 | 1 | 2 | 2 | 2 (3) |
PTem | 2 | 2 | 2 or 3 | 3 | 3 | 2 or 3 | 2 | 3 | 2 | 3 (4) |
DSR | 17 | 19 (17 in |
17 | 17-17-15 | 15 | 17-17-15 | 15-15-15 | 17-17-15 | 15-15-15 | 17-17-15 |
Ven | 241 | 220-227 | 215-228 | 223-226 ♂ | 234 | 167-188 | 186 | 211-212 | 225-244 | 179-194 ♂, 207 ♀ |
Prec | divided | single | single | single | single | divided | divided (entire in |
single | single | divided |
Subc | 155-208 | 81-96 | 72-99 | 91-92 ♂ | 81-83 | 52-74 | 70 | 87-90 | 93-111 | 45-75 ♂ |
BodySc | keeled | keeled | smooth | upper 3 or 4 rows keeled | keeled | smooth | smooth | smooth | keeled | smooth |
Measurements (in mm), dentition and scalation data of Lycodon species from India. Data taken from
L. anamallensis | L. flavicollis | L. flavomaculatus | L. gammiei | L. hypsirhinoides | L. mackinnoni | L. nympha | L. striatus | L. tiwarii | L. travancoricus | |
---|---|---|---|---|---|---|---|---|---|---|
TL | 522 | 543 | 520 | 1150 | 717 ♂, 563 ♀ | 365 | 574 | 432 | 790 | 600 ♂, 625 ♀ |
Teeth max | 8–10 | |||||||||
SL | 9 | 9 | 9 | 8 (7,9) | 9 | 8 (7) | 7 (8 or 6) | 9 | 9 | |
SL/orbit | 3–5 | 3–5 | 3–5 | 3–5 (3–4) | 3–5 | 3–5 | 3–4 | 3–5 | 3–5 | |
IL | 10 or 11 | 11 | 10 | 10 | 8 | 11 | ||||
PreOc | 1 | 1 | 1 | 1 | 1 | 1 | 1 or 2 | 1 | 1 | |
PostOc | 2 or 3 | 2 | 2 | 2 (1) | 2 | 2 | 2 | 2 | 2 | |
Lor | 1/1 (except Holotype 2/2) | 1 | 1 | 1 | 1 | 1 (0 in |
1 | 1 | 1 | |
Lor/eye | no | no | no | no | no | yes | no | no | ||
Atem | 2 | 2 (3) | 2 (1) | 2 or irregular | 2 | 1 or 2 | 2 | 2 rarely 1 | 2 or 3 | |
PTem | 3+4 | 3 (rarely 2) | 3 (rarely 2) | 2 or irregular | 3 | 2 or 3 | 2 or 3 | 3 rarely 2 | 3 | |
DSR | 17-17-15 | 17-17-15 | 17-17-15 | 17-17 (19)-15 | 17-17-15 | 17-17-15 | 13-13-13 | 17-17-15 | ?-17-15 | 17-17-15 |
Ven | 174–186 ♂, 186–204 ♀ | 210-224 | 165-183 | 205-220 | 188–202 ♂, 199–210 ♀ | 163- 187 | 200-243 | 153-178 | 218-237 | 176-206 |
Prec | divided (except holotype) | divided | divided | single | divided | divided | divided | divided | divided | single |
Subc | 63–73 ♂, 60–74 ♀ | 65-72 | 53-63 | 98-111 | 68–75 ♂, 61–68 ♀ | 48-56 | 65-88 | 42-66 | 61-102 | 64-76 |
BodySc | smooth | smooth with single apical pit | smooth | 9 dorsal rows keeled, 5 rows at each side smoot | smooth | smooth | keeled | smooth | smooth |
Measurements (in mm), dentition and scalation data of Lycodon species from the Philippines. Data taken from
L. alcalai | L. bibonius | L. chrysoprateros | L. dumerilii | L. fausti | L. ferroni | L. muelleri | L. philipinus | L. solivagus | L. tessellatus | |
---|---|---|---|---|---|---|---|---|---|---|
TL | 787 ♂ | 511 | 727 | 547 ♂, 521 ♀ | 337 | 382 | 302 ♂, 204 ♀ | 486 | 946 | 900 |
Teeth max | 11–13 | 11–14 | 11–13 | 13–15 | 13 | 12 | 14–15 | 8 | 11–13 | |
SL | 9 | 7–9 | 9 | 11–13 | 9 | 10 | 9 | 7 | 9 | 8 or 9 |
SL/orbit | 4–5 | 3–5 (4–5) | 3–5 | 4–5 | 4–5 | 4–6 | 4–5 | 3–4 | 4–5 | 4–5 |
IL | 10 | 9 or 10 | 10 | 9 or 10 | 9 or 10 | 10 | 10 | 7 | 10 | |
PreOc | 2 | 2 | 2 | 1 or 2 | 2 | 2 | 1 or 2 | 0 or 1 | 2 | 1 |
PostOc | 3 | 2 or 3 | 2 or 3 | 2 | 3 | 2 | 2 or 3 | 2 or 3 | 2 or 3 | 2 |
Lor | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Lor/eye | no | no | no | no (only when fused with PreOc) | no | no | yes | no | no | |
Atem | 2 | 2+3 | 2+3+4 | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
PTem | 3 | 2+3+3 | 2+3+3 | 3 | 3 or 2 | 3+4 | 3+4 | 3 | 3 | 2 or 3 |
DSR | 19-17-15 | 19-17-15 | 19-17-15 | 19-17-15 | 19- 17- 15 | 19-17-15 | 19-17-15 | 15 | 19-17-15 | 17 or 21 |
Ven | 203-207 | 204-212 | 186-194 | 195-221 | 207 or 215 | 203 | 205-213 | 216-225 | 198-203 | 222-232 |
Prec | single | single | single | single | single | single | single | single | single | divided |
Subc | 108-126 | 110-120 | 111-117 | 111-120 | 135-148 | 109 | 112-117 | 87-99 | 112-115 | 56 |
BodySc | smooth | smooth | smooth | smooth | smooth | smooth | smooth | smooth |
Measurements (in mm), dentition and scalation data of Lycodon species from Sri Lanka, Malaysia, Japan and Indonesia. Data taken from
L. carinatus | L. cavernicolus | L. multifasciatus | L. orientalis | L. semicarinatus | L. sidiki | L. stormi | L. tristrigatus | |
---|---|---|---|---|---|---|---|---|
TL | 730 | 508.2 | 700 | 660 | 1100 | 715 | 597 | 360 |
Teeth max | 10 or 11 | 7 | 8 or 10 | |||||
SL | 8 or 9 | 9 or 10 | 8 | 8 | 8 | 8 | 7 | |
SL/orbit | 3-5 | 4-6 | 3-5 | 3-5 | 3-5 | 3-4 | 3-4 | |
IL | 10 or 11 | 10/9 | ||||||
PreOc | 1 | 1 | 0 | 1 | 0 | 1 | 0 | |
PostOc | 2 | 2 | 2 | 2 | 2 | 2 | 2 | |
Lor | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
Lor/eye | no | yes | no | yes | no | yes | no | yes |
Atem | 2 | 3 (2) | 2 | 2 | 2 | 1 | 2 | |
PTem | 2 or 3 | 3 or 4 | 3 | 3 | 2 | 3 | 2 or 3 | |
DSR | 17 or 19-19-17 | 17-17-15 | 17-17-? | 17 | 17 | 17-17-15 | 19 | 15 |
Ven | 185-202 | 245 ♂, 232 ♀ | 232-237 ♂ 229-235 ♀ | 200-208 | 211-234 | 195 | 217 | 224 |
Prec | single | single | divided | single | divided | single | single | |
Subc | 51-64 | 113 ♂, 92 ♀ | 115-119 ♂ 106- 117 ♀ | 68-74 | 65-105 | 85 | 75 | 86 |
BodySc | strongly keeled | the 8 medial rows weakly keeled | keeled | scales with a very faint keel along their anterior half | scales keeled along anterior half (4 outer rows smooth, other with a feeble though distinct keel on the basal half of each scale) | keeled | smooth | keeled |
Our phylogenetic analyses reveal Lycodon pictus sp. nov. to be the sister taxon to a clade containing L. multizonatus and L. liuchengchaoi from China, but only with strong statistical support in the BI. The new species differed from the latter by at least 7.5% in uncorrected pairwise sequence distance. There has been some taxonomic confusion in the genus Lycodon. Two of the L. liuchengchaoi sequences (KC733201, KC733202) in the phylogenetic tree had previously been identified as L. fasciatus, but the phylogenetic analysis by
This new discovery increases the number of Lycodon known from Vietnam to 16, of which nine are confined to karst formations, underlining the importance of this habitat in promoting reptile speciation (
We are grateful to the directorates of the Forest Protection Department of Cao Bang Province, Forest Protection Units of Ha Lang and Trung Khanh districts for support of our field work and issuing relevant permits. Thanks to D.T. Le, H.T. An (Hanoi), S. Herbst, T. Lehmann, and M. Bonkowski (Cologne) for their assistance, E. Sterling (New York) and K. Koy (Berkeley) for providing the map. We thank J. Wang from the State Key Laboratory of Biocontrol / The Museum of Biology, School of Life Sciences, Sun Yat-sen University, Guangzhou for kindly providing the translation of the original description of Lycodon multizonatus. Many thanks also to B.L. Stuart (Raleigh) and T.T. Nguyen (Hanoi) for helping to improve a previous version of the manuscript. For the fruitful cooperation within joint research projects we cordially thank S.V. Nguyen (IEBR, Hanoi), as well as T. Pagel and C. Landsberg (Cologne Zoo). Cologne Zoo is partner of the World Association of Zoos and Aquariums (WAZA): Conservation Project 07011 (Herpetodiversity Research). This research is supported by the National Foundation for Science and Technology Development (NAFOSTED, Grant No. 106.05-2017.329). Field work in Cao Bang was partially supported by the Nagao Natural Environment Foundation (Japan).
Comparative specimens examined
Lycodon fasciatus. Vietnam: Quang Binh Province (
Lycodon fasciatus. Vietnam: Quang Binh Province (
Lycodon fasciatus. Vietnam: Quang Binh Province (
Lycodon futsingensis. Vietnam: Cao Bang (IEBR 4165)
Lycodon futsingensis. Vietnam: Cao Bang (IEBR 4170)
Lycodon futsingensis. Vietnam: Vinh Phuc (
Lycodon laoensis. Cambodia: Phnom Penh (
Lycodon laoensis. Vietnam: Dong Nai (
Lycodon meridionalis. Vietnam: Quang Ninh (
Lycodon meridionalis. Vietnam: Hai Phong (
Lycodon meridionalis. Vietnam: Bac Giang (
Lycodon meridionalis. Vietnam: Vinh Phuc (
Lycodon paucifasciatus. Vietnam: Quang Binh (
Lycodon paucifasciatus. Vietnam: Quang Binh (
Lycodon paucifasciatus. Vietnam: Quang Binh (
Lycodon subcinctus. Indonesia: Bali (
Lycodon subcinctus. Vietnam: Dong Nai (