taxonID	type	description	language	source
03A1E66DFFDB7839FF5BFF131244F92C.taxon	description	Figs. 2 – 5; Table 3.	en	Le, Manh Van, Phan, Khanh Duy, Nguyen, Thanh Luan, Murphy, Robert W., Lam, Ngon Quang, Nguyen, Sang Ngoc, Che, Jing (2026): A new snake of the genus Hebius (Serpentes: Natricidae) from the Ngoc Linh Mountain Range, Vietnam. Zootaxa 5748 (4): 480-498, DOI: 10.11646/zootaxa.5748.4.2, URL: https://doi.org/10.11646/zootaxa.5748.4.2
03A1E66DFFDB7839FF5BFF131244F92C.taxon	materials_examined	Holotype. ILS H. 20386, adult male, collected from the Ngoc Linh Mountain Range, Dak Glei District, Kon Tum Province, Vietnam; coordinates 15 o 05 ’ 18.7 ” N, 107 o 52 ’ 45.5 ” E; elevation 1746 m a. s. l by Manh V. Le on 17 th June 2024 (Figs. 2 & 3). Paratypes (two specimens). ILS H. 20756, subadult male, collected from the Ngoc Linh Mountain Range, Dak Glei District, Kon tum Province, Vietnam; coordinates 15 ° 06 ’ 47.2 ” N, 107 ° 55 ’ 09.7 ” E; elevation 1219 m a. s. l by Manh V. Le on 20 th June 2024; ILS H. 20765, adult female, collected from the Ngoc Linh Mountain Range, Dak Glei District, Kon tum Province, Vietnam; coordinates 15 ° 07 ’ 47.4 ” N, 107 ° 54 ’ 18.2 ” E; elevation 1248 m a. s. l by Khanh D. Phan and Manh V. Le on 22 th June 2024 (Figs. 4 & 5).	en	Le, Manh Van, Phan, Khanh Duy, Nguyen, Thanh Luan, Murphy, Robert W., Lam, Ngon Quang, Nguyen, Sang Ngoc, Che, Jing (2026): A new snake of the genus Hebius (Serpentes: Natricidae) from the Ngoc Linh Mountain Range, Vietnam. Zootaxa 5748 (4): 480-498, DOI: 10.11646/zootaxa.5748.4.2, URL: https://doi.org/10.11646/zootaxa.5748.4.2
03A1E66DFFDB7839FF5BFF131244F92C.taxon	diagnosis	Diagnosis. Hebius ngoclinhensis sp. nov. can be distinguished from all other congeners by the following combination of morphological characters: (1) medium-sized body with keeled dorsal scales; (2) 19 - 19 - 17 dorsal scale rows, with the first row entirely smooth; (3) 143 – 148 ventrals; (4) 95 – 97 subcaudals; (5) 8 or 9 supralabials; (6) 10 infralabials; (7) 24 – 26 maxillary teeth, gradually enlarged posteriorly, with two last teeth distinctly enlarged; (8) cloacal plate divided; (9) hemipenis short, stout, spinose, and undivided, with a tiny and short extension near the anterior one-third of its length, and extending to 8 th subcaudal; (10) dorsal surface of the body and tail dark with numerous irregular dark yellow spots; (11) two reddish-brown dorsolateral stripes on the 4 th – 7 th dorsal scale rows, intermixed with irregular black dots; (12) ventral surface of the body and tail reddish-orange to orange, with dark brown lateral margins on ventrals and subcaudals.	en	Le, Manh Van, Phan, Khanh Duy, Nguyen, Thanh Luan, Murphy, Robert W., Lam, Ngon Quang, Nguyen, Sang Ngoc, Che, Jing (2026): A new snake of the genus Hebius (Serpentes: Natricidae) from the Ngoc Linh Mountain Range, Vietnam. Zootaxa 5748 (4): 480-498, DOI: 10.11646/zootaxa.5748.4.2, URL: https://doi.org/10.11646/zootaxa.5748.4.2
03A1E66DFFDB7839FF5BFF131244F92C.taxon	description	Description of holotype (Figs. 2 & 3). Adult male, 637 mm in total length; head elongate, distinct from neck; body elongate, snout to vent length 428 mm; tail long, 209 mm, equal to 33 % of total length. Head scalation. Head scales smooth; rostral broader than high (3.3 mm width vs. 1.6 mm height), visible from above, touching nasals, 1 st supralabial on both sides, and internasals; internasals (1.6 mm in length) shorter than prefrontals (2.2 mm in length); frontal bell-shaped (4.8 mm in length), shorter than parietal (6.7 mm in length), and slightly longer than its distance from the tip of snout (4.5 mm); parietals bordered with frontal, supraocular, postocular, and temporals; 8 / 8 supralabials, first two in contact with nasal, 2 nd and 3 rd in contact with loreal, 4 th and 5 th bordering eye, and 7 th largest; 1 / 1 loreal, longer than high (1.3 mm vs. 1.0 mm), touching nasal, prefrontal, preoculars, and 2 nd and 3 rd supralabials; 2 / 2 preoculars, upper larger than lower; 3 / 3 postoculars; 1 + 2 / 1 + 1 temporals; 10 / 10 infralabials, first pairs in contact with each other, first five in contact with anterior chin shield, 5 th and 6 th largest and touching posterior chin shield; chin shields with posterior pair longer than anterior ones (5.8 mm vs. 4.7 mm). Body scalation. Dorsal scale at neck in 19 rows with 15 medial rows keeled, at midbody in 19 rows with 17 medial rows keeled, and before vent in 17 rows with 15 medial rows keeled; dorsal scale row reduction from 19 to 18 at ventral 90 on the left side and from 18 to 17 at ventral 91 on the right side; ventrals 147, broad, smooth; cloacal plate divided; subcaudals 97, all paired; terminal caudal scale forming a pointed cap. Dentition. Maxillary teeth 26, comprising 24 gradually enlarged teeth followed by two distinctly enlarged posterior teeth (Fig. 3 C). Hemipenis. In situ, the hemipenis extending to the 8 th subcaudal scale. When everted, organ short, stout, spinose, and undivided, with a distinct spinose diverticulum-like structure located at the anterior one-third of its length, forming a tiny and short lateral lobe. Sulcus spermaticus undivided, S-shaped, and extending to apex. Ornamentation of dense spines covering body and the short lobe; spines becoming slightly sparser toward base, where several enlarged spines present, forming prominent basal hooks; apex smooth. No calyculate structures observed (Fig. 2 G – H). Coloration in life. Dorsal surface of head reddish-brown with irregular small dark yellow streaks and blotches; nuchal region dark red with a short longitudinal dark yellow stripe, about four scales in length, starting behind the parietals; lateral surface of head with iris reddish-rust; loreal region dark yellow; suplabials region dark yellow to light yellow with distinct black edging along margins of each supralabials; a discontinuous light yellow streak starting from behind eye to dorsolateral stripes; dorsal surface of body and tail dark brown, with numerous irregular dark yellow spots, especially concentrated on the anterior one-fifth of the body, rendering this region lighter than the remainder; dorsolateral stripe reddish-brown, on 4 th – 6 th dorsal scale rows, two rows wide, intermixed with numerous irregular black dots; throat surface light yellow; infralabials white-cream with several irregular black spots; ventral surface of the body and tail reddish-orange, with lateral margins of ventrals and subcaudals dark brown (Fig. 2 A – F). Coloration in preservation. Dorsal surface of head changed to black, with parietal regions brown; dorsal surface of body changed to black, with dorsolateral stripes light brown; ventral surface of body changed to pale orange (Fig. 3 A & B, D – G). Variation. In paratype ILS H. 20765, a continuous cream streak extending from behind the eye to the dorsolateral stripes; ventral surface of body and tail orange, and lateral surface of the head with white-cream stripes. In paratype ILS H. 20756, the reddish-brown dorsolateral stripe present on 4 th – 7 th dorsal scale rows, three rows in width on each side. Color variation of paratypes in life and in preservation was shown in Figs. 4 & 5. Morphological variation among paratypes was provided in Table 3. Sexual dimorphism. Female is bigger than male (SVL 448 mm vs. 428 mm). The tail base of males is distinctly more swollen than that of female. Etymology. The specific epithet ngoclinhensi s is a toponym derived from the Ngoc Linh Mountain Range, Vietnam, where the new species was discovered. We recommend “ Ngoc Linh Keelback Snake ” and “ R ắn sãi ng ọc linh ” as the common English and Vietnamese names of the new species, respectively. Distribution. The new species is currently known from the Ngoc Linh Mountain Range in Kon Tum and Quang Nam provinces, Vietnam (Fig. 6 A). Field notes. All specimens were collected at night (9: 00 – 12: 00 PM) in evergreen forest. The holotype was found on the forest floor near a stream (Fig. 6 C); paratype ILS H. 20756 was collected on a trail near a small stream, and paratype ILS H. 20765 was encountered at the edge of a waterfall. Comparisons. Hebius ngoclinhensis sp. nov. has 19 dorsal scale rows at midbody which can be easily distinguished from its following congeners with 15 or 17 dorsal scale rows: H. annamensis (David et al. 2021); H. arquus (David & Vogel) (David & Vogel 2010); H. celebicus (Peters & Doria) (Boulenger 1893); H. chapaensis (David et al. 2021); H. citrinoventer Xu, Yang, Gong, Ouyang, Weng, Deng, Huang & Peng (Xu et al. 2024); H. frenatus (Dunn) (Dunn 1923); H. groundwateri (Smith) (Taylor 1965); H. maximus (Malnate); (Li et al. 2022); H. nigriventer (Wall) (David et al. 2021); H. sarasinorum (Boulenger) (Boulenger 1896); H. sarawacensis (Günther) (Boulenger 1893); H. sauteri (Boulenger 1909); H. taronensis (Smith) (David et al. 2021); H. venningi (Wall) (David et al. 2021); and H. youjiangensis Yang, Xu, Wu, Gong, Huang & Huang (Xu et al. 2023). Among remaining congeners possessing 19 dorsal scale rows at midbody, the new species can be readily distinguished by its reddish-orange or orange coloration on venter of body and tail, in contrast to: cream in H. andreae (Ziegler & Le 2006); yellow-orchre in H. bitaeniatus (Wall 1925); yellowish in H. clerki (Wall) (Wall 1925); light lemon in H. concelarus (Malnate) (Ota & Iwanaga 1997); yellowish in H. craspedogaster (Boulenger 1899); creamish-yellow in H. deschauenseei (Taylor) (David et al. 2021); white in H. flavifrons (Boulenger) (Boulenger 1887, 1893); overall dark in H. igneus (David et al. 2021); light yellow in H. ishigakiensis (Malnate & Munsterman) (Ota & Iwanaga 1997); light yellow in H. jingdongensi Ma, Shi, Ayi & Jiang (Ma et al. 2023); ivory in H. lacrima Purkayastha & David (Purkayastha & David 2019); red with narrow black ventro-lateral stripes formed by a mark near both lateral corners of each ventral in H. metusia (Inger, Zhao, Shaffer & Wu) (Inger et al. 1990); green in H. miyajimae (Maki) (Maki 1931); pale ochre-brown or pale brown in H. modestus (Günther) (David et al. 2021); pale yellow in H. octolineatus (Boulenger) (Hou et al. 2021); creamy pale yellow or bright coral red, with black ventro-lateral stripes and its separated from the black color of the dorsum by a pale line in H. optatus (David et al. 1998); yellowish in H. petersii (Boulenger) (Boulenger 1893); yellowish in H. popei (Schmidt 1925); light lemon in H. pryeri (Boulenger) (Ota & Iwanaga 1997); crimson in H. sanguineus (Smedley) (Smedley 1932); ivory cream in H. sangzhiensis Zhou, Qi, Lu, Lyu & Li (Zhou et al. 2019); pale yellow in H. septemlineatus (Hou et al. 2021); pinkish-cream in H. terrakarenorum Hauser, Smits & David (Hauser et al. 2022); creamy yellow in H. vibakari (Boie) (Gao et al. 2024); white cream in H. viperinus (Schenkel) (Schenkel 1901); yellow pale in H. weixiensis Hou, Yuan, Wei, Zhao, Liu, Wu, Shen, Chen, Guo (Hou et al. 2021); and milk white in H. yanbianensis Liu, Zhong, Wang, Liu & Guo (Liu et al. 2018). In addition, Hebius ngoclinhensis sp. nov. differs from H. andreae by having fewer ventrals (143 – 148 vs. 179), fewer subcaudals (95 – 97 vs. 99), more infralabials (10 vs. 9), and fewer maxillary teeth (24 – 26 vs. 34) (Ziegler & Le 2006); from H. bitaeniatus by having fewer ventrals (143 – 148 vs. 160 – 172), more subcaudals (95 – 97 vs. 83 – 92), and more maxillary teeth (24 – 26 vs. 23) (Wall 1925); from H. clerki by having fewer ventrals (143 – 148 vs. 175) and fewer subcaudals (95 – 97 vs. 106) (Wall 1925); from H. concelarus by having fewer ventrals (143 – 148 vs. 157 – 169), presence (vs. absence) of dorso-lateral stripe on both sides, and absence (vs. presence) of white vertical streaks on body (Ota & Iwanaga 1997; Bhora et al. 2025); from H. craspedogaster by having the first dorsal scale row at midbody smooth (vs. keeled), one (vs. two) anterior temporal, and two (vs. one) preoculars (Boulenger 1899; David et al. 2007); from H. deschauenseei by having fewer ventrals (143 – 148 vs. 149 – 168) and fewer subcaudals (95 – 97 vs. 115 – 141) (David et al. 2021); from H. flavifrons by having a larger body size (637 mm in males vs. 243 mm in male), presence (vs. absence) of dorso-lateral stripe on both sides, and two (vs. 1) preoculars (Boulenger 1887, 1893; David et al. 2007); from H. igneus by having fewer ventrals (143 – 148 vs. 159 – 169), fewer subcaudals (95 – 97 vs. 115 – 129), and fewer maxillary teeth (24 – 26 vs. 29 – 30) (David et al. 2021); from H. ishigakiensis by having a smaller body size (637 mm vs. 932 mm), fewer ventrals (143 – 148 vs. 164 – 178), and more preoculars (2 vs. 1) (Ota & Iwanaga 1997); from H. jingdongensis by having fewer ventrals (143 – 148 vs. 163 – 166) and more subcaudals (95 – 97 vs. 71 – 74) (Ma et al. 2023); from H. lacrima by having a larger body size (637 mm vs. 487 mm), more subcaudals (95 – 97 vs. 89), and fewer maxillary teeth (24 – 26 vs. 27) (Purkayastha & David 2019); from H. metusia by having a smaller body size (637 mm vs. 705 – 885 mm), fewer ventrals (143 – 148 vs. 159 – 164), and more subcaudals (95 – 97 vs. 72 – 85) (Inger et al. 1990); from H. miyajimae by having more subcaudals (95 – 97 vs. 87 – 92) and more maxillary teeth (24 – 26 vs. 20) (Maki 1931); from H. modestus by having fewer subcaudals (95 – 97 vs. 104 – 122) and fewer maxillary teeth (24 – 26 vs. 27 – 30) (David et al. 2021); from H. octolineatus by having fewer ventrals (143 – 148 vs. 150 – 154) and more subcaudals (95 – 97 vs. 70 – 80) (Hou et al. 2021); from H. optatus by having fewer ventrals (143 – 148 vs. 152 – 169), keeled on 17 dorsal scale rows at midbody (vs. mostly smooth, some feebly keeled on the 9 – 17 upper dorsal scale rows), and presence (vs. absence) of dorsolateral stripe on both sides (David et al. 1998; Bohra et al. 2025); from H. petersii by having a larger body size (637 mm vs. 370 mm), more sucaudals (95 – 97 vs. 65 – 79), and the first dorsal scale row at midbody smooth (vs. strongly keeled) (Boulenger 1893); from H. popei by having more ventrals (143 – 148 vs. 130 – 137), more subcaudals (95 – 97 vs. 78 – 86), and more maxillary teeth (24 – 26 vs. 20) (Schmidt 1925); from H. pryeri by having a smaller body size (SVL up to 428 mm in males and 448 mm in female vs. 454 – 752 in males and 465 – 883 in females), fewer ventrals (143 – 148 vs. 166 – 183), and fewer subcaudals (95 – 97 vs. 112 – 130) (Ota & Iwanaga 1997); from H. sanguineus by having fewer ventrals (143 – 148 vs. 155) and the first dorsal scale row at midbody smooth (vs. strongly keeled) (Smedley 1932); from H. sangzhiensis by having fewer ventrals (143 – 148 vs. 160 – 164), more subcaudals (95 – 97 vs. 81 – 82), and more maxillary teeth (24 – 26 vs. 23) (Zhou et al. 2019); from H. septemlineatus by having fewer ventrals (143 – 148 vs. 164 – 175) and fewer number of dorsolateral stripe on each side (1 vs. 4) (Hou et al. 2021); from H. terrakarenorum by having fewer ventral (143 – 148 vs. 159 – 171) and fewer subcaudals (95 – 97 vs. 107 – 130) (Hauser et al. 2022); from H. vibakari by having more subcaudals (95 – 97 vs. 54 – 89) and more maxillary teeth (24 – 26 vs. 21 – 22) (Gao et al. 2024); from H. viperinus by having more ventrals (143 – 148 vs. 101) and more subcaudals (95 – 97 vs. 59) (Schenkel 1901); from H. weixiensis by having fewer ventrals (143 – 148 vs. 171 – 182) and more subcaudals (95 – 97 vs. 74 – 88) (Hou et al. 2021); and from H. yanbianensis by having fewer ventrals (143 – 148 vs. 172), more subcaudals (95 – 97 vs. 90), and keeled on 17 dorsal scale rows at midbody (vs. weakly keeled on 15 rows) (Liu et al. 2018).	en	Le, Manh Van, Phan, Khanh Duy, Nguyen, Thanh Luan, Murphy, Robert W., Lam, Ngon Quang, Nguyen, Sang Ngoc, Che, Jing (2026): A new snake of the genus Hebius (Serpentes: Natricidae) from the Ngoc Linh Mountain Range, Vietnam. Zootaxa 5748 (4): 480-498, DOI: 10.11646/zootaxa.5748.4.2, URL: https://doi.org/10.11646/zootaxa.5748.4.2
