Opisthotropis haihaensis Ziegler, Pham, Nguyen, Nguyen, Wang, Wang, Stuart & Le, 2019

Zhang, Tierui, Ren, Jinlong, Li, Maoliang, Xu, Yuhao, Wang, Xinge, Poyarkov, Nikolay A., Nguyen, Tan Van & Huang, Song, 2025, First description of the male and hemipenial morphology of Opisthotropis haihaensis Ziegler et al., 2019 (Serpentes, Natricidae), with updated diagnosis and distribution, Biodiversity Data Journal 13, pp. e 167521-e 167521 : e167521-

Opisthotropis haihaensis Ziegler, Pham, Nguyen, Nguyen, Wang, Wang, Stuart & Le, 2019

Materials

Type status: Other material. Occurrence: catalogNumber: ANU 20240076 ; individualCount: 1; sex: male; lifeStage: adult; occurrenceID: 37B587F0-02CC-5439-B859-E7923E8C247A; Taxon: taxonID: urn:lsid:biosci.ohio-state.edu:osuc_names:275502; scientificName: Opisthotropis haihaensis ; class: Reptilia; order: Squamata; family: Natricidae ; genus: Opisthotropis ; specificEpithet: haihaensis ; scientificNameAuthorship: Ziegler, Pham, Nguyen, Nguyen, Wang, Wang, Stuart & Le, 2019; Location: country: China; countryCode: CN; stateProvince: Guangxi; county: Qinbei; municipality: Qinzhou; locality: Tianmushan National Nature Reserve, Mt. Xianrending ; verbatimLocality: 570 m; verbatimElevation: 1200 m; verbatimLatitude: 22.006365 ° N; verbatimLongitude: 108.206833 ° E; verbatimCoordinateSystem: WGS 84; Event: eventDate: 25-Jun-24; eventRemarks: collected by Tierui Zhang; Record Level: language: en; collectionCode: Reptilia; basisOfRecord: PreservedSpecimen

Type status: Other material. Occurrence: catalogNumber: ANU 20240077 ; individualCount: 1; sex: female; lifeStage: adult; occurrenceID: AAD9F7D6-CE03-591A-AD77-98734F6D0E95; Taxon: taxonID: urn:lsid:biosci.ohio-state.edu:osuc_names:275502; scientificName: Opisthotropis haihaensis ; class: Reptilia; order: Squamata; family: Natricidae ; genus: Opisthotropis ; specificEpithet: haihaensis ; scientificNameAuthorship: Ziegler, Pham, Nguyen, Nguyen, Wang, Wang, Stuart & Le, 2019; Location: country: China; countryCode: CN; stateProvince: Guangxi; county: Qinbei; municipality: Qinzhou; locality: Tianmushan National Nature Reserve, Mt. Xianrending ; verbatimLocality: 570 m; verbatimElevation: 1200 m; verbatimLatitude: 22.006365 ° N; verbatimLongitude: 108.206833 ° E; verbatimCoordinateSystem: WGS 84; Event: eventDate: 25-Jun-24; eventRemarks: collected by Tierui Zhang; Record Level: language: en; collectionCode: Reptilia; basisOfRecord: PreservedSpecimen

Description of male specimen ANU 20240076

Measurements and scalation. Body slender and cylindrical (TL 428.0 mm); head short and broad, dorsally depressed, barely distinct from neck (HL / HW 1.87); snout moderate (SnL / SnW 0.74); eyes in medium size (ED / SoL 0.97); pupil round; interorbital distance large (IOD / HW 0.66); minute granular asperities absent on head scales; tail relatively long, tapering posteriorly (TaL 113.9 mm, TaL / TL 0.27); nostril oval-shaped, locating in the upper middle part of nasal, directed upwards.

Dorsal scales in 15 rows throughout the body; the outermost rows of dorsal scales slightly enlarged, while the rest ones homogeneous in size, smooth throughout; vertebral scales not enlarged; preventrals 1, ventrals 168; cloacal plate divided; subcaudals 87 paired, with single terminal rigid tip, smooth entirely.

Rostral crescent-shaped, wider than high, visible from above; nasals large, wider than high, divided below nostril by a distinct furrow; nasals in contact with the first two supralabials, rostral, internasal, prefrontal and loreal; internasals paired, trapezoid, longer than wide, curved outward posteriorly, in contact with rostral, nasal, and prefrontal; prefrontal single, much broader than long, anteriorly pointed, in contact with internasals, nasals, loreals, preoculars, and frontal; frontal single, pentagonal or near equilateral triangle, almost equal in width and length, tapering posteriorly, equal to its distance from tip of snout; parietals nearly 1.8 times as long as wide, parietal sutures nearly equal to frontal in length; 1 / 1 supraocular, distinctly longer than wide, not in contact with prefrontal; 1 / 1 loreal, pentagonal, wider than high, not entering orbit, surrounded by second and third supralabials, nasal, prefrontal and preocular; 1 / 1 preocular, large, hexagonal, higher than wide, reaching frontal; subocular absent; 2 / 2 postocular, upper pair is almost twice the length and width of lower pair; 7 / 7 supralabials, 1 st – 5 th higher than wide, only 5 th entering orbit on left lateral, 4 th and 5 th entering orbit on right lateral (4-1 - 2 / 3 - 2 - 2), 7 th largest; 1 + 1 / 1 + 1 temporals, anterior one very long and narrow, in broad contact with 5 th – 7 th supralabials and parietals, posterior one more strongly developed; infralabials 8 / 8, first pair in contact behind small mental, 1 st – 5 th / 1 st – 5 th in contact with anterior chin shields, 5 th infralabial largest; anterior chin shields longer than posterior ones, posterior chin shields do not contact with each other.

Dentition. Maxillary teeth 22, subequal, densely set, without diastema.

Coloration in life (Figs 1 , 2 ). Scales on dorsum of head glossy black with scattered yellow flecking; ventral of head yellow with brownish black mottling on the margins of each scale; upper lip yellow with brownish-black anterior and lateral margins on each supralabial; dorsum of body and tail glossy black with iridescence above, with single bright yellow spot on each scale, yellow spots becoming larger on sides of body; ventrals yellow with brownish black lateral margins; subcaudals yellow with brownish black anterior and lateral margins.

Coloration in preservation. Coloration and pigmentation patterns of newly preserved specimens (with 75 % ethanol) significantly faded, bright yellow spots on dorsals and scattered yellow flecking on dorsum of head turn milky white, background color of ventrals fades to pale yellow. Gloss of scales remains distinct.

Hemipenis (Fig. 3 ). Fully everted hemipenis is relatively long, measuring 15.71 mm in length and 2.52 mm in width; slender, single, cylindrical, slightly clavate apically. Organ entirely spinose, with spines relatively uniform in size and distribution; spines slightly sparser in the proximal region; no basal nude area present. Basal hook absent. Sulcus spermaticus unforked, centripetal, extending straight to the apex; sulcus lips well developed, broad, and smooth along the entire length. When retracted, the hemipenis reaches the level of the 31 st subcaudal scale.

Description of additional female specimen ANU 20240077

Measurements and scalation. Body slender and cylindrical (TL 485.0 mm); head short and broad (HL / HW 1.76), dorsally depressed, barely distinct from neck; snout moderate (SnL / SnW 0.60); eye small, (ED / SoL 0.81); pupil round; interorbital distance large (IOD / HW 0.60); minute granular asperities absent on head scales; tail relatively long, tapering posteriorly (TaL 94.9 mm, TaL / TL 0.20); nostril oval-shaped, locating in the upper middle part of nasal, directed upwards.

Dorsal scales in 15 rows throughout the body; the outermost rows of dorsal scales slightly enlarged, while the rest ones homogeneous in size, smooth throughout; vertebral scales not enlarged; preventrals 1, ventrals 165; cloacal plate divided; subcaudals 71, paired, with single terminal rigid tip, smooth entirely.

Rostral crescent-shaped, wider than high, visible from above; nasals large, wider than high, divided below nostril by a distinct furrow; nasals in contact with the first two supralabials, rostral, internasal, prefrontal and loreal; internasals coalesced into one, pentagonal, wider than long, concaved inward posteriorly, in contact with rostral, nasal, and prefrontal; prefrontal single, much broader than long, anteriorly pointed, in contact with internasals, nasals, loreals, preoculars, and frontal; frontal single, pentagonal or near equilateral triangle, almost equal in width and length, tapering posteriorly, equal to its distance from tip of snout; parietals nearly 1.8 times as long as wide, parietal sutures nearly equal to frontal in length; 1 / 1 supraocular, right supraocular small and partially coalesced with upper postocular, distinctly longer than wide, not in contact with prefrontal; 1 / 1 loreal, pentagonal, wider than high, not entering orbit, surrounded by second and third supralabials, nasal, prefrontal and preocular; 1 / 1 preocular, large, hexagonal, higher than wide, reaching frontal; subocular absent; 2 / 2 postocular, upper pair in almost equal size of the lower pair; 7 / 7 supralabials, 1 st – 5 th higher than wide, 1 st and 2 nd partially coalesced on left lateral, only 4 th entering orbit on left lateral, 4 th and 5 th entering orbit on right lateral, 7 th largest; 1 + 1 / 1 + 1 temporals, anterior one very long and narrow, in broad contact with 5 th – 7 th supralabials and parietals, posterior one more strongly developed; infralabials 7 / 8, first pair in contact behind small mental, 1 st – 4 th / 1 st – 5 th in contact with anterior chin shields, 5 th infralabial largest; anterior chin shields longer than posterior ones, posterior chin shields do not contact with each other.

Dentition. Maxillary teeth 22, subequal, densely set, without diastema.

Coloration in life and preservation (Fig. 4 ). Similar to specimen ANU 20240076 .

Variation.

The newly collected specimens conform to both the holotype ( IEBR A. 2016.34) from Vietnam and specimen SYS r 000537 from China in general morphology, but exhibit the following differences (Tables 2 , 3 ): shorter total and snout-vent lengths: TL 428.0–485.0 mm, SVL 314.1–387.1 mm (vs. TL 500.2–509.0 mm, SVL 391.3–396.0 mm); lower number of supralabials: 7 (vs. 8); broader range of tail length: TaL 113.9 mm and TaL / TL 0.27 in the male; TaL 94.9 mm and TaL / TL 0.20 in the female (vs. TaL 108.9–113.0 mm and TaL / TL 0.22 in females); wider range of subcaudal counts: 87 in the male and 71 in the female (vs. 75–79 in females); variation in supralabials entering the orbit: 4 th and 5 th or only 4 th or 5 th (vs. consistently 4 th and 5 th).

Revised diagnosis.

Opisthotropis haihaensis can be distinguished from all congeners by the following combination of characters: (1) adult females reach a total length (TL) of 485–509 mm, and the only examined adult male measures 428 mm in TL; (2) the tail is relatively long, with a TaL / TL ratio of 0.20–0.22 in females and 0.27 in the male; (3) the species exhibits 7–8 supralabials, with the 4 th and 5 th or either the 4 th or 5 th, entering the orbit; (4) the 6 th supralabial is not elongated and is nearly or less than half the length of the anterior temporal; (5) preocular one, postoculars one or two; (6) the internasals do not contact the loreal, and the prefrontals are separated from the supraoculars, while the frontal is in contact with the preocular; (7) the temporal formula is either 1 or 1 + 1; (8) the species has 164–169 ventrals and 87 subcaudals in the male and 71–79 in females; (9) dorsal scales in 15–15 – 15 rows and are smooth on the body, with the tail scales either smooth or indistinctly keeled; (10) the chin shields are yellow with brownish black mottling, and the body and tail dorsum is dark, each dorsal scale bearing a distinct pale spot; (11) the maxillary teeth number 22–24, are subequal in size, closely spaced, and lack a diastema; (12) the hemipenis is single, cylindrical, fully spinose throughout, and lacks a basal hook.

Distribution

Opisthotropis haihaensis is currently known from three localities in northern Vietnam and southern China (Fig. 5 , Table 4 ): (1) the type locality in Quang Son Commune, Hai Ha District, Quang Ninh Province, Vietnam; (2) Shiwandashan National Nature Reserve, Shangsi County, Fangchenggang City, Guangxi ZAR, China; and (3) Qinbei District, Qinzhou City, Guangxi ZAR, China.

Natural history notes.

Opisthotropis haihaensis inhabits small, slow-flowing mountain streams within south subtropical evergreen broad-leaved forests at elevations of 500–950 m above sea level in northern Vietnam and southern China. These streams are consistently clear and rocky, with occasional deposits of humus on the streambed. In captivity, both examined specimens exhibited a strong predatory response to earthworms ( Pheretima guillelmi Michaelsen ) measuring 90–150 mm in length, suggesting feeding behavior similar to that observed in other congeners.

Figures

Figure 1. Live photographs of Opisthotropis haihaensis (specimen ANU 20240076, male) in situ from Qinzhou, Guangxi, China. Photographed by T. R. Zhang.

Figure 2. Opisthotropis haihaensis prior to preservation (specimen ANU 20240076, male): A dorsal view of whole body; B ventral view of whole body; C dorsal view of head; D ventral view of head; E right lateral view of head; F left lateral view of head; G close-up of mid-body dorsal scales. Photographs by T. R. Zhang.

Figure 3. Hemipenis of Opisthotropis haihaensis (specimen ANU 20240076, male). A Sulcal view of the fully everted organ; B Lateral view showing overall shape and spine distribution; C Apical view of the hemipenial lobes. Photographs by J. J. Huang. Scale bar = 5 mm.

Figure 4. Opisthotropis haihaensis prior to preservation (specimen ANU 20240077, female): A dorsal view of whole body; B ventral view of whole body; C dorsal view of head; D ventral view of head; E right lateral view of head; F left lateral view of head; G close-up of midbody dorsal scales. Photographs by T. R. Zhang.

Figure 5. Distribution ranges of Opisthotropis maculosa complex species. Numbers correspond to locality records (see Table 4 for locality details).