Opisthotropis shenzhenensis, Wang, Ying-Yong, Guo, Qiang, Liu, Zu-Yao, Lyu, Zhi-Tong, Wang, Jian, Luo, Lin, Sun, Yan-Jun & Zhang, Yan-Wu, 2017

Wang, Ying-Yong, Guo, Qiang, Liu, Zu-Yao, Lyu, Zhi-Tong, Wang, Jian, Luo, Lin, Sun, Yan-Jun & Zhang, Yan-Wu, 2017, Revisions of two poorly known species of Opisthotropis Günther, 1872 (Squamata: Colubridae: Natricinae) with description of a new species from China, Zootaxa 4247 (4), pp. 391-412 : 402-405

Opisthotropis shenzhenensis sp. nov.

Figs. 5 and 6 a

Holotype. SYS r001018, adult male, collected by Jian Zhao and Run-Lin Li on 15 September, 2014 from Mt. Wutong (22°34′54.8″N, 114°12′2.7″E; 260 m a.s.l.), Shenzhen City, Guangdong Province, China.

Paratypes. SYS r000635, an adult male, collected by JHY and RLL on 11 April, 2012 from the same locality as the holotype . Three adult female specimens: SYS r000636 collected by JHY and RLL on 11 April, 2012 from the same locality as the holotype ; SYS r001021 collected by JZ and RLL on 17 September, 2014 from Sanzhoutian (22°38′52.16″N, 114°16′32.08″E; 314 m a.s.l.), Shenzhen City ; SYS r001032 collected by JZ and RLL on 19 September, 2014 from Mt. Tiantou (22°41′1.75″N, 114°24′17.58″E; 327 m a.s.l.), Shenzhen City ; SYS r001145 collected by JW and ZTL on 13 April, 2015 from Mt. Yingping (22°52′40.54″N, 114°9′12.27″E; 155 m a.s.l.), Dongguan City, Guangdong Province, China.

Etymology. The specific name “ shenzhenensis ” is derived from the type locality of the new species, Shenzhen City, Guangdong Province, China. We propose the common name in English “Shenzhen Mountain Stream Snake” and “Shenzhen Hou Leng She” in Chinese.

Diagnosis. Opisthotropis shenzhenensis sp. nov. differs from other species of Opisthotropis by a combination of the following characters: (1) TL 328–412 mm; (2) tail short, TaL 16–19% of TL; (3) rostral, narrowed, RW 25– 30% of HW; (4) nasal in contact with first, second and third supralabials; (5) nasal cleft invariably pointing to the middle of upper edge of second supralabial; (6) loreal 1.3–1.6 times as long as deep; (7) loreal not entering the orbit, not in contact with second supralabials in all known specimens; (8) supralabials 9–10, the last one smaller than adjacent preceding one; (9) infralabials 8–10; (10) dorsal scale rows 19:19:19; (11) dorsal scales keeled throughout, weakly keeled on neck, posteriorly strongly keeled; (12) ventrals 162–179; subcaudals 53–60; (13) olive-green above in life, each scale with black edge, forming fine mesh pattern; yellow beneath, ventral surface of head and tail mottled with blackish grey.

Description of holotype. Body cylindrical; TL 407 mm (SVL 337 mm, TaL 70 mm); tail short, TaL 17% of TL; head small, indistinct from neck; rostral nearly flatted, small, slightly less than twice as broad as deep, RW 25– 30% of HW, barely visible from above; two internasals, crescentic-shaped, in contact with each other medially behind the rostral, not in contact with loreal, posteriorly in contact with prefrontal; a single prefrontal, in contact with loreal, preocular and supraocular laterally, with frontal posteriorly; a single frontal, pentagonal, in contact with supraocular laterally, with two parietals posteriorly; parietals large, in contact with each other medially; nasal directed dorsolaterally, polygonal, in contact with first, second and third supralabials ventrally, with loreal and prefrontal posteriorly, with internasal dorsally, with rostral anteriorly; nostril horizontally oval, in the upper part of nasal; a short vertical cleft below the nostril and dividing nasal into anterior and posterior parts, pointing to the middle of upper edge of second supralabial; a single loreal, trapezoid, 1.4 times as long as deep, not entering the orbit, in contact with third and fourth supralabials, but not with second infralabial; a single supraocular; a single preocular; two postoculars; a single anterior temporal, significantly elongate; two posterior temporals; supralabials 9/9, the last one shorter than the adjacent preceding supralabial; fifth and sixth supralabials entering orbit; infralabials 9/9, the first one in contact with its fellow behind the mental; two pairs of chin shields; anterior chinshields large, in contact with each other medially, and in contact with the first five infralabials on both sides; posterior chin shields small and separated from each other by small scales; dorsal scale rows 19:19:19; dorsal scales weakly keeled on neck, posteriorly gradually strongly keeled; the outermost a dorsal scale row smooth at midbody, those following keeled; V 172; cloacal plate divided; subcaudals 53, paired.

Coloration in life. Olive-green above, each scale with black edge, forming a fine mesh pattern; the outer second and third scale rows with yellow spots, upper part of the most outer scale row dark green, lower part yellow; yellow beneath, ventral surface of head and tail mottled with blackish-grey.

Coloration in ethanol. Greenish-black above, barely perceptible black edge on each scale; yellowish beneath.

Variation. Measurements, scalation and body proportions of type series of Opisthotropis shenzhenensis sp.nov. are given in Table 5. In specimen SYS r001032, anterior chin-shields in contact with first six infralabials in both sides. In the SYS r001021, only fifth supralabial entering the orbit in both sides. In the SYS r001032 and 1145, fifth and six supralabials entering the orbit in left side, fifth entering the orbit in right side.

Comparisons. Opisthotropis shenzhenensis sp. nov. is mostly similar to O. andersonii and O. maxwelli in habitus, color and pattern. In our phylogenetic tree, the new species is the sister taxon of O. andersonii , from which it differs in having (1) DSR 19:19:19 vs. 17:17:17; (2) dorsal scales keeled throughout, weakly keeled on neck, posteriorly strongly keeled vs. smooth on the anterior neck, posteriorly feebly keeled, rather strongly keeled on posterior part of body; (3) rostral small, RW 25–30% of HW vs. rostral slightly large, RW 31–37% of HW; (4) nasal in contact with first, second and third supralabials vs. only with first and second, not in contact with third; (5) loreal 1.3–1.6 times as long as deep vs. 2.1–2.9 times as long as deep; (6) loreal not in contact with second supralabial vs. loreal in contact with second supralabial. Opisthotropis shenzhenensis sp. nov differs from O. maxwelli in having (1) DSR 19:19:19 vs. 17:17:17; (2) tail short, TaL 16–19% of TL vs. TaL 20–23% of TL; (3) the last supralabial smaller than adjacent preceding one vs. the last supralabial is the longest one; (4) dorsal scales keeled throughout, weakly keeled on neck, posteriorly strongly keeled vs. smooth on the anterior neck, feebly keeled posteriorly, rather strongly keeled on posterior part of body; (5) nasal cleft invariably pointing to the middle of upper edge of second supralabial vs. invariable pointing to the apex angle of first supralabial; (6) nasal in contact with first, second and third supralabials vs. in contact only with first and second, but not with third. See Fig. 6 .

Opisthotropis shenzhenensis sp. nov., O. andersonii , O. lateralis and O. kuatunensis are sympatric species from Mt. Wutong, Shenzhen. O. shenzhenensis differs from O. lateralis by having DSR 19:19:19 vs. 17:17:17; a single preocular vs. two preoculars; uniformly olive-green above with black mesh pattern on dorsal surface of body and tail vs. brown above, with a distinct longitudinal black stripe on both sides of body. O. shenzhenensis differs from O. kuatunensis by having 9–10 supralabials, all of which entire vs. 13–16 supralabials, first six to eight entire, posterior ones divided horizontally; dorsal scales weakly keeled on neck, strongly keeled on body and tail vs. extremely strongly keeled throughout; olive-green above with black mesh pattern on dorsal body and tail vs. brown above, with black longitudinal stripes on body and tail.

Opisthotropis shenzhenensis sp. nov. can be easily distinguished from other Chinese congeners as follows: It differs from O. latouchii in having DSR 19:19:19 vs. 17:17:17; loreal not entering the orbit vs. entering the orbit; olive-green above with black mesh pattern vs. yellowish green above, with alternate longitudinal black and yellow stripes. It differs from O. cheni in having DSR 19:19:19 vs. 17:17:17; loreal not entering the orbit vs. entering the orbit; olive-green above with black mesh pattern vs. dark olive brown above, with yellow crossbars or marks. It differs from O. laui in having DSR 19:19:19 vs. 25:23:23; olive-green above with black mesh pattern vs. dark olive above, with pale yellow crossbars. It differs from O. balteata in having DSR 19:19:19 vs. 19:19:17; V 162–179, SC 53–60 vs.V 190–205, SC 56–86; dorsal scales keeled throughout, weakly keeled on neck, posteriorly strongly keeled vs. smooth anteriorly, keeled posteriorly; olive-green above with black mesh pattern on dorsal body and tail vs. yellow or orange-yellow above, with at least 40 pairs of black bands. It differs from O. guangxiensis in having DSR 19:19:19 vs.17:15:15; dorsal scales keeled vs. smooth; olive-green above with black mesh pattern vs. olivebrown above, with narrow light yellow crossbars. It differs from O. maculosa in having DSR 19:19:19 vs.15:15:15; dorsal scales keeled vs. smooth; olive-green above, each scale with black edge vs. olive-brown above, each scale with single yellow spot. Lastly, it differs from O. jacobi in having DSR 19:19:19 vs.15:15:15; dorsal scales keeled vs. smooth.

Opisthotropis shenzhenensis differs from the other 10 congeners not occurring in China in having DSR 19:19:19 vs. DSR 17:17: 17 in O. daovantieni Orlov, Darevsky & Murphy, 1998 and O. spenceri Smith, 1918 , 19:17: 17 in O. tamdaoensis Ziegler, David & Vu, 2008 , 19:17: 15 in O. rugosa (Lidth de Jeude, 1890) , 17 dorsal scale rows at midbody in O. atra Günther, 1872 , 19:21: 17 in O. durandi Teynié, Lottier, David, Nguyen & Vogel, 2013 , 15 dorsal scale rows at midbody in O. kikuzatoi Okada & Takara, 1958 ; loreal not in contact with internasal in both sides of head vs. in contact in O. alcalai Brown & Leviton, 1961 , O. cucae David, Pham, Nguyen & Ziegler, 2011 , O. typica ( Mocquard, 1890) , O. atra , O. daovantieni , O. durandi , O. rugosa and O. spenceri ; SPL 9– 10 vs. 12–13 in O. alcalai , 7 in O. atra and O. cucae , 6–7 in O. durandi , 12–13 in O. rugosa , 11–12 in O. typica ; V 162–179 and SC 53–60 vs. V 195 in O. alcalai , V 191 and SC 44 in O. cucae , V 189–194 and SC 39–47 in O. daovantieni , SC 88–90 in O. durandi , V 180–198 in O. kikuzatoi , SC 82–95 in O. typica ; dorsal scales keeled throughout vs. smooth throughout in O. alcalai , O. cucae , O. daovantieni , O. durandi , and O. spenceri .

Distribution and habitat. Opisthotropis shenzhenensis sp. nov. occurs from the low mountain ranges in the eastern Shenzhen and southern Dongguan, Guangdong Province, China, including Mt. Wutong, Sanzhoutian and Mt. Tiantou, and Mt. Yinping (four red dots in Fig. 1 ). All specimens were collected at night from slow-flowing streams covered with bare rocks at elevations between 155 and 327 m a.s.l., where we observed a large number of freshwater snails, aquatic insects, shrimps, crabs, and fishes, and amphibians such as Leptolalax laui and Paramesotriton hongkongensis occur ( Fig. 7 ).

Remarks. Opisthotropis shenzhenensis , O. andersonii , O. kuatunensis and O. lateralis are sympatric and they were found frequently in two streams on Mt. Wutong, where a total of 17 specimens were collected between 2012 and 2015, including five of O. kuatunensis , five of O. lateralis (see Appendix), four of O. andersonii and three of O. shenzhenensis .

Figures

FIGURE 1. Sampling localities of Opisthotropis in China. 1: Hong Kong; 2: Mt. Wutong; 3: Sanzhoutian; 4: Mt. Tiantou; 5: Mt. Yinping; 6: Mt. Maofeng; 7: Nan’ao Island; 8: Huboliao Nature Reserve; 9: Wulong Village; 10: Guadun Village; 11: Qixiling Nature Reserve; 12: Shimentai Nature Reserve; 13: Heishiding Nature Reserve; 14: Shangchuan Island. The red dot represent localities of Opisthotropis shenzhenensis sp. nov.. See Table 1 for locality codes and detailed locality information.

FIGURE 5. General aspect and scalation of head of Opisthotropis shenzhenensis sp. nov.. A: Dorsal view of the holotype SYS r 001018. B: Ventral view of the holotype. C: Dorsolateral view of head and anterior neck of the holotype in life. D: General aspect of SYS r 001145 in life. Photos by JW and JZ.

FIGURE 6. Comparisions of head scalation of a: Opisthotropis shenzhenensis sp. nov. (holotype SYS r 001018), b: O. maxwelli (SYS r 000841), c and d: O. andersonii (SYS r 001020, SYS r 001082). Line illustration by ZTL.

FIGURE 7. Habitat of Opisthotropis shenzhenensis sp. nov. at the type locality, Mt. Wutong, Shenzhen City, Guangdong Province, China, which is inhabited also by the other three sympatric species O. andersonii, O. kuatunensis and O. lateralis.