Lycodon cathaya, Wang & Qi & Lyu & Zeng & Wang, 2020

Wang, Jian, Qi, Shuo, Lyu, Zhi-Tong, Zeng, Zhao-Chi & Wang, Ying-Yong, 2020, A new species of the genus Lycodon (Serpentes, Colubridae) from Guangxi, China, ZooKeys 954, pp. 85-108 : 85

Lycodon cathaya sp. nov. Figures 3A , 4 , 5A, B

Holotype.

SYS r001542, adult male, collected on 20 July 2016 by Jian Wang from Huaping Nature Reserve (25.62521N, 109.91376E (DD); ca 1000 m a.s.l.), Longsheng County, Guilin City, Guangxi Zhuang Autonomous Region, China.

Paratypes.

SYS r001630, adult male, collected on 2 September 2016 by Jian Wang from Huaping Nature Reserve (25.62667N, 109.91351E (DD); ca 850 m a.s.l.).

Etymology.

The specific name cathaya is a noun referring to the monotypic botanic genus Cathaya Chun & Kuang, 1958. The single species C. argyrophylla Chun & Kuang, 1958 is an endangered relict plant, and was firstly discovered from Huaping Nature Reserve by the investigation team of Sun Yat-sen University. In memory of the predecessors and their contributions on the taxonomy of Chinese flora and fauna, we denominate this new snake species from Huaping Nature Reserve as Lycodon cathaya sp. nov. Its common name is suggested as "Huaping wolf snake" in English and "Hua Ping Bai Huan She ( 花坪白环蛇)” in Chinese.

Diagnosis.

Lycodon cathaya sp. nov. can be differentiated from its congeners by the combination of the following morphological characters: (1) dorsal scales in 17-17-15 rows, smooth throughout; (2) supralabials eight, third to fifth in contact with eye, infralabials 9; (3) ventral scales 199-200 (plus two preventral scales), subcaudals 78; (4) loreal single, elongated, in contact with eye or not, not in contact with internasals; (5) a single preocular not in contact with frontal, supraocular in contact with prefrontal, two postoculars; (6) maxillary teeth 10 (4+2+2+2); (7) two anterior temporals, three posterior temporals; (8) precloacal plate entire; (9) ground color from head to tail brownish black, with 31-35 dusty rose bands on body trunk, 13-16 on tail; (10) bands in 1-2 vertebral scales broad in minimum width; (11) bands separate ground color into brownish black ellipse patches, similar arrangement in a row along the top of body and tail; (12) elliptical patches in 3-6 scales of the vertebral row in maximum width; (13) ventral surface of body with a wide brownish black strip, margined with a pair of continuous narrow greyish white ventrolateral lines.

Comparisons.

The detailed comparisons among all Lycodon congeners are given in Table 1 , with distinguishing characters marked in bold.

In our phylogenetic tree (Fig. 2 ), Lycodon cathaya sp. nov. (Figs 3A , 4 , 5A, B ) is relatively close to L. futsingensis (Figs 3B , 5C ) and L. namdongensis . However, the new species possesses significant morphological differences: (1) 10 maxillary teeth (vs. MT 12-15 in L. futsingensis ), bands on dorsal body and tail link with each other and separate ground color into ellipse patches (vs. bands on dorsal body and tail separate with each other in L. futsingensis ), venter line on ventral body margined with a pair of continuous ventrolateral line (vs. ventrolateral lines discontinuous, interrupted by black patches in L. futsingensis ); (2) ten maxillary teeth (vs. MT 12 in L. namdongensis ), nine infralabials (vs. IFL ten in L. namdongensis ), two postocular (vs. PtO 3 in L. namdongensis ), three posterior temporals (vs. pTMP 3 in L. namdongensis ), ventral scales 199-200 (vs. V 218 in L. namdongensis ), dorsal body with 31-35 dusty rose bands (vs. dorsal body with 23 greyish cream bands in L. namdongensis ).

Lycodon cathaya sp. nov. can be further distinguished from L. ruhstrati (Figs 3C , 5D ), which used to be confused with L. futsingensis , to which it is morphologically similar ( Pope 1935; Vogel et al. 2009), by the following morphological characters: (1) dorsal scales smooth throughout (vs. dorsum with keeled scales); (2) subcaudals 78 (vs. subcaudals ≥ 90); (3) bands on dorsal body and tail link with each other and separate ground color into ellipse patches (vs. bands on dorsal body and tail separate with each other); (4) ventral with a brownish black venter strip margined with a pair of continuous greyish white ventrolateral lines (vs. brownish black venter strip absent, and ventrolateral lines discontinuous, interrupted by black patches).

Lycodon cathaya sp. nov. can be significantly distinguished from L. albofuscus , L. banksi , L. butleri , L. capucinus , L. cardamomensis , L. carinatus , L. cavernicolus , L. davidi , L. fasciatus , L. flavozonatus , L. gammiei , L. gibsonae , L. gongshan , L. gracilis , L. liuchengchaoi , L. meridionalis , L. multifasciatus , L. nympha , L. orientalis , L. paucifasciatus , L. rosozonatus , L. semicarinatus , L. septentrionalis , L. sidiki , L. subannulatus , L. subcinctus , L. synaptor , L. tristrigatus and L. zoosvictoriae by its smooth dorsal scales (vs. dorsal body with keeled scales). By having dorsal scales in 17-17-15 rows, Lycodon cathaya sp. nov. can be easily distinguished from L. alcalai (DSR 19-17-15), L. bibonius (DSR 19-17-15), L. chrysoprateros (DSR 19-17-15), L. davisonii (DSR?-13-?), L. dumerilii (DSR 19-17-15), L. fausti (DSR 19-17-15), L. ferroni (DSR?-13-?), L. kundui (DSR 15-15-15), L. muelleri (DSR 19-17-15), L. philippinus (DSR?-15-?), L. solivagus (DSR 19-17-15) and L. stormi (DSR?-19-?). From the remaining 18 congeners, Lycodon cathaya sp. nov. can be easily distinguished from L. ophiophagus , L. pictus , and L. zawi by having fewer maxillary teeth; from L. anamallensis , L. effraenis , L. flavicollis , L. flavomaculatus , L. hypsirhinoides , L. laoensis , L. striatus , and L. travancoricus by having fewer supralabials; from L. anamallensis , L. aulicus , L. effraenis , L. flavicollis , L. flavomaculatus , L. hypsirhinoides , L. laoensis , L. multizonatus , L. ophiophagus , L. pictus , and L. striatus by having fewer infralabials and from L. mackinnoni by having more infralabials; from L. aulicus , L. flavicollis , L. flavomaculatus , L. hypsirhinoides , L. jara , L. laoensis , L. mackinnoni , L. multizonatus , L. sealei , L. striatus , L. tessellatus , and L. tiwarii by having an entire precloacal plate (vs. precloacal plate divided); from L. jara , L. mackinnoni , and L. striatus by having more ventrals and from L. pictus , L. tessellatus , and L. tiwarii by having fewer ventrals; from L. anamallensis , L. flavicollis , L. hypsirhinoides , L. jara , L. laoensis , L. flavomaculatus , L. mackinnoni , L. multizonatus , L. striatus , L. tessellatus and L. zawi by having more subcaudals and from L. ophiophagus and L. pictus by having fewer subcaudals; from L. effraenis and L. sealei by the presence of a single loreal (vs. loreal absent).

Description of holotype.

Adult male. Body slender, TL 562.5 mm (SVL 451.4 mm, TaL 111.1 mm, TaL/TL ratio 0.198); dorsal scales in 17-17-15 rows, smooth throughout, the vertebral scales not enlarged; head elongate, moderately distinct from neck, rather flattened, longer than wide, and narrow anteriorly, HL 17.2 mm, HW 11.1 mm (HW/HL ratio 0.643); eye large, ED 2.2 mm, pupil vertically elliptic; rostral triangular, much broader than high, barely visible from above; nostril lateral, located in the middle of nasal; nasal divided into two scales by nostril; two internasals, anteriorly rounded, almost as wide as high, bordered by two large, pentagonal prefrontals posteriorly; a single enlarged hexagonal frontal, narrowed posteriorly; parietals paired, longer than wide, in contact with each other medially, with upper anterior and posterior temporals, paraparietal laterally and four nuchal scales posteriorly; paraparietal slightly elongate, nearly rectangular; one elongated loreal on each side, in contact with eye, not in contact with internasals; one preocular located above loreal, in contact with eye and supraocular posteriorly, with prefrontal anteriorly, and not in contact with frontal; two postoculars, almost equal in length, upper one in contact with eye anteriorly, with supraocular and parietal, and with upper temporal posteriorly, lower one in contact with eye anteriorly, with anterior temporals posteriorly, and with fifth and sixth supralabials below; eight supralabials on each side, first and second in contact with nasal, third to fifth entering orbit; nine infralabials on each side, first pair in broad contact with each other, first to fourth in contact with anterior pair of chin shields, fourth to fifth in contact with posterior chin shields; two pairs of chin shields, elongate, anterior pair larger, second pair meeting in midline; two anterior temporals, almost equal in size, three posterior temporals, upper one smallest, lower one largest; 199 ventrals plus two preventrals; 78 pairs of subcaudals, excluding tail tip; precloacal plate entire.

Dentition.

10 (4+2+2+2) maxillary teeth on both sides, four small anterior teeth, enlarged posteriorly; two noticeably enlarged snag shaped teeth (second largest); two moderately enlarged teeth; two moderately enlarged kukri liked teeth (the anterior one larger, both with posterior cutting edges). Diastemas present between the above-mentioned maxillary teeth groups.

Hemipenis.

Hemipenis elongated, apex not fully everted after injection of formalin. Truncus bulbous, lower 1/3 smooth without spines, spine ornamentation starting at upper part with somewhat enlarged, medium sized spines. Apex with dense microspines. Sulcus spermaticus stretches to base of apex. Apex not fully everted, ending somewhat widened with an oblique opening, with microspines inside.

Coloration of holotype.

In life (Figs 3A , 4 ), dorsal surface of head brownish black, a distinctly dusty rose collar band that crosses over the head and nape of the neck; ventral surface of head almost white, mental, the 1st-3rd supralabials and the anterior pair of chin shields with brownish black patches, the 4th and 5th and the posterior pair of chin shields with brownish black mottles. Ground color of dorsal surface brownish black, with 35 transverse dusty rose bands on body trunk and 16 similarly colored bands on tail, including two incomplete bands between collar band and the first complete transverse band; each band in 1-2 scales of the vertebral row in minimum width and widen laterally to a width of 3-4 scales; bands link with each other in ventrolateral body and tail, and separate the ground color into brownish black ellipse patches: such patches in 3-6 scales of the vertebral row in maximum width, and arranged in a row along the top of body and tail; a brownish black ventrolateral blotch on each ventrolateral side of bands. Middle of each ventral with irregular brownish black blotches forming a relatively continuous venter strip, and greyish white on both sides, forming a pair of continuous ventrolateral lines, which run in parallel along the venter strip. Subcaudals almost entirely light brown. In preservative (Fig. 5A ), the collar band faded to beige, bands become darker, and the ventral surface faded to beige.

Variations.

Measurements, body proportions and scale counts of the two specimens are listed in Table 4 . The paratype has a relatively small and faint collar band, just crossing over the nape of the neck; dorsal bands are faint and there are more dark brown speckles than in the holotype. It appears that this specimen represents an older age group than the holotype, and differences in coloration may indicate an ontogenetic development. The loreal is in contact with eye in the holotype, while the loreal is separated from the eye by the preocular and the third supralabial.

Distribution and habits.

Currently, Lycodon cathaya sp. nov. is only known from its type locality, Huaping Nature Reserve (Fig. 1 ; ca 850-1000 m a.s.l.), and is sympatric with L. meridionalis and L. ruhstrati . All of them are nocturnal species. The holotype was observed climbing on a wilted bush by the roadside, approximately half a meter above the ground (Fig. 4 ). The paratype and an individual of its sympatric species L. ruhstrati is (Fig. 3C ) were found on the ground on the same night. The surrounding environment consisted of well-preserved montane evergreen broad-leaved forest or mixed forest.

Figures

Figure 1. The type locality of Lycodon cathaya sp. nov., Huaping Nature Reserve, Guangxi, China.

Figure 2. Bayesian Inference and Maximum Likelihood phylogenies.

Figure 3. General aspects in life and close-ups of body scales of A Lycodon cathaya sp. nov. (SYS r 001542, holotype) from Huaping Nature Reserve, Guangxi, China B L. futsingensis (SYS r 002123) from Gaoping Nature Reserve, Shaoguan City, Guangdong, China, and C L. ruhstrati (SYS r 001631) from Huaping Nature Reserve, Guangxi, China.

Figure 4. General aspect of Lycodon cathaya sp. nov. (SYS r 001542, holotype) in life when observed.

Figure 5. Comparative characters of head scalation and color patterns (in preservative) of A Lycodon cathaya sp. nov. (SYS r 001542, holotype) B Lycodon cathaya sp. nov. (SYS r 001630, paratype) C L. futsingensis (SYS r 002123), and D L. ruhstrati (SYS r 001631). Scale bars: 10 mm.