Sibynophis grahami ( Boulenger, 1904 )

Sibynophis grahami ( Boulenger, 1904) View in CoL

Graham’s collared snake

( Tables 1–2 View TABLE 1 View TABLE 2 ; Figs. 2 View FIGURE 2 , 4–5 View FIGURE 4 View FIGURE 5 ; Appendices I, V)

Polyodontophis grahami Boulenger, 1904: 132 View in CoL

– Holotype: NHMUK 1946.1.15.73; subadult female from between Yunnanfu (nowaday Kunming City) and Kali Tring Fou (nowaday Qujing City), Yunnan Province, China, collected by J. Graham.

Sibynophis grahami View in CoL — Pope (1935: 81, 88, 89); Wu et al. (1985: 275–276); Guo et al. (2023).

Sibynophis chinensis grahami View in CoL — Yang & Rao (2008: 331–332).

Sibynophis (collaris) grahami View in CoL —Mell (1929: 201).

Sibynophis chinensis miyiensis Zhao & Kou View in CoL in Zhao (1987: 1–6) — Holotype CIB 105027; male from Miyi County, Panzhihua City, Sichuan Province, China (altitude 880 m) collected by Kang Shaohe in 1986.

Sibynophis chinensis miyiensis — Guo et al. (2012: 337–338, in part).

Sibynophis chinensis (non Ablabes chinensis Günther, 1889 )— Wu et al. (1985: 272–275, in part); Zhao et al. (1998: 298–300, in part); Zhao (2006: 275–276, in part); Che et al. (2020: 732, in part); Wu et al. (2023: Appendix, in part).

Specimens examined (n=3; all from China):— Yunnan Province: NHMUK 1946.1 About NHMUK .15.73 (holotype of Polyodontophis grahami , one subadult female) from between Kunming City and Qujing City — Sichuan Province: CIB DL no number (one subadult male) from Panzhihua City ; MNHN RA-1912.265 (one adult male) no exact location .

Referred material from the literature (n=37, all from China):— Sichuan Province: CIB 105027 (male, holotype of Sibynophis chinensis miyiensis ) ; CIB 105025 (one female, allotype of Sibynophis chinensis miyiensis ) ; CIB 105026, CIB 105028, CIB 105030, CIB 105031 (four females, paratypes of Sibynophis chinensis miyiensis ) ; CIB 105029 (one female, paratypes of Sibynophis chinensis miyiensis ) from Miyi County, Panzhihua City [see details in Zhao 1987]. – Yunnan Province: YU 857012, YU 857013, YU 857021 (three males) from Lugu Lake, Sichuan-Yunnan border (altitude 2,600 m) ; AMNH 12804 (one male) from Wuding County, Chuxiong City [see detail in Pope 1935] ; CIB _ Yunnan (one male) from Kumning City [see detail in Zhao et al. 1998] ; KIZ 76002, KIZ 87I003 (two males) and KIZ 77005, KIZ 79010, KIZ 83015 (three juveniles) from Kumning City [see detail in Yang & Rao 2008] — Guizhou Province: No. 750513 (one male) from Chishui County, Zunyi City; No. 76004636, No. 7620069, No. 7620070 (three males) & No. 63II5008, No. 760037 (two females) from Leishan County, Qiandongnan City ; No. 780150 (one male) from Qingzhen County, Guiyang City; No. 781392, No. 781390, No. 781407, No. 781187, No. 781106, No. 781028, No. 781391 (seven males) & No. 781389, No. 781388, No. 781387, No. 781229 (four females) from Weining County, Bijie City ; No. 63III5335 (one female) from Xingyi City ; No. 740662 (one female) from Guiding County, Qiannan City [see detail in Wu et al. 1985] .

Revised diagnosis of Sibynophis grahami . Medium-sized species, maximum snout-vent length 671 mm, relative tail length about 0.21–0.38 [mean 0.29]; 41–46 maxillary teeth; dorsal scale rows 17–17–17, all smooth; 179–208 [mean 191.53] ventrals; 90–130 [mean 105.03] subcaudals, paired; cloacal plate divided; 9 supralabials with 4 th –6 th SL touching the eye; 1 preocular, 2 postoculars; 2 anterior temporals, the lower larger and in contact with the seventh, 2 posterior temporals; background colour of the body brown or greyish-brown with three dark brown longitudinal lines, which become more and more indistinct after the anterior fourth of the body; head dark brown, with a black streak on each side and a black bar behind the parietals; a white streak along the upper labials and another behind the occipital bar; lower parts white, with a black dot at the outer end of each shield; on the posterior part of the body and on the tail these dots are confluent into a black lateral line; venter yellow with black sposts on the outer tips of ventrals (based on Boulenger 1904; Pope 1935; Zhao 1987; Wu et al. 1985; Yang & Rao 2008; this study).

Redescription of the holotype of Sibynophis grahami ( Fig. 2 View FIGURE 2 ). Body slender, cylindrical; head ovoid, relartively short, thick, barely distinct from the thick neck, flattened; snout short, slight projecting over the lower jaw, blunt seen from above, rounded in profile view; nostril round, piercing between the two parts of the nasal; eye large, with a round pupil; tail long and tapering.

Body size. SVL 191 mm, TaL 60 mm, TL 251 mm, ratio TaL/TL 0.239.

Body scalation. Dorsal scale rows 17–17–17, scales small, ovoid, all smooth, no apical pits; 185 ventrals, laterally slight angulate; 83 subcaudals, paired and laterally slightly angulate; cloacal plate divided.

Head scalation. Rostral wider than high, triangular, barely visible from above; nasal vertically divided into two scales; internasal subrectangular, much more elongate transversely than deep, in broad contact, much shorter than prefrontals; prefrontals pentagonal, wider than long; frontal hexagonal, bell-shaped, pointing backwards, elongate; one supraocular on each side, distinctly longer than wide; parietals large, pentagonal in broad contact with each other; loreal 1/1, subrectangular, slight higer than long, not in contact with eye; preocular 1/1; subocular absent; postoculars 2/2, the uppermost scale slightly larger than the lowermost one prasocular; anterior temporals 2/2, the lower larger and in contact with the seventh; posterior temporals 2/2; supralabials 9/9, first and second in contact with nasal, second and third in contact with loreal, four and sixth in contact with eye, eigth supralabial largest; infralabials 9/9, number one to four in contact with the anterior pair of chin shields; mental subtriangular in ventral profile, longer than wide; posterior chin shields equal in size relative to anterior shields.

Coloration in preservation. Body and tail reddish brown above, with three dark brown longitudinal lines, which become more and more indistinct after the anterior fourth of the body; head dark brown, with a black streak on each side and a black bar behind the parietals; a white streak along the upper labials and another behind the occipital bar; lower parts white, with a black dot at the outer end of each shield; on the posterior part of the body and on the tail these dots are confluent into a black lateral line; venter yellow with black sposts on the outer tips of ventrals.

Variation. See Appendix I and Figs. 2 View FIGURE 2 , 4–5 View FIGURE 4 View FIGURE 5 for the details. The longest known male specimen is 850 mm long (specimen KIZ 76002; SVL 617 mm, TaL 233 mm; see Yang & Rao 2008). The longest known female is 630 mm long (specimen No. 740662; SVL 430 mm, TaL 200 mm; see Wu et al. 1985). Ratio TaL/TL 0.22–0.38 [mean 0.30±004, n=22], without sexual dimorphism (0.22–0.38 [mean 0.30±0.05, n=14] in males, 0.27–0.32 [mean 0.30±0.02, n=8] in females).

Body scalation. Dorsal scale in 17–17–17 rows, scales small, ovoild, all smooth, no apical pits; VEN 179–208 [mean 191.53±6.84, n=41), without sexual dimorphism; SC 90–130 [mean 105.03±9.53, n=31], without sexual dimorphism.

Head scalation. SL 9 (rarely 10), IL 9 (rarely 8 or 10); loreal not touching the eye; temporals 2+2.

Dentition. Total of 41–46 maxillary teeth on each upper jaw, small, subequal and closely set, the first and the last two or three slightly smaller than the rest (see Pope 1935; Yang & Rao 2008).

Colouration and pattern. The dorsal surface is brown or greyish-brown with three dark brown longitudinal lines, which become more and more indistinct after the anterior fourth of the body; head dark brown, with a black streak on each side and a black bar behind the parietals; a white streak along the upper labials and another behind the occipital bar; lower parts white, with a black dot at the outer end of each shield; on the posterior part of the body and on the tail these dots are confluent into a black lateral line. The chin, infralabials and throat are cream or ivory, uniforn or marbled with brown or spotted with black; infralabials often edged with black. The iris is golden brown in life. The venter is cream-yellow or yellow with black sposts on the outer tips of ventrals.

Comparisons. Sibynophis grahami is most similar to S. chinensis and S. collaris (see Table 2 View TABLE 2 ; Figs. 5–6 View FIGURE 5 View FIGURE 6 ). Therefore, the comparisons of these three species appear to be the most pertinent.

Sibynophis grahami is distinguished from S. chinensis (data from Stejneger 1925, Schimidt 1925, Fan 1931, Maki 1931, Chang 1938, Maslin 1950, Wu et al. 1985, Zhao et al. 1998, Shi et al. 2011, Qi et al. 2012, Sun et al. 2013, Hecht et al. 2013, and this study; see Appendix I) by having: bigger maximum size in males (max SVL 617 mm vs. 415 mm), but smaller maximum size in females (max SVL 430 mm vs. 521 mm); higher number VEN in both sexes (179–208 [mean 191.53±6.84, n=41] vs. 158–187 [mean 173.44±6.83, n=32]; slight higher number VEN+SC in both sexes (267–314 [mean 294.41±13.50, n=34] vs. 254–302 [mean 284.68±10.52, n=22]).

Sibynophis grahami is distinguished from S. collaris (data from Che et al. 2020 and this study) by having: temporals 2+2 (vs. usually 1+2); lower number SL (9 vs. 10); bigger maximum size in males (max SVL 617 mm vs. 472 mm), but smaller maximum size in females (max SVL 430 mm vs. 565 mm); higher number VEN in both sexes (179–208 [mean 191.53±6.84, n=41] vs. 164–180 [mean 172.61±4.26, n=18]; slightly higher number VEN+SC in both sexes (267–314 [mean 294.41±13.50, n=34] vs. 270–297 [mean 285.42±6.80, n=12]).

Distribution. ( Fig. 7 View FIGURE 7 , Appendix V). Currently, Sibynophis grahami must be regarded as edemic of the Yunnan-Guizhou (or Yungui) Plateau. It is known from southwestern Sichuan (Panzhihua and Xichang cities), Yunnan Province (Kunming Qujing, Chuxiong, Yuxi, Lijiang, Sanglila, Mengzi cities; Wuding and Ninglang counties; Honghe Hani and Yi Autonomous Prefecture) and Guizhou Province (Xingyi and Zunyi cities, Guiyang Capital, Guding and Weining counties; Qiandongnan Miao and Dong Autonomous Prefecture), China (see Wu et al. 1985; Zhao 1998; Yang & Rao 2008; Guo et al. 2023; this study). Given its geographic proximity, its occurrence in northernwest Vietnam (such as Lao Cai Province) should be expected.

Natural history notes and conservation status. Prior to this study, the biological data of Sibynophis grahami were very limited. This species is distributed at an altitude of 800–2,200 m asl ( Zhao 1998; Wu et al. 1985; Zhao 1987). It is a non-toxic, terrestrial, and diurnal species, closely associated with hilly and mountainous areas. It is often found in bushes on the roadside not far from water bodies or near rice fields, in caves, and under trees. It has a long tail and is capable of winding. It can escape very quickly when in danger ( Wu et al. 1985; Yang & Rao 2008). It feeds mainly on lizards, but also frogs and snakes; it is oviparous ( Wu et al. 1985). Sibynophis grahami is distributed over a large area including several protected areas. The species appears to be quite rare in its native regions. There appear to be no significant threats to this species however habitat loss and degradation are most likely potential threats to this species (T.V. Nguyen pers. obser.). Its extent of occurrence (EOO) is 293,283 km 2. Thus, we tentatively suggest Sibynophis grahami be considered a Least Concern (LC) species, following the IUCN’s Red List Categories (IUCN Standards and Petitions Committee 2024).