Lycodon serratus WANG, YU, VOGEL & CHE, 2020
Can you confirm these amateur observations of Lycodon serratus?
|Higher Taxa||Colubridae, Colubrinae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Serrate-banded Wolf Snake|
Chinese: "?????" (Pinyin: Ju Wen Bai Huan She)
|Synonym||Lycodon serratus WANG, YU, VOGEL & CHE 2020|
|Distribution||China (Yunnan: Deqin County, Derong County)|
Type locality: Jinsha River Valley near Geyading Village, Deqin County, northwest Yunnan Province, China (28.7720o N, 99.1128o E, WGS84, elevation 2200m).
|Types||Holotype: KIZ 038335, adult male, collected by Zhongbin Yu and Wenjie Dong on 25 July, 2020|
|Diagnosis||Diagnosis: Lycodon serratus can be diagnosed from recognized congeners by a combination of the following morphological characters: (1) body size moderate, slender, ToL 628mm, SVL 480 mm; (2) tail long, TAL 23.6% ToL; (3) head flat, distinct from neck, snout narrow; (4) eye large, vertical ellipse in shape; (5) dorsal body scales smooth, 19 rows at one-head-length behind the neck, 17 rows at midbody, and 15 rows at one-head-length before vent; (6) ventral scale count 198; (7) subcaudal scale count 84; (8) cloacal plate divided; (9) supralabials 8 or 9, 2-3-3 or 2-4-3; (10) infralabials 10(5); (11) preocular single, postocilar 2; (12) loreal scale entering orbit; (13) enlarged paraparietal 2, bordered by 7 additional nuchal scales other than posterior upper temporal and parietal; (14) maxillary teeth 12 in four groups (6-1-1-4 or 6-1-2-3), sixth and seventh much larger, first and second gap about same size, twice as distance between first two teeth; (15) dorsal surface dirty Tawny Olive (Color 17) with narrow, strongly serrated Jet Black (Color 300) cross-bands, two-scale broad middorsally at anterior 1/7 of body, single-scale broad for the remaining ones; (16) single collar-band on neck, 66 cross-bands on dorsum, 26 on tail; (17) first dorsal cross-band at 10th ventral scale; (18) anterior 1/3 of ventral surface uniform white, remaining 2/3 of ventral body and whole tail speckled with Dark Neutral Gray (Color 299) (Wang et al. 2021).|
Comparisons: Lycodon serratus is morphologically most similar and closely related to L. multizonatus, where both species have divided cloacal plate, large eyes, and similar number of black bands across the body. However, the new species can be differentiated from L. multizonatus by having more DSRH (19 vs. 17), more IL (9 or 10 vs. 8), more IL-aCS (5 vs. 4), a flatter head that is distinct from the neck (vs. robust and indistinct), a narrower snout (vs. wide), much narrower black bands on the middle to posterior body (mostly single scale broad, rarely two vs. ?3 scales), more black bands on the tail (26 vs. 11-19), and a distinct ventral ornamentation patterns (irregular speckles vs. regularly paired black spots or complete black bands) (Fig. 5).
For remaining species that are found in the close proximity in the Hengduan Mountain Region (L. fasciatus, L. gongshan, L. liuchengchaoi, L. ruhstrati, L. chapaensis comb. nov., and L. synaptor), L. serratus differs from all by having more DSRH (19 vs. 17), smooth dorsal scales (vs. feebly or distinctively keeled medially), a narrow snout (vs. robust and wide), larger and laterally compressed eyes (ED 15.2% HL, VED 17.5% HL vs. not laterally compressed, <12%), more cross-bands on the body and tail (66 on body, 26 on tail vs. L. fasciatus: 19-37 on body, 7-21 on tail; L. gongshan 32-40 on body, 13-15 on tail; L. liuchengchaoi 40-45 on body, 10-15 on tail; L. ruhstrati 33-46 on body, 14-28 on tail; L. chapaensis comb. nov. 23-37 on body, 11-16 on tail; L. synaptor 30 or 31 on body, 9 on tail), different-shape and width of the bands (narrow [mostly single-scale broad] and strongly serrated vs. broader [mostly two- to three-scale broad and less serrated] and less serrated), and a distinct body coloration (Tawny Olive [Color 17] with Jet Black [Color 300] bands vs. Jet Black [Color 300] with white or yellowish bands). Additionally, L. serratus differs from L. fasciatus, L. gongshan, and L. ruhstrati by having divided cloacal plate (vs. entire), presence of neck collar-band in adult (vs. absence), and a distinct ventral ornamentation pattern (randomly speckled vs. regular transverse bands [L. fasciatus, L. gongshan] or mostly uniform white [L. ruhstrati and L. chapaensis comb. nov.]); from all but L. fasciatus and L. chapaensis comb. nov. by having more IL-aCS (5 vs. 4); from all but L. chapaensis comb. nov. by having non-overlapping SC (84 vs. L. gongshan 92-96; L. liuchengchaoi 68-77; L. ruhstrati 97-114; L. synaptor 68 or 69); from L. liuchengchaoi by having fewer VEN (198 vs. 202-206); from L. chapaensis comb. nov. and L. synaptor by having loreal entering orbit (vs. separated) and a divided cloacal plate (vs. entire). For the junior synonym of L. fasciatus that is currently available, L. serratus differs from Dinodon yunnanensis Werner, 1922 by more DSRH (19 vs. 17), smooth or feebly keeled dorsal body scale rows (strongly keeled), a divided cloacal plate (vs. entire), and more cross-bands on the dorsum (66 vs. 23).
For remaining three species that have genetic data and are in the same clade (i.e. L. butleri, L. pictus, and L. cavernicolus), L. serratus differs from all by having a distinct body coloration (Tawny Olive [Color 17] with Jet Black [Color 300] bands vs. Jet Black [Color 300] with white or yellowish bands). Additionally, the new species differs from L. pictus by more DSRH (19 vs. 17), a divided cloacal plate (vs. entire), more cross-bands on the body (66 vs. 28 or 29) and tail (26 vs. 13), much narrower cross-bands (mostly single scale-broad, rarely two vs. 2-4 scale broad), and by the presence of collar band in adult (vs. absence); from L. cavernicolus by having smooth dorsal scales (vs. keeled), fewer SL (8 vs. 9 or 10), and more NDB (66 vs. 36-45); and from L. butleri by having smooth dorsal scales (vs. keeled) and a divided cloacal plate (vs. entire).
For all the remaining 55 species of the genus, L. serratus differs from all by having a distinct dorsal coloration (Tawny Olive [Color 17] with Jet Black [Color 300], strongly serrated bands vs. black or brownish with white, yellow, or red cross-bands that are less serrated or smooth, or with no complete cross-bands but reticulated ornamentations). Additionally, L. serratus differs from all except 18 species (i.e. L. cardamomensis, L. carinatus, L. flavozonatus, L. futsingensis, L. hypsirhinoides, L. jara, L. laoensis, L. mackinnoni, L. meridionalis, L. nympha, L. orientalis, L. sealei, L. septentrionalis, L. sidiki, L. striatus, L. tessellatus, L. tiwarii, and L. zawi) by having a divided cloacal plate (vs. entire). For the excluded 17 species, the new species differs from L. cardamomensis, L. carinatus, L. flavozonatus, L. meridionalis, L. nympha, L. sealei, and L. sidiki by having smooth dorsal scales (vs. keeled); from L. futsingensis, L. hypsirhinoides, L. jara, L. laoensis, L. mackinnoni, L. striatus, L. tessellatus, and L. zawi by having more DSRH (19 vs. 17); from L. orientalis by the presence of preocular scale (vs. absence); and from L. tiwarii by having fewer ventral scales (198 vs. 218-237) (Wang et al. 2021).
Color in life: In life, the background coloration of the dorsal and lateral surfaces of the head and body is Tawny Olive (Color 17). The dorsal surface of the head is speckled with Dark Neutral Gray (Color 299), particularly on the frontal and parietal scales. A single Jet Black (Color 300) collar-band on neck, 66 cross-bands of the same color are present on the dorsum, and another 26 cross-bands are present on the tail. Cross-bands on the anterior 1/7 of SVL are broader, expending across two dorsal scales in width, and the remaining bands are rather narrow, expanding only a single dorsal scale in width. All bands are strongly serrated. The immediate bordering margins of each black band are Pale Buff (Color 1). Ventral surface of the head is white. The immediate bordering regions between infralabials and between infralabials and chin shields are speckled with Dark Neutral Gray (Color 299). The ventral surface of the body and tail is white: the anterior 1/7 of the SVL is uniform white with no patterns, and the remaining section of the ventral body and the tail is speckled with Dark Neutral Gray (Color 300), with the tail more heavily speckled (Wang et al. 2021).
|Comment||Sympatry: Diploderma sp., Gekko jingjiangensis, and Scincella monticola (Yang & Rao, 2008; Wang et al., In press). |
Diet: the holotype of L. serratus sp. nov. was found at night searching for food on a bush, where several individuals of Diploderma sp. were sleeping on. As the genus Lycodon is known to feed predominantly on lizards (Zhao et al., 1998), it is likely that these sympatric lizard species constitute main preys of the new species (Wang et al. 2021)
Similar species: Lycodon multizonatus
Conservation: While the distribution range of the species remains unknown, habitat destructions from road constructions were observed at and near the type locality of the new species (Wang et al., In press). We recommend Data Deficient (DD) for the IUCN status of the new species, and we call for population studies to assess its conservation status in the near future.
|Etymology||The Latin species name serratus means "serrated", which describes the diagnostic narrow, serrated black cross-band of the new species.|