Research Article |
Corresponding author: Jian-Huan Yang ( jhyang@kfbg.org ) Academic editor: Uwe Fritz
© 2022 Ho Yuen Yeung, Michael W. N. Lau, Jian-Huan Yang.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Yeung HY, Lau MWN, Yang J-H (2022) A new species of Calamaria (Squamata: Colubridae) from Guangdong Province, southern China. Vertebrate Zoology 72: 433-444. https://doi.org/10.3897/vz.72.e84516
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A new species of the genus Calamaria Boie, 1827, Calamaria arcana sp. nov., is described based on a single male specimen collected from Mt. Dadongshan, Guangdong, southern China. The new species can be distinguished from all known congeners by the significant genetic divergence in the mitochondrial cytochrome-b gene fragment (p-distance ≥ 13.9%), and morphologically by the combination of the following characters: (1) ten modified maxillary teeth; (2) four supralabials, second and third supralabials entering orbit; (3) preocular present; (4) mental not touching anterior chin shields; (5) six scales and shields surrounding the paraparietal; (6) 170 ventral scales; (7) 22 paired subcaudals; (8) tail not gradually tapering, abruptly tapering at the tip; (9) dorsal scales reduced to five rows above last subcaudal at tail; (10) dorsum of body and tail brownish; (11) dark collar on nuchal region absent; (12) two outermost dorsal scale rows light yellow with upper margins partly dark pigmented; (13) ventral scales immaculate, without dark outermost corners and pigmentation anteriorly; and (14) absence of distinct dark longitudinal line or scattered spots on the underside of tail. Calamaria arcana sp. nov., represents the fifth species of the genus recorded in China. Following the IUCN Red List Categories and Criteria, we propose the new species to be listed as Data Deficient.
Calamaria arcana sp. nov., Calamariinae, integrative taxonomy, morphology, phylogeny, snake, Southeast Asia
Southeast Asian reed snakes of the genus Calamaria Boie, 1827 are small semi-fossorial snakes ranging from north-east India to the Maluku Islands of east Indonesia (
During long-term and extensive biodiversity surveys conducted by Kadoorie Farm and Botanic Garden in Southern China between 1997 and 2002, a Calamaria specimen was collected from Mt. Dadongshan of Guangdong Province, and initially identified as Calamaria pavimentata in the survey report (
The specimen were preserved in 80% ethanol and deposited at the Herpetological Collection of Kadoorie Farm and Botanic Garden (KFBG), Hong Kong SAR, under voucher no. KFBG 14611.
Genomic DNA was extracted from the muscle tissue using a Qiagen DNeasy Blood & Tissue Kit (Qiagen Biotech). We amplified fragments of mitochondrial 12S rRNA, 16S rRNA, and cytochrome-b (cyt-b) genes using the primer pairs L1091/H1478 (
In addition to our new specimen of Calamaria, we included sequences of all species of Calamaria in mainland Southeast Asia and China for which 12S rRNA, 16S rRNA, and cyt-b sequences were available from GenBank for genetic analysis (for accession numbers see Table
Species | Voucher no. | Locality | GenBank no. (12S, 16S, cyt-b) |
(1) Calamaria arcana sp. nov. | KFBG 14611 | Mt. Dadongshan, Guangdong, China | ON464176, ON464177, ON482335 |
(2) C. septentrionalis | KFBG 14506 | Hainan Island, China | MH445960, MH445962, MH445956 |
(3) C. septentrionalis | FTB2839 | Unknown | KR814612, KR814637, KR814699 |
(4) C. septentrionalis | ROM 35597 | Cao Bang, Vietnam | KX694584, KX694624, KX694890 |
(5) C. septentrionalis | ROM 35605 | Cao Bang, Vietnam | —, —, AF471081 |
(6) C. pavimentata | KFBG 14507 | Ningming, Guangxi, China | MH445959, MH445963, MH445957 |
(7) C. yunnanensis | ROM 41547 | Simao, Yunnan, China | KX694572, KX694625, KX694891 |
(8) C. yunnanensis | Unknown | JQ598801, JQ598863, JQ598922 | |
(9) C. andersoni | SYS r001699 | Yingjiang, Yunnan, China | MH445958, MH445961, MH445955 |
(10) C. nebulosa | FMNH 258666 | Phongsaly, Laos | —, MW699929, MN338524 |
(11) C. lumbricoidea | USMHC 1450 | Penang, Peninsular Malaysia | —, —, MN338526 |
(12) C. schlegeli | LSUHC 10278 | Perak, Peninsular Malaysia | —, —, MN338525 |
(13) Elaphe quatuorlineata | LSUMZ 40626 | Turkey, European Turkey | AY122798, AF215267, AY486931 |
(14) Lycodon rufozonatus | LSUMZ 44977 | Unknown | AF233939, HM439978, AF471063 |
(15) Orientocoluber spinalis | MVZ 211019 | Yinnan, Ningxia, China | AY541508, AY376773, AY486924 |
Terminology and measurements follow
EyeD eye horizontal diameter; Eye–Mouth D eye–mouth distance, measured from the anterior point of the eye to the mouth; HL head length (from tip of snout to posterior margin of the mandible); HW maximum head width; SVL snout–vent length (from tip of snout to posterior margin of cloacal plate); TaL tail length (from posterior margin of cloacal plate to tip of tail); TL total length (from tip of snout to tip of tail); TaL/TL ratio tail length/total length.
Comparative morphological data from other species of Calamaria found in mainland Southeast Asia and China were obtained from examined specimens (Appendix
The fragments of mitochondrial 12S rRNA, 16S rRNA, and cytochrome-b (cyt-b) genes of specimen KFBG 14611 were successfully extracted. Both the ML tree and BI analyses based on the concatenated alignment strongly support the placement of KFBG 14611 from Mt. Dadongshan in the genus Calamaria (Fig.
The uncorrected pairwise divergence of the cyt-b fragments between the specimen KFBG 14611 and other seven congeners included in the study were ≥ p = 13.9%, with the minimum value observed in the comparison with sequences of C. septentrionalis (P = 13.9–14.8%) (see Table
Bayesian inference (BI) tree derived from partial sequences of the combined fragments of 12S rRNA, 16S rRNA, and cyt-b genes. Numbers above branches are Bayesian posterior probabilities (>70% retained), and numbers below branches indicate bootstrap support values for maximum likelihood analyses (>70 retained).
Uncorrected p-distances (%) among the sequences based on the cyt-b gene fragment. The numbers of base substitutions per site from between sequences are shown.
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) | (11) | (12) | (13) | (14) | (15) | |
(1) Calamaria arcana sp. nov. | — | ||||||||||||||
(2) C. septentrionalis | 14.8 | — | |||||||||||||
(3) C. septentrionalis | 13.9 | 2.0 | — | ||||||||||||
(4) C. septentrionalis | 14.3 | 5.2 | 4.6 | — | |||||||||||
(5) C. septentrionalis | 14.4 | 6.0 | 4.9 | 0.0 | — | ||||||||||
(6) C. pavimentata | 22.2 | 18.6 | 17.7 | 19.2 | 19.8 | — | |||||||||
(7) C. yunnanensis | 21.2 | 16.4 | 16.2 | 15.9 | 15.9 | 20.6 | — | ||||||||
(8) C. yunnanensis | 20.9 | 16.2 | 16.0 | 15.9 | 15.7 | 20.4 | 0.0 | — | |||||||
(9) C. andersoni | 20.7 | 16.8 | 16.0 | 16.7 | 16.6 | 22.0 | 10.5 | 10.3 | — | ||||||
(10) C. nebulosa | 21.1 | 18.8 | 19.3 | 19.8 | 19.6 | 21.6 | 19.4 | 19.2 | 19.4 | — | |||||
(11) C. lumbricoidea | 27.1 | 25.4 | 24.8 | 24.5 | 24.8 | 27.1 | 26.3 | 25.8 | 26.0 | 24.4 | — | ||||
(12) C. schlegeli | 27.5 | 23.1 | 23.2 | 24.1 | 23.5 | 24.7 | 25.3 | 24.9 | 24.6 | 21.4 | 19.9 | — | |||
(13) Elaphe quatuorlineata | 27.7 | 25.2 | 24.5 | 25.3 | 25.6 | 27.8 | 25.7 | 25.3 | 27.5 | 26.6 | 25.4 | 25.9 | — | ||
(14) Lycodon rufozonatus | 28.4 | 25.7 | 24.4 | 26.3 | 26.2 | 28.1 | 29.7 | 29.2 | 28.4 | 28.5 | 24.7 | 25.3 | 17.8 | — | |
(15) Orientocoluber spinalis | 28.9 | 26.9 | 26.3 | 26.5 | 27.2 | 31.0 | 28.3 | 27.8 | 28.3 | 26.8 | 26.1 | 26.0 | 20.1 | 20.2 | — |
Calamaria pavimentata
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Lingnan Reed Snake (English), 岭南两头蛇 (Chinese)
KFBG 14611 (Figs
The species epithet “arcana” is the nominative form the Latin adjective “arcanus” meaning “hidden”, “secret” and is given in feminine form to match the female genitive declension of the genus name Calamaria. It refers to the fact that this species is difficult to find with only a single specimen discovered during our long term survey in southern China. For common name we suggested as “Lingnan reed snake” in English and “Ling Nan Liang Tou She (岭南两头蛇)” in Chinese, referring to the Lingnan (岭南, means ‘South of the Nanling Mountains’) region where the new species is found. Lingnan is a geographic area referring to the lands in the south of the Nanling Mountains, covering the modern Chinese provinces of Guangdong, Guangxi and Hainan, as well as northern Vietnam.
Calamaria arcana sp. nov. is assigned to the genus Calamaria by its molecular phylogenetic position and the following morphological characters: dorsal scales in 13 rows throughout body, possessing elongate, cylindrical bodies, along with internasals and prefrontals fused, four supralabials and five infralabials (
Calamaria arcana sp. nov. could be distinguished from all other species of Calamaria by the combination of the following characters: (1) ten modified maxillary teeth; (2) four supralabials, second and third supralabials entering orbit; (3) preocular present; (4) mental not touching anterior chin shields; (5) six scales and shields surrounding the paraparietal; (6) 170 ventral scales; (7) 22 paired subcaudals; (8) tail not gradually tapering, abruptly tapering at the tip; (9) dorsal scales reduced to five rows above last subcaudal at tail; (10) dorsum of body and tail brownish; (11) dark collar on nuchal region absent; (12) two outermost dorsal scale rows light yellow with upper margins partly dark pigmented; (13) ventral scales immaculate, without dark outermost corners and pigmentation anteriorly; and (14) absence of distinct dark longitudinal line or scattered spots on the underside of tail.
Male. Rostral wider than high (height 1.8 mm, width 2.2 mm), portion visible from above about equal to prefrontal suture; prefrontal shorter than frontal, not entering orbit, and touching first two supralabials; frontal hexagonal, about 2.2 times maximum width of supraocular; paraparietal surrounded by six shields and scales; a single preocular present, higher than postocular; postocular one, higher than wide, not as high as eye diameter; eye diameter 1.4 mm, larger than eye-mouth distance 0.8 mm; distance from anterior corner of eye to nostril 1.9 mm and to the tip of snout 3.1 mm; pupil rounded; supralabials 4/4 (left/right, hereafter), second and third entering orbit, fourth longest, third about 0.9 times of second in length, first shorter than third and as wide as second; mental semicircular to triangular, not touching anterior chin shields; infralabials 5/5, first three touching anterior chin shields; first pair of chin shields meeting in midline, second pair touching anteriorly and separated posteriorly by first gular scales; three gulars in midline between second chin shields and first ventrals; dorsal scales in 13 rows throughout body, reducing to eight rows above 3rd subcaudal, to seven rows above 8th subcaudal, to six rows above 10th subcaudal, and to five rows above the last subcaudal on tail; ventral scales 170, subcaudals 22, divided, followed by a shield covering tail tip; anal scale single.
Head length 7.1 mm; head width 5.1 mm; SVL 281.5 mm; TaL 21.7 mm; TL 303.2 mm; body thickness about 5.8 to 6.4 mm; body thickness index at mid body 0.021; tail root 4.5 mm thick; tail not as thick as body, slightly tapering then abruptly tapering at tip; TaL/TL ratio 7.2%; maxillary teeth modified, 10/10.
Dorsal surface of body grey-brown above, somewhat iridescent; dark collar at nuchal region absent; indistinct light ring behind head present, nearly invisible; a narrow interrupted light ring at root of tail present, followed by few light spots on middle and tip of tail. Underside of head orangish-beige with black flecks on the infralabials; ventral scales of body and tail immaculate orangish-red, without dark pigmentation on outermost corners and anterior margins; underside of tail without dark longitudinal line or blotches.
Color preserved in ethanol fade to caramel-brown above. Dorsal head and upper parts of supralabials brown, lower parts of supralabials light yellow; underside of head light yellow with brownish spots on the infralabials; presence of an indistinct narrow yellow ring about 5 scales wide on neck, nearly invisible; dorsum of body caramel-brown, with light flecks on each dorsal scale; two outermost dorsal scale rows light yellow with upper margins partly dark pigmented; a narrow interrupted light ring at root of tail, light spots on middle and tip of tail still visible; ventral scales of body and tail uniformly light yellowish-beige; underside of tail without dark median line or blotches.
We compared Calamaria arcana sp. nov. with 18 congeners of the genus Calamaria from China and mainland Southeast Asia listed above. Unrelated taxa from the Greater Sunda Islands are omitted from comparisons for the sake of simplicity.
Calamaria arcana sp. nov. can be readily distinguished from C. albiventer, C. lumbricoidea, C. prakkei and C. schlegeli by having lower number of supralabials (four vs. five), and the pattern of supralabials shields touching the orbit (2nd and 3rd supralabials touching orbit vs. 3rd and 4th supralabials touching orbit). Additionally, these four species only occur south of the Isthmus of Kra in Peninsular Malaysia where is extremely far from the type locality of C. arcana sp. nov.
Calamaria arcana sp. nov. can be further easily distinguished with C. lovii, C. nebulosa, C. thanhi and C. yunnanensis by the presence of a preocular scale (vs. absence of preocular scale).
Calamaria arcana sp. nov. differs from C. abramovi by having eye diameter larger than distance from eye to mouth edge (vs. reverse condition in C. abramovi), posterior chin shields meeting in midline (vs. separated in C. abramovi), dorsal scales reduced to five rows at tail (vs. reduced to four rows in C. abramovi), and a distinctly different coloration (body black and with yellow-orange spots on venter in C. abramovi).
Calamaria arcana sp. nov. differs from C. andersoni by having dorsal scales reduced to five rows at tail (vs. reduced to four rows in C. andersoni), light color spots at root of tail present (vs. absent in C. andersoni. Fig.
Calamaria arcana sp. nov. differs from C. buchi by having rostral shield width larger than length (vs. reverse condition in C. buchi), eye diameter larger than distance from eye to mouth edge (vs. equal to or shorter in C. buchi), mental not touching anterior chin shields (vs. touching in C. buchi), dorsal scales reduced to five rows at tail (reduced to four rows in C. buchi), and six shields and scales surrounding paraparietal (vs. five in C. buchi).
Calamaria arcana sp. nov. differs from C. concolor by having lower number of supralabials (4 vs. 5 in C. concolor), eye diameter larger than distance from eye to mouth edge (vs. reverse condition in C. concolor), mental not touching anterior chin shields (vs. touching in C. concolor), tail not flatted (vs. slight flatted laterally in C. concolor), dorsal scales reduced to five rows at tail (vs. reduced to four rows in C. concolor), and lower number of ventral scales in males (170 vs. 209 in C. concolor).
Calamaria arcana sp. nov. differs from C. dominici by having dorsal scales reduced to five rows at tail (vs. reduced to four rows in C. dominici), absence of distinct yellow blotches on dorsum (vs. present in C. dominici), venter immaculate without any dark stripes or spots (vs. ventral side dark with yellow blotches and bands).
Calamaria arcana sp. nov. differs from C. gialaiensis by having mental not touching anterior chin shields (vs. touching in C. gialaiensis), lower number of ventral scales (170 in males vs. 191 in unknown gender), dorsal scales reduced to five rows at tail (vs. reduced to four rows in C. gialaiensis), absence of a dark longitudinal line under of tail (vs. present in C. gialaiensis), and absence of dark collar in nuchal region (vs. an indistinct dark collar present in nuchal region in C. gialaiensis).
Calamaria arcana sp. nov. differs from C. sangi by having mental not touching anterior chin shields (vs. touching in C. sangi), dorsal scales reduced to five rows at tail (vs. reduced to four rows in C. sangi), lower number of ventral scales (170 vs. 190 in C. sangi), absence of dark collar in nuchal region (vs. presence of dark collar in nuchal region in C. sangi), and venter immaculate (vs. venter cream with dark transverse bands in C. sangi).
Calamaria arcana sp. nov. differs from C. strigiventris by having eye diameter larger than distance from eye to mouth edge (vs. reverse condition in C. strigiventris), lower number of subcaudals in males (22 vs. 29–33 in males), higher number of ventrals in males (170 vs. 130–157), dorsal scales reduced to five rows at tail (vs. reduced to four rows in C. strigiventris), venter immaculate (vs. presence of three interrupted longitudinal black stripes in C. strigiventris).
Calamaria arcana sp. nov. differs from C. pavimentata by having rostral shield width larger than length (vs. reverse condition in C. pavimentata), tail slowly tapering anteriorly and abruptly tapering at tip (vs. tail tapering gradually to a point in C. pavimentata, Fig.
Calamaria arcana sp. nov. can be distinguished from the sister taxon of C. septentrionalis by having tail abruptly tapering at the tip of end (vs. tail not tapering in C. septentrionalis), higher number of maxillary teeth (10 vs. 8–9 in C. septentrionalis), higher number of ventral scales in males (170 vs. 148–166 in C. septentrionalis), higher numbers of subcaudals in males (22 vs. 15–19 in C. septentrionalis), dorsal scales reduced to five rows at tail (vs. reduced to four rows in C. septentrionalis), absence of black line or spots on venter of tail (vs. venter of tail with broad and distinct median black stripe), absence of dark outermost corners on ventral scales (vs. present in C. septentrionalis, Fig.
The holotype was found active on a cloudy morning along a trail in tall shrubland and secondary forest.
Calamaria arcana sp. nov. is currently only known from a single specimen from its type locality, Mt. Dadongshan, Nanling National Nature Reserve, Guangdong Province, China (Fig.
Comparative characters of the head shape and body coloration of Calamaria arcana sp. nov., C. andersoni, C. septentrionalis, C. pavimentata. A–C dorsal view of head and body, and dorsolateral view of body of C. pavimentata (KFBG 14507). D–F dorsal view of head and body, and dorsolateral view of body of C. septentrionalis (KFBG 14506). G–I dorsal view of head and body, and dorsolateral view of body of holotype of C. arcana sp. nov. (KFBG 14611). J–L dorsal view of head and body, and dorsolateral view of body of C. andersoni (SYS r001699).
Comparison of the tail shape and coloration among Calamaria arcana sp. nov., C. andersoni, C. septentrionalis and C. pavimentata. A–C dorsal, lateral and ventral views of the tail of C. pavimentata (KFBG 14507). D–F dorsal, lateral and ventral views of the tail of C. septentrionalis (KFBG 14506). G–I dorsal, lateral and ventral views of the tail of holotype of C. arcana sp. nov. (KFBG 14611). J–L dorsal, lateral and ventral views of the tail of C. andersoni (SYS r001699).
The description of Calamaria arcana sp. nov. brings the total number of Calamaria species in China to five, namely C. andersoni, C. arcana, C. pavimentata, C. septentrionalis and C. yunnanensis. While new species of Calamaria were continuously described from adjacent country Vietnam in the past decades (
This study was supported by Kadoorie Farm and Botanic Garden, Hong Kong. We would like to thank the provincial and local forestry departments of Guangdong Province for permission to conduct fieldwork and logistics support during the survey. We thank Uwe Fritz, Bryan Stuart, Gernot Vogel and Justin Lee for their valuable comments on the manuscript.
Examined specimens
Calamaria septentrionalis (N = 3). China: Hainan: Bawangling Nature Reserve: KFBG 14506; China: Hong Kong: KFBG 14613; China: Guangdong: Baiyong Nature Reserve: KFBG 14614.
Calamaria pavimentata (N = 3). China: Guangxi: Nonggang Nature Reserve: KFBG 14507, SYS r001725–1726.
Calamaria andersoni (N = 1). China: Yunnan: Yingjiang County: SYS r001699.