Research Article |
Corresponding author: Shuo Qi ( qishuo1992@outlook.com ) Academic editor: Philipp Wagner
© 2022 Shuo Qi, Jin-Long Ren, Zeng Wang, Hao-Cong Yang, Ke Jiang.
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:
Qi S, Ren J-L, Wang Z, Yang H-C, Jiang K (2022) On the occurrence of Lygosoma siamense Siler, Heitz, Davis, Freitas, Aowphol, Termprayoon & Grismer, 2018 (Squamata, Scincidae) in China. Herpetozoa 35: 51-58. https://doi.org/10.3897/herpetozoa.35.e80151
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The genus Lygosoma Hardwicke & Gray, 1827 is a group of semi-fossorial supple skink from Southeast Asia, the members of which are still understudied in Indochina. Lysosoma quadrupes (Linnaeus, 1766) was once recorded from China based on historical literature; until recent its Indochina specimens were revised and placed into a newly described species, i.e., L. siamense Siler, Heitz, Davis, Freitas, Aowphol, Termprayoon & Grismer, 2018. However, Lygosoma quadrupes had long been unknown from China but the historical record had not been confirmed. Here we report a vouchered record for L. siamense from China for the first time based on four specimens collected in Sanya, Hainan, China. Furthermore, the taxonomic history of Lygosoma from China is also reviewed.
distribution, supple skink, taxonomic revision, taxonomy, writhing skink
The genus Lygosoma Hardwicke & Gray, 1827 is generally known as writhing skink or supple skink, which formerly contained more than 30 species distributed across Africa, India, Southeast Asia, the western and southern Philippines, as well as Christmas Island (Australia) (
The type species of Lygosoma, L. quadrupes (Linnaeus, 1766) was previously known as a widely distributed species, from Indochina, Thailand, southern China (including Hong Kong), Western Malaysia, Indonesia, and the Philippines (
For example, L. quadrupes was once recorded from China (including “South China” and “Hong Kong”) based on historical literature (
During a recent field survey from 2019 to 2021, four elongate-bodied skink specimens were collected in Sanya City, Hainan Province, southern China. The results of morphological comparisons and molecular analysis indicated these specimens should be referred to Lygosoma siamense, thus we confirm the distribution of L. siamense in Hainan Island, southern China. Furthermore, we provide the first detailed description of L. siamense in China, the coloration in life, and life history of this semi-fossorial species.
Four specimens of Lygosoma siamense were collected from Linchunling Forest Park, Sanya City (18°15.8151'N, 109°31.2985'E; ca 109 m a.s.l.), Hainan Province, southern China. Muscle or liver samples were dissected from euthanized specimens, preserved in 95% ethanol and stored at –40 °C. The specimens were fixed in 10% buffered formalin and later transferred to 70% ethanol, and deposited in the Museum of Biology, Sun Yat-sen University (
Genomic DNA was extracted from muscular tissue using a DNA extraction kit from Tiangen Biotech (Beijing) Co., Ltd. We sequenced partial segments of the mitochondrial 16S rRNA gene (16S) of the two samples of Lygosoma siamense from China (specimen voucher number:
Six sequences from five known Lygosoma species plus two outgroup sequences from Subdoluseps bowringii Günther, 1864, which were used to root the tree, were obtained from GenBank and composed the dataset (Table
Localities, voucher information, and GenBank accession numbers for all specimens used in this study.
Species name | Locality | Specimen voucher | 16S | References |
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Ingroup: Lygosoma | ||||
(1) L. isodactylum | Vietnam | FMNH 262154 | MK414547 |
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(2) L. koratense | Thailand | N/A | AB028817 |
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(3) L. quadrupes | Indonesia | ENS 13639 | MG367368 |
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(4) L. siamense | Sanya, Hainan, China |
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OM569680 | This study |
(5) L. siamense | Sanya, Hainan, China |
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OM569681 | This study |
(6) L. siamense | Thailand | N/A | AB028818 |
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(7) L. tabonorum | Philippines | PNM9820 | MK414557 |
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(8) L. tabonorum | Philippines | PNM9821 | MG367367 |
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Outgroup: Subdoluseps | ||||
(9) S. bowringii | Cambodia | FMNH 261839 | MK414544 |
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(10) S. bowringii | Malaysia | LSUHC 7993 | MK414545 |
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Measurements were taken following
Sex was determined by dissection. Enlarged gonads were considered evidence of adulthood.
The ML and BI analyses resulted in identical topologies (Fig.
Uncorrected p-distance (%) of 16S rRNA fragment among five Lygosoma species used in this study.
Species name | Specimen voucher | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
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1 | Lygosoma isodactylum | FMNH 262154 | 0.00 | |||||||
2 | Lygosoma koratense | N/A | 10.57 | |||||||
3 | Lygosoma quadrupes | ENS 13639 | 5.85 | 9.58 | ||||||
4 | Lygosoma siamense |
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4.33 | 9.11 | 5.19 | |||||
5 | Lygosoma siamense |
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4.33 | 9.11 | 5.19 | 0.00 | ||||
6 | Lygosoma siamense | N/A | 4.12 | 9.59 | 4.97 | 0.99 | 0.99 | |||
7 | Lygosoma tabonorum | PNM 9820 | 6.97 | 9.58 | 1.99 | 6.26 | 6.26 | 6.04 | ||
8 | Lygosoma tabonorum | PNM 9821 | 7.19 | 9.82 | 2.20 | 6.48 | 6.48 | 6.26 | 0.20 | 0.00 |
Measurements (mm) and scale counts of Lygosoma siamense from China. See materials and methods for abbreviations. * indicates dropped or regenerated tail.
Sex | SVL | AGD | MBW | MBD | TL | TW | TD | HL | HW | HD | ED | END | |
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Male | 72.2 | 56.0 | 5.2 | 4.1 | 57.9 | 4.1 | 3.7 | 6.1 | 4.7 | 3.6 | 1.3 | 1.5 |
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Subadult | 49.3 | 35.7 | 3.7 | 2.4 | 33.7* | 2.4 | 2.0 | 4.2 | 3.8 | 2.0 | 1.1 | 1.2 |
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Subadult | 46.2 | 33.7 | 3.4 | 2.4 | 23.9* | 2.3 | 2.0 | 4.1 | 3.7 | 1.8 | 1.0 | 1.1 |
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Subadult | 41.7 | 28.6 | N/A | N/A | 2.6* | N/A | N/A | 3.5 | N/A | N/A | 0.8 | 0.8 |
SNL | IND | FLL | HLL | MBSRC | AGSRC | PVSRC | Fin3Lam | Toe4Lam | SuprL | InfrL | SO | SC | |
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2.6 | 1.1 | 3.2 | 6.1 | 27 | 89 | 119 | 5 | 7 | 6 | 6 | 4 | 6 |
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1.9 | 1.0 | 2.4 | 4.0 | 25 | 94 | 119 | 5 | 6 | 6 | 6 | 4 | 6 |
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1.9 | 0.9 | 2.2 | 3.8 | 27 | 92 | 116 | 5 | 5 | 6 | 7 | 4 | 6 |
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1.2 | 0.6 | 2.0 | 3.2 | 24 | 95 | 115 | 5 | 6 | 7 | 6 | 4 | 6 |
Family Scincidae Gray, 1825
Genus Lygosoma Hardwicke & Gray, 1828
Lygosoma siamensis Siler, Heitz, Davis, Freitas, Aowphol, Termprayoon & Grismer, 2018, J. Herpetol., 52 (3): 339, figs 4–5. Holotype: FMNH 177496 (field no. EHT 1390; figs 4, 5), adult male, collected on 7 June 1956 in Thailand, Pattani Province by E. H. Taylor.
Lygosoma chalcides — Boulenger, 1887: 340 (in part).
Lygosoma quadrupes
— Smith, 1935: 290 (in part); Taylor, 1963: 1049;
Lygosoma siamensis
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Lygosoma siamense
—
The species name siamense was derived from the exonym “Siam”, a term formerly used as the name of Thailand. The name was chosen in recognition of Thailand as the center of the species’ known distribution (
The grammatical gender of the generic nomen Lygosoma Hardwicke & Gray, 1827 has been confused in the literature where it was treated as both feminine (
Siamese Supple Skink (in English); 泰国蝘蜓 (Tài Guó Yán Tíng) (in Chinese).
Main description according to an original tail adult specimen (
Body small, slender, SVL 72.2 mm; head small, weakly differentiated from neck, roughly equal in width to body, HL 6.1 mm, HW 4.7 mm, HD 3.6 mm; snout slightly pointed, rounded in dorsal and lateral profile; head scales large, smooth, SNL 42.6% HL; external ear opening small, transverse diameter slightly larger than longitudinal diameter; eyes small, ED 21.3% HL, 86.7% END; body moderately depressed, nearly uniform in thickness, MBW 126.8% MBD; scales smooth, glossy, imbricate; longitudinal scale rows at midbody 27 (24–27); paravertebral scale rows 119 (115–119); axilla-groin scale rows 89 (92–95); limbs short, diminutive, pentadactyl; Finger III lamellae five, Toe IV lamellae seven; FLL 5.7% AGD, 4.4% SVL; HLL 10.9% AGD, 8.4% SVL; original TL 56.0 mm, SVL/TL=1.29, tail nearly as wide as body, gradually tapered towards end, TW 78.8% MBW.
Rostral wider than high, in contact with first supralabials and nasals laterally, frontonasal dorsally; frontonasal wider than long, single, in contact with nasal and first loreal laterally, prefrontal and frontal posteriorly; nostril ovoid; supranasals present; postnasals small, triangular-shaped; prefrontals small, widely separated, contacting loreals laterally, first superciliary and frontal posteriorly; frontal large, its anterior margin in broad contact with frontonasal, contacting first two supraoculars laterally; four supraoculars; frontoparietals fused into single large scale, in contact with all four supraoculars laterally and parietals and interparietal posteriorly; interparietal somewhat triangular-shaped, eyespot present posteriorly; parietals in broad contact medially behind interparietal; enlarged nuchals absent; two loreals contacting supralabials; supralabials six, first and sixth largest, fourth and fifth subocular; two preoculars, lower much larger than upper; uninterrupted superciliaries six, first one large, in contact prefrontal anteriorly, first supraoculars dorsally; subocular scale row complete, in contact with supralabials; lower eyelid bearing scales; postoculars two; primary temporals two; secondary temporals two, larger than primary temporals; infralabials six, first two contacting postmental, first smaller than second; mental wider than long, in contact with first infralabial laterally, postmental posteriorly; postmental large, single; two pairs of large chin-shields, first pair in contact, second pair narrowly separated by single medial scale; scales on limbs smaller than body scales; single row of supradigitals (Figs
Four specimens (
The general aspect and close-up views of the adult male specimen of Lygosoma siamense (
All four specimens were collected during the day, beneath flowerpots, leaf litter substrates or other surface material. Their reduced limbs are folded alongside body during rapid locomotion (
Diet and reproductive habits remain poorly known. Nevertheless, a large number of ants were observed where the specimens were collected, and probably served as their main food source, which was similar to the habitats as inferred from
The distribution of Lygosoma chalcides (now L. quadrupes) from Southern China was provided by
On the other hand, the exact time of the delisting of L. quadrupes from China is also not clear. Although previous studies indeed recorded L. quadrupes in China (1887–1963;
We thank Ye-Jie Lin (Institute of Zoology, Chinese Academy of Sciences), Jun-Jie Huang (Chengdu Institute of Biology, Chinese Academy of Sciences), Tian-Yu Qian (Central South University of Forestry and Technology), and Ying-Yong Wang (Sun Yat-Sen University), for their help in the fieldwork and the manuscript preparation. We thank L. Lee Grismer and Philipp Wagner for their helpful comments and suggestions on the manuscript. This work was supported by DFGP Project of Fauna of Guangdong-202115, the National Animal Collection Resource Center, China, and Biological Resources Programme, Chinese Academy of Sciences (KFJ-BRP-017-65).