Sunday, July 10, 2022

[Herpetology • 2021] Tropidophorus guangxiensis hongjiangensis • Neotype Designation and Redescription of Tropidophorus guangxiensis Wen, 1992 (Sauria: Scincidae), with Description of A New Subspecies from central South China


Tropidophorus guangxiensis hongjiangensis Guo & Deng, 

in Guo, Shu, Wu, ... et Deng, 2021.

The genus Tropidophorus consists of small semi-aquatic lizards that dwell in lowland forest steams (Barbour, 1921; Bauer & Jackman, 2008). Here, we designate the neotype and re-describe T. guangxiensis Wen, 1992 based on newly collected topotypic specimens. We also describe a new subspecies from Xuefeng Mountain, Hongjiang County, Hunan Province, central South China. Based on two mitochondrial genes (12S rRNA and 16S rRNA), the phylogenetic position of T. guangxiensis is allocated for the first time. Additionally, our data strongly support that the new subspecies is phylogenetically closely related to T. g. guangxiensis. We also present a morphological identification key for known species and subspecies of Tropidophorus in China.


Tropidophorus guangxiensis guangxiensis Wen, 1992

Chresonymy: Tropidophorus guangxiensis
Wen YT, 1992, Asiatic Herpetological Research, Berkeley, 4: 18–22. 
Type locality: Damingshan, Wuming Xian (county), Guangxi Zhuang Autonomous Region, China, 1 240 m a.s.l.

Diagnosis: Upper head scales strongly striated; supranasal absent; frontonasals 2, joined, longer than wide; prefrontals 2, joined or separated by small scale; interparietal single and small, without small transparent spot; parietals separated by interparietal, posterolateral border surrounded by 5–6 scales on each side; nuchal scales absent; supraciliaries 8, supraciliary row complete along length of lateral edge of supraoculars; loreals 2; presuboculars 1, upper anterior and lower posterior margin slightly convex, and terminal pointed; supralabials 8; infralabials 6–7; shallow groove on loreal-labial border, from posterior corner of nasal across subocular obliquely downward to end of sixth supralabial; midbody scales in 28–29 rows; paravertebral scales 45–50, not widened; ventral scales 50–53; midbody ventral scales 27–29; ventral scales of neck keeled; scale rows at tenth subcaudal 11–13; lamellae under fourth toe 17–18; scales of limbs keeled above and below; supralabials and infralabials black, each scale with white spot center; chin and throat grayish white with black marble; ventral of neck gray, each scale white in middle forming longitudinal white stripes; venter yellowish white; underside of tail white, subcaudals darkened on both sides, forming longitudinal white stripes.

Distribution and ecology: Tropidophorus guangxiensis guangxiensis is currently known only from the Daming Mountain National Nature Reserve (type locality) and Mulun Nature Reserve in Guangxi Zhuang Autonomous Region, southern China (Figure 1A; Supplementary Table S6). Individuals were found beneath withered branches and fallen leaves in roadside ditches under evergreen broadleaf forest at 1 240–1 280 m a.s.l. (Supplementary Figure S4). These skinks are known to be active in late August, but their diet and reproductive biology remain unknown. This subspecies is sympatric with Gonyosoma frenatum (Gray, 1853), Pareas boulengeri (Angel, 1920), and Takydromus sp.


    

Type specimens of Tropidophorus guangxiensis hongjiangensis ssp. nov. Guo & Deng
 C, D: Dorsal, ventral, and lateral views of head of neotype (HNU GKJ-2016009) in preserved sample (C) and paraneotype (HNU GKJ-200704003) in life (D). Scale bars: 0.5 cm.
E, F: Dorsal and ventral views of neotype body (HNU GKJ-2016009) in preserved sample (E) and paraneotype body (HNU GKJ-200704003) (F). Scale bars: 2 cm.
 Photos by Ke-Ji Guo.
 
Tropidophorus guangxiensis hongjiangensis ssp. nov. Guo & Deng  

Chresonymy: Tropidophorus guangxiensis:
 Guo KJ, Mi XQ and Deng XJ, 2010, Chinese Journal of Zoology, 45(1):159–162; Mi XQ, Xiong JW, Shu Y, Huang Z, Guo KJ, Huang Y, et al. 2012. Hunan Forestry Science & Technology, 39(4), 50–53.
 
Etymology: This new subspecies is named after its type locality in “Hongjiang County.”

Diagnosis: Loreals 2; infralabials 6; supralabials 8; paravertebral scales 45–47; parietals separated; supraciliaries 6–8; supraciliary row complete; upper anterior and lower posterior margin of presuboculars slightly concave, terminal blunt and rounded; scales on upper head and dorsal body striated or keeled; ventral scales smooth; midbody scale rows 30–33; lamellae under fourth toe 16–19; throat and ventral of neck black; ventral limbs brown, darker than ventral body; middle and posterior ventral tail black.

Distribution: Tropidophorus guangxiensis hongjiangensis ssp. nov. is currently known only from the Xuefeng Mountain National Forest Park in Hongjiang County, Hunan Province, China (Figure 1A; Supplementary Table S6).

Natural history: Tropidophorus guangxiensis hongjiangensis ssp. nov. is a semi-aquatic, leaf-litter specialist inhabiting the forest floor of subtropical evergreen broadleaf and mixed forests. Specimens were collected in the late afternoon and evening (1600–2200 h) from under withered branches and fallen leaves in roadside ditches (Supplementary Figure S5), or near rocky forest streams. The diet of the new subspecies remains unknown. The gravid female holotype carried four eggs on 5 June 2016. This subspecies is sympatric with Plestiodon elegans (Boulenger, 1887), Oreocryptophis porphyraceus (Cantor, 1839), Pareas stanleyi (Boulenger, 1914), and Takydromus intermedius Stejneger, 1924.


Ke-Ji Guo, Fu Shu, Nan-Fei Wu, Shun-De Chen, Mian Hou, Sheng-Chao Shi and Xue-Jian Deng. 2021. Neotype Designation and Redescription of Tropidophorus guangxiensis Wen, 1992 (Squamata: Sauria: Scincidae), with Description of A New Subspecies from central South China. Zoological Research. 42(5); 606-613. DOI: 10.24272/j.issn.2095-8137.2020.363