Monday, June 27, 2022

[Herpetology • 2022] Calamaria arcana • A New Species of Calamaria (Serpentes: Colubridae: Calamariinae) from Guangdong Province, southern China


Calamaria arcana 
Yeung, Lau & Yang, 2022

Lingnan Reed Snake | 岭南两头蛇  ||  DOI: 10.3897/vz.72.e84516
Photographs by Michael W.N. Lau. 

Abstract
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.

Keywords: Calamaria arcana sp. nov., Calamariinae, integrative taxonomy, morphology, phylogeny, snake, Southeast Asia

  Head of the holotype of Calamaria arcana sp. nov. (KFBG 14611):
 A right side B left side C dorsal view D ventral view.

Holotype of Calamaria arcana sp. nov. (KFBG 14611) in life:
 A dorsolateral view B ventral view C lateral view of left side of head.
Photographs by Michael W.N. Lau. 


Calamaria arcana sp. nov.
 
Calamaria pavimentata – Kadoorie Farm and Botanic Garden (2003); 
Li et al. (2011).

Suggested common names: Lingnan Reed Snake (English), 
岭南两头蛇 (Chinese)

Diagnosis: 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 (Inger and Marx 1965; Ziegler et al. 2008).

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.


Etymology: 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.


Ho Yuen Yeung, Michael W. N. Lau and Jian-Huan Yang. 2022. A New Species of Calamaria (Squamata: Colubridae) from Guangdong Province, southern China. Vertebrate Zoology. 72: 433-444. DOI: 10.3897/vz.72.e84516