Pareas hamptoni (Boulenger, 1905)

Nguyen, Tan Van, Brakels, Peter, Maury, Nathanael, Sudavanh, Somchit, Pawangkhanant, Parinya, Idiiatullina, Sabira, Lorphengsy, Sengvilay, Inkhavilay, Khamla, Suwannapoom, Chatmongkon & Poyarkov, Nikolay A., 2020, New herpetofaunal observations from Laos based on photo records, Amphibian & Reptile Conservation (e 248) 14 (2), pp. 218-249 : 238-239

Pareas hamptoni (Boulenger, 1905)

Hampton’s Slug Snake ( Fig. 9D )

Three adult individuals of P. hamptoni were observed by P. Brakels and N. Maury on 28 December 2018, in Bortaen District site 1, Xaignabouli Province (17°43.118’N, 101°06.670’E; elevation 1,400 m asl) and by P. Brakels, P. Pawangkhanant, S. Idiiatullina, and T. V. Nguyen on 17 July 2019 in Longcheng District site 1, Xaisomboun Province (19°00.983’N, 102°59.645’E; elevation 1,370 m asl) .

Morphological characters of the individuals from Xaignabouli and Xaisomboun provinces agreed well with the descriptions of Smith (1943), Guo et al. (2009), Vogel (2009), and Wang et al. (2019). The photographed individual ( Fig. 9D ) agrees with the diagnosis of P. hamptoni in the following characters: body small-sized, slender, compressed laterally; head elongate, distinct from neck; eye moderately large; pupil vertical; loreal present; 1 preocular; 1 postocular; 1 crescent-like subocular; 1 anterior temporal; 2 posterior temporals; 7 supralabials, 1 st and 2 nd in contact with the nasal, 2 nd in contact with loreal, 2 nd –5 th supralabials in contact with suboculars, not contacting the eye, 7 th largest; prefrontals in contact with eye; mental groove absent; dorsal scale rows smooth; anterior vertebral scales slightly enlarged; ventrals 188; cloacal undivided; subcaudals 78, divided. Coloration of dorsum brown with blackish-brown bars or spots on the flanks, head with a thick black line extending from above the eye to the nape; ventral surface orange with some small black spots; iris orange.

Ecological notes. The individuals from Bortaen District were observed at ca. 2100 h at a height of ca. 3–5 m in a tree, while the individuals from Longcheng District were found at ca. 2000–2100 h on the rocks and in the trees along a stream. The surrounding habitat at both sites was montane mixed secondary evergreen forest of small hardwoods, shrubs, and arrowroot.

Distribution. In Laos, this species has been previously recorded only from Houaphan and Champasak provinces ( Teynié and David 2010; Teynié et al. 2014). This is the third record from the country as well as the first from northwestern Laos and from Xaisomboun and Xaignabouli provinces. Elsewhere, this species has been reported from China, Myanmar, Vietnam, Cambodia, and Thailand ( Uetz et al. 2020).

Remarks. A number of recent molecular phylogenetic studies demonstrated that populations of P. hamptoni from Vietnam and southeastern China are more closely related to P. formosensis (Van Denburgh) , than to typical P. hamptoni from the western part of Yunnan Province of China and, supposedly, Myanmar ( You et al. 2015; Li et al. 2020). Li et al. (2020) refer the Indochinese populations of this species as P. formosensis , however populations from Laos were not included in the molecular phylogenetic analysis so their taxonomic status requires further study.

Figures

Fig. 9. (A) Bungarus candidus in Khongxedone District, Salavan Province; (B) Subsessor bocourti in Champhone District, Savannakhet Province; (C) Pareas carinatus in Keo Oudom District, Vientiane Province; (D) P. hamptoni in Longcheng District, Xaisomboun Province. Photos by P. Brakels (A–C) and P. Pawangkhanant (D).