Pareas macularius Theobald, 1868

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 : 239-240

Pareas macularius Theobald, 1868

Spotted Slug Snake ( Fig. 10A )

One adult individual of P. macularius was observed 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) . Two subadults were observed by N. Maury and P. Brakels on 24–25 October 2019 in Paksong (2) District , Champasak Province (near 15°11.178’N, 106°15.716’E; elevation 1,350 m asl) .

Morphological characters of the individuals from Xaisomboun and Champasak provinces agreed well with the descriptions of Teynié and David (2010) and Hauser (2017). The photographed individual ( Fig. 10A ) agrees with the diagnosis of P. macularius in the following characters: body small-sized, slender, laterally compressed; head elongate, distinct from neck; eye size medium; pupil vertical; loreal present, not entering the orbit; 1 preocular; 1 postoculars; 1 crescent–like subocular; 1 anterior temporal; 2 posterior temporals; 7 supralabials, 1 st and 2 nd in contact with nasal, 2 nd in contact with loreal, 3 rd –5 th supralabials in contact with suboculars, not contacting the eye, 7 th largest; prefrontals in contact with eye; mental groove absent; upper dorsal scale rows slightly keeled; anterior vertebral scales slightly enlarged; ventrals 156; cloacal undivided; subcaudals 44, divided. Coloration of dorsum dark grayish-brown with irregular black or white spots localized always on single scales; nuchal region with and grayish-white “W-shaped” marking sparsely speckled with brown; ventral surfaces cream with dense speckling and few larger blotches; iris dark.

Ecological notes. The individual at Xaisomboun Province was found at 2300 h crossing the mountain dirt road. The surrounding habitat was secondary montane evergreen forest. The first individual from Champasak Province was found on a path in a coffee plantation at ca. 1830 h and the second individual was found in a patch of secondary mixed evergreen forest along a coffee plantation at ca. 1900 h.

Distribution. In Laos, this species has been previously recorded from Phongsali and Houaphan provinces ( Hauser 2017). These are the first records from Xaisomboun and Champasak provinces. Elsewhere, this species has been reported from China, Myanmar, Vietnam, and Thailand ( Uetz et al. 2020).

Figures

Fig. 10. (A) Pareas macularius in Longcheng District, Xaisomboun Province; (B) P. margaritophorus in Khounkham District, Khammouan Province; (C) adult male and (D) adult female of Trimeresurus gumprechti in Bortaen District, Xaignabouli Province; (E) adult male and (F) adult female of T. popeiorum in Xay District, Oudomxai Province. Photos by P. Brakels (A, C–F) and N. Maury (B).