 |
| Lycodon pictus
Janssen, Pham, Ngo, Le, Nguyen and Ziegler, 2019
|
Abstract
A new species of the genus Lycodon is described from Cao Bang Province, Vietnam, based on three individuals with distinct differences in morphology and molecular data. The new species is differentiated from its congeners by a combination of the following characters: dorsal scales in 17-17-15 rows, smooth throughout; supralabials usually eight (rarely nine); infralabials ten; one elongated loreal on each side, in contact with the eye; precloacal plate single; ventral scales 212–218 (plus one or two preventral scales); subcaudals 90 or 91; maxillary teeth 13 or 14; dorsal surface of body with 28 or 29 light body bands; dorsal surface of tail with 13 cream bands, forming a distinct blotch in the vertebral region. Based on phylogenetic analyses of mitochondrial cytochrome b sequence data, the new species is recovered as the sister species to a clade containing L. multizonatus and L. liuchengchaoi with strong support from the Bayesian analysis. The new species is at least 7.5% divergent from other species within this clade in uncorrected pairwise distance calculated using a fragment of more than 1000 bp of the mitochondrial cytochrome b. This discovery increases the number of Lycodon species known from Vietnam to 16.
Keywords: Cao Bang Province, Lycodon pictus sp. nov., morphology, phylogeny, taxonomy
 |
| Figure 2. Holotype of Lycodon pictus sp. nov. (IEBR 4166) in life. Photograph T. Lehmann. |
Lycodon pictus sp. nov.
Diagnosis: Lycodon pictus sp. nov. can be differentiated from its congeners by the following morphological characters: dorsal scales in 17–17–15 rows, all smooth; supralabials usually eight (rarely nine); infralabials ten; one elongated loreal on each side, in contact with the eye; precloacal plate single; ventral scales 212–218 (plus one or two preventral scales); subcaudals 90 or 91; a total length of 597+ mm in males and 543 mm in females; tail / total length ratio 0.211–0.215; maxillary teeth 13 or 14; dorsal surface of body with 28 or 29 light body bands; dorsal surface of tail with 13 cream bands forming a distinct blotch in the vertebral region; ventral surface of body and tail mostly cream with the dark body bands in part extending towards the venter, sometimes forming complete dark bands around the body.
...
 |
| Figure 4. Female paratype of Lycodon pictus sp. nov. (ZFMK 93746) in life. Photographs T.Q. Nguyen. |
 |
| Figure 8. Habitat of Lycodon pictus sp. nov.: the female paratype (ZFMK 93746) was found in Ha Lang District, Cao Bang Province. |
 |
| Figure 7. Map showing the type locality of Lycodon pictus sp. nov. in Cao Bang Province. |
Distribution: Lycodon pictus sp. nov. is currently known only from Ha Lang and Trung Khanh districts, Cao Bang Province, northern Vietnam (Fig. 7).
Etymology: The name of the species pictus means painted or decorated in Latin and refers to its unique dorsal colour pattern.
Natural history: Lycodon pictus sp. nov. seems to be closely associated with karst environment. Specimens were found at night between 19:00 and 23:00, on forest paths or on the ground near cave entrances. The surrounding habitat was secondary karst forest, consisting of medium and small hardwood trees mixed with shrubs and vines. Air temperature was 23.4–29.6°C and humidity was 66–79%. Other reptiles were also found at the site, including Acanthosaura lepidogaster (Cuvier, 1829), Gekko adleri Nguyen, Wang, Yang, Lehmann, Le, Ziegler & Bonkowski, 2013, Goniurosaurus luii Grismer, Viets & Boyle, 1999, Lycodon futsingensis (Pope, 1928), and Protobothrops trungkhanhensis Orlov, Ryabov & Nguyen, 2009 (Fig. 8).
Helen Y. Janssen, Cuong T. Pham, Hanh Thi Ngo, Minh Duc Le, Truong Q. Nguyen, Thomas Ziegler. 2019. A New Species of Lycodon Boie, 1826 (Serpentes, Colubridae) from northern Vietnam. ZooKeys. 875: 1-29. DOI: 10.3897/zookeys.875.35933