No abstract

We describe a new species of the genus Lycodon based on an adult male specimen from Thanh Hoa Province, Vietnam. Lycodon namdongensis sp. nov. is differentiated from its congeners by a combination of the following characters: dorsal scales in 17−17−15 rows, all smooth; supralabials 8; infralabials 10; one large loreal on each side, separated from the eye; cloacal single; ventral scales 218 (plus two preventral scales); subcaudals 85, paired; a total length of 723 mm; tail / total length ratio 0.205; dorsal head pattern whitish grey; dorsal surface of body with 23 narrow greyish cream bands; dorsal surface of tail with 14 cream bands; ventral surface of body mostly cream with a few small dark spots posteriorly; ventral surface of tail dark grey. Based on molecular comparisons, Lycodon namdongensis sp. nov. is recovered as a sister species to L. futsingensis with strong support values from all three analyses. The new species is at least 6.5% genetically divergent from other species within this clade as shown by a fragment of more than 1000 pbs of the mitochondrial cytochrome b. This discovery increases the number of Lycodon species known from Vietnam to 15.

Four species of reptiles, of which one is represented by one of its subspecies, are recorded for the first time from Laos: Cyrtodactylus phongnhakebangensis, Lycodon futsingensis, and Lycodon ruhstrati, as Lycodon ruhstrati abditus, from limestone forests in Khammouane Province and Cyrtodactylus pseudoquadrivirgatus from hill evergreen forest in Salavan Province. These discoveries of lizards and snakes bring the total species number of reptiles to 189 in Laos.

Gia Lai bent-toed gecko (Cyrtodactylus gialaiensis) was firstly described in 2017, and is an endemic species with very restricted distributional range, estimated to be less than 10 km2 in coffee plantation in Gia Lai province, Central Highland of Vietnam. This species is listed as Critically Endangered (CR) in the IUCN Red List. To date, the natural history of this species is totally unknown. In this paper, we provide the first-of-ever natural history data on this highly threatened gecko species, with emphasis on morphometrics, habitat preferences, thermal ecology, and activity patterns. In 23 days of surveys, we captured 42 C. gialaiensis individuals and recaptured 4 of them. Sex ratio was not skewed from equality and juveniles accounted for 23.8% of the observed individuals. The two sexes did not differ in terms of mean Snout-to-Vent Length, Tail Length and weight, but the adult females had longer head than adult males. Geckos were observed at a mean substratum temperature of 24.2±1°C (n=14), and exhibited a mean body temperature of 29.5±2.5°C (n=14). There was no significant correlation between substratum and body temperatures. Body temperatures were significantly higher than substratum temperatures. The study species exhibited a clearly nocturnal above-ground activity, with main peak occurring between 20:00-21:30 h.

We describe a new snake of the genus Achalinus based on an adult female specimen from Ninh Binh Province, Vietnam. Achalinus tranganensis sp. nov. is differentiated from its congeners genetically and by a unique combination of the following characters: 1) maxillary teeth 29; 2) suture between the internasals distinctly longer than that between the prefrontals; 3) loreal distinctly wider than high, extending from the nasal to the eye; 4) dorsal scales in 25–23–23 rows, keeled; 5) two pairs of prefrontals; 6) supralabials six; 7) infralabials six; 8) temporals 2+3, the two anterior temporals in contact with eye; 9) ventrals 171; 10) subcaudals 73+, unpaired; 11) cloacal plate entire; 12) dorsum in preservative reddish to greyish brown above; 13) the lower part of head side and chin region somewhat paler than the dorsum; 14) venter greyish cream, with the anterior region of each ventral and subcaudal somewhat darker. Based on molecular comparisons using a fragment of the mitochondrial cytochrome c oxidase subunit I (COI), the new species differs from other members of the genus by at least 11.8%. This discovery increases the number of Achalinus species known from Vietnam to seven.