Gekko sengchanthavongi, Luu, Vinh Quang, Calame, Thomas, Nguyen, Truong Quang, Le, Minh Duc & Ziegler, Thomas, 2015

Luu, Vinh Quang, Calame, Thomas, Nguyen, Truong Quang, Le, Minh Duc & Ziegler, Thomas, 2015, Morphological and molecular review of the Gekko diversity of Laos with descriptions of three new species, Zootaxa 3986 (3), pp. 279-306 : 290-299

Gekko sengchanthavongi sp. nov.

( Fig. 7 )

Holotype. VFU R.2014.14, adult male, in karst forest of Bualapha Town (17o19.444’N, 105o41.576’E, at an elevation of 210 m a.s.l.), Khammouane Province, central Laos, collected by Vinh Quang Luu and Thidtavanh Suliyavong on 20 June 2014 .

Paratypes. Two adult males NUOL R-2015.3, IEBR A.2015.33 and one adult female VFU R.2014.16, the same data as the holotype .

Diagnosis. Gekko sengchanthavongi sp. nov. can be distinguished from its congeners in the Gekko japonicus group by a combination of the following characters: a medium-sized gecko species (SVL 67.7–77.3 mm); nares in contact with rostral; internasals absent; postmentals enlarged; supralabials 8–10; infralabials 6 or 7; dorsal tubercles absent; ventral scale rows from mental to cloacal slit 175–184; scale rows around midbody 120–135; ventral scale rows 35–43; webbing weakly developed between fingers and toes; tubercles on dorsal surface of limbs and tail absent; precloacal pores 3+1 or 3+ 2 in the males, separated from each other by one poreless scales, absent in the female; postcloacal tubercles 2/2; subcaudals enlarged; dorsum with dark bars.

Description of holotype. Adult male, total length 146.8 mm (SVL 67.7 mm, TaL 79.1 mm); body slender, elongate (ratio of AG/SVL 0.44); head longer than wide (ratio of HL/HW 1.48); rostral quadrangular, two times wider than high (ratio of RW/RH 2.14) and wider than mental (ratio of RW/MW 1.36 mm), without medial suture; rostral bordered by first supralabial and supranasal on each side; nostrils round, surrounded by rostral, first supralabial, supranasal, and two enlarged nasals posteriorly; posterior nasal region deeply concave; internasals absent; preorbital scales 17, preorbital region slightly concave; interorbital sacles 28; eye large (ratio of OD/HL 0.24), pupil vertical, superciliaries with six tiny spines posteriorly; ear oval–shaped, oblique, approximately half of eye diameter (ratio of TD/OD 0.48); mental triangular, wider than long (ratio of MW/ML 1.57); enlarged postmentals two, hexagonal, two times longer than wide, bordered by mental, first infralabial on each side and 6 gular scales posteriorly, outer gular scales larger than inner scales; supralabials 10/9; infralabials 7/7; dorsal scales smooth, small, round or oval, granular and juxtaposed; lateral skin folds present; ventral scales smooth, medial scales 3 or 4 times larger than dorsal scales, and largest in the middle of belly; ventral scales at midbody 35; scale rows around midbody 126; ventral scale rows between mental and cloacal slit 179; scales on dorsal limbs slightly enlarged; tubercles on limbs absent; enlarged femoral scales absent; fingers and toes webbed at base; subdigital lamellae under first finger 12/11, under fourth finger 14/13, under first toe 13/11, under fourth toe 15/15; precloacal pores 3+2, separated by one poreless scale, precloacal scales enlarged; postcloacal tubercles 2/2; tail basally thickened, without dorsal tubercles; subcaudals enlarged, smooth.

Coloration in life. Ground coloration of dorsal head dark brown; dorsal head and neck with dark and grey spots; dorsum with six bands between limb insertions, edged in yellowish brown, and irregular transverse dark brown bars; dorsal surface of limbs with dark blotches; dorsal surface of tail grey with 10 or 11 dark bands, edged in white; chin, throat, dorsolateral region and lower surface of limbs grey with light spots; chest, middle of belly grey; ventral tail grey in anterior part and with nearly closed bands in posterior part.

Sexual dimorphism. Measurements and scalation characters of the female paratype are provided in Table 4 . The following scale counts slightly vary between the female and males: scale rows in line from mental to the front of cloacal slit 175 (179–184 in males), and precloacal pores absent in the female paratype.

Comparisons. Based on examination of specimens and data obtained from the literature ( Boulenger 1907; Ota et al. 1995; Rösler et al. 2005, 2010, 2011; Yang et al. 2012, Nguyen et al. 2013; Luu et al. 2014; Ngo et al. 2015; Yang 2015) we compared the new species from Laos with its congeners of the Gekko japonicus group sensu Rösler et al. (2011) (see Table 5).

Both correspondence and cluster analyses supported Gekko sengchanthavongi sp. nov. as a sister taxon to G. bonkowskii sp. nov. and G. thakhekensis ( Figs. 3−4 ). Molecular phylogenetic analyses also demonstrated the close relationships between these species (see Fig. 1 ).

Gekko sengchanthavongi sp. nov. is lacking dorsal tubercles, which are present in the following species: G. adleri , G. auriverrucosus , G. c a n h i, G. chinensis , G. japonicus , G. hokouensis , G. kwangsiensis , G. liboensis , G. palmatus , G. scabridus , G. shibatai , G. similignum , G. swinhonis , G. vertebralis , G. wenxianensis .

Gekko sengchanthavongi sp. nov. differs from G. aaronbaueri by having fewer supralabials and infralabials (8–10 versus 13 or 14 and 6 or 7 versus 10 or 11, respectively), fewer interorbital scales (28–32 versus 34–37), more scale rows around midbody (120–135 versus 98–104), fewer lamellae under first toes (11–14 versus 14–17), and more precoloacal pores in males (4 or 5 versus 3 or 4); from G. bonkowskii sp. nov. by a larger size (SVL reaching 77.3 versus 69.2), having fewer supralabials and infralabials (8–10 versus 12–14 and 6 or 7 versus 10 or 11, respectively), more interorbitals (28–32 versus 26 or 27), more scales from mental to cloacal slit (175–184 versus 154–169), more scale rows around midbody (120–135 versus 117), and fewer precloacal pores in males (4 or 5 versus 6); from G. melli by having a smaller size (SVL reaching 77.3 versus 84.6 mm), the absence of internasal (versus present), postmentals enlarged (versus not enlarged), fewer infralabials (6 or 7 versus 9–12), fewer scale rows around midbody (120–135 versus 147–160), fewer ventral scales (35–43 versus 43–49), and fewer precloacal pores in males (4 or 5 versus 9–11); from G. scientiadventura by its larger size (SVL reaching 77.3 versus 73.0 mm), having fewer interorbitals (28–32 versus 41–51), more scales from mental to cloacal slit (175–184 versus 118–140), fewer scale rows around midbody (120–135 versus 139–143), and fewer precloacal pores in males (4 or 5 versus 5–8); from G. subpalmatus by the absence of internasals (versus present), having fewer infralabials (6 or 7 versus 7–12), postmentals enlarged (versus not enlarged), fewer ventral scales (35–43 versus 48), and fewer precloacal pores in males (4 or 5 versus 5–11); from G. t a i b a i e n s i s by its larger size (SVL reaching 77.3 versus 69.0 mm), having fewer infralabials (6 or 7 versus 8–10), having more lamellae under first and fourth toes (11–14 versus 6 or 7 and 13–17 versus 7 or 8, respectively); from G. tawaensis by its larger size (SVL reaching 77.3 versus 71.0 mm) the absence of internasals (versus present), postmentals enlarged (versus not enlarged), and the presence of precloacal pores in males (versus absent); from G. thakhekensis by having fewer infralabials (6 or 7 versus 10 or 11), more ventral scales between mental and cloacal slit (175–184 versus 165–174), more precloacal pores in males (6 versus 1–5), more scale rows around midbody (120–135 versus 110–116), and color pattern of dorsum (banded versus blotches); from G. truongi by its smaller size (SVL reaching 77.3 versus 95.9 mm), having more ventral scales between mental and cloacal slit (175–184 versus 160–172), and fewer precloacal pores in males (4 or 5 versus 10–11); and from G. yakuensis by the absence of internasals (versus present), having postmentals enlarged (versus not enlarged), fewer precloacal pores in males (4 or 5 versus 6–8), and the absence of dorsal tubercles on tail (versus present).

Distribution. G. sengchanthavongi sp. nov. is currently known only from the type locality in Bualapha Town, Khammouane Province, central Laos ( Fig. 5 ).

Etymology. We name the new species in honour of Mr. Sinnasone Sengchanthavong, Natural Resources and Environment Department of Khammouane Province, Laos, in recognition of his great support of our field research in Hin Nam No NPA. As common names, we suggest Sengchanthavong’s Gecko (English) , Kap Ke Sengchanthavong (Laotian), and Sengchanthavongis Gecko (German) .

TABLE 5. Morphological comparisons among the species of the Gekko japonicus group (modified after Luu et al. 2014, extended by Ngo et al. 2015, Yang 2015, abbreviations defined in text, data unavailable).

Character G. bonkowskii G. aaronbaueri adleri auriverrucosus canhi chinensis japonicus hokouensis kwangsiensis

sp. nov. sengchanthavongi

sp.nov.

Maximum SVL (mm) 69.2 77.3 80.0 75.3 69 99.2 72 74 70 69.7 ......continued on the next page Continued.

......continued on the next page TABLE 5. (Continued) ......continued on the next page Continued.

......continued on the next page ......continued on the next page Continued.

Character G. G. swinhonis taibaiensis tawaensis thakhekensis truongi vertebralis wenxianensis yakuensis

bonkowskii sengchanthavongi

sp. nov. sp.nov.

Natural history. Specimens of G. sengchanthavongi were collected on karst walls at night from 20:00 to 21:30 during small rain, ca. 1.5–4 m above the ground, at an elevation of ca. 210 m a.s.l. The surrounding area was disturbed secondary forest ( Fig. 8 ).

Figures

FIGURE 1. Single most parsimonious tree recovered by the MP analysis. Number above and below branches are MP / ML bootstrap values and Bayesian posterior probabilities (> 50 %), respectively. Asterisk denotes 100 % value.

FIGURE 3. Correspondence analysis showing species association of the Gekko japonicus group sensu Rösler et al. (2011) based on morphological comparisons.

FIGURE 4. Cluster analysis showing species correlation of the Gekko japonicus group based on morphological comparisons (1000 bootstrap replicates).

FIGURE 5. Map showing the type locality (black circle) of three new species of Gekko in Khammouane Province, central Laos.

FIGURE 7. A) Dorsal view and B) portrait of the holotype (VFU R. 2014.14) of Gekko sengchanthavongi sp. nov. Photos V. Q. Luu.

FIGURE 8. A) Microhabitat of the paratype (VFU R. 2014.16) and B) macrohabitat of Gekko sengchanthavongi sp. nov. Photos V. Q. Luu.