Gekko thakhekensis, Luu, Vinh Quang, Calame, Thomas, Nguyen, Truong Quang, Le, Minh Duc, Bonkowski, Michael & Ziegler, Thomas, 2014

Luu, Vinh Quang, Calame, Thomas, Nguyen, Truong Quang, Le, Minh Duc, Bonkowski, Michael & Ziegler, Thomas, 2014, A new species of the Gekko japonicus group (Squamata: Gekkonidae) from central Laos, Zootaxa 3895 (1), pp. 73-88 : 76-86

Gekko thakhekensis sp. nov.

( Figs. 2 and 4 )

Holotype. IEBR A.2014.6, subadult male, collected on 29 April 2012 by Thomas Calame and Peter Jäger on a karst wall of a karstic massif, ca. 1.5 m above the forest floor, in a mixed secondary forest of hardwoods and shrubs near Thakhek Town (17o27.64’N, 104o55.24’E), Khammouane Province, Laos, at an elevation of 170 m a.s.l .

Paratype. VFU R.2014.9, adult male, collected on 0 2 June 2014 by Vinh Quang Luu and Thomas Calame on a liana near the wall of a karstic massif, ca. 2 m above the forest floor, in a mixed secondary forest of hardwoods and shrubs near Thakhek Town (17o27.707’N, 104o52.496’E), Khammouane Province, Laos, 4 km from the holotype locality at an elevation of 168 m a.s.l .

Diagnosis. The new species differs from its relatives on the basis of the following combination of characters: size moderate (SVL 67.6–79.2 mm); nares in contact with rostral; internasals absent; postmentals enlarged; interorbital scales between anterior corners of the eyes 22–26; dorsal tubercles absent; ventral scales between mental and cloacal slit 165–174; midbody scale rows 110–116; ventral scale rows 32–40; subdigital lamellae on first toe 11–13, on fourth toe 14–15; finger and toe webbing present at base, about one fifth of length of digits; tubercles on upper surface of fore and hind limbs absent; precloacal pores 1–5 in males; postcloacal tubercles two; tubercles absent on dorsal surface of tail base; subcaudals enlarged; dorsal surface of body with greyish brown blotches.

regenerated partially; for other abbreviations see material and methods).

Description of holotype. Size moderate, SVL 67.6 mm, tail partially regenerated, TaL 66.7 mm, AG 29.3 mm; head longer than wide (HL 18.5 mm, HW 14.1 mm); rostral quadrangular, wider than high (RW 3.3 mm, RH 1.6 mm) and wider than mental (MW 2.2 mm), without suture; rostral in contact with first supralabial and supranasal; nostrils round, each surrounded by rostral, first supralabial, supranasal, and two enlarged nasals posteriorly; internasal absent; preorbitals 18; interorbitals 22; eye large (EE 4.5 mm, HL 18.5 mm), pupil vertical; ear opening oval, oblique, about 40% of the eye diameter (maximum tympanum diameter 1.7 mm, horizontal eye diameter 4.5 mm; mental triangular, wider than long (MW 2.2 mm, ML 1.7 mm); postmentals two, relatively trapezoidal, twice longer than wide, and longer than length of mental, in contact with mental and first infralabials anteriorly, medial suture between; postmentals longer than the length of mental; postmental in contact with 5 gular scales posteriorly, outer gular scales larger than inner scales; supralabials 10/11; infralabials 10/9; dorsal scales on body smooth, round, granular and juxtaposed; lateral fold weakly developed; ventral scales much larger than dorsal scales, smooth, relatively hexagonal, imbricate, and largest in the middle of belly; ventrals between lateral folds 32; scales around midbody in 110 rows; ventral scales in a line between mental and cloacal slit 174; scales on upper and lower arm slightly enlarged; tubercles absent on dorsal surface of fore and hind limbs; scales on anterior and ventral parts of thigh larger than those on dorsal and posterior parts; enlarged femoral scales absent; fingers and toes basally webbed (about 1/5); subdigital lamellae under first finger 13/13, under fourth finger 15/15, under first toe 13/13, under fourth toe 15/15; precloacal pore one, precloacal scales enlarged; postcloacal tubercles 2/2, blunt; tail thickened at base, without tubercles on dorsal surface of tail base; dorsal caudal scales approximately twice the size than dorsal body scales, flat, in regular transverse rows; subcaudals flat, enlarged.

Coloration in ethanol. Dorsal surface of head, body, limbs, and tail greyish brown with irregular vertebral blotches; nuchal surface with a light-colored patch, nuchal loop absent; upper eyelids greyish black; snout and interorbital region vermiculate; some small light spots present in temporal region and on sides of neck; neck with a light grey blotch; dorsum without vertebral stripe; some light and grey spots present on dorsal surface; a row of light spots present along lateral folds; limbs with small light spots and bars; throat, venter, and precloacal region yellowish cream with dark marbling; lower surface of tail brown. For coloration in life see Fig. 4 .

Variation. Measurements and scalation characters of the paratype are shown in Table 2 . The following scale counts vary between the paratype and the holotype: interobitals 22–26, scale rows from mental to the front of cloacal slit 165–174, ventrals 32–40, and precloacal pores 1–5.

Distribution. Gekko thakhekensis sp. nov. is currently known only from the type locality in Khammouane Province, Laos ( Fig. 5 ).

Ecological notes. The type specimens were collected at night, between 1.5–2.0 m above the ground in a small belt of the secondary vegetation in front of a limestone cliff, at elevations of 168–170 m a.s.l.

Etymology. The specific epithet thakhekensis refers to the name of the type locality, Thakhek Town, Khammouane Province, Laos. Suggested common name: Thakhek Gecko .

Character Gekko sp. nov. adleri auriverrucosus canhi chinensis japonicus hokouensis liboensis melli palmatus scabridus scientiadventura ......continued on the next page TABLE 3 . (Continued) ......continued on the next page TABLE 3 . (continued)

Character Gekko sp. nov. shibatai similignum subpalmatus swinhonis taibaiensis tawaensis vertebralis wenxianensis yakuensis . .....continued on the next page Comparisons. We compared the undescribed gecko species from Khammouane Province, central Laos with all other members of the Gekko japonicus group 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). Although only two male specimens were available for morphological comparisons, the undescribed species from Laos clearly differs from the remaining species of the G. japonicus group by a unique suite of features.

The new Gekko species differs from the members of the G. japonicus group as follows: from G. adleri by lacking internasals (vs. one in G. adleri ), dorsal tubercles absent (vs. present in G. adleri ), fewer scale rows around midbody (110–116 vs. 123–144 in G. a d l e r i), fewer precloacal pores in males (1–5 vs. 17–21 in G. a d l e r i), more postcloacal tubercles (two vs. one in G. adleri ), and tubercles on dorsal surface of hind limbs absent (present in G. adleri ); from G. auriverrucosus Zhou & Liu by having a nostril touching rostral (not touching in G. auriverrucosus ), postmentals enlarged (not enlarged in G. auriverrucosus ), dorsal body tubercles absent (vs. present in G. auriverrucosus ), and fewer precloacal pores in males (1–5 vs. 8–11 in G. auriverrucosus ); from G. canhi Rösler, Nguyen, Doan, Ho & Ziegler by having fewer interorbitals (22–26 vs. 49–50 in G. canhi ), internasal absent (vs. present in G. canhi ), dorsal tubercles absent (vs. present in G. canhi ), fewer scale rows around midbody (110–116 vs. 205–227 in G. canhi ), fewer ventral scale rows (32–40 vs. 49–51 in G. c a n h i), and tubercles on dorsal surface of hind limbs absent (present in G. c a n h i); from G. chinensis Gray by lacking internasals (vs. one in G. chinensis ), fewer interorbitals (22–26 vs. 35–48 in G. chinensis ), dorsal tubercles absent (vs. present in G. chinensis ), tubercles on dorsal surface of hind limbs absent (present in G. chinensis ), fewer precloacal pores in males (1–5 vs. 17–27 in G. ch i n e n s i s), more postcloacal tubercles (two vs. one in G. chinensis ), and tubercles on dorsal surface of tail absent (vs. present in G. chinensis ); from G. japonicus (Schlegel) by having fewer interorbitals (22–26 vs. 32–35 in G. japonicus ), postmentals enlarged (vs. not enlarged in G. japonicus ), dorsal tubercles absent (vs. present in G. japonicus ), fewer scale rows around midbody (110–116 vs. 130–144 in G. japonicus ), tubercles on dorsal surface of fore and hind limbs absent (present in G. japonicus ), fewer precloacal pores in males (1–5 vs. 6–9 in G. japonicus ), and tubercles on dorsal surface of tail absent (vs. present in G. japonicus ); from G. hokouensis Pope by lacking internasals (vs. one or two in G. hokouensis ), fewer interorbitals (22–26 vs. 30–33 in G. hokouensis ), postmentals enlarged (vs. not enlarged in G. hokouensis ), dorsal tubercle rows absent (vs. present in G. hokouensis ), fewer precloacal pores in males (1–5 vs. 5–9 in G. hokouensis ), more postcloacal tubercles (two vs. one present in G. hokouensis ), and tubercles on dorsal surface of tail absent (vs. present in G. hokouensis ); from G. liboensis Zhao & Li by having fewer interorbitals (22–26 vs. 40 in G. l i b o e n s i s), dorsal tubercle rows absent (vs. present in G. liboensis ), and more postcloacal tubercles (two vs. one in G. l i b o e n s i s); from G. melli Vogt by lacking internasals (vs. one present in G. melli ), fewer interorbitals (22–26 vs. 34–40 in G. melli ), postmentals enlarged (vs. not enlarged in G. melli ), fewer scales in a line from mental to the front of cloacal slit (165–174 vs. 181–200 in G. melli ), fewer scale rows around midbody (110–116 vs. 147–160 in G. melli ), fewer ventral scale rows (32–40 vs. 43–49 in G. melli ), fewer precloacal pores in males (1–5 vs. 9–11 in G. melli ), and more postcloacal tubercles (two vs. one in G. melli ); from G. palmatus by having dorsal tubercle rows absent (vs. present in G. palmatus ), fewer precloacal pores in males (1–5 vs. 23–30 in G. palmatus ), more postcloacal tubercles (two vs. one in G. palmatus ), and tubercles on dorsal surface of tail absent (vs. present in G. palmatus ); from G. scabridus Liu & Zhou by lacking internasals (vs. present in G. scabridus ), fewer interorbitals (22–26 vs. 30 in G. scabridus ), postmentals enlarged (vs. not enlarged in G. scabridus ), dorsal tubercle rows absent (vs. present in G. scabridus ), tubercles on dorsal surface of fore and hind limbs absent (present in G. scabridus ), fewer precloacal pores in males (1–5 vs. 10–15 in G. scabridus ), and tubercles on dorsal surface of tail absent (vs. present in G. scabridus ); from G. scientiadventura by having fewer interorbitals (22–26 vs. 41–51 in G. scientiadventura ), more scale rows from mental to cloacal slit (165–174 vs. 118–140 in G. scientiadventura ), fewer scale rows around midbody (110–116 vs. 139–143 in G. scientiadventura ), and fewer precloacal pores in males (1–5 vs. 5–8 in G. scientiadventura ); from G. shibatai Toda, Sengoku, Hikida & Ota by having fewer interorbitals (22–26 vs. 37–52 in G. shibatai ), postmentals enlarged (vs. not enlarged in G. shibatai ), dorsal tubercle rows absent (vs. present in G. shibatai ), more postcloacal tubercles (two vs. one in G. shibatai ), and tubercles on dorsal surface of tail absent (vs. present in G. shibatai ); from G. similignum Smith by having fewer interorbitals (22–26 vs. 46–48 in G. similignum ), lacking internasals (vs. present in G. similignum ), postmentals enlarged (vs. not enlarged in G. similignum ), dorsal tubercle rows absent (vs. present in G. similignum ), fewer scale rows around midbody (110–116 vs. 144–153 in G. similignum ), fewer precloacal pores in males (1–5 vs. 17 in G. similignum ), more postcloacal tubercles (two vs. one in G. similignum ), and tubercles on dorsal surface of tail absent (vs. present in G. similignum ); from G. subpalmatus Günther by having fewer interorbitals (22–26 vs. 32 in G. subpalmatus ), postmentals enlarged (vs. not enlarged in G. subpalmatus ), internasals absent (vs. present in G. subpalmatus ), fewer ventral scale rows (32–40 vs. 48 in G. subpalmatus ), and fewer precloacal pores in males (1–5 vs. 5–11 in G. subpalmatus ), and more postcloacal tubercles (two vs. one in G. subpalmatus ); from G. swinhonis Günther by having postmentals enlarged (vs. not enlarged in G. swinhonis ), dorsal tubercle rows absent (vs. present in G. swinhonis ), tubercles on dorsal surface of fore and hind limbs absent (present in G. swinhonis ), and fewer precloacal pores in males (1–5 vs. 7–9 in G. swinhonis ); from G. taibaiensis Song by having a larger size (SVL 79.2 vs. 69.0 mm in G. taibaiensis ), more lamellae under first and fourth toes (11–13 vs. 6−7 and 14–15 vs. 7–8, respectively, in G. taibaiensis ), and fewer precloacal pores in males (1–5 vs. 4–6 in G. taibaiensis ); from G. tawaensis Okada by lacking internasals (vs. present in G. tawaensis ), postmentals enlarged (vs. not enlarged in G. tawaensis ), precloacal pores present (vs. absent in G. tawaensis ), and more postcloacal tubercles (two vs. one in G. tawaensis ); from G. vertebralis Toda, Sengoku, Hikida & Ota by having fewer interorbitals (22–26 vs. 35−50 in G. vertebralis ), postmentals enlarged (vs. not enlarged in G. vertebralis ), dorsal tubercle rows absent (vs. present in G. vertebralis ), and tubercles on dorsal surface of tail absent (vs. present in G. vertebralis ); from G. wenxianensis Zhou & Wang by lacking internasals (vs. present in G. wenxianensis ), dorsal tubercle rows absent (vs. present in G. wenxianensis ), fewer ventral scale rows (32–40 vs. 42−44 in G. wenxianensis ), tubercles on dorsal surface of hind limbs absent (present in G. wenxianensis ), and fewer precloacal pores in males (1–5 vs. 6–8 in G. wenxianensis ); and from G. yakuensis Matsui & Okada by having internasals absent (vs. present in G. yakuensis ), postmentals enlarged (vs. not enlarged in G. yakuensis ), fewer precloacal pores in males (1–5 vs. 6–8 in G. yakuensis ), more postcloacal tubercles (two vs. one in G. yakuensis ), and tubercles on dorsal surface of tail absent (vs. present in G. yakuensis ).

Figures

FIGURE 2. Holotype of Gekko thakhekensis sp. nov. (IEBR A. 2014.6) in preserved state: A) dorsolateral view and B) ventral view. Photos V. Q. Luu.

FIGURE 4. Adult male paratype (VFU R. 2014.9) of Gekko thakhekensis sp. nov. in life. Photo T. Calame.

FIGURE 5. Map showing the type locality of Gekko thakhekensis in Khammouane Province, Laos.

Tables

TABLE 2. Measurements (in mm) and morphological characters of the type series of Gekko thakhekensis sp. nov. (* =

Sex SVL	IEBR A.2014.6 (holotype) subadult male 67.6	VFU R.2014.9 (paratype) adult male 79.2
TaL AG HL	66.7* 29.3 18.5	76.5 35.7 23.0
HW HH SE EE	14.1 8.0 7.7 4.5	16.3 8.7 9.4 5.6
RW RH MW ML	3.3 1.6 2.2 1.7	3.4 1.7 2.2 1.5
CS N PO I	3/5 3/3 18 0	3/5 3/3 18 0
SPL IFL IO PM	10/11 10/9 22 2	12/13 11/11 26 2
GP DTR GSDT	5 0 0	5 0 0
SMC SR V LF1	174 110 32 13/13	165 116 40 13/10
LF4 LT1 LT4 PP	15/15 13/13 15/15 1	13/13 11/12 14/14 5
PAT	2/2	2/2

TABLE 3. Morphological comparisons among the species of the Gekko japonicus group (modified after Nguyen et al. 2013, abbreviations defined in text, - = data unavailable)

Maximum SVL (mm) 79.2	75.3	69	99.2 72	74	70	85	84.6 79.7	77	73
SPL (min) 10	10	9	14 10	9	10	12	10 11	9	12
SPL (max) 13	15	11	14 14	13	14	12	13 15	11	14
IFL (min) 9	9	9	10 9	8	8	11	9 9	9	9
IFL (max) 11	13	11	12 13	13	11	11	12 13	11	13
Nostril touching rostral 1	1	0	1 1	1	1	1	1 1	1	1
N (min) 3	3	3	3 2	3	3	3	3 3	3	3
N (max) 3	3	3	3 3	3	3	3	3 3	3	3
I (min) 0	1	0	1 1	0	1	0	1 0	1	0
I (max) 0	1	1	1 1	1	2	0	1 3	2	0
IO (min) 22	27	25	49 35	32	30	40	34 27	30	41
IO (max) 26	36	25	50 48	35	33	40	40 36	30	51
Postmentals 1 (enlarged = 1, not enlarged = 0) DTR (min) 0	1 7	0 16	1 1 11 10	0 9	0 12	0 10	0 1 0 4	0 17	1 0
DTR (max) 0	11	20	12 10	14	18	10	0 12	21	0
SMC (min) 165	168	-	168 156	169	153	-	181 160	-	118
SMC (max) 174	190	-	170 167	188	174	-	200 194	-	140
SR (min) 110	123	-	205 118	130	119	-	147 116	-	139
SR (max) 116	144	-	227 140	144	130	-	160 147	-	143
V (min) 32	35	-	49 37	39	36	-	43 36	-	38