Cyrtodactylus takouensis, Tri, Ngo Van & Bauer, Aaron M., 2008

Tri, Ngo Van & Bauer, Aaron M., 2008, Descriptions of two new species of Cyrtodactylus Gray 1827 (Squamata: Gekkonidae) endemic to southern Vietnam, Zootaxa 1715, pp. 27-42 : 28-35

Cyrtodactylus takouensis sp. nov.

Figures 1–5

Holotype. Zoological Collection of the University of Natural Sciences, Hochiminh City ( UNS) 0209; adult male; Hang To Cave (10o48.815’N, 107o53.718’E), Ta Kou Nature Reserve, Binh Thuan Province, southern Vietnam; collected by Ngo Van Tri on 14 March 2006.

Paratypes. All paratypes were collected at the type locality by Ngo Van Tri. UNS 0211-0212, September 2003; UNS 0 210, 0 213, 12 November 2005; UNS 0 214, 14 March 2006.

Diagnosis. A medium-sized Cyrtodactylus (SVL 74.7–81.1 mm), body slender, limbs and digits and tail long and slender ( Fig. 1 ). Cyrtodactylus takouensis may be distinguished from all other congeners by the combination of: two pairs of enlarged postmental scales, the first in broad contact with one another; dorsum with 9–10 rows of smooth tubercles; 39–40 ventral scales across belly between ventrolateral folds; no precloacal groove; a patch of enlarged precloacal scales with 3–4 precloacal pores arranged in an angular series with a single, poreless median scale in males; a series of 3–5 greatly enlarged femoral scales at distal end of thigh, separated from enlarged precloacal scales by most of length of femur ( Fig. 2 ), one minute femoral pore in distal or penultimate enlarged femoral scale; 8 broad basal lamellae and 10–12 narrow distal lamellae beneath 4th toe of pes; median row of subcaudals transversely enlarged; dorsal pattern of five pale yellow bands, alternating with dark brown bands, between the nape and sacrum, a dark brown canthal stripe continuous with nuchal loop and bordered by a narrow, pale yellow edge that fades gradually into a mottled brownish crown, with scattered brown spots, and original portion of tail dark brown with series of narrow pale bands, proximal two yellow, more distal bands white.

Among its Vietnamese congeners Cyrtodactylus takouensis sp. nov. differs from C. cryptus Heidrich et al., 2007 , C. irregularis (Smith, 1921) , and a new species from central Vietnam (Rösler et al. 2008) in possessing transversely enlarged subcaudal scales, from C. nigriocularis Nguyen et al., 2006 , C. badenensis Nguyen et al., 2006 , C. chauquangensis Hoang et al., 2007 , C. cryptus and the new central Vietnamese species in possessing enlarged femoral scales, from C. irregularis , C. intermedius (Smith, 1917) , C. cryptus , C. caovansungi Orlov et al., 2007 , C. chauquangensis and the new central Vietnamese species in its lower number of precloacal pores (3–4 versus 5 or more) in males, from C. phongnhakebangensis Ziegler et al., 2002 in having a diastema between precloacal and femoral pores (versus a continuous series of 32–42 precloacal-femoral pores), from C. irregularis , C. paradoxus ( Darevsky & Szczerbak, 1997) , C. badenensis , and C. chauquangensis in its greater number of scales across mid-venter (39–40 versus 38 or fewer), from C. cryptus and the new central Vietnamese species in its lower number of scales across mid-venter (39–40 versus 41 or greater), and from C. condorensis (Smith, 1920) in a pattern of alternating light and dark bands (versus irregular spots or blotches).

Among other congeners C. takouensis may be distinguished from C. annulatus (Taylor, 1915) , C. aurensis Grismer, 2005 , C. cavernicolus (Inger & King, 1961) , C. fumosus (Müller, 1895) , C. marmoratus (Kuhl, 1831) , C. papuensis (Brongersma, 1934) , C. philippinicus (Steindachner, 1867) , C. pubisulcus Inger, 1958 , C. pulchellus Gray, 1827 , C. semenanjungensis Grismer & Leong, 2005 , C. tiomanensis Das & Lim, 2000 , C. rubidus (Blyth, 1860) , and C. sadleiri Wells & Wellington, 1985 by the absence of a precloacal groove, from C. agusanensis (Taylor, 1915) , C. gubernatoris (Annandale, 1913) , C. ayeyarwadyensis Bauer, 2003 , C. brevidactylus Bauer, 2002 , C. annandalei Bauer, 2003 [incorrectly coded as having transversely enlarged median subcaudal plates by Youmans & Grismer 2006 and Heidrich et al. 2007], C. khasiensis (Jerdon, 1870) , C. darmandvillei (Weber, 1890) , C. elok Dring, 1979 , C. gansi Bauer, 2003 , C. lateralis (Werner, 1896) , C. matsuii Hikida, 1990 , C. quadrivirgatus Taylor, 1962 , C. wakeorum Bauer, 2003 , C. sworderi (Smith, 1925) , C. yoshii Hikida, 1990 , C. seribuatensis Youmans & Grismer, 2005 , C. buchardi David et al., 2004 , C. serratus Kraus, 2007 , C. adleri Das, 1997 , C. gordongekkoi (Das, 1993) , and C. wetariensis (Dunn, 1927) by the presence of a single series of transversely enlarged median subcaudal scales, from C. jellesmae (Boulenger, 1897) , C. laevigatus Darevsky, 1964 , C. sermowaiensis (de Rooij, 1915) and C. thirakhupti Pauwels et al., 2004 , by the presence of precloacal pores in males, from C. fraenatus (Günther, 1864) , C. cracens Batuwita & Bahir, 2005 , C. edwardtaylori Batuwita & Bahir, 2005 , C. ramboda Batuwita & Bahir, 2005 , C. subsolanus Batuwita & Bahir, 2005 , C. soba Batuwita & Bahir, 2005 , C. chrysopylos Bauer, 2003 , C. ingeri Hikida, 1990 , C. peguensis (Boulenger, 1893) , C. malayanus (de Rooij, 1915), C. murua Kraus & Allison, 2006 , C. sumonthai Bauer et al., 2002 and C. tigroides Bauer et al., 2003 by the presence of enlarged femoral scales, from C. feae (Boulenger, 1893) , C. consobrinoides (Annandale, 1905) , C. jarujini Ulber, 1993 , C. loriae (Boulenger, 1898) , C. angularis (Smith, 1921) , C. louisiadensis (de Vis, 1892), C. malcolmsmithi (Constable, 1949) , C. novaeguineae (Schlegel, 1844) , C. papilionoides Ulber & Grossmann, 1991 , C. tuberculatus (Lucas & Frost, 1900) , C. variegatus (Blyth, 1859) , and C. chanhomae Bauer et al., 2003 , by the presence of a diastema between the enlarged femoral scales and femoral pores and the precloacal pores, from C. aaroni Günther & Rösler, 2003 , C. baluensis (Mocquard, 1890) , C. consobrinus (Peters, 1871) , C. derongo Brown & Parker, 1973 , C. interdigitalis Ulber, 1993 , C. mimikanus (Boulenger, 1914) , C. russelli Bauer, 2003 , C. aequalis Bauer, 2003 , C. slowinskii Bauer, 2002 , C. irianjayaensis Rösler, 2001 and C. redimiculus King, 1962 by the presence of 9–10 longitudinal rows of dorsal tubercles (vs. 14 or more rows), from C. biordinis Brown & McCoy, 1980 by the presence of a single (when present at all), versus double row of femoral pores, and from C. oldhami (Theobald, 1876) by a banded (versus striped) dorsal pattern. We have excluded species of Geckoella from our comparisons, as well as other species sometimes assigned to Cyrtodactylus (e.g., Youmans & Grismer 2006) that we believe to be assignable to other genera.

Description. (Based on holotype, USN 0209) Adult male, SVL 80.4 mm. Head long (HeadL/SVL 0.28), relatively narrow (HeadW/HeadL 0.62), somewhat depressed (HeadH/HL 0.37), distinct from slender neck.

Lores and interorbital region weakly inflated, canthus rostralis especially prominent, frontonasal region strongly concave, Snout elongate (SnEye/HeadL 0.43), pointed, much longer than eye diameter (OrbD/SnEye 0.54); scales on snout and forehead small, granular, homogeneous; scales on snout larger than those on occipital region. Eye large (OrbD/HeadL 0.23); pupil vertical with crenulated margins; supraciliaries short, bearing minute conical spines posteriorly. Ear opening oval, large (EarL/HeadL 0.09); eye to ear distance equal to diameter of eye (EyeEar/OrbD 1.0). Rostral approximately 63% deep (1.7 mm) as wide (2.7 mm), incompletely divided (60%) by rostral groove; supranasals separated from each other by a single enlarged internasal; rostral in contact with supralabial I, supranasals and single internasal; nostrils round, each surrounded by supranasal, rostral, first supralabial and three enlarged postnasals; 2-3 rows of small scales separate orbit from supralabials. Mental triangular, wider (2.2 mm) than deep (2.0 mm); anterior pair of enlarged trapezoidal postmentals, each bordered anteromedially by mental, medially in broad contact with other postmental, bordered anterolaterally by first infralabial, laterally by second infralabial (left side only), posterolaterally by posterior triangular postmental, and posteriorly by three slightly enlarged chin scales; posterior postmentals separated from each other by chin scales. Supralabials to midorbital position 8 (right) to 9 (left); enlarged supralabials to angle of jaws 10 (right) to 11 (left); infralabials 10 (right) to 11 (left). Interorbital scale rows across narrowest point of frontal bone 17.

Body slender, relatively short (TrunkL/SVL 0.41) with distinct ventrolateral folds. Dorsal scales granular to weakly conical, intermixed with small tubercles (2-3 times size of adjacent scales) extending from occipital region on to back and tail base; each tubercle smooth; tubercles in approximately 10 rows at midbody, smaller on flanks, and smallest in occipital region. Ventral scales much larger than dorsal, smooth, relatively round, and subimbricate, largest posteriorly; midbody scale rows across belly to base of ventrolateral folds 39; gular region with relatively homogeneous, smooth scales. Enlarged rhomboidal patch of precloacal scales extending posteriorly from pore-bearing scales to approximately 2 mm anterior of cloacal lip; no precloacal groove present; four precloacal pores arranged in an angular series with a single median poreless scale separating two pores on each side; series of five variably-sized enlarged femoral scales at distal end of thigh, separated from enlarged precloacal scales by a wide diastema; distalmost (right) or penultimate (left) enlarged femoral scale bearing a minute pore. Scales of plams and soles smooth, flattened; ventral/preaxial limb surfaces with smooth, subimbricate scales; dorsal/postaxial limb surfaces with flattened to very weakly conical juxtaposed to subimbricate scales.

Fore and hindlimbs long, slender (ForeaL/SVL 0.16; CrusL/SVL 0.19). Digits moderately short, strongly inflected at basal interphalangeal joints, all bearing slightly curved claws; subdigital lamellae widened beneath basal phalanx to approximately half digital width (5-6-7-7-6 manus; 4-6-8-8-9 pes); narrow lamellae distal to digital inflection and not including ventral claw sheath (7-9-9-10 -10 manus; 9-9-11-11-12 pes). One to several rows of small, non lamellar granules between basal and distal lamellar series on some digits; interdigital webbing present but weakly developed. Length of digits (manus; measurement in mm in parentheses): III(5.1)> IV(4.8)> II(4.5)>V(4.4)> I(4.1); (pes): IV(7.0)> V(6.8)> III(6.2)> II(5.1)> V(3.7).

Tail long, slender, tapering to tip; longer than snout vent length (tailL/SVL 1.13); original portion of tail (41.0 mm) segmented with 9 scale rows on each segment, two basalmost segments with 8 parasagittal rows of enlarged, smooth tubercles continuing from body dorsum; subcaudal scales forming a single median row of enlarged subimbricate plates approximately one half width of tail, three such plates per tail segment; dorsal caudal scales flat, smooth, rectangular with rounded posterior edge; a series of three enlarged, conical, laterally compressed cloacal spurs on each side of tail base, anterodorsalmost largest.

Coloration (in preservative). Dorsum with five relatively narrow cream bands between nape and groin (one on nape, four between axilla and groin), another across posterior part of sacrum, each alternating with a wider brown band with a darker, more well-defined posterior edge and a more diffuse and somewhat paler anterior edge. A dark brown canthal stripe from tip of snout, through ventral portion of orbit and above ear to form a complete nuchal loop. Crown of head cream with scattered brown pigment on parietal table and two irregular dark brown spots at posterodorsal corner of orbits. Cream nape band extending anteriorly through ear to corner of mouth. Labial scales, especially anteriorly, very dark brown, particularly along labial margins. A cream to white streak between labials and canthal stripe from posterior border of nostril to last supralabial. Limbs and digits with alternating cream and mottled brown bands. Original portion of tail with alternating narrow cream and broad brown bands; banding indistinct on regenerated tail. Body venter pale cream with minute brown flecks on most scales, denser on neck and edges of jaws, flanks and limbs; palms and soles more darkly pigmented; tail venter, particularly regenerated portion, heavily suffused with brown pigment.

In life ( Fig. 3 ) pale cream-colored dorsal regions of head and dorsum distinctly pale lemon yellow. Supraciliary scales bright yellow. Sacral band and anteriormost tail band pale lemon yellow, two more posterior bands bright white. Yellow markings on limbs duller than those of body. Venter whitish.

Variation. Variation in mensural and meristic characters among the type series are presented in Table 1. Paratypes UNS 0211–0212 (figs. 4–5) have a variant dorsal pattern in which the first and second yellow bands behind the axilla are fused dorsally. Among the paratypes only one of the male paratypes, UNS 0 211, has a pair of minute femoral pores, like the holotype. Both precloacal and femoral pores are lacking in the female paratypes.

UNS 0 209 UNS 0 210 UNS 0 211 UNS 0 212 UNS 0 213 UNS 0 214 min-max

Holotype Paratype Paratype Paratype Paratype Paratype ±S.D. Sex ɗ Ψ ɗ Ψ ɗ Ψ n=6 SVL 80.4 81.1 77.5 74.7 78.5 77.3 74.7–81.1

78.2+2.3 ForeaL 12.8 12.4 11.9 11.9 12.1 11.9 11.9–12.8

12.2+0.4 CrusL 15.6 15.3 13.9 13.8 15.1 14.5 13.8–15.6

14.7+0.8 TailL 91.0 90.3 77.7 43.7 79.2 80.8 43.7– 91.0

77.1+17.3 TailW 6.8 6.3 5.8 5.5 6.6 6.5 5.5–6.8

6.2+0.5 TrunkL 32.9 33.2 34.5 29.2 33.0 32.3 29.2–34.5

32.5+1.8 HeadL 22.3 22.1 21.9 21.5 22.3 21.1 21.1–22.3

21.9+0.5 HeadW 13.9 14.0 13.6 12.6 13.9 13.3 12.6–14.0

13.6+0.5 HeadH 8.2 7.9 7.7 7.5 8.1 8.1 7.5–8.2

7.9+0.3 OrbD 5.2 5.1 4.9 5.0 5.1 5.1 4.9–5.2

5.1+0.1 EyeEar 5.2 5.8 4.5 4.7(left) 5.4 5.0 4.5–5.8

5.1+0.5 SnEye 9.7 10.5 9.9 9.1 10.0 9.2 9.1–10.3

9.7+0.5 Interorb 5.9 5.8 6.4 5.2 6.2 5.9 5.2–6.4

5.9+0.4 EarL 2.0 2.1 1.4 1.3 2.0 1.8 1.3–2.1

1.8+0.3 Internar 2.1 2.1 2.5 1.9 2.1 2.1 1.9–2.5

2.1+0.2 TubRows 10 10 9 9 10 9 9–10

9.5+0.6 VenScales 39 39 40 39 39 40 39–40

39.3+0.5

Precloacal 4 0 4 0 3 0 3–4 pores (ɗɗ only) Femoral 1+1 0 1+1 0 0 0 0–2 pores (ɗɗ only) Subdigital I:5+ 7 I:5+ 7 I:5+ 7 I:6+ 7 I:6+ 7 I:5+7

scansors II:6+ 9 II:6+ 8 II:6+ 7 II:6+ 8 II:7+ 8 II:6+8

(manus) III:7+ 9 III:7+ 9 III:7+ 8 III:7+ 9 III:6+ 8 III:7+8 —

IV:7+ 10 IV:7+ 10 IV:8+ 9 IV:7+ 9 IV:8+ 8 IV:7+10

V:6+ 10 V:5+ 10 V:6+ 10 V:7+ 8 V:7+ 9 V:6+9

Subdigital I:4+ 9 I:5+ 11 I:5+ 8 I:6+ 7 I:4+8

scansors II:6+ 9 II:6+ 11 II:6+ 9 — II:8+ 8 II:6+8

(pes) III:8+ 11 III:8+ 11 III:8+10 damaged III:8+ 11 III:8+11 —

IV:8+ 11 IV:8+ 12 IV:8+ 11 IV:8+ 10 IV:8+11

V:9+ 12 V:8+ 11 V:8+ 12 V:9+ 11 V:9 +11

Etymology. The specific epithet refers to Ta Kou Mountain, the type and only known locality for the new species. This is an isolated mountain that is not part of the main Truong Son Mountain Range that runs along the length of southern Vietnam. Local people in the area where C. takouensis occurs refer to this gecko as “ than lan nui ” or “ than lan da ” meaning gecko living on a mountain or in rocky areas. We suggest Ta Kou bent-toed gecko as the English common name for this species.

Distribution and natural history. All voucher specimens were collected during day at a depth of 7 m in Hang To cave in 7 m depth. The cave is located in deciduous forest ( Fig. 6 ) at an elevation of 450 m a.s.l. Hang To cave is often disturbed n the dry season by visitors and pilgrims who go down the bottom of the cave to get fresh water that they believe will bring them luck. Cyrtodactylus takouensis sp. nov. is only found in the Ta Kou Nature Reserve ( Fig. 7 ), an isolated mountain with the highest peak of about 662 m a.s.l. In paratype UNS 0 211 the skin of the occiput and neck was torn as the result of a fall by the collector in the cave.

Figures

FIGURE 1. Adult male holotype (USN 0209) of Cyrtodactylus takouensis sp. nov. from Ta Kou Nature Reserve, Binh Thuan province, Vietnam. Scale bar = 20 mm.

FIGURE 2. Cloacal and ventral surface of hindlimbs of holotype (USN 0209) of Cyrtodactylus takouensis sp. nov. showing the disposition of the enlarged precloacal and femoral scales and precloacal and femoral pores. Small arrows indicate precloacal pore-bearing scales. Large arrows indicate the proximal and distal ends of the enlarged femoral scale series. The distalmost enlarged femoral scale bears a single pore. Scale bar = 5 mm.

FIGURE 3. Holotype (USN 0209) adult male of Cyrtodactylus takouensis sp. nov. in life.

FIGURE 4. Paratype (USN 0212) adult female of Cyrtodactylus takouensis sp. nov. in life.

FIGURE 5. Dorsal pattern variation among members of the type series of Cyrtodactylus takouensis sp. nov. From left to right: USN 0 211, 0 213, 0 212, 0 210, 0 209 (holotype), 0 214. Note the asymmetrical patterns of USN 0 211 (far left) and 0 212 (third from left).

FIGURE 6. Habitat of Cyrtodactylus takouensis sp. nov. in Ta Kou Nature Reserve, Binh Thuan province, Vietnam during the rainy season.

FIGURE 7. Map of southern Vietnam illustrating the type localities of Cyrtodactylus takouensis (circle) and C. huynhi (star). Base map from Central Intelligence Agency.