Cyrtodactylus dati, Tri, Ngo Van, 2013

Tri, Ngo Van, 2013, Cyrtodactylus dati, a new forest dwelling Bent-toed Gecko (Squamata: Gekkonidae) from southern Vietnam, Zootaxa 3616 (2), pp. 151-164 : 153-159

Cyrtodactylus dati sp. nov.

Figs. 1–3

Holotype. ITBCZ 2375, adult male collected by Ngo Van Tri at 20:30 on 20 September 2011 among dry roots beneath the canopy of secondary evergreen forest in Bu Dop State Forest Enterprise, Bu Dop District, Binh Phuoc Province, southern Vietnam (12º 01’252”N, 106º 54’227E) at 100 m in elevation.

Paratypes. The paratypes ITBCZ 2348–51 bear the same data as the holotype. Paratype ITBCZ 2343 was collected by the same collector at the same locality but on 1 January 2011.

Diagnosis. Cyrtodactylus dati sp. nov. differs from all other congeners by the following combination of characters: maximum SVL 70.1 mm; original tail relatively short (TL/SVL: 1.03–1.08; n =2); no distinct dark brown blotches on head; nuchal loop broken into dark fragments; irregular dark blotches on the dorsum; original tails bearing 10 dark brown alternating rings; 4–10 intersupranasals; a series of five or six precloacal pores in males medially interrupted by one poreless scale; no precloacal groove; three or four femoral pores on each thigh in males; 4–7 enlarged scales beneath thighs; 17–19 interorbital scales on the frontal bone; 23–26 scales in a straight line between eye and nostril; 42–48 rows of ventral scales between ventrolateral folds; 20–22 irregular, longitudinal rows of keeled tubercles at midbody between the ventrolateral folds; 34–35 paravertebral tubercles between limb insertions; 12–13 subdigital lamellae on first toe; 18–19 subdigital lamellae on fourth toe; and small subcaudal scales.

Description of holotype ( Figs. 1A , 2 ). Adult male, SVL 55.7 mm. Head moderately long (HeadL/SVL: 0.26), relatively narrow (HeadW/HeadL: 0.63), depressed (HeadH/HeadL: 0.32), distinct from neck; lores and interorbital region inflated, canthus rostralis absent, frontonasal region concave; snout elongate (SnEye/HeadL: 0.37), pointed, longer than eye diameter (OrbD/SnEye: 0.74); scales on snout small, rounded, granular, homogeneous, larger than those on occipital region. Eye large (OrbD/HeadL: 0.27), pupils bronze blue with red crenelated margins; supraciliaries short, bearing tiny conical spines posteriorly. Ear opening oval, oblique, small (EarL/HeadL: 0.07); eye to ear distance greater than diameter of eye (EyeEar/OrbD: 1.03). Rostral scale smooth, wider (2.4mm) than high (1.0mm), incompletely divided posteriorly by a shallow Y-shaped dorsal groove; two enlarged supranasals separated by six intersupranasals arranged in three transverse rows, the anterior row includes a single intersupranasal encroaching on the rostral, the second and third rows consisting of two and three intersupranasals, respectively; rostral in contact with first supralabial and nostril; nostril oval, surrounded by supranasal, rostral, first supralabial, and three enlarged postnasals; 3–4 rows of small scales separate orbit from supralabials. Mental triangular, wider (1.8 mm) than deep (1.4 mm); one pair of enlarged postmentals, in broad contact medially, bordered anteromedially by mental, bordered anterolaterally by first infralabial, posterolaterally by six enlarged lateral chinshields. Eleven supralabials and 9 infralabials on each side; 18 interorbital scale rows on the frontal bone; 24 scales between eye and nostril.

Body slender, elongate (TrunkL/SVL: 0.42). Dorsal scales conical; regularly distributed keeled tubercles (4–9 times size of adjacent scales) extend from occipital region to base of tail; tubercles arranged in 20 irregular rows at midbody between ventrolateral folds; tubercles are smallest on flanks and occipital region; 35 paravertebral tubercles between limb insertions. Ventral scales larger than dorsals, smooth, relatively round, subimbricate, largest posteriorly; 44 scale rows across belly between ventrolateral folds; gular region with relatively homogeneous, smooth scales. Precloacal groove absent; precloacal scales enlarged; a series of five precloacal pores medially interrupted by one poreless scale; five enlarged femoral scales beneath each thigh, the three median scales bearing pores beneath thigh at the knee corner bear three pores. Femoral and precloacal pores separated by a wide diastema. Scales on palm and hind limbs smooth, granular with scattered, weakly keeled tubercles which are smaller than those on dorsum.

Fore and hind limbs moderately slender (ForeL/SVL: 0.14; CrusL/SVL: 0.16); digits moderately slender, strongly inflected at basal interphalangeal joints, all bearing slightly curved claws; basal subdigital lamellae nearly as broad as digit, without scansorial surface: 5–5–5–7–6 manus; 5–6–6–8–8 pes; narrow lamellae distal to digital inflection and not including ventral claw sheath: 6–6–10–9 –7 manus; 7– 7–9–10–9 pes; one or two rows of small, non- lamellar granules between basal and distal lamellar series; interdigital webbing present but weakly developed. Length of digits in mm: (manus) III (4.0)> IV (3.9)> II (3.5)> V (3.4)> I (2.6); (pes): V (5.3)> IV (5.6)> III (4.7)> II (3.9)> I (2.0).

Tail length 57.3 mm; tail original, slender, tapering to a point; shorter than snout vent length; two smooth, whitish postcloacal tubercles at base; base of tail with five parasagittal and three longitudinal rows of keeled, paravertebral tubercles on each side of the midline, followed by three rows of smaller tubercles on the first two segments of tail, decreasing to one row towards the posterior segments and absent in the next ones; ventral tail scales smooth, subimbricate, small throughout the length of the tail.

Coloration in life ( Fig. 1 ). Top of head dull brown with or without small dark blotches or spots; dark green eye with orange-yellow vertical pupil, eye rings yellowish; nuchal loop not continuous, normally V-shaped posteriorly and broken into fragments; irregular dark blotches on dorsum between limb insertions, one V- shaped band immediately posterior to hind limbs; small dark blotches scattered on the flanks; dorsal side of limbs brown, scattered with darker bands or blotches; original tail bearing ten dark rings alternating with light rings, regenerated portion brown, scattered with small dark spots. Ventral surface of body is whitish.

Variation. Color pattern variations of Cyrtodactylus dati sp. nov. are shown in Figure 1 . Subadults show some small spots on the upper surface their head. Mensural and meristic data of the type series are presented in Table 1. Based on the type series, adult females are larger, with a maximum SVL of 70.1 mm as opposed to males, which have a maximum SVL of 57.1 mm ( Fig. 3 ).

Etymology. The specific epithet honours Prof. Hoàng ứ c ạ t, former Dean of Hue University, who was the first teacher in the graduate program. Suggested common names: English: ạ t Bent–toed Gecko; Vietnamese: Thằn lằn chân ngón Hoàng ứ c ạ t; French: Cyrtodactyle de Dat.

Distribution and natural history. Cyrtodactylus dati sp. nov. is currently known only from the secondary evergreen forests of Bu Dop District in Binh Phuoc Province, Southern Vietnam. The distribution of C. dati sp. nov. may potentially encompass a larger area in the Mondulkiri Province and other provinces of Cambodia due to the continuation of this forest type into these areas.

All specimens were observed and collected at night on tree branches and leaves or among dry roots close to dry fallen trees or decayed trees, beneath the canopy, 0.1 m–1.0 m above forest floor.

Comparison with other taxa.

Cyrtodactylus dati sp. nov. is compared in Table 2 with all other Cyrtodactylus species with precloacal pores separated from femoral pores by a diastema. Cyrtodactylus dati sp. nov. differs by having a higher number of femoral pores from C. takouensis and C. yangbayensis (6–7 vs. 0–2).

Cyrtodactylus dati sp. nov. differs from C. aaroni Günther & Rösler, C. aequalis Bauer, C. agusanensis (Taylor) , C. annandalei Bauer, C. auribalteatus Sumontha, Panitvong & Deein, C. baluensis Mocquard, C. bichnganae Ngo & Grismer, C. biordinis Brown & McCoy, C. brevipalmatus (Smith), C. caovansungi Orlov, Nguyen, Nazarov, Ananjeva & Nguyen, C. capreoloides Rösler, Richards & Günther, C. consobrinus Malkmus, C. dumnuii Bauer, Kunya, Sumontha, Niyomwan, Pauwels, Chanhome & Kunya, C. erythrops Bauer, Kunya, Sumontha, Niyomwan, Panitvong, Pauwels, Chanhome & Kunya, C. gubernatoris (Annandale), C. huongsonensis Luu, Nguyen, Do & Ziegler, C. huynhi Ngo & Bauer, C. interdigitalis Ulber, C. louisiadensis ( De Vis), C. mcdonaldi Shea, Couper, Wilmer & Amey, C. pulchellus Gray, C. mimikanus (Boulenger) , C. redimiculus King, C. russelli Bauer, C. sadleiri Wells & Wellington, C. salomonensis Rösler, Richards & Günther, C. slowinskii Bauer, C. tigroides Bauer, Sumontha & Pauwels and C. wetariensis (Dunn) by having a lower number of precloacal and/or femoral pores (see Table 2 for a comparison among all Asian and Australian species). Additionally, Cyrtodactylus dati sp. nov. differs from C. ziegleri Nazarov, Orlov, Nguyen & Ho by its dorsal pattern (blotches vs. 4–6 irregular bands).

Figures

FIGURE 2. Precloacal and femoral region of holotype of Cyrtodactylus dati sp. nov. showing the diastema between the precloacal and femoral pores (marked by blue dots), and the small subcaudal scales.

FIGURE 3. Preserved paratypes of Cyrtodactylus dati sp. nov.

FIGURE 1. A: Male holotype of Cyrtodactylus dati sp. nov. (ITBCZ 2375) in life; B: paratype of Cyrtodactylus dati sp. nov. (ITBCZ 2343) with newly regenerated tail; C: paratype of Cyrtodactylus dati sp. nov. (ITBCZ 2351), subadult male showing small light spots on its head; D: Paratype of Cyrtodactylus dati sp. nov. (ITBCZ 2350); subadult female showing some small light spots on its head.