Cyrtodactylus yangbayensis Tri & Onn, 2010, sp. nov.
Creators: name: Tri, Ngo Van
name: Onn, Chan Kin
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Gekkonidae
Cyrtodactylus
Cyrtodactylus yangbayensis

description: Cyrtodactylus yangbayensis sp. nov.
Plates 1–3
Holotype. UNS 0 476, adult male collected by Ngo Van Tri on 3 June 2009 in rocky outcrops around Yang Bay waterfall, Dien Khanh district, Khanh Hoa province, Southern Vietnam (approximately 12°11’N, 108°54’E) at 500–600 m elevation.
Paratypes. The paratypes UNS 0 475 and UNS 0 477 have the same collection data as the holotype. UNS 0407–0412 were collected by Ngo Van Tri between 19:00 – 22:00 on 20 August 2008 in Hon Ba Nature Reserve (approximately 12o06’N, 108o59’E), Dien Khanh district, Khanh Hoa province, Southern Vietnam at 500–550m elevation.
Diagnosis. Cyrtodactylus yangbayensis differs from all other congeners by the following combination of characters: mean SVL of 83.5 mm (± 4.7 mm); original tail long (TL/SVL: 1.28); dark brown blotches on head; nuchal loop broken into two dark fragments or V–shaped; dorsal pattern consisting of five to seven PLATE 1. (A) Male holotype of Cyrtodactylus yangbayensis sp. nov. (UNS 0472), (B) Female paratype UNS 0 411, (C) Female paratype UNS 0 409.
PLATE 2. Holotype of Cyrtodactylus yangbayensis sp. nov. showing: (A) Rostral scales, (B) Mental scales, (C) Tubercle rows on the dorsum, (D) Enlarged precloacal scales bearing eight precloacal pores arranged in a chevron, (E) Dorsal view of tail base, (F) Median row of enlarged subcaudal scales.
PLATE 3. (A) Size comparison between male (holotype UNS 0407) and female (paratype UNS0409) Cyrtodactylus yangbayensis, (B) Habitat of Cyrtodactylus yangbayensis in secondary monsoon evergreen forest, Khanh Hoa province.
irregular rows of narrow, dark brown bands between limb insertions; 6–8 precloacal pores in males; 5–16 enlarged scales beneath thighs; 18–23 interorbital scales on the frontal bone; 26–32 scales in a straight line between eye and nostril; 39–46 rows of ventral scales between ventrolateral folds; 20–23 irregular, longitudinal rows of weakly–keeled, conical tubercles at midbody between the lateral folds; 28–34 paravertebral tubercles between limb insertions; 18–20 subdigital lamellae on first toe; 15–17 subdigital lamellae on fourth toe; 9–10 enlarged scales on heel; 9–11 irregular bands on original tail; median row of enlarged subcaudal scales.
Description of holotype. Adult male, SVL 81.5 mm (Plate 1A). Head moderately long (HeadL/SVL: 0.28), narrow (HeadW/HeadL: 0.67), depressed (HeadH/HeadL: 0.38), distinct from neck; lores and interorbital region inflated, canthus rostralis absent, frontonasal region concave; snout elongate (SnEye/ HeadL: 0.38), pointed, longer than eye diameter (OrbD/SnEye: 0.70); scales on snout small, rounded, granular, homogeneous, larger than those on occipital region. Eye large (OrbD/HeadL: 0.37), pupils dark blue with red crenelated margins; supraciliaries short, bearing tiny conical spines posteriorly. Ear opening oval, oblique, small (EarL/HeadL: 0.09); eye to ear distance greater than diameter of eye (EyeEar/OrbD: 1.03). Rostral scales smooth, incompletely divided posteriorly by a shallow dorsal groove; two enlarged supranasals in broad contact with three smaller intersupranasals (Plate 2A); rostral in contact with first supralabial and nostril; nostril oval, surrounded by supranasal, rostral, first supralabial, and three enlarged postnasals; 2–3 rows of small scales separate orbit from supralabials. Mental triangular, wider (2.7 mm) than deep (2.1 mm); one pair of enlarged postmentals, in broad contact medially, bordered anteromedially by mental, bordered anterolaterally by first infralabial, posterolaterally by four enlarged lateral chinshields (Plate 2B). 11 (R and L) infralabials; 18 interorbital scale rows across the frontal bone; 27 scales between eye and nostril.
Body slender, elongate (TrunkL/SVL: 0.44). Dorsal scales conical; regularly distributed keeled tubercles (5–8 times size of adjacent scales) extend from occipital region to base of tail; tubercles arranged in 22 rows at midbody between ventrolateral folds (Plate 2C); tubercles are smallest on flanks and occipital region; 29 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; eight precloacal pores arranged in a chevron (Plate 2D); 16 enlarged femoral scales beneath thigh continuous with enlarged precloacal scales but not contiguous with precloacal pores. Scales on palm and hind limbs smooth, granular with scattered, weakly keeled tubercles which are smaller than those on dorsum.
Fore and hindlimbs moderately slender (ForeL/SVL: 0.14; CrusL/SVL: 0.17); digits moderately robust, strongly inflected at basal interphalangeal joints, all bearing slightly curved claws; basal subdigital lamellae nearly as broad as digit, without scansorial surface: 6–6–6–7–7 manus; 8–10–7–7 –7 pes; narrow lamellae distal to digital inflection and not including ventral claw sheath: 9– 9–11–9–9 manus; 12–12–11–10 –7 pes; one or two rows of small, non lamellar granules between basal and distal lamellar series; interdigital webbing present but weakly developed. Relative length of digits in mm: (manus) IV (7.1)> III (6.5)> V (5.9)> II (5.8)> I (4.4); (pes): II (7.7)> I (7.5)> III (6.7)> IV (5.5)>V (3.8).
Tail original; tail length 104.7 mm, slender, tapering to a point; longer than snout vent length (TailL/SVL: 1.28); two smooth, whitish postanal tubercles at base; base of tail with five parasagittal and four longitudinal rows of keeled, paravertebral tubercles on each side of the midline, followed by three rows on the first 1/3 portion of tail, decreasing to two rows towards the posterior (Plate 2E); ventral scales smooth, juxtaposed; median row of enlarged subcaudal scales throughout the length of tail (Plate 2F).
Coloration in life (Plate 1). Top of head brown with small dark blotches; eye rings yellowish; thick, dark brown postorbital stripe which tapers above the ear opening and forms a curve at the nape; no continuous nuchal loop; six irregular dark bands on dorsum between limb insertions, one immediately posterior to hind limbs; small dark blotches scattered on the flanks; dorsal side of limbs light brown, scattered with darker bands or blotches; original tail with eight dark bands, regenerated portion is brown, scattered with small dark spots. Ventral side of body is whitish.
Variation. Colour pattern variation in Cyrtodactylus yangbayensis sp. nov. is shown in Plate 1B–1C. The presence of one extremely minute pit under each thigh of paratype UNS 0 475, an adult male, collected from the type locality was noted. These pits are shallow and appear to contain no secretory material, so we have not considered these structures to represent true femoral pores. Variation in pholidosis is presented in Table 1. Paratypes from Yang Bay waterfall and Hon Ba Nature Reserve in the Dien Khanh district do not different from one another in tubercles rows at midbody (22–23 vs. 20–22), paravertebral tubercles (28–30 vs. 32–34), or ventral scale rows at midbody (40–44 vs. 39–46). Adult females are larger, with a maximum SVL of 92.3 mm and average SVL of 85.3 mm (n=5) as opposed to males which have a maximum SVL of 85.8 mm and average SVL of 81.3 mm (n=4) (see Plate 3A).
continued next page Etymology. The specific epithet is commemorates the type locality of the new species, the evergreen forest of Yang Bay Waterfall. Suggested common name: Yang Bay Bent–toed Gecko; Vietnamese name: Thằn lằn chân ngón Yang Bay.
Distribution and Natural History. Cyrtodactylus yangbayensis is currently known only from the monsoon evergreen forests of Hon Ba Nature Reserve and Yang Bay Waterfall in Khanh Hoa province, Southern Vietnam (Figure 1). All specimens were observed at night on rocky outcrops in the vicinity of streams. Three females (UNS 0409–11) from Hon Ba Nature Reserve were gravid with two eggs each. One individual was seen in a tree–hole at dawn but eluded capture. Cyrtodactylus yangbayensis lives in sympatry with Gekko grossmanni Günther in Hon Ba Nature Reserve.
Comparisons with other species. Cyrtodactylus yangbayensis differs from other congeners in the C. irregularis group, namely C. irregularis (Smith), C. ziegleri Nazarov et al. and C. cattienensis Geissler et al. by the absence of a nuchal loop and presence of a median row of enlarged subcaudal scales. It differs further from C. buchardi David et al. and C. pseudoquadrivirgatus Rösler et al. by having enlarged femoral scales (see Table 2).
Cyrtodactylus yangbayensis can be distinguished from C. badenensis Nguyen et al., C. darmandvillei (Weber), C. eisenmanae Ngo, C. grismeri Ngo, C. jarakensis Grismer et al., C. jellesmae (Boulenger), C. laevigatus (Darevsky), C. semenanjungensis Grismer & Leong, C. semowaiensis (De Rooij), C. thirakhupti Pauwels et al. and C. wallacei Hayden et al. by the presence of precloacal pores in males and from C. aaroni Günther & Rösler, C. aequalis Bauer, C. agusanensis (Taylor), C. annandalei Bauer, C. auribalteatus Sumontha et al., C. baluensis Mocquard, C. batucolus Grismer et al., C. biordinis Brown & McCoy, C. brevipalmatus (Smith), C. caovansungi Orlov et al., C. capreoloides Rösler et al., C. chanhomae Bauer et al., C. consobrinoides Annandale, C. consobrinus Peters, C. deveti (Brongersma), C. epiroticus Kraus, C. erythrops Bauer et al., C. feae (Boulenger), C. fumosus (Müller), C. gubernatoris (Annandale), C. halmahericus (Mertens), C. huynhi Ngo & Bauer, C. interdigitalis Ulber, C. jarujini Ulber, C. klugei Kraus, C. loriae (Boulenger), C. louisianensis (De Vis), C. macrotuberculatus Grismer & Ahmad, C. marmoratus Gray, C. mimikanus (Boulenger), C. novaeguineae (Schlegel), C. phongnhakebangensis Ziegler et al., C. pulchellus Gray, C. redimiculus King, C. robustus Kraus, C roesleri Ziegler et al., C. russelli Bauer et al., C. sadleiri Wells & Wellington, C. salomonensis Rösler et al., C. seribuatensis Youmans & Grismer, C. serratus Kraus, C. slowinskii Bauer, C. takouensis Ngo & Bauer, C. tigroides Bauer et al., C. tiomanensis Das & Lim, C. tripartitus Kraus, C. tuberculatus (Lucas & Frost), C. variegatus (Blyth), C. wetariensis (Dunn), and C. zugi Oliver et al. by the absence of femoral pores which are continuous or discontinuous with the precloacal pores. Comparisons with other Indochinese Cyrtodactylus with preclocal pores are presented in Table 2.
C. elok C.hontreensis C. intermedius C. irregularis C. nigriocularis C. oldhami C. paradoxus
n 1 7 7 1 10 2 11 SVL 67.5 72.4–88.9 68.3–85.1 79.0 82.7–107.5 65 52.0–84.0 TailL – 84.2–106.5 72.8–110.0 – 70.6–121.0 75 95.0–111.0 VenS 44 40–42 40–50 41–46 42–49 34–38 30–34 TubR 5–10 14 18–22 17 smooth 20–28? Pre–pores 7– 8 7–8 8–10 5–7 0–2 minute 0–4 0–4 Femoral 0 0 0 0 0 0 0 Pores
EnlfemS absent absent 6–10 7–8 absent present present Subcaudal median enlarged enlarged round median Scales enlarged enlarged enlarged enlarged SupL 11–12 11–13 11–12 11 13–14 12–13 10–12 Infra 9– 10 9–12 9–11 9 13– 15 9–11 8–11 Tail pattern? dark bands bands bands bands rings
description: Published as part of Tri, Ngo Van & Onn, Chan Kin, 2010, A new species of Cyrtodactylus Gray, 1826 (Squamata: Gekkonidae) from Khanh Hoa province, Southern Vietnam, pp. 47-60 in Zootaxa 2504 on pages 48-55, DOI: 10.5281/zenodo.293249