Cyrtodactylus huynhi, 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 : 35-40

Cyrtodactylus huynhi sp. nov.

Figures 8 –11

Holotype. UNS 0256; adult male; Chua Chan Mountain (10o57.595’N, 107o22.579’E), Xuan Truong commune, Xuan Loc district, Dong Nai Province, southeastern Vietnam, 300 m a.s.l.; collected by Ngo Van Tri, 28 December 2005.

Paratypes. UNS 0257; adult female; Chua Chan Mountain (10o55.806’N, 107o21.640’E), Suoi Cat commune, Xuan Loc district, Dong Nai province, southeastern Vietnam, ~ 70 m a.s.l.; collected by Ngo Van Tri, 27 December 2005. UNS 0 215 and UNS 0 325 (adult females); same locality as UNS 0257; collected by Ngo Van Tri, 31 December 2005. UNS 0 326 (adult male) 0 327 (subadult male) and UNS 0 328 (adult female); same locality as UNS 0257; collected by Ngo Van Tri, August 2006.

Additional material. UNS 0 329 (adult male); Chua Chan Mountain (10o55.806’N, 107o21.640’E), Suoi Cat commune, Xuan Loc district, Dong Nai province, southeastern Vietnam, ~ 70 m a.s.l.; collected by Ngo Van Tri, 31 December 2005.

Diagnosis. A medium-sized Cyrtodactylus , adult snout-vent length 68.5–79.8 mm, body slender, limbs and digits relatively long, slender, original tail long. Cyrtodactylus huynhi sp. nov. may be distinguished from all of its congeners on the basis of the following combination of characters: no precloacal groove; two pairs of enlarged postmental scales, anterior pair in broad contact with one another, posterior pair separated by two enlarged chin granules; dorsal scalation with approximately 16–18 irregular rows of weakly keeled tubercles; 43–46 ventral scales across belly between ventrolateral folds; no precloacal groove; a patch of enlarged precloacal scales with 7–9 precloacal pores arranged in an angular series in males; a series of 3–5 enlarged femoral scales at distal end of thigh, separated from enlarged precloacal scales by a large diastema ( Fig. 9 ); 1-5 femoral pores per thigh in males; 8–10 broad basal lamellae and 9–11 narrow distal lamellae beneath 4th toe of pes; subcaudal scales heterogeneous, with alternating series of single and paired median scales; dorsum light brown with 5–6 irregular broad dark brown bands between shoulder and sacrum, each bordered anteriorly and posteriorly by yellow to cream rows of tubercles; a prominent dark brown complete nuchal loop, tail with alternating light and dark brown banding.

Among its Vietnamese congeners Cyrtodactylus huynhi sp. nov. differs from C. nigriocularis , C. badenensis , C. chauquangensis , C. caovansungi , C. paradoxus , C. condorensis , C. intermedius , C. phongnhakebangensis and C. takouensis in lacking a single series on greatly enlarged median subcaudal scales, from C. cryptus and a new species from central Vietnam (Rösler et al. 2008) in possessing enlarged femoral scales, and from C. irregularis in its greater number of scale rows across mid-venter (43–46 versus 30–34).

Among other congeners C. huynhi may be distinguished from C. annulatus , C. aurensis , C. cavernicolus , C. fumosus , C. marmoratus , C. papuensis , C. philippinicus , C. pubisulcus , C. pulchellus , C. semenanjungensis , C. tiomanensis , C. rubidus , and C. sadleiri by the absence of a precloacal groove, from C. agusanensis , C. brevidactylus , C. elok , C. gansi , C. matsuii , C. sworderi , C. yoshii , C. buchardi and C. chrysopylos by the presence of enlarged femoral scales, from C. gordongekkoi , C. jellesmae , C. laevigatus and C. sermowaiensis by the presence of precloacal pores in males, from C. ayeyarwadyensis , C. lateralis , C. quadrivirgatus , C. adleri and C. irianjayaensis by the presence of femoral pores, from C. seribuatensis , C. serratus , C. loriae , C. angularis , C. malcolmsmithi , C. novaeguineae , C. papilionoides and C. variegatus by the presence of a diastema between the enlarged femoral scales and femoral pores and the precloacal pores, from C. gubernatoris , C. khasiensis , C. darmandvillei , C. wakeorum , and C. wetariensis by a greater number of ventral scales across mid-body (43–46 versus <40), from C. annandalei , C. interdigitalis and C. mimikanus by a lower number of precloacal pores (8 versus 11 or more), from C. derongo , by the presence of 16–18 longitudinal rows of dorsal tubercles (versus 20 rows) and much smaller body size (maximum ~ 80 mm versus 120 mm SVL), from C. biordinis by the presence of a single versus double row of femoral pores, and from all other species by the lack of a single median row of transversely enlarged subcaudal plates.

Description. (Based on Holotype, UNS 0256) Adult male, SVL 68.5 mm. Head long (HeadL/SVL 0.28), relatively narrow (HeadW/HeadL 0.65), somewhat depressed (HeadH/HL 0.42), distinct from slender neck. Lores and interorbital region weakly inflated, canthus rostralis not especially prominent, frontal nasal region strongly concave, Snout elongate (SnEye/HeadL 0.43), rounded; longer than eye diameter (OrbD/SnEye ratio 0.55); scales on snout and forehead small, granular, homogeneous; scales on snout larger than those on occipital region. Eye large (OrbD/HeadL 0.24), pupil vertical with crenulated margins; supraciliary scales bearing minute conical spines posteriorly. Ear opening oval, moderate in size (EarL/HeadL 0.06); eye to ear distance greater than diameter of eye (EyeEar/OrbD 1.09).

Rostral 55% deep (1.6 mm) as wide (2.9 mm), incompletely divided (~30%) by rostral groove; supranasals separated from one another by a small pentagonal internasal scale. Rostral in contact with first supralabial, internasal, and supranasals only; nostril round, surrounded by supranasal, rostral, first supralabial and three enlarged postnasals; 2–3 rows of small scales separate orbit from supralabials. Mental triangular, wider (2.3 mm) than deep (1.75 mm); two pairs of enlarged postmentals, each five-sided anterior postmental bordered anteromedially by mental, medially in broad contact with other postmental, bordered anterolaterally by first infralabial, posterolaterally by posterior postmental, and posteriorly by a single enlarged round chin granule; posterior, roughly triangular, postmentals separated from each other by two enlarged chin granules. Supralabials to midorbit 8 (right) to 9 (left); enlarged supralabials to angle of jaws 11 (left and right); infralabials 9 (left) to 10 (right); interorbital scale rows across narrowest point of frontal bone 19.

Body slender, relatively short (TrunkL/SVL 0.41) with small but distinct ventrolateral folds. Dorsal scales granular to weakly conical, interspersed with approximately 16 irregular rows of small (3–5 times size of adjacent scales), weakly-keeled to conical tubercles extending from occipital region to tail base; tubercles smaller on flanks than dorsum, and smallest in occipital region. Ventral scales much larger than dorsals, smooth, relatively round, and subimbricate, largest posteriorly; midbody scale rows across belly to base of ventrolateral folds 44; gular region with relatively homogeneous, smooth scales. Enlarged circular patch of precloacal scales extending posteriorly from one row anterior to pore-bearing scale row to approximately 1 mm anterior of cloacal lip; no precloacal groove present; eight precloacal pores arranged in an angular series; series of 3 enlarged, round to oval femoral scales at distal end of thigh, separated from enlarged precloacal scales by a wide diastema; one (right) or two (left) minute femoral pores. Scales of plams and soles smooth, flattened; ventral/preaxial limb surfaces with smooth to weakly conical, subimbricate scales; dorsal/postaxial limb surfaces with granular to very weakly conical juxtaposed scales intermixed with small to moderate sized weakly keeled to conical tubercles (numerous on thighs and shanks).

Fore and hind limbs moderate (ForeL/SVL 0.15; CrusL/SVL 0.18); 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; (6-7-6-7-7 manus; 9-6-7-9-9 pes); narrow lamellae distal to digital inflection and not including ventral claw sheath: 7-8-9-9-9 manus; 8-9-11-11-10 pes; interdigital webbing present but weakly developed. Length of digits (manus; measurement in mm in parentheses): IV(5.5)> III(5.3)> V(4.3)> II(4.2)> I(2.5); (pes): IV(6.6)> III(6.3)> V(5.9)> II(4.5)> I(2.6).

Tail longer than snout vent length (tailL/SVL 1.04), slender, tapering to tip; original portion of tail (48.9 mm) not obviously segmented, except for 2 basalmost segments where 8 parasagittal rows of enlarged, weakly keeled tubercles continue from the body dorsum; subcaudal scales smooth, imbricate, heterogeneous, with alternating series of single and paired enlarged median scales (i.e., not forming a single median row of transversely enlarged plates); dorsal caudal scales flat, smooth, hexagonal, with rounded posterior margins. Two small, rounded, slightly laterally compressed cloacal spurs on each side of tail base.

Coloration (in preservative). Dorsum pale brown with 5–6 irregular dark brown crossbands between shoulder and sacrum, each bordered anteriorly and posteriorly by a pale edge incorporating rows of whitish tubercles. Several crossbands strongly asymmetrical and partly fused with adjacent bands. A very dark brown, well-defined complete nuchal loop continuing anteriorly to posteroventral portion of orbit, no dark canthal stripe present. Nuchal loop bordered anteriorly and posteriorly by a narrow cream edge. Crown mottled brown on cream with a dark brown transverse marking across occiput and a similar, but fainter marking between occiput and nape. Two small, irregular, dark brown blotches on parietal table just behind frontal bone. Tip of snout darker than crown; labial scales mottled brown and white. Side of neck mottled brown with irregular whitish blotches extending to forearm insertion. Limbs and digits with alternating light and dark brown bands or blotches. Tail with alternating light and dark brown bands; dark bands somewhat wider than light; 10 dark bands from posterior edge of sacrum to tail tip. Body venter cream with minute brown flecks on most scales yielding a brownish suffusion, especially under limbs, on soles and palms, neck, and margins of flanks and jaws. Tail venter mottled brown and white; median scale rows predominantly paler than ventrolateral scales. In life ( Figs. 10–11 ) dorsal pale margins of dark bands cream to yellow; tubercles cream colored. Nuchal loop blackish.

Variation. Variation in mensural and meristic characters among the type series are presented in Table 2. An adult male non-type, UNS 0 329, has 5 enlarged femoral scales on each thigh, bearing 4 (right)-5(left) minute femoral pores. Other members of the type series have up to 4 femoral pores per thigh. Female paratypes have dimpled precloacal scales corresponding to the pored scales of males and in one instance (USN 0328) corresponding dimples or pits are present in the enlarged femoral scales. Female paratypes also have very small cloacal spurs. Pattern variation is extensive among the paratypes. UNS 0 257 is especially boldly patterned with strongly contrasting light and dark markings ( Fig. 11 ); its limbs are more mottled and less banded than those of the holotype. Its venter is darker, especially the chin, which is light brown with only a few irregular pigmentless patches. UNS 0 329 is particularly irregularly patterned with extensive fusion between adjacent dark dorsal bands and with weak contrast between the dorsal bands and the pale edging tubercles. Both UNS 0 329 and UNS 0 257 have 18, rather than 16 midbody scale rows.

Etymology. The specific epithet is derived from the name of Professor Dang Huy Huynh, the first director of the Institute of Ecology and Biological Resources (IEBR), Hanoi, who contributed greatly to the development of zoological research in Vietnam. The local common name for this species is the general “ than lan nui ” or “ than lan rung ” meaning gecko living on a mountain or in a forest. We suggest Huynh’s bent-toed gecko as the English common name of the species.

Distribution and natural history. The holotype was collected during daytime on 28 December 2005 in a 15 m deep cave in the isolated Chua Chan Mountain (highest peak ~ 836 m a.s.l.) ( Fig. 7 ). The landscape surrounding the cave was secondary deciduous forest at an elevation of 300 m a.s.l. ( Fig. 12 ) Paratype UNS 0 257 was collected at 20h14 on 27 December 2005 at the entrance to a rocky cave; paratypes UNS 0 215 and UNS 0 325 were collected between 20h12 and 20h45 on 31 December 2005 at the same cave entrance, in an area of secondary deciduous forest at elevation about 70 m a.s.l. Gekko gecko (Linnaeus, 1758) and Gehyra mutilata (Wiegmann, 1834) were found in sympatry with Cyrtodactylus huynhi sp. nov.

USN 0 256 UNS 0 215 USN 0 257 UNS 0 325 UNS 0 326 UNS 0 327 UNS 0 328 min-max Holotype Paratype Paratype Paratype Paratype Paratype Paratype ±S.D. Sex ɗ Ψ Ψ Ψ ɗ ɗ Ψ n=7

SVL 68.5 79.8 77.7 79.0 67.2 54.8 74.4 54.8–79.8

71.6+8.9 ForeL 10.0 10.6 10.7 10.6 10.7 7.6 11.4 7.6–11.4

10.2+1.2 CrusL 12.3 13.1 13.0 12.9 13.9 10.3 14.2 10.3–13.9

12.8+1.3 TailL 70.9 61.5 broken 73.2 78.6 29.1 51.7 29.1–78.6

60.8+18.2 TailW 5.1 5.8 5.2 5.2 5.3 5.2 5.4 5.1–5.8

5.3+0.2 TrunkL 28.2 32.7 31.4 33.8 25.5 20.3 31.5 20.3–33.8

29.1+4.8 HeadL 19.1 21.8 22.5 22.1 18.7 15.5 21.2 15.5–22.5

20.1+2.5 HeadW 12.5 13.9 14.2 13.8 12.1 10.2 13.3 10.2–14.2

12.9+1.4 HeadH 8.1 7.7 8.2 8.4 7.5 5.7 8.5 5.7–8.4

7.7+1.0 OrbD 4.5 5.0 4.9 4.9 5.0 3.5 5.2 3.5–5.2

4.7+0.6 EyeEar 4.9 5.8 6.8 5.5 4.5 3.8 6.0 3.8––6.8

5.3+1.0 SnEye 8.2 9.7 9.5 9.6 6.9 5.9 7.9 5.9–9.7

8.2+1.5 Interorb 5.1 6.1 7.3 6.0 4.9 4.4 5.6 4.4–7.3

5.6+0.9 EarL 1.1 1.7 1.6 1.3 1.1 0.8 1.4 0.8–1.7

1.3+0.3 Internar 2.0 2.5 2.0 2.4 1.4 1.2 2.2 1.2–2.5

2.0 + 0.5 TubRows 16 18 18 18 16 18 18 16–18

17.4+1.0 VenScales 44 44 43 46 46 44 45 43–46

44.6 + 1.1 Precloacal 8 (8 pitted (8 pitted 0 7 9 (6 pitted 7–9 pores scales) scales) scales) (ɗɗ only) Femoral 2+1 0 0 0 2 + 2 4 + 4 (3 + 3 pitted 3–8 pores scales) (ɗɗ only) Subdigital I:6+ 7 I:5+ 8 I:7+ 7 I:6+ 9 I:5+ 7 I:6+ 7 I:7+7

scansors II:7+ 8 II:6+ 8 II:7+ 8 II:5+ 9 II:7+ 7 II:6+ 6 II:5+8 — (manus) III:6+ 9 III:7+ 8 III:7+ 8 III:6+ 9 III:6+ 10 III:6+ 8 III:6+9

IV:7+ 9 IV:6+ 8 IV:7+ 8 IV:6+ 10 IV: 7+ 10 IV: 6+ 9 IV: 6+9

V:7+ 9 V:7 + 9 V:7+ 8 V:7+ 9 V: 7+ 9 V: 6+ 7 V: 7+8

Subdigital I:9+ 8 I:10+ 7 I:9+ 7 I:9+ 7 I:8+ 8 I:7+ 6 I:7+6

scansors II:6+ 9 II:6+ 9 II:6+ 9 II:6+ 10 II:6+ 9 II:7+ 7 II:7+8 — (pes) III:7+ 11 III:7+ 10 III:7+ 9 III:6+ 10 III:6+ 9 III:7+ 10 III:9+8

IV:9+ 11 IV:8+ 10 IV:8+ 10 IV:8+ 9 IV:10+ 11 IV:8+ 9 IV:8+9

V:9+ 10 V:9+ 10 V:9+ 10 V:8+ 10 V:9+ 12 V:9+ 10 V:9+9

Figures

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

FIGURE 8. Adult male holoptype (USN 0256) of Cyrtodactylus huynhi sp. nov. from Chua Chan Mountain, Dong Nai province, southeastern Vietnam. Scale bar = 20 mm.

FIGURE 9. Cloacal and ventral surface of hindlimbs of holotype (USN 0256) of Cyrtodactylus huynhi sp. nov. showing the disposition of the enlarged precloacal and femoral scales and precloacal and femoral pores. Larger arrows indicate the extent of the enlarged femoral scale series (pores are minute and not clearly visible). Smaller arrows indicate lateralmost pore-bearing precloacal scales. Scale bar = 5 mm.

FIGURE 10. Holotype (USN 0256) adult male Cyrtodactylus huynhi sp. nov. in life.

FIGURE 11. Paratype (USN 0257) adult female of Cyrtodactylus huynhi sp. nov. in life. This specimen exhibits a particularly bold dorsal pattern.

FIGURE 12. Habitat of Cyrtodactylus huynhi sp. nov. on Chua Chan Mountain, Dong Nai province, southeastern Vietnam.