Cyrtodactylus auribalteatus, Sumontha, Montri, Panitvong, Nonn & Deein, Gridsada, 2010

Sumontha, Montri, Panitvong, Nonn & Deein, Gridsada, 2010, Cyrtodactylus auribalteatus (Squamata: Gekkonidae), a new cave-dwelling gecko from Phitsanulok Province, Thailand, Zootaxa 2370, pp. 53-64 : 54-60

Cyrtodactylus auribalteatus sp. nov.

Figures 1–3 .

Holotype. Thailand Natural History Museum, THNHM 15901 (Field number MS 360), adult male; Thailand, Phitsanulok Province, Thung Salaeng Luang National Park, Phra Wang Daeng Cave; 16o40’41”N 100o41’24”E, ca. 80 m a.s.l. approximately 25 m. from cave entrance, collected on 7 April 2008, ca. 19.30h by Gridsada Deein.

Paratypes. Chulalongkorn University Museum of Zoology, CUMZ-R-2009,6,24-1 (Field number MS 06), adult male; same locality as holotype, approximately 15 m. from cave entrance, collected on 7 April 2008, ca. 19.45 hours by Gridsada Deein. THNHM 15902 (Field number MS 211), adult female; same locality as holotype, approximately 40 m. from cave entrance, collected on 11 April 2008, ca. 10.17h by Gridsada Deein.

Etymology. The specific epithet of this species is derived from Latin, aurum meaning ‘gold’, balteatus meaning ‘girdled or belted’, pertaining to golden belts of its coloration pattern.

We suggest the following common names: Tuk-kai Plong-thong ( Thai); Golden-belted bent-toed gecko (English)

Definition. A moderately sized Cyrtodactylus , maximum snout-vent length at least 90.5 mm; body slender, limbs and digits long, slender; original tail very long and slender, one pair of enlarged postmental scales in broad contact with one another; dorsum relatively smooth textured, with 22–24 rows of small tubercles; 38–40 ventral scales across belly between weakly-developed ventrolateral folds; no precloacal groove, 6 precloacal pores separated by a diastema of 12–14 smaller poreless scales from a series of 4–5 femoral pores on each thigh in males, absent in females. 7–9 broad proximal lamellae and 12–14 narrow distal lamellae beneath 4th toe of pes. Median subcaudal scales forming broad transverse plates, but distinctly narrower than tail width. Dorsal pattern consisting of distinct, alternating purplish-brown and creamy-white bands, with a series of brown spots in each white band; three bands on trunk and one across sacrum. Dorsum of head pale brown with whitish posterior edge and symmetrical dark brown markings.

Description of holotype. THNHM 15901 (MS 360), adult male, SVL 90.54 mm. Head moderately long (HeadL/SVL = 0.29), relative narrow (HeadW/HeadL = 0.65), some what depressed (HeadH/HeadL = 0.38), distinct from slender neck. Lores and interorbital region weakly inflated, canthus rostralis not especially prominent, frontonasal region concave. Snout elongate (SnEye/HeadL = 0.43), pointed; longer than eye diameter (OrbD/SnEye =0.63); scales on snout and forehead small, rounded, granular, homogeneous; scales on snout larger than those on occipital region. Eye large (OrbD/HeadL = 0.27); pupil vertical with crenelated margins; superciliaries short, bearing 14 minute conical spines posteriorly. Ear opening oval, relatively small (EarL/HeadL = 0.07); eye to ear distance equal to diameter of eye (EyeEar/OrbD = 0.99). Rostral approximately half as deep (2.25 mm) as wide (4.30 mm), partially divided (67 %) dorsally by rostral groove; two enlarge supranasals in broad medial contact, a square internasal positioned between rostral and supranasals and a triangular internasal positioned between supranasals and granular forehead scales; rostral in contact with first supralabial, supranasals and anterior internasal; nostrils round, each surrounded by supranasal, rostral, first supralabial and three postnasals. Mental triangular, wider than deep (Mental Depth/ Width = 0.40); one pair of enlarged postmentals; each bordered anteromedially by mental, medially by other postmental, anterolaterally by first infralabial, posterolaterally by an enlarged lateral chinshield and three small chinshields, posteromedially by a small chinshield; gular scales small, granular; supralabials to midorbital position 8; enlarged supralabials to angle of jaws 10; infralabials 10; interorbital scale rows across narrowest point of frontal bone 18.

Body slender, relatively short (TrunkL/SVL = 0.42) with very weakly demarcated, non-denticulate ventrolateral folds. Dorsal scales granular to weakly conical; regularly distributed tubercles extending from occipital region on-to back and base of tail; each tubercle conical, forming a weak keel on the anterior-facing surface, especially in mid-dorsal tubercle rows; tubercles in approximately 22 rows at midbody, absent from flanks. Ventral scales much larger than dorsals, smooth, and subimbricate, largest posteriorly; mid ventral scale rows between ventrolateral folds 40; gular region with relatively homogeneous, smooth scales. Continuous series of 46 precloacofemoral scales; 6 precloacal pores separated by a diastema of 14 (right) and 12 (left) poreless femoral scales from series of 7 (right) and 6 (left) enlarged femoral scales with 5 weakly developed femoral pores on each thigh. Scales on palm and sole smooth, rounded; scalation on dorsal aspects of hind limbs heterogeneous, with enlarged, weakly conical tubercles interspersed among smaller scales; tubercles on forelimb smaller than on hind limb or dorsum.

Fore and hind limbs long, slender (ForeaL/SVL = 0.20; CrusL/SVL = 0.22); digits long, slender, strongly inflected at interphalangeal joints, all bearing robust, slightly recurved claws; proximal subdigital lamellae nearly as broad as digit, oval to rectangular, without scansorial surfaces, number of lamellae on digits I-V: 4- 7-5-6-8 (right) manus; 5-6-5-6-5 (right) pes; narrow lamellae distal to digital inflection and not including ventral claw sheath: 12-12-13-13 -13 (right) manus; 10-13-15-14 -14 (right) pes; interdigital webbing absent. Relative length of digits (measurements in mm in parenthesis): IV (11.6)> III (10.8) ≈ II (10.6)> V (9.5)> I (8.75) manus; IV (12.1)> III (11.3)> V (11.0)> II (9.9)> I (8.8) pes.

Partly regenerated tail slender, gently tapering to tip, slightly longer than snout-vent length (TailL/SVL = 1.27); dorsal caudal scales flat, smooth, homogeneous except for basal segments where 6 parasagittal rows of enlarged, weakly keeled tubercles continue from the dorsum; ventral scales smooth, enlarged median scales extending 50% of tail width; five such transverse plates per tail segment. Series of three enlarged, smooth, conical postcloacal spurs on each side of tailbase.

Coloration of holotype in preservative. Dorsal pattern of distinct alternating purplish-brown and creamy-white bands continues on to tail, a series of brown spots in each whitish band, three sets of such alternating bands between limb insertions and one across sacrum. Dorsal pattern faded on flank, original portion of tail distinctly brown and whitish cream segmented, regenerated portion brown, distalmost part of tail very pale. A prominent brown, postocular stripe with a white upper edge from posterior border of orbit through ear; connected to postocular stripe of other side by a brown spot on nape. Dorsum of head pale brown with whitish posterior edge and symmetrical dark brown markings on posterior portion of head. A light line bordering the nape band extends from posterodorsal border of orbit and on to occiput. Limbs brown, marked by irregular white markings. Venter cream to beige.

Coloration of holotype in life. much bolder, dark bands purplish-brown, paler bands yellowish-cream with dark purplish-brown dots, pale purplish-brown on head, a little darker spots with yellowish border, tail distinctly brown and yellowish-cream segmented, faded to whitish in posterior part of tail. Iris greenishbrown.

Variation. The paratypes resemble the holotype in all aspects of morphology, except that both paratypes have a prominent complete brown collar with darker margins incorporating the postocular stripes; the female paratype, THNHM 15902, lacks both precloacal and femoral pores. Color of the regenerated tails of holotype and male paratype, CUMZ-R-2009,6,24-1, purplish-brown compared to purplish-brown with creamy-white banding of the complete tail of female paratype, THNHM 15902.

Comparisons. We compare the new taxon to species currently known from Thailand and neighboring Laos, Myanmar and Cambodia. Table 2, modified from Rösler & Glaw (2008), presents important characters of each species in the region.

Cyrtodactylus auribalteatus sp. nov. can be distinguished from other species in the region by absence of precloacal groove versus presence in C.rubidus (Blyth) and C. pulchellus ; from C. thirakhupti by the presence of precloacal pores; from C. angularis , C. ayeyarwadyensis Bauer, C. brevidactylus Bauer , C. gansi Bauer , C. intermedius , C. khasiensis (Jerdon) , C. oldhami , C. papilionoides , C. peguensis , quadrivirgatus , C. sumonthai and C. wakeorum Bauer by the presence of femoral pores; from C. chanhomeae , C. consobrinoides (Annandale) , C. feae (Boulenger) , C. jarujini and C. variegatus by the presence of a diastema between the series of femoral pores and precloacal pores; from C. aequalis Bauer , C. buchardi David et al. and C. slowinskii Bauer by the presence of greatly enlarged subcaudal plates at least in the original tail; and from C. brevipalmatus and C. interdigitalis by the absence of a denticulate tail margin. It may be distinguished from C. consobrinus by much lower ventral scales count, 38–40 versus 65–70. It may be distinguished from C. erythrops by much higher ventral scales count, 38–40 versus 28. It may be distinguished from C. annandalei Bauer , C. chrysopylos Bauer , and C. tigroide s by its higher number of dorsal tubercular scale rows, 22–24 versus 18 or less; and from C. russelli Bauer by a lower number of precloacal pores, 6 versus 15.

Distribution and Natural History. Cyrtodactylus auribalteatus sp. nov. is currently only known from Phra Wang Daeng Cave in Thung Salaeng Luang National Park, Phitsanulok Province, northern Thailand. Phra Wang Daeng Cave is situated in densely wooded limestone karst. It is the longest cave system in Thailand with major passages as long as 13 km. The underground system includes a perennial stream that supports three species of troglobitic fishes, Schistura speciesi Vidthayanon & Kottelat , S. deansmarti Vidthayanon & Kottelat and Neolisocheilus subteraneus Vidthayanon & Kottelat, that are endemic to this system ( Vidthayanon & Kottelat 2003). The only other reptile found in the area by the survey team during three visits was Dixonius siamensis (Boulenger) , which was found foraging on the ground outside the cave. This area is characterized by extensive karstic formations and there are many other caves in the vicinity. We are certain that more populations of the new taxa will be discovered in the near future.

Tham Phra Wang Daeng Cave can be divided into two sections, the outer section is a large cavern that is penetrated by daylight. To get to the inner section one must pass through a small hole. Light never reaches the inner section of the cave. We have visited the cave on three occasions. On the first two occasions, at night, the geckos were observed in the outer section of the cave. Three and four animals were observed on each occasion, respectively, mostly clinging to the side of the cave near holes and crevices, into which they would retreat if approached. On the third occasion, during daytime, none were observed in the first section but two were observed in the dark inner section of the cave, which has extremely high humidity due to the presence of the running stream.

Figures

FIGURE 1. Adult male holotype of Cyrtodactylus auribalteatus, sp. nov. (THNHM 15901). Scale bar equals 30 mm.

FIGURE 2. Cloacal region of holotype (THNHM 15901) of Cyrtodactylus auribalteatus, sp. nov. illustrating the discontinuous series of precloacal and femoral pores (positions indicated by black dots). Scales bar equals 10 mm.

FIGURE 3. Head region of the holotype (THNHM 15901) of Cyrtodactylus auribalteatus, sp. nov. Scale bar equals 10 mm.