Holotype. An adult male ( ZFMK 86037), Phong Nha - Ke Bang National Park, Quang Binh province, central Vietnam, collected by Dang Ngoc Kien on 7 July 2006 in the limestone forest of U Bo at an altitude of ca. 520 m.
Description of holotype.
SVL 92.5 mm; TaL 69.5 mm (of which 28.0 mm are regenerated); HL 22.0 mm; HW 17.7 mm; HH 8.8 mm; SE 9.7 mm; EE 7.4 mm; DE 3.6 mm; DEA 0.9 mm.
Proportion of SVL / HL 4.21; HL / HW 1.5; HL / HH 2.5; SE / EE 1.31; DE / DEA 4.0.
Rostral scale 1.4 times wider than high, paritially divided dorsally with a straight median suture extending to the centre of the scales; 10 / 8 supralabials, 8 / 8 sublabials; nares in contact with rostral, first supralabial and 3 / 4 nasals; nasorostrals (see Rösler 1995, 20 p.) between 2.5 times larger than supranasals; one internasal, half as large as nasorostrals; snout scales medially granular, flattened in the preorbital region, smooth, cycloid, juxtaposed, contacting with supralabials 2–3 times larger than median snout scales; upper ciliaries anteriorly 2–3 times larger than posterior ciliaries; head scales granular, half as large as median snout scales; head centre and temporal region with tubercles; head tubercles rounded, flat, twice the size of the surrounding granules; mental in part destroyed (presumably triangular), as large as rostral scale; two postmentals, trapezoidal, longer than wide, each contacts seven gular scales; gular scales granular, the granule being as large as median snout scales; dorsals granular, as large as median snout scales; dorsal tubercles round, conical, three times as large as dorsals, surrounded approximately by ten dorsal scales, and arranged in 20 irregular longitudinal rows; ventrals flat, smooth, those medially twice the size of dorsal scales, in 48 longitudinal rows at midbody; upper and lower arm dorsally granular, lower arm with rounded, flat tubercles that are 1.5– 2 times larger than surrounding scales; upper and lower leg dorsally granular with scattered round, conical tubercles, three times as large as surrounding scales; femoral region medially sharply subdivided into large anterior and small posterior scales (see Fig. 2View FIGURE 2); uninterrupted series of enlarged subdigital lamellae below first finger 10 / 10, below fourth finger 17 / 18, below first toe 11 / 11, and below fourth toe 21 / 20; second, third and fourth digits with narrow skin seams; claws surrounded by a small dorsal and a large ventral scale; nine precloacal pores in a rightangled row, 26 enlarged precloacal scales; 3 / 3 nearly equal-sized postanal tubercles, arranged in an oblique row; original tail with whorls; dorsal tail scales flat, smooth, subimbricate, twice the size of median snout scales, arranged in regular transverse rows; the third tail whorl with nine scale rows; no enlarged subcaudal plates; subcaudals flat, smooth, imbricate, 2–3 times larger than dorsal tail scales, four rows per whorl, each of the last two per whorl enlarged; tail tubercles round, flat, 2 –2.5 times the size of the surrounding scales, the first whorl with six and the fifth whorl with four tubercles; regenerated tail dorsally and ventrally with flat, smooth, imbricate scales.
The dorsum of the ethanol-preserved holotype is brownish-olive; labials brown with white blotches; head above with rounded, arched and ornate brown blotches dorsally; nuchal band triangular, dark violet brown, with white margins and with a wide stripe extending from the outermost neck band corner to the posterior margin of each eye (this band is often referred to as the nuchal loop); dorsum with four dark violet-brown, narrow buff margined transverse undulate bands; the anterior dorsal band located behind the axilla, the posterior dorsal band located in the sacral region; small to larger dark violet-brown irregular blotches with narrow buff margins between the dorsal bands; flanks greyish-brown with buff blotches; venter greyish-brown; jaws and throat with white stripes and blotches; precloacal region dirty white; limbs, including fingers and toes, with white and brown stripes; original tail with white and dark brown rings; regenerated tail brown, with white blotches on the ventral side and scarcely visible white blotches on the dorsum. For the coloration and pattern in life see Fig. 1View FIGURE 1.
Paratypes. VNUH 7.7.0 6 (adult male) and ZFMK 86038 (adult female), Phong Nha - Ke Bang National Park, Quang Binh province, central-Vietnam, collected by Dang Ngoc Kien on 7 July 2006 in the limestone forest of U Bo at an altitude of ca. 520 m. VNUH 17.7.0 6 and ZFMK 86039 (adult females), Phong Nha - Ke Bang National Park, Quang Binh province, Central Vietnam, collected in the limestone forest of Cha Noi (35 km from the type locality) at an altitude of 300 to 400 m: VNUH 17.7.0 6 collected by Astrid Heidrich on 5 August 2006, and ZFMK 86039 by Ralf Hendrix on 7 August 2006.
Variation of paratypes. The single male paratype differs from the pattern of the male holotype in having only three dark transverse body bands. Its venter is whitish-grey and the tail bears ten dark and ten light alternating bands. The female paratypes have 4–5 dark transverse body bands with yellow margins, greyish-brown to whitish-grey venters and 10–11 dark brown bands on the tail. The measurements and pholidosis of the paratype series are presented in Table 1. In addition, the female ZFMK 86038 had the postmentals in contact each with eight scales, and the dorsal tubercles surrounded by 9–11 dorsal scales.
Diagnosis. A medium-sized Cyrtodactylus with a slender habitus and a maximum total length of 176.6 mm (SVL 62.5–90.8 mm) that can be distinguished from all congeners on the basis of the following combination of characters: 1) rounded body in cross-section, not wider than head; 2) neck band, extending to posterior margin of eyes; 3) dorsum with 3–5 dark transverse bands with yellow margins and dark spots; 4) ventrolateral skin folds along the body or enlarged lateral tubercles absent; 5) tubercles present on top of head, body, forearm, hind limbs and tail; 6) 19–20 irregular longitudinal rows of dorsal tubercles; 7) 47–50 longitudinal rows of ventral scales at midbody; 8) segmented tail with whorls, not depressed, base not enlarged; 9) 0–3 cloacal spurs on each side of tail base; 10) 9–11 precloacal pores in angular series in males and 16–27 enlarged precloacal scales in both sexes; 11) enlarged femoral scales and femoral pores absent; 12) precloacal groove absent; 13) subcaudals small, not transversally enlarged; 14) uninterrupted series of 20–23 lamellae beneath 4 th toe; 15) tail and limbs banded.
Further records. During field research within Phong Nha - Ke Bang National Park from July to August 2006, 14 additional specimens of C. cryptus sp. n. were collected by Dang Ngoc Kien, Astrid Heidrich, Ralf Hendrix and local people. They were identified, sexed, weighed and measured before their subsequent release (see Table 2). The male specimens that were captured on 6 and 10 August 2006 had 11 precloacal pores. Some sexual dimorphism in the coloration of the ventral surfaces was observed (females were somewhat darker). Coloration and pattern in two captured juveniles did not differ from that of adult specimens. In two specimens the transverse body bands were fragmented into large, broad blotches ( Fig. 4View FIGURE 4).
. Etymology. The name of the species derives from the Greek adjective kryptos (Latin cryptus) meaning “concealed”, “hidden”, because the new species had been overlooked during the previous decade of herpetological investigations in the Phong Nha - Ke Bang National Park.
Natural history and distribution. All observations of Cyrtodactylus cryptus sp. n. took place at night. Specimens were found on karst cliffs, on tree trunks and in branches or leaves up to 2 m height, but also on rotten trees, on stones and one specimen even on the ground on a forest street. For climate and microhabitat information see Table 3. In the U Bo region, C. cryptus sp. n. was the only bent-toed gecko we were able to record and the new species inhabited both karst cliffs and tree trunks ( Figs. 6–7View FIGURE 6View FIGURE 7). In the second site of the Phong Nha - Ke Bang National Park, where we recorded the new species (in Cha Noi area, Fig. 8View FIGURE 8), C. cryptus sp. n. occurred in sympatry with C. phongnhakebangensis. According to our observations it seems that these two species inhabit different microhabitats when occurring together, with C. cryptus sp. n. mainly occupying tree trunks and C. phongnhakebangensis karst cliffs. In the U Bo area we marked eight individuals of the new species along 138 m of karst stream. After three weeks, three animals (37.5 %) were recaptured up to 5 m away from the original collecting locations. However, similar studies carried out in the primary forest gave different results: A male and a female were released on a tree trunk distant from streams and karst cliffs, and recaptured during the subsequent two nights. However, we failed to see these animals during searches conducted ten days later. During capture-recapture studies we only were able to recapture C. cryptus sp. n. on karst cliffs, but never on primary forest trees. Detailed data concerning capture-recapture research and the feeding ecology of C. cryptus sp. n. will be published elsewhere (Heidrich et al., in prep.). One female specimen, kept in a terrarium for some time laid two hard-shelled, oval eggs of 12 x 14.3 mm size on 28 September, 2006, in the early rainy season. Both eggs were deposited in a tube-shaped stone hole.
Currently, the species is known only from its type locality ( Fig. 9View FIGURE 9).
Systematic position. Among the species of Cyrtodactylus distributed in South East Asia, C. cryptus sp. n. is mainly characterised by the absence of enlarged subcaudals, a precloacal groove, femoral pores and enlarged femoral scales. The new species is superficially similar in colouration and pattern to the sympatric C. phongnhakebangensis. However, C. cryptus sp. n. is clearly set apart from C. phongnhakebangensis among others by lacking enlarged subcaudal plates, femoral pores and enlarged femoral scales, as well as by a lower number of precloacal pores. C. cryptus sp. n. is very similar to C. papilionoides in habitus, body size and colour pattern ( Ulber & Grossmann 1991, Chan-Ard et al. 1999), but differs in the presence of round and flat tail tubercles versus pointed tail tubercles in C. papilionoides, the lack of enlarged femoral scales, a higher number of ventral scales (47–50 versus 30–34 in C. papilionoides), the presence of a continuous series of 20– 23 subdigital lamellae under the 4 th toe versus an interrupted series of 12–16 lamellae under the 4 th toe and 3– 7 scales, a higher number of longitudinal rows of dorsal tubercles (19–20 irregular versus 12–14 regular) and precloacal pores (9–11 versus 4–6), which are arranged in acute-angled rows (versus obtused-angled rows in C. papilionoides), as well as by having larger precloacal scales (compared with ventral and femoral scales). Furthermore, the two species have different egg shapes (oval in C. cryptus, almost round in C. papilionoides, with a diameter of 14.9 x 14.0 mm according to Schäfer 1991). Future (molecular) analyses must clarify the systematic relationships of the new species.
TABLE 1. Pholidosis and measurements (in mm) of the paratype series of Cyrtodactylus cryptus sp. n. (for abbreviations see material and methods); * with regenerated tail tip.
VNUH 7.7.0 6 male 11/11
VNUH 17.7.0 6 ZFMK 86038 female female 8/10 10/10
ZFMK 86039 female 10/10
TABLE 2. Mensural data (in mm) of 14 captured and released specimens of Cyrtodactylus cryptus sp. n. from Phong Nha - Ke Bang (for abbreviations see material and methods). Further abbreviations are as follows: f = female; m = male; juv. = subadult; * with regenerated tail tip; ** tail tip missing.
Nr. Date Locality
Weight [g] SVL
9 6 August 0 6 Cha Noi
10 6 August 0 6 Cha Noi
11 7 August 0 6 Cha Noi
12 10 August 0 6 Cha Noi
13 10 August 0 6 Cha Noi
TABLE 3. Ecological details for the 14 captured and released specimens of Cyrtodactylus cryptus sp. n. from Phong Nha - Ke Bang. Abbreviations are as follows: f = female; m = male; juv. = subadult; Temp. = temperature.