Cnemaspis caudanivea Grismer & Ngo, 2007

Grismer, Lee, Wood, Perry L., Anuar, Shahrul, Riyanto, Awal, Ahmad, Norhayati, Muin, Mohd A., Sumontha, Montri, Grismer, Jesse L., Onn, Chan Kin, Quah, Evan S. H. & Pauwels, Olivier S. A., 2014, Systematics and natural history of Southeast Asian Rock Geckos (genus Cnemaspis Strauch, 1887) with descriptions of eight new species from Malaysia, Thailand, and Indonesia, Zootaxa 3880 (1), pp. 1-147 : 44-46

Cnemaspis caudanivea Grismer & Ngo, 2007

Hon Tre Island Rock Gecko

Fig. 19

Holotype. UNS 83 . Type locality: “ Hon Tre Island , Kien Hai District, Kien Giang Province, Vietnam (09°58.3429 N, 104°50.9559 E)” at 100 m in elevation.

Diagnosis. Maximum SVL 47.2 mm; eight or nine supralabials; seven or eight infralabials; smooth ventral scales; 0–2 round, discontinuous, pore-bearing, precloacal scales; 20–24 paravertebral tubercles; tubercles linearly arranged but absent from flanks; caudal tubercles not restricted to a single paravertebral row nor encircling tail; caudal tubercles occasionally in lateral caudal furrows anteriorly only; ventrolateral caudal tubercles variably present anteriorly; lateral caudal tubercle row occasionally present anteriorly; subcaudals smooth, sometimes bearing a median row of slightly enlarged scales; one or two postcloacal tubercles on each side; no enlarged femoral or subtibial scales; subtibials smooth to weakly keeled; weakly enlarged submetatarsal scales occasionally present on first toe; 23–30 subdigital fourth toe lamellae; large, black, round spots on nape and anterior portion of body; dark elongate mid-gular marking; wide black and yellow bands on tail; posterior portion of tail immaculate white dorsally and ventrally (Tables 6,7).

Color pattern ( Fig. 19 ). Dorsal ground color gray, overlain by a dark pattern of reddish brown, irregularly shaped markings on top of head and snout; squarish, semi-transversely arranged, large, black blotches on neck and body separated by dull white blotches; irregularly shaped bands on limbs; wide, black and dull-yellow bands encircling tail; wide, poorly defined, dark-brown postorbital stripes edged below in white extending onto side of neck; ventral surfaces of neck, body, and limbs dull beige, immaculate; gular region smudged with darker coloration and light spots, bearing a dark mid-gular stripe; last 25% of original tail immaculate, brilliant white dorsally and ventrally.

Distribution. Cnemaspis caudanivea is known only from the type locality of Hon Tre Island, Kien Hai District, Kien Giang Province, Vietnam ( Fig. 3 ).

Natural history. Hon Tre is a small (70 km 2) island lying 15 km off the southern coast of Vietnam in Rach Gia Bay, 28.3 km nearly due west of the port of Rach Gia in Kien Giang Province. The island is steep-sided, reaching 315 m in elevation and dominated by secondary and primary semi-deciduous forest covering a landscape composed of nearly continuous outcrops of large, granitic boulders ( Fig. 19 ). Grismer & Ngo (2007) noted lizards occurred on granite boulders throughout the island, from the coastline to near the summit. During the day, lizards are only observed on shady, inclined surfaces and within rock cracks and cave-like cavities formed by boulders piled on top of one another. At night, lizards venture onto the exposed outer surfaces of the boulders but appear inactive. Lizards are exceptionally wary both day and night and typically escape capture at surprisingly high speeds, often hopping while running. Grismer & Ngo (2007) reported lizards curling and elevating their tail above their back when alarmed and moving the posterior 25% from side to side, thus displaying the strikingly white coloration. The dexterity with which the tail is waved back and forth, however, exceeds that of all other Cnemaspis we have observed. Cnemaspis caudanivea can fold the end of the tail forward 180° on itself while rolling and unrolling it slowly in a lateral plane, making it look like a small, white worm wiggling on a rock. This behavior and color pattern is maintained in regenerated tails as well, suggesting it is strongly selected for.

Relationships. Cnemaspis caudanivea is the sister species to a monophyletic group composed of C. tucdupensis and C. nuicamensis ( Fig. 2 ).

Material examined. Vietnam: Kien Giang Province, Kien Hai District, Hon Tre Island UNS 83 , 84 (type series). Material examined since Grismer & Ngo (2007) : Vietnam; Kien Giang Province, Kien Hai District, Hon Tre Island LSUHC 8247 , 9543–48 .

Figures

FIGURE 2. Maximum-likelihood phylogram (–InL 73957.608688) of the species of the genus Cnemaspis with Bayesian posterior probabilities (BPP) and maximum-likelihood (ML) bootstrap values, respectively based on the concatenated 3 gene dataset. Black circles are nodes supported by BBP and ML values greater than 0.95 and 70, respectively. Gray circles are nodes supported only by ML values greater than 70. White circles are nodes supported only by BPP values greater than 0.95. The distribution maps on the right delimit the ranges of the four major clades.

FIGURE 3. Distribution of the species and species groups in the Ca Mau and Northern Sunda clades. Stars indicate type localities.

FIGURE 19. Cnemaspis caudanivea from Hon Tre Island, Kien Giang Province, Vietnam. Upper left: adult male (LSUDPC 3056) in the light color pattern phase. Upper right: adult female (LSUDPC 3045) in the dark color pattern phase. Lower: granite boulder microhabitat on Hon Tre Island. Photographs by LLG.