Cyrtodactylus cardamomensis, Murdoch & Grismer & Wood Jr & Neang & Poyarkov & Tri & Nazarov & Aowphol & Pauwels & Nguyen & Grismer, 2019

Murdoch, Matthew L., Grismer, L. Lee, Wood Jr, Perry L., Neang, Thy, Poyarkov, Nikolay A., Tri, Ngo Van, Nazarov, Roman A., Aowphol, Anchalee, Pauwels, Olivier S. G., Nguyen, Hung Ngoc & Grismer, Jesse L., 2019, Six new species of the Cyrtodactylus intermedius complex (Squamata: Gekkonidae) from the Cardamom Mountains and associated highlands of Southeast Asia, Zootaxa 4554 (1), pp. 1-62 : 32-38

Cyrtodactylus cardamomensis sp. nov.

Cardamom Mountains Bent-toed Gecko

Figs. 14 & 15 , Table 11.

Cyrtodactylus intermedius Daltry and Traeholt 2003: 89 –90; Emmet and Olsson 2005: 34 –35; Stuart and Emmet 2006: 17; Grismer, Thy, Chav, Wood, Oaks, Holden, Grismer, Szutz, and Youmans 2008: 165.

Holotype. Adult male LSUHC 7947 collected on 10 August 2006 by L. Lee Grismer, Neang Thy, Thou Chav, Perry L. Wood Jr., Jamie R. Oaks, Jeremy Holden, Jesse L. Grismer, Thomas R. Szutz, Timothy M. Youmans from Camp 3, Phnom Samkos Wildlife Sanctuary, Pursat Province, Cambodia (1211’52’’N, 10303’10’’E; 336 m in elevation).

Paratypes. Adult female LSUHC 7936 and female juvenile LSUHC 7943 bear the same collection data. Adult female LSUHC 7918 was collected at camp 2 (1212’N, 10304’E, 331 m in elevation) by the same collectors. Adult female LSUHC 10096 was collected near O’Som village Pursat Province, Cambodia (1204’ N 10309 ’E) on 23 August 2011 by the same collectors plus Evan S. H. Quah. Adult male FMNH 263344 was collected in the Thmar Baing district , Koh Kong Province, Cambodia (1140’12’’ N 10342 ’46’’E) 820 m in elevation on 28 February, 2004 by Bryan L. Stuart. Adult male FMNH 263345 was collected in the Thmar Baing district, Koh Kong, Cambodia along the Russei Chrum river (1157’24’’ N 10318 ’43’’E) 420 m in elevation 31 December, 2003 by Bryan L. Stuart .

Diagnosis. Adult males reaching 80.6 mm SVL, adult females reaching 84.1 mm SVL; 7–9 supralabials, 8–10 infralabials; 29–34 paravertebral tubercles; 17–21 longitudinal rows of dorsal tubercles; 36–43 rows of ventral scales; five or six expanded subdigital lamellae proximal to the digital inflection, 12 or 13 unmodified, distal, subdigital lamellae; 17–19 total subdigital lamellae on fourth toe; enlarged femoral and precloacal continuous; 23– 28 enlarged femoral scales; proximal femoral scales ranging from greater than one-half the size to the same size as distal femoral scales; nine or 10 enlarged precloacal scales with pores in each in males; two or three rows of enlarged post-precloacal scales; two or three postcloacal tubercles; no interdigital pocketing present; dark pigmented blotches absent from top of head; posterior border of nuchal loop rounded; and four or five dark body bands ( Table 11). These characters are scored across all species of the Cyrtodactylus intermedius complex in Table 7.

Description of holotype. Adult male SVL 80.6 mm; head moderate in length (HL/SVL 0.28) and width (HW/ HL 0.70), somewhat flattened (HD/HL 0.37), distinct from neck, and triangular in dorsal profile; lores concave anteriorly, weakly inflated posteriorly, prefrontal region deeply concave, canthus rostralis rounded; snout elongate (ES/HL 0.38), rounded in dorsal profile; eye large (ED/HL 0.24); ear opening elliptical, obliquely oriented, moderate in size (EL/HL 0.07); eye to ear distance greater than diameter of eye; rostral rectangular, partially divided dorsally by L-shaped furrow, bordered posteriorly by large left and right supranasals and one large azygous internasal, bordered laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal, posteriorly by two moderately sized postnasals, bordered ventrally by first supralabial; 8(R,L) rectangular supralabials extending to below midpoint of eye, second supralabial slightly larger than first; 10(R,L) infralabials tapering smoothly to just below and slightly past the termination of enlarged supralabials; scales of rostrum and lores flat to slightly raised, larger than granular scales on top of head and occiput; scales of occiput intermixed with distinct, enlarged tubercles; dorsal superciliaries not elongate or keeled; mental triangular, bordered laterally by first infralabials and posteriorly by large left and right trapezoidal postmentals which contact medially for 50% of their length posterior to mental; one row of slightly enlarged, elongate sublabials extending posteriorly to seventh infralabial; gular and throat scales small, granular, grading posteriorly into slightly larger, flatter, smooth, imbricate, pectoral and ventral scales.

Body relatively short (AG/SVL 0.47) with poorly defined ventrolateral folds; dorsal scales small, granular interspersed with relatively large, conical, semi-regularly arranged, weakly keeled tubercles; tubercles extend from occiput onto base of tail but end at regenerated tail; similarly sized and spaced tubercles continue onto nape and occiput but diminish in size and distinction on top of head; approximately 17 longitudinal rows of tubercles at midbody between ventrolateral, body folds; 32 paravertebral tubercles; 37 flat, imbricate, ventral scales between ventrolateral body folds, ventral scales much larger than dorsal scales; nine large, pore-bearing, precloacal scales; no deep precloacal groove or depression; and two rows of post-precloacal scales.

Forelimbs moderate in stature, relatively short (FL/SVL 0.14); granular scales of forearm larger than those on body, interspersed with large, conical tubercles; palmar scales rounded, slightly raised; interdigital pocketing absent; digits well-developed, inflected at basal, interphalangeal joints; digits slightly more narrow distal to inflections; subdigital lamellae transversely expanded proximal to joint inflections, more granular distal to inflection; claws well-developed, claw base sheathed by a dorsal and ventral scale; hind limbs more robust than forelimbs, moderate in length (TBL/SVL 0.17), covered dorsally by granular scales interspersed with large, conical tubercles and anteriorly by flat, slightly larger scales; ventral scales of thigh flat, imbricate, larger than dorsals; subtibial scales flat, imbricate; one row of 13(R,L) enlarged femoral scales in contact with enlarged precloacal scales, terminate just before the inflection of the knee; femoral pores absent; proximal femoral scales same size as distal femorals, form abrupt union with smaller, rounded, ventral scales of posteroventral margin of thigh; plantar scales flat; interdigital pocketing absent; digits relatively long, well-developed, inflected at basal, interphalangeal joints; 6(R,L) transversely expanded subdigital lamellae on fourth toe proximal to joint inflection that extends onto the sole; 13(R,L) unmodified lamellae distal to inflection; 18 total number of subdigital lamellae, and claws welldeveloped, sheathed by a dorsal and ventral scale at base.

Tail 103 mm in length, first 34 mm original, last 69 mm regenerated, 6.4 mm in width at base, tapering to a point; dorsal scales of original portion of tail, flat, square; regenerated portion of tail covered with small, smooth rectangular scales dorsally; median row of transversely expanded subcaudal scales, significantly larger than dorsal caudal scales; slightly keeled caudal tubercles present on original portion; base of tail bearing hemipenal swellings; two postcloacal tubercles on either side of base of hemipenal swellings; and postcloacal scales flat, imbricate.

Coloration in alcohol. Dorsal ground color of head, body, limbs, and tail brown; dark-brown nuchal loop with rounded posterior border extends from posterior margin of one eye to posterior margin of other eye; nuchal loop edged with thin, light, lines; four similarly colored dorsal bands with slightly lightened centers occur between limb insertions; second band slightly hourglass shaped; first band terminates at shoulders; second and third bands terminate dorsal to ventrolateral fold; fourth band terminates at anterior margin of hind limb insertions; a single similarly colored blotch present to the right of dorsal midpoint; tubercles bordering body bands bright white in color giving a speckled appearance; body band/interspace ratio 1.2; three dark and two light caudal bands present before giving way to uniform brown regenerated tail ( Fig 14 ).

Variation. The paratypes closely approach the holotype in coloration ( Fig. 14 ). LSUHC 7918 and 7943 have rounded distal body band borders terminating with a clear lightly colored border before the ventrolateral fold. LSUHC 10096 has five body bands as opposed to four. In life, there is light edging along the dark dorsal bands and the tubercles are pale yellow to a darker butterscotch color. Tubercles on dorsal margin of thigh slightly lighter than base color ( Fig 15 ). Meristic differences among the type specimens and additional specimens examined are presented in Table 11.

Additional specimens examined. Three additional specimens examined (LSUHC 10081–82) were collected near O’Som village Pursat Province, Cambodia (1204’ N 10309 ’E) on 23 August, 2011. LSUHC 7855 was collected 7 August 2006 at camp 1, Phnom Samkos, Pursat Province, Cambodia (1208' N 10308 E; 331 m in elevation). FMNH 263346 was collected at Tatai Leu, Thmar Baing district, Koh Kong (11 48’59’’ N 103 31’ 51’’E) 430 m on 27 January 2004 ( Table 11).

Distribution. Cyrtodactylus cardamomensis sp. nov. is presently known from three locations ranging across the Cardamom Mountains from Phnom Samkos Wildlife Sanctuary, and the forests around O’Som and Thmar Baing. The population from Koh Rong may prove to be C. cardamomensis sp. nov. and if this is the case the species should be present in the hills south of the known populations.

Etymology. The specific epithet, cardamomensis , is an adjective in reference to the mountain range where the type locality, Phnom Samkos, is located. While the Cardamom mountains refer broadly to all highlands located in southwestern Cambodia we have chosen this group to be named as such as it occurs broadly through a large and mostly contiguous segment of the mountain range rather than being restricted to specific isolated geological features such as Phnom Aural, Phnom Dalai or the Bokor Plateau.

Natural history. The type locality is a former Khmer Rouge hideout situated along an unnamed river at the base of Phnom Samkos at 1290 m elevation in a transitional zone between dry dipterocarp forest and hill evergreen forest. No sign of extensive logging was evident at the time of collection and the understory was relatively free of vegetation. Specimens were collected at night and found on the ground among small rocks and on vegetation no higher than one meter above the ground. All material collected from secondary lowland forest at O’Som was also found at night in low vegetation. Stuart & Emmet (2006) note that specimens collected from Thmar Baing were found in hill evergreen forest as well as disturbed lowland dry evergreen forest.

Comparisons. Cyrtodactylus cardamomensis sp. nov. is a member of the western group and the sister to C. intermedius complex incertae sedis 1 from Koh Rong Island, Cambodia from which it is separated by 3.5% sequence divergence ( Table 4). The PCA analysis shows Cyrtodactylus cardamomensis sp. nov. is separated in morphospace from all species with the exceptions of C. phuquocensis , C. auralensis sp. nov., and C. bokorensis sp. nov. with which there is overlap. ( Fig 6 ). The DAPC analysis shows C. cardamomensis sp. nov. as distinct from all other species within the complex with the exceptions of C. intermedius , C. septimontium sp. nov., and C. auralensis sp. nov. with which there is some overlap ( Fig. 7 ). Cyrtodactylus cardamomensis sp. nov. is welldifferentiated from all species of the C. intermedius complex by having combinations of statistically different mean values of supralabial and infralabial scales, paravertebral tubercles, longitudinal rows of tubercles, ventral scales, unmodified, expanded, and total number of subdigital lamellae, enlarged femoral scales, precloacal scales, and postcloacal tubercles ( Table 6). It differs from C. auralensis sp. nov. by lacking any dark pigmented blotches on the top of the head. It differs from C. bokorensis sp. nov. in having a nuchal loop with a rounded posterior border. It differs from C. laangensis sp. nov. in having contact between femoral and precloacal scales. It differs from all other species with the exception of C. thylacodactylus sp. nov. in having its proximal and distal femoral scales being of approximately the same size and shape as opposed to having proximal femoral scales less than one-half the size of the distal scales. It is further differentiated from C. thylacodactylus sp. nov. in lacking interdigital pocketing ( Table 7).

Remarks. The populations from the Cardamom mountains and Koh Rong Island have a sequence divergence of 3.5% ( Table 3) despite a physical distance of 100km, 15km of which is open ocean. Conversely, C. cardamomensis sp. nov. and C. thylacodactylus sp. nov. have a 3.7% sequence divergence but are only separated by 20km with significant morphological differentiation. No specimens of the population from Koh Rong Island were available for morphological analysis so differences with C. cardamomensis sp. nov. could not be assessed. Additionally, no specimens have been collected in the 100km gap, so it is unknown if there are intermediate populations allowing for gene flow. Thus, for the purpose of this research the population from Koh Rong Island will be referred to as incertae sedis 1.

Figures

FIGURE 6. Principal component analysis (PCA) of the species of the Cyrtodactylus intermedius complex showing ordination along the first two principal components.

FIGURE 7. Discriminant analysis of principal components (DAPC) of the species of the Cyrtodactylus intermedius complex emphasizing between-group variance and minimizing within-group variance based on retention of the first eight components. Circles represent 95% confidence intervals.

FIGURE 14. Type series and additional specimens examined of Cyrtodactylus cardamomensis sp. nov. Upper: Type series from left to right: holotype LSUHC 7947, paratypes LSUHC 7918, 7936, 7943,10096, FMNH 263344. Lower Right: paratype FMNH 263345. Lower Left: additional specimens examined.

FIGURE 15. Cyrtodactylus cardamomensis sp. nov. Upper left: adult male from Phnom Samkos, Pursat province, Cambodia (photo by Neang Thy). Upper right adult female from O’Som village, Pursat province, Cambodia LSUDPC 6072 (photo by L. Grismer). Lower left: adult male from O’Som village, Pursat province, Cambodia LSUDPC 6071 (photo by L. Grismer). Lower right: forested microhabitat from the slopes of Phnom Samkos (photo by L. Grismer).