Cyrtodactylus regicavernicolus, Chhin & Neang & Chan & Kong & Ou & In & Samorn & Sor & Lou & Sin & Chhim & Stuart & Grismer, 2024

Chhin, Sophea, Neang, Thy, Chan, Somaly, Kong, Kimsreng, Ou, Ratanak, In, Visatha, Samorn, Vireak, Sor, Ratha, Lou, Vanny, Sin, Sopha, Chhim, Meng, Stuart, Bryan L. & Grismer, L. Lee, 2024, A new species in the Cyrtodactylus intermedius (Squamata: Gekkonidae) group from an isolated limestone karst formation in southwestern Cambodia, Zootaxa 5474 (1), pp. 1-20 : 9-17

Cyrtodactylus regicavernicolus sp. nov.

urn:lsid:zoobank.org:act:A825F9F4-0086-4DFF-AB0E-A57D7526C4BF

Figures 4 , 5

Holotype. CBC 03257 (field tag NT 01474), adult male, Cambodia, Kampot Province, Banteaymeas District, Touk Meas Khang Lech Commune, Chrorkley Village , Phnom Preah Kuhear Loung Natural Heritage Site, 10.66459ºN 104.53687ºE, coll. 29 January 2021 by Thy Neang, Vireak Samorn, Visatha In, Ratha Sor, and Sopha Sin.

Paratypes. CBC 03256 (male), same data as holotype except 10.66459ºN 104.53687ºE . CBC 03258 (one female), same data as holotype . CBC 03259–60 (two males), same data as holotype except 10.67058ºN 104.54023ºE, coll. 29–30 January 2021 . CBC 03261 (one male), same data as holotype except 10.65109ºN 104.52284ºE, coll. 30 January 2021 . CBC 03262 (one male), same data as holotype except 10.66745ºN 104.51744ºE, coll. 13 February 2021 . CBC 03264 (one female), same data as holotype except 10.66987ºN 104.51725ºE, coll. 13 February 2021 . CBC 03266 (one male), same data as holotype except 10.66668ºN 104.54284ºE, coll. 14 February 2021 . NCSM 110189 (one male), same data as holotype except 10.67081ºN 104.51947ºE, coll. 13 February 2021 . NCSM 110190 (one male), same data as holotype except 10.66699ºN 104.54253ºE, coll. 13 February 2021 . NCSM 110187–88 , CBC 03299 (three males), CBC 03298 (one female), same data as holotype except 10.66459ºN 104.53687ºE, coll. 14 September 2022 by Thy Neang, Vireak Samorn, Sophea Chhin , and Meng Chhim ; CBC 03304 (one male), Cambodia, Kampot Province, Banteaymeas District , Touk Meas Khang Lech Commune , Chrorkley Village , Phnom Totung , 10.69681ºN 104.52457ºE, coll. 14 September by Thy Neang, Vireak Samorn, Sophea Chhin, and Meng Chhim.

Referred material. CBC 03300 (one subadult male), CBC 03301 (juvenile), CBC 03302 (one juvenile), same data as holotype except 10.66459ºN 104.53687ºE, coll. 14 September 2022 by Thy Neang, Vireak Samorn, Sophea Chhin, and Meng Chhim. CBC 03305 (one subadult female), same data as holotype except 10.66698ºN 104.54255ºE, coll. 14 September 2022 by Thy Neang, Vireak Samorn, Sophea Chhin, and Meng Chhim. CBC 03263 (one juvenile), same data as holotype except 10.66987ºN 104.51725ºE, coll. 13 February 2021. CBC 03265 (one juvenile), same data as holotype except 10.67058ºN 104.54023ºE, coll. 13 February 2021. CBC 03303 (one juvenile), same data as holotype except 10.66459ºN 104.53687ºE, coll. 14 September 2022 by Thy Neang, Vireak Samorn, Sophea Chhin, and Meng Chhim.

Etymology. The specific epithet taken from regis (L.) for “of the king,” caverna (L.) for “cave,” and cola (L.) for “dweller,” in reference to its type locality at Phnom Preah Kuhear Loung, a name in the Khmer language that translates to “Royal Cave Mountain”.

Suggested Common Names. Royal Cave Bent-toed Gecko (English), តុកែភ្នំព្រºគុហ]រហ្លួង (Khmer).

Diagnosis. ( Tables 3 , 4 ). Cyrtodactylus regicavernicolus sp. nov. can be differentiated in morphology from other nominal species in the C. intermedius group by having the following combination of characters: maximum snout-vent length of adult male 77.6 mm, of adult female 80.7 mm; head length 17.5–20.7 mm; interorbital distance 3.7–5.2 mm; infralabials 6–9; longitudinal dorsal rows of enlarged tubercles 15–18; rostral bordered posteriorly by a single internasal scale ( Fig. 5 ); nostril bordered posteriorly by two or three postnasal scales; enlarged femoral scales (both sides combined) 7–23; precloacal pores in males 6–9 ( Fig. 5 ); no femoral pores in males or females; post cloacal spurs in both sexes 2–5; expanded subdigital lamellae on fourth toe 7–10; unexpanded subdigital lamellae on fourth toe 12–14; total subdigital lamellae on fourth toe 19–23; dark brown body bands four or five, width equal to or greater than light interspace; dark brown caudal bands 13–15; interphalangeal pockets absent; and discontinuous enlarged femoral and precloacal scales.

Description of the holotype. Adult male, SVL 69.6 mm; head slightly elongated, approximately one-fourth SVL, HeadL 18.0 mm, HeadL/SVL 26%, moderately widened, HeadW 13.0 mm, HeadW/HeadL 0.72, slightly depressed, HeadD 8.3 mm, HeadD/HeadL 0.46, distinct from neck, subtriangular in dorsal profile; snout elongated, rounded in rostral region, ESD 8.7 mm, approximately one-half HeadL, ESD/HeadL 0.48, frontonasal region flattened dorsally, strongly depressed laterally, prefrontal region concave, forming elongated medial rostral groove, canthus rostralis rounded, slightly angled between loreal region and rostral groove; posterior region to lores depressed, anterior region to orbit flattened; eye large, eyeball rounded, slightly protruding, EyeD 4.9 mm, shorter than distance from eye to ear, Eye-EarD 5.4 mm, pupil vertical, covered by crenellate supraciliaries; ear opening suboval, deeply sunk, relatively small, elongated obliquely, longer than its diameter in horizontal position, EarD 1.5 mm; rostral large, subrectangular, height 1.5 mm, shorter than its width 3.1 mm, medially divided dorsally by linear furrow 0.6 mm, reaching to about one-third of rostral height, in contact with first SL and nostrils laterally, two supranasals and single internasal dorsally ( Fig. 4 ); nostrils pierced at anterior angle of snout, directed lateroposteriorly, surrounded by rostral anteriorly, first SL ventrally, supranasals dorsally, and three small postnasal scales posteriorly; internarial distance narrow, IND 2.1 mm, supranasals two, subheptagonal, separated by single intersupranasal, much smaller in size, in contact with rostral anteriorly, nostrils laterally, four small scales posteriorly; intersupranasal single, subpentagonal, slightly protruding to rostral suture, in contact with one scale posteriorly; interorbital relatively narrow, IOD 4.8 mm, subequal to EyeD, shorter than Eye-EarD; SL nine each side, subrectangular, anterior SL separated from smaller scales on loreal region by row of slightly enlarged scales; IL nine each side, first bordered by mental anteriorly, first and second by postmental ventrally, second by second postmental, enlarged gular scale ventrally, IL 3–9 on both sides bordered ventrally by row of slightly enlarged chin shield scales; mental large, subtriangular, width 2.9 mm, length 2.1 mm, in contact with ninth IL laterally and two postmentals posteriorly; postmentals in two pairs, first pair largest, elongated, pentagonal, in broad contact medially, second pair enlarged, much smaller in size than first pair, separated by three small gular scales medially, each in contact with five smaller scales posteriorly on right side, four on left side. Scales on frontonasal, prefrontal, loreal regions small, almost homogenous, but much larger than those on top of head, with scattered small conical tubercles; scales on occiput, region between orbits, and region above ear opening small, intermixed with scattered, larger, more rounded, more prominent tubercles.

Body slightly slender, AG 32.0 mm, nearly half SVL,AG/SVL 0.460, with well-defined narrow vertebral furrow posteriorly; scales on dorsum small, mostly homogenous, granular, interspersed with larger, low, weakly keeled, irregularly arranged, tubercles; longitudinal dorsal rows of enlarged tubercles approximately 17, each surrounded by smaller scales between about 10 and 12; paravertebral tubercles 29; tubercles on nape within dark brown nuchal loop, anterior dorsal surface at level above shoulder smaller, more rounded, sparser than those on mid-dorsum and posterior dorsal surface, more prominent, being denser, weekly keeled, more regularly arranged on sacral and tail base region; tubercles on lateral body sparsely; ventral scales small, slightly imbricate, those along midventral line larger than lateral and dorsal scales; scales on throat and gular region the smallest; distinct ventrolateral folds with regenerated. Other abbreviations defined in text.

nov. Comparative data come from Murdoch et al. (2019) and Grismer et al. (2023). emerged few larger raised tubercles; ventral scales at midbody between ventrolateral folds 44; precloacal region moderately enlarged, a few rows of enlarged precloacal non-pore bearing scales anterior to pore bearing precloacal scales; enlarged precloacal scales eight, in angular series, bearing seven pores on each ( Fig. 4 ); post precloacal scale rows three, the first row immediately posterior to the angular precloacal pore-bearing scale with a single scale, similar in size to pore-bearing precloacal scales, the second row with three scales in angular series, the medial largest, all much larger than the first row, the third row with four scales, larger than the first row, smaller than those on the second row; enlarged femoral scales (8R, 8L), two or three times larger than proximal and distal scales, separated from precloacal scales by small diastemal scales; precloacal groove absent; primary hemipenes with fully everted 3.3 mm, ending with two short sheath.

Limbs rather short, slender; digits well developed, with strongly inflected interphalangeal joints; dorsal surface of forelimbs with moderate granular scales, larger than those on ventral surface, interspersed with scattered conical tubercles, palmar scales more rounded, smaller than those on forelimbs, bearing five relatively slender fingers, moderately bowed, ending with curved claws, ForeL/SVL 0.164; expanded proximal subdigital lamellae on fourth finger 7(R, L), unmodified distal subdigital lamellae on fourth finger 9 (R, L), total subdigital lamellae on fourth finger 16 (R, L); hind limbs with granular scales, larger on anterior thigh, much smaller on dorsal, posterior thigh, interspersed with scattered conical tubercles more prominent on dorsal surface, bearing five relatively slender toes, strongly bent, ending with curved claws, CrusL/SVL 0.194; expanded proximal subdigital lamellae on fourth toe 9 (R, L), unmodified distal subdigital lamellae on fourth toe 13 (R, L), total subdigital lamellae on fourth toe 22 (R, L); all digits lacking scansorial setae on ventral surface; scales on limbs small, interspersed with larger, low, conical, weakly keeled tubercles; scales on palmar and plantar surfaces small.

Tail length 92.6 mm from the base to the tip, moderately wide anteriorly, TaW 6.1 mm, segmented, cylindrical, becoming slender toward tip; dorsal caudal longitudinal tubercle rows at base of tail 8; scales on dorsal surface of tail larger than those on body; subcaudal scale row distinctly transversely enlarged anteriorly, smaller with some parts splitting into two smaller scales, more regularly divided subcaudal scales posteriorly.

Color of holotype in life ( Fig. 4A ). Top of head, dorsal surface, nape, and anterior part of tail light brown; top of head with two dark brown spots; nuchal loop with large dark brown band, rounded, extending between posterior margins of eyes, bordered above and below by yellow margins; four dorsal dark brown bands on body, bordered by yellowish margins, ratio between dark brown bands/interspace light brown 1.109, all dark brown body bands ending near to mid-flank region, not reaching to lateral folds except first band reaching to shoulder; 15 dark brown bands on tail, alternating with interspace light brown on anterior tail, light grey to greyish white on the posterior on entire non-regenerated tail, dark brown bands almost same wide as light brown interspaces on anteriormost part of tail, wider to almost twice the width of greyish white interspaces posteriorly, 1 st –3 rd bands not encircling venter, 4 th –15 th bands indistinctly encircling ventral scales. Subcaudal scales lighter brown anteriorly, darker posteriorly; limbs dark brown with orangish or yellowish enlarged tubercles; ventral surface between ventrolateral folds, chin, throat, and ventral surfaces of limbs white with tiny black dots on tip of scales; ventral surfaces of palmar, plantar, fingers and toes dark brown. In preservative, all yellowish, yellowish-white or orange coloration fades to white, cream.

Variation. Variable morphometric and meristic characters within the type series are presented in Table 3 . The paratypes generally resemble the holotype except that males have precloacal pores and females have precloacal pits ( Fig 5 ). CBC 03259 and NCSM 110188 have irregular fourth dark body bands, and CBC 03259 has an irregular first dark tail band. Dark spots on the head vary considerably, with NCSM 110189 having one, CBC 03266 having four, and NCSM 110187, CBC 03262, CBC 03259, CBC 03298 having none. CBC 03260 has one dark spot on nuchal region between nuchal loop and first body band.

Comparisons. Raw meristic, normalized morphometric, and categorical data are presented in Tables 3 , 4 , and 1S. ANOVA adjusted p -values for the statistical differences are presented in Table 2 . Cyrtodactylus regicavernicolus sp. nov. can be differentiated from all other named members of the C. intermedius group ( Murdoch et al. 2019; Grismer et al. 2015, 2020a, 2021a,b) based on a number of statistically different meristic and normalized morphometric characters. Cyrtodactylus regicavernicolus sp. nov. is most closely related ( Fig. 2 ) and geographically proximate ( Fig. 1A ) to C. laangensis , but differs statistically in the morphometric characters HeadL, IOD, and IND and the meristic character TTL. It differs further from C. laangensis in having the rostral bordered posteriorly by a single internasal scale (versus two in C. laangensis ) and nostril bordered posteriorly by two or three postnasal scales (versus four in C. laangensis ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. auralensis in the morphometric characters AG, HeadL, HeadW, IOD, Ear-EyeD and ForeL and the meristic character TTL. It potentially differs further from C. auralensis in having the rostral bordered posteriorly by one or two internasal scales (versus three in C. auralensis ); and fewer (7–23) enlarged femoral scales (versus 23–28 in C. auralensis ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. bokorensis in the morphometric characters SVL, AG, HeadL, HeadW, IOD, Ear-EyeD and ForeL and the meristic characters IL, LDRT, and TTL. It potentially differs further from C. bokorensis in having a smaller (80.7 mm) maximum SVL of females (versus 93.0 mm in C. bokorensis ); fewer (7–23) enlarged femoral scales (versus 26–30 in C. bokorensis ); and 7–9 precloacal pits in females (versus absent in females of C. bokorensis ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. cardamomensis in the morphometric characters AG, HeadL, HeadW, IOD, and Ear-EyeD and the meristic character TTL. It potentially differs further from C. cardamomensis in having fewer (7–23) enlarged femoral scales (versus 23–28 in C. cardamomensis ); and enlarged femoral scales and enlarged precloacal scales discontinuous (versus continuous in C. cardamomensis ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. hontreensis in the morphometric characters HeadL, IOD, Ear-EyeD, EyeND, ESD and ForeL and the meristic characters LDRT, PVY, TTL, and BB and morphometric character CrusL. It potentially differs further from C. hontreensis in having a higher number (7–23) of enlarged femoral scales (versus 4–9 in C. hontreensis ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. intermedius in the morphometric characters AG, HeadL, IOD, ForeL and CrusL and the meristic character TTL. It potentially differs further from C. intermedius in having the enlarged femoral scales and precloacal scales discontinuous (versus continuous in C. intermedius ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. kohrongensis in the morphometric characters HeadL and the meristic character IL. It potentially differs further from C. kohrongensis in having the rostral bordered posteriorly by a single internasal scale (versus two in C. kohrongensis ); post cloacal spurs in both males and females (versus in males only of C. kohrongensis ); and higher number (13–15) of dark brown caudal bands on an original tail (versus 8–11 in C. kohrongensis ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. kulenensis in the morphometric characters SVL, AG, HeadL, HeadW, HeadD, IOD, IND, Ear-EyeD, ForeL, and CrusL and the meristic characters PVT and TTL. It potentially differs further from C. kulenensis in having that the enlarged femoral scales and precloacal scales discontinuous (versus continuous in C. kulenensis ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. phuquocensis in the morphometric characters AG, HeadL, IOD, IND, Ear-EyeD, and ForeL and the meristic character TTL. It potentially differs further from C. phuquocensis in having fewer (7–23) enlarged femoral scales (versus 27–28 in C. phuquocensis ); and enlarged femoral scales and precloacal scales discontinuous (versus continuous in C. phuquocensis ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. septimontium in the morphometric characters SVL, HeadL, HeadW, IOD, and IND and the meristic character TTL. It potentially differs further from C. septimontium in having a smaller (80.7 mm) maximum SVL of females (versus 90.4 mm in females of C. septimontium ); variable and greater number (2–5) of post cloacal spurs (versus two in C. septimontium ); fewer (7– 23) enlarged femoral scales (versus 24–33 in C. septimontium ); and enlarged femoral scales and precloacal scales discontinuous (versus continuous in C. septimontium ).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. sp. 1 in the morphometric characters SVL, AG, HeadL, HeadW, IND and the meristic character TTL. It potentially differs further from C. sp. 1 in having more TB, 13–15 (versus 10–12, in C. sp. 1).

Cyrtodactylus regicavernicolus sp. nov. differs statistically from C. thylacodactylus in the morphometric characters HeadL, IOD, ESD and CrusL, the meristic characters LDRT and TTL, and lacking interphalangeal pocketing between digits of forefeet and hindfeet (versus present in C. thylacodactylus ). It potentially differs further from C. thylacodactylus in having enlarged femoral scales and precloacal scales discontinuous (versus continuous in C. thylacodactylus ).

Distribution and natural history. The new species is known only from limestone karst habitat in the vicinity of Chrorkley Village in Touk Meas Khang Lech Commune, Banteaymeas District, Kampot Province, Cambodia.All individuals were found at night inside limestone karst caves, around cave entrances, or on tree trunks in the karst vegetation near to cave entrances. Most observed individuals were very wary and shy and escaped quickly into rock crevices or holes, or moved higher up the walls from the ground, when illuminated with light. The holotype, CBC 03258, and CBC 03301 were found on tree saplings 0.3–0.5 m above the ground at the entrance to Preah Kuhear Loung Cave ( Fig. 1C ). CBC 03256, CBC 03263, CBC 03265–66, CBC 03298–300, CBC 03302–05, and NCSM 110187–88, NCSM 110190 were collected from rocks and boulders at various cave entrances. CBC 03259–62, CBC 03264 were on rocks and rock walls inside the caves, between 3–7 m from the entrance ( Fig. 1B ). NCSM 110189 was found in a deep cave tunnel, 20 m from the cave entrance.

Figures

FIGURE 1. A. Map illustrating the type localities of C. regicavernicolus sp. nov. (circle) and its closest relatives in both phylogeny and geography, C. laangensis (pentagon) and C. bokorensis (triangle). B. Paratype (CBC 03259) locality of C. regicavernicolus sp. nov. C. Holotype locality of C. regicavernicolus sp. nov. at Phnom Preah Kuhear Loung. Photograph by Saveng Ith.

FIGURE 2. Fifty percent majority-rule consensus phylogram resulting from partitioned Bayesian analysis of 1,035 characters of the coding region of the mitochondrial ND2 gene from Cyrtodactylus geckos. Numbers at nodes are Bayesian posterior probabilities (left) and bootstrap values ≥ 50 from a separate maximum likelihood analysis (right). Species names are followed by voucher numbers (where known) and GenBank accession numbers in parentheses. The holotype of C. regicavernicolus sp. nov. is illustrated.

FIGURE 4. Photographs of C. regicavernicolus sp. nov. in life. A. Holotype adult male CBC 03257. B. Paratype adult male CBC 03259. C. Unsexed juvenile CBC 03263 from holotype locality. Photographs by Thy Neang.

FIGURE 5. Photographs of C. regicavernicolus sp. nov. in preservative. A. Rostral region of holotype male CBC 03257 illustrating rostral bordered posteriorly by a single internasal scale (arrow). B. Precloacal region of holotype male CBC 03257 precloacal pores (arrows). C. Precloacal region of paratype female CBC 03298 illustrating precloacal pits (arrows).