Cyrtodactylus phnomchiensis, Neang & Henson & Stuart, 2020

Neang, Thy, Henson, Adam & Stuart, Bryan L., 2020, A new species of Cyrtodactylus (Squamata, Gekkonidae) from Cambodia's Prey Lang Wildlife Sanctuary, ZooKeys 926, pp. 133-158 : 133

Cyrtodactylus phnomchiensis sp. nov. Figures 3 , 4 , 5 , 6

Holotype.

CBC 03012, adult male (Fig. 3 ), Cambodia, Kampong Thom Province, Sandan District, Phnom Chi, Prey Lang Wildlife Sanctuary, 12°56'11.6"N, 105°39'17.1"E, 237 m elevation, collected on 18 July 2019 by Thy Neang and En E.

Paratypes.

All from Cambodia, Kampong Thom Province, Sandan District, Phnom Chi, Prey Lang Wildlife Sanctuary: CBC 03003, adult male, 12°56'09.2"N, 105°39'12.7"E, 269 m elevation, coll. 13 June 2019 by Thy Neang; CBC 03004, adult female, 12°56'09.7"N, 105°39'14.4"E, 271 m elevation, coll. 13 June 2019 by Thy Neang; CBC 03013, adult female, same data as holotype; CBC 03014, adult female, same data as holotype except 12°56'08.7"N, 105°39'12.6"E, 284 m elevation.

Etymology.

The specific epithet is taken from the type locality of Phnom Chi and the Latin suffix - ensis meaning "originating from." The specific epithet is masculine in agreement with the gender of Cyrtodactylus .

Diagnosis.

Cyrtodactylus phnomchiensis sp. nov. is distinguished from the 19 other named species in the C. irregularis group ( Ngo and Chan 2010; Nguyen et al. 2013, 2017; Pauwels et al. 2018) by having the combination of SVL 76.1-80.7 mm; relatively long body, AG/SVL 0.451-0.481; relatively long tibia, CrusL/SVL 0.172-0.200; subdigital lamellae on fourth finger 18-20; subdigital lamellae on fourth toe 20-23; longitudinal dorsal rows of tubercles 18-20; paravertebral rows of tubercles 31-36; ventral scales 45-54; enlarged femoral scales 0-8, without pores; enlarged precloacal scales 7-10, bearing pores 4 or 5 in males, pits 1-7 in females; precloacal groove absent; median row of transverse subcaudal scales only slightly enlarged; posterior border of nuchal loop unbroken and pointed, bordered anteriorly and posteriorly by broad yellow or yellowish white band; dark brown body bands 3 or 4, the first intact, the second, third and fourth more irregular, alternating with two or three yellowish white or light brown body bands, about half the width of dark brown body bands; and yellow spots on top of head.

Description of holotype.

Adult male with SVL 76.1 mm; head slightly elongate, HeadL 22.1 mm, about 30% of SVL, moderately widened, HeadW 14.1 mm, HeadW/HeadL 0.64, slightly depressed, HeadD 9.4 mm, HeadD/HeadL 0.43, distinct from neck, triangular in dorsal profile; snout rather elongated, rounded in rostral region, ESD 9.0 mm, slightly less than HeadD, ESD/HeadL 0.41, frontonasal region flattened, prefrontal region slightly concave, forming elongated medial rostral groove, canthus rostralis flattened, slightly angled between loreal region and rostral groove; lores posterior to nostrals depressed, anterior to orbit flattened; eye large, eyeball rounded, slightly protruding, EyeD 5.1 mm, shorter than the distance between eye and ear, Eye-EarD 5.7 mm, pupil vertical, covered by crenellate supraciliaries; ear opening oval, deeply sunk, rather small, elongated in oblique position, EarDV 1.2 mm, almost twice longer than its diameter in horizontal position, EarDH 0.7 mm; rostral large, subrectangular, height 1.9 mm, shorter than its width 3.6 mm, medially divided dorsally by a suture, reaching to about half way of rostral height, in contact with 1stSL and nostrils laterally, supranasals and internasal dorsally (Fig. 4 ); nostrils pieced at anterior angle of snout, directed lateroposteriorly, surrounded by rostral anteriorly, 1stSL ventrally, supranasals dorsally, and three small postnasal scales; internarial distance narrow, IND 2.9 mm; supranasals subrectangular, separated by intersupranasal, slightly smaller in size, in contact with rostral anteriorly, nostrals laterally, four small scales posteriorly; intersupranasal single, subpentagonal, slightly protruding rostral, in contact with two small scales posteriorly; interorbital rather narrow, IOD 5.5 mm, longer than EyeD, slightly shorter than Eye-EarD 5.7 mm; supralabials (12R, 13L), subrectangular anteriorly, circular shape posteriorly, anterior SL separated from small scales on loreal region by row of slightly enlarged scales; infralabials (9R, 9L), larger than SL, first InL bordered by mental anteriorly, first postmental ventrally, second InL bordered by second enlarged postmental, enlarged chin shield scale ventrally, 3-7thInL bordered by a row of slightly enlarged chin shield scales ventrally; mental large, triangular, width 3.3 mm in width, 2.3 mm in length, in contact with first InL laterally, two pairs postmentals posteriorly; the first pair largest, subrectangular, in broad contact medially, second pair enlarged, half the size of the first pair, separated by four smaller gular scales medially, in contact with smaller scales posteriorly (Fig. 4 ). Scales on frontonasal, prefrontal, loreal regions small, almost homogenous, slightly larger than those on top of head; scales on occiput intermixed with scattered larger, more rounded, conical tubercles, more prominent tubercles on region between orbit and area above ear opening, a noticeably larger tubercle (compared to those surrounding) at the corner of jaw.

Body slightly slender, AG 36.6 mm, nearly half SVL, AG/SVL 0.481 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 18; paravertebral tubercles 32; 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, not imbricate, those near midline larger than lateral and dorsal scales; scales on throat and gular region the smallest; faint ventrolateral folds with few emerged tubercles; ventral scales at midbody between ventrolateral folds 47; precloacal region moderately enlarged, a few rows of enlarged precloacal non-pore bearing scales anterior to pore bearing precloacal scales; enlarged precloacal scales 7, in angular series, bearing 5 pores, terminal scale on each side poreless; post precloacal scale rows 3, the first row immediately posterior to enlarged precloacal pore-bearing scales with six scales in angular series, the second row with four scales in angular series, the third row with three scale in straight line, the medial scale largest; femoral scales slightly enlarged (8R, 8L), distal scales more than twice the size of proximal scales, all smaller than those of pore-bearing precloacal scales, separated from precloacal scales by diastema; precloacal groove absent; fully everted hemipenes thick, 5.9 mm in length, two penes at each sheath, two sockets posterior to hemipenal bases (Fig. 5 ).

Limbs rather slender; digits with strongly inflected interphalangeal joints; forelimbs bearing five relatively slender fingers, moderately bowed, ending with curved claws, ForeL/SVL 0.162; expanded proximal subdigital lamellae on fourth finger 6, unmodified distal subdigital lamellae on fourth finger 12, total subdigital lamellae on fourth finger 18; hind limbs bearing five relatively slender toes, strongly bent, ending with curved claws, CrusL/SVL 0.176; expanded proximal subdigital lamellae on fourth toe 7, unmodified distal subdigital lamellae on fourth toe 15, total subdigital lamellae on fourth toe 22; 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 moderately wide anteriorly, TaW 5.5 mm, segmented, cylindrical, becoming slender toward tip, regenerated posteriorly; dorsal caudal longitudinal tubercle rows at base of tail 8; 2 transverse rows of dorsal caudal tubercles at posterior margin of third band on tail, 22.7 mm from tail base; vertebral caudal surface with scattered bump at approximate intervals of 3 mm; subcaudal scale rows smooth, small, differing in size and irregular in shape, usually alternating between a single slightly enlarged and two smaller scales, 2 or 3 times larger than neighboring lateral caudal scales (Fig. 5 ).

Color of holotype in life

(Fig. 3 ). Dorsal surface, nape, and tail yellowish white to light brown; top of head with yellowish spots; interorbital region, rostral and loreal regions lighter brown with scattered yellowish scales; eye ring yellowish; rostral, mental lighter brown; supralabials, corner of jaw, and region extending through dorsal margin of ear opening to shoulder yellowish; nuchal loop with large dark brown band, pointed, extending between posterior margins of eyes, bordered anteriorly by broad yellow band along upper edge of dark brown nuchal loop, posteriorly by yellowish white band; three dorsal dark brown bands on body, the first more regular, the second and third bands irregular, interrupted by white irregular blotches; all dark brown bands ending near to mid-flank region, bordered below by lighter brown extending to lateral folds; dark brown body bands bordered by yellowish white or light brown bands about half the width of dark brown body bands, the last light brown band ending on tail base; anterior and posterior margins of body bands with darker brown coloration; dark brown bands 6 on regenerated tail, margins at tail base darker; white bands on tail 5, nearly encircling the tail except subcaudal scale row; subcaudal scales lighter brown than dorsal caudal scales; limbs lighter brown with orangish or yellowish on enlarged tubercles; ventral surfaces between ventrolateral folds, chin, throat, and limbs white with tiny black dots on tip of scales; ventral surfaces of fingers and toes dark brown. In preservative, all yellowish, yellowish white or orange coloration faded to white, cream, or light brown (Fig. 6 ).

Variations.

Morphometric and meristic characters of the type series are presented in Table 1 . The paratypes generally resemble the holotype (Fig. 6 ), except as follows. CBC 03003 has four enlarged post precloacal scale rows in an angular series, the last row with only a single enlarged scale. CBC 03004 and CBC 03014 have darker brown body bands. CBC 03003-03004 have a more pointed nuchal loop. CBC 03003 has more dense dark dots causing ventral surfaces to be darker brown. CBC 03003 has more slender, fully everted hemipenes. Females have enlarged precloacal scales with pits rather than pores.

Distribution and natural history.

The new species is known only from the type locality at Phnom Chi in Prey Lang Wildlife Sanctuary, Kampong Thom Province, Sandan District, Cambodia. All individuals were found at night between 2001-2147 hr in evergreen-large dipterocarp dominated forest associated with rocky terrain (Fig. 7 ). The holotype CBC 03012 was found on a rock face following evening rain, paratypes CBC 03013-14 were on boulders following evening rain, paratype CBC 03003 was on leaf litter along a forest trail, and paratype CBC 03004 was on a rock wall at the entrance to a cave. Only five individuals were found during five-survey nights, suggesting the species is relatively uncommon. None were encountered during a brief survey by NT in the wet season of 2014 ( Hayes et al. 2015). The new species is the only member of the C. irregularis complex known to occur west of the Mekong River ( Nguyen et al. 2017; Pauwels et al. 2018).

Comparisons.

Cyrtodactylus phnomchiensis sp. nov. is distinguishable from all 19 other members of the C. irregularis group by a unique combination of morphological characters (and in mitochondrial DNA; Fig. 2 ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. bidoupimontis Nazarov, Poyarkov, Orlov, Phung, Nguyen, Hoang & Ziegler, 2012 by having ventral scales 45-54 (vs. 38-43 in bidoupimontis ), precloacal pits in females 1-7 (vs. absent in bidoupimontis ), dark brown body bands larger than yellowish white or light brown dorsal bands (vs. dark brown bands, when present, narrower than light yellow dorsal bands in bidoupimontis ), and distinct large yellow band on anterior margin of dark brown nuchal loop (vs. narrow light margin in bidoupimontis ), and yellow spots on top of head (vs. dark spots in bidoupimontis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. buchardi by having SVL 76.1-80.7 mm (vs. 60-65 mm in buchardi ), SDLF4 18-20 (vs. 14 in buchardi ), SDLT4 20-23 (vs. 12-14 in buchardi ), ventral scales 45-54 (vs. 30 in buchardi ), LDRT 18-20 (vs. 25 in buchardi ), precloacal pores in males 4-5 (vs. 9 in buchardi ), and irregular dorsal body bands (vs. blotches in buchardi ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. bugiamapensis Nazarov, Poyarkov, Orlov, Phung, Nguyen, Hoang & Ziegler, 2012 by having LDRT 18-20 (vs. 20-24 in bugiamapensis ), ventral scales 45-54 (vs. 36-46 in bugiamapensis ), precloacal pores in males 4-5 (vs. 7-11 in bugiamapensis ), SDLF4 18-20 (vs. 15-17 in bugiamapensis ), SDLT4 20-23 (vs. 17-20 in bugiamapensis ), CrusL/SVL in adult specimens 0.172-0.200 (vs. 0.144-0.157 in bugiamapensis ), large nuchal loop bordered anteriorly and posteriorly by broad yellow bands (vs. narrow nuchal loop bordered by distinct narrow white lines in bugiamapensis ), dark brown body bands 3-4 (vs. seven highly irregular dark blotches with light margins in bugiamapensis ), and top of head with yellowish spots (vs. distinct dark brown spots in bugiamapensis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. caovansungi Orlov, Nguyen, Nazarov, Ananjeva & Nguyen, 2007 by having SVL 76.1-80.7 mm (vs. 90.4-94.0 mm in caovansungi ), ventral scales 45-54 (vs. 38-44 in caovansungi ), femoral pores absent (vs. 6 in caovansungi ), precloacal pores in males 4-5 (vs. 9 in caovansungi ), SDLF4 18-20 (vs. 22 in caovansungi ), and enlarged subcaudals absent (vs. present in caovansungi ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. cattienensis Geissler, Nazarov, Orlov, Böhme, Phung, Nguyen & Ziegler, 2009 by having SVL 76.1-80.7 mm (vs. 69.0 mm maximum in cattienensis ), ventral scales 45-54 (vs. 28-42 in cattienensis ), SDLF4 18-20 (vs. 12-16 in cattienensis ), and SDLT4 20-23 (vs. 14-19 in cattienensis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. cucdongensis Schneider, Phung, Le, Nguyen & Ziegler, 2014 by having SVL 76.1-80.7 mm (vs. 55.8-65.9 mm in cucdongensis ), ventral scales 45-54 (vs. 35-44 in cucdongensis ), SDLF4 18-20 (vs. 13-18 in cucdongensis ), and SDLT4 20-23 (vs. 15-20 in cucdongensis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. cryptus Heidrich, Rösler, Vu, Böhme & Ziegler, 2007 by having precloacal pores in males 4-5 (vs. 9-11 in cryptus ), and precloacal pits in females 1-7 (vs. absent in cryptus ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. dati Ngo, 2013 by having SVL 76.1-80.7 mm (vs. 70.1 mm maximum in dati ), regenerated TaL 56.9-79.1 mm vs. (vs. 50.3 mm maximum, non-regenerated TaL in dati ), femoral pores in both sexes absent (vs. present in dati ), nuchal loop continuous (vs. broken in dati ), and dark brown body bands (vs. irregular dark brown blotches on body in dati ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. gialaiensis Luu, Dung, Nguyen, Le & Ziegler, 2017 by having SVL 76.1-80.7 mm (vs. 62.8 mm maximum in gialaiensis ), precloacal pores in males 4-5 (vs. 9-10 in gialaiensis ), SDLF4 18-20 (vs. 14-15 in gialaiensis ), and SDLT4 20-23 (vs. 15-17 in gialaiensis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. huynhi Ngo & Bauer, 2008 by having SDLF4 18-20 (vs. 14-17 in huynhi ), AGL/SVL 0.451-0.481 (vs. 0.370-0.428 in huynhi ), ventral scales 45-54 (vs. 43-46 in huynhi ), precloacal pores in males 4-5 (vs. 7-9 in huynhi ), dark brown body bands 3-4 (vs. 5-6 in huynhi ); femoral pores in both sexes absent (vs. 3-8 in huynhi ), and nuchal loop bordered anteriorly and posteriorly by broad yellow bands (vs. narrow cream margin in huynhi ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. irregularis by lacking enlarged triangular tubercles at base of tail (vs. present in irregularis ), CrusL/SVL 0.172-0.200 (vs. 0.138-0.156 in irregularis ), LDRT 18-20 (vs. 22-24 in irregularis ), paravertebral tubercles 31-36 (vs. 38-48 in irregularis ); ventral scales 45-54 (vs. 38-45 in irregularis ), SDLF4 18-20 (vs. 15-16 in irregularis ), SDLT4 20-23 (vs. 18-20 in irregularis ), dark brown body bands 3-4 (vs. 5-7, mostly as irregular blotches in irregularis ), and yellowish spots on top of head (vs. distinct dark brown spots in irregularis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. kingsadai Ziegler, Phung, Le & Nguyen, 2013 by having SVL 76.1-80.7 mm (vs. 83.0-94.0 mm in kingsadai ), enlarged femoral scales 0-8 (vs. 9-12 in kingsadai ), precloacal pore in males 4-5 (vs. 7-9 in kingsadai ), and subcaudal scales not enlarged (vs. enlarged in kingsadai ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. phuocbinhensis Nguyen, Le, Tran, Orlov, Lathrop, MacCulloch, Le, Jin, Nguyen, Nguyen, Hoang, Che, Murphy & Zhang, 2013 by having SVL 76.1-80.7 mm (vs. 46.0-60.4 in phuocbinhensis ); precloacal pits in females 1-7 (vs. absent in phuocbinhensis ), top of head with yellow spots (vs. dark brown spots in phuocbinhensis ), and dark brown body bands (vs. two dark brown longitudinal stripes or blotches in phuocbinhensis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. pseudoquadrivirgatus Rösler, Vu, Nguyen, Ngo & Ziegler, 2008 by having yellow spots on top of head (vs. dark blotches on top of head in pseudoquadrivirgatus ) and dark brown body bands (vs. highly irregular body blotches in pseudoquadrivirgatus ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. sangi Pauwels, Nazarov, Bobrov & Poyarkov, 2018 by having SVL 76.1-80.7 mm (vs. 56.3 mm maximum in sangi ), paravertebral tubercles 31-36 (vs. 27-29 in sangi ), ventral scales 45-54 (vs. 37 in sangi ), precloacal pores in males 4-5 (vs. 7 in sangi ), and first dark brown body band complete, second, third, and fourth more irregular (vs. highly irregular bands in sangi ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. takouensis Ngo & Bauer, 2008 by having LDRT 18-20 (vs. 9-10 smooth tubercles in takouensis ); ventral scales 45-54 (vs. 39-40 in takouensis ), SDLF4 18-20 (vs. 16-17 in takouensis ), SDLT4 20-23 (vs. 18-20 in takouensis ), and dark brown canthal stripe absent (vs. present in takouensis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. taynguyenensis Nguyen, Le, Tran, Orlov, Lathrop, MacCulloch, Le, Jin, Nguyen, Nguyen, Hoang, Che, Murphy & Zhang, 2013 by having supralabials 11-13 (vs. 8-9 in taynguyenensis ), precloacal pits in females present (vs. absent in taynguyenensis ), SDLF 18-20 (vs. 13-18 in taynguyenensis ), top of head with yellow spots (vs. dark brown blotches in taynguyenensis ), and dark brown body bands (vs. black irregular blotches margined by light brown in taynguyenensis ).

Cyrtodactylus phnomchiensis sp. nov. differs from C. yangbayensis Ngo & Chan, 2010 by having SDLT4 20-23 (vs. 15-17 in yangbayensis ) and lacking enlarged subcaudal scales (vs. present in yangbayensis ).

Cyrtodactylus phnomchiensis sp. nov. is most closely related in mitochondrial DNA to C. ziegleri Nazarov, Orlov, Nguyen & Ho, 2008 (Fig. 2 ), but differs in morphology from C. ziegleri by having SVL 76.1-80.7 mm (vs. 84.6-93.0 mm in ziegleri ), paravertebral tubercles 31-36 (vs. 38-46 in ziegleri ), ventral scales 45-54 (vs. 33-45 in ziegleri ), HeadL/SVL 0.287-0.305 (vs. 0.263-0.284 in ziegleri ), ESD/SVL 0.116-0.123 (vs. 0.103-0.113 in ziegleri ), CrusL/SVL 0.172-0.200 (vs. 0.140-0.168 in ziegleri ), AG/SVL 0.451-0.481 (vs. 0.390-0.444 in ziegleri ), eyeD/SVL 0.059-0.067 (vs. 0.053-0.057 in ziegleri ), top of head with yellow spots (vs. dark brown spots in ziegleri ), large dark brown nuchal loop (vs. narrow in ziegleri ), distinct, broad yellow band on anterior margin of dark brown nuchal loop (vs. absent in ziegleri ), and dark brown body bands bordered by yellowish white or light brown bands about half the width of dark brown bands (vs. light yellow or light brown body bands about same width as dark brown body bands in ziegleri ).

Figures

Figure 2. Upper (A) and lower (B) portions of a fifty percent majority-rule consensus phylogram resulting from partitioned Bayesian analysis of 717 aligned characters of the mitochondrial cytochrome c oxidase subunit I (COI) gene from geckos in the Cyrtodactylus irregularis group. The outgroup Hemidactylus frenatus (GenBank accession GQ 245970) and exemplars of other Cyrtodactylus clades including C. auribalteatus (GenBank accession AP 018116), C. badenensis (KF 929505), C. chanhomeae (MF 169908), C. interdigitalis (MF 169919), C. intermedius (MF 169920), C. jellesmae (MF 169923), C. peguensis (AP 018114), C. russelli (MF 169938), and C. thirakhupti (AP 018115) were also included in the analysis (not shown). Black circles at nodes indicate Bayesian posterior probabilities ≥ 0.99, and open circles at nodes indicate Bayesian posterior probabilities ≥ 0.95. Numbers at terminal tips are GenBank accession numbers.

Figure 3. Cyrtodactylus phnomchiensis sp. nov. in life. A Male holotype CBC 03012 and B female paratype CBC 03013.

Figure 4. Head of male holotype CBC 03012 of Cyrtodactylus phnomchiensis sp. nov. in preservative. A Dorsal view illustrating the rostral, supranasal and internsupranasal scales B ventral view illustrating the mental and postmental scales.

Figure 5. Cloacal region of male holotype CBC 03012 of Cyrtodactylus phnomchiensis sp. nov. in preservative illustrating the enlarged precloacal scales, enlarged femoral scales, and not enlarged subcaudal scales.

Figure 6. Dorsal view of the type series of Cyrtodactylus phnomchiensis sp. nov. in preservative.

Figure 7. Habitat at Phnom Chi, the type locality of Cyrtodactylus phnomchiensis sp. nov.