Cnemaspis auriventralis, Rujirawan & Yodthong & Ampai & Termprayoon & Aksornneam & Stuart & Aowphol, 2022

Rujirawan, Attapol, Yodthong, Siriporn, Ampai, Natee, Termprayoon, Korkhwan, Aksornneam, Akrachai, Stuart, Bryan L. & Aowphol, Anchalee, 2022, A new rock gecko in the Cnemaspis siamensis group (Reptilia, Gekkonidae) from Kanchanaburi Province, western Thailand, Zoosystematics and Evolution 98 (2), pp. 345-363 : 345

Cnemaspis auriventralis sp. nov.

Figs 3 , 4 , 5 , 6 , 7 , 8

Cnemaspis huaseesom Yodthong, Rujirawan, Stuart, Grismer, Aksornneam, Termprayoon, Ampai & Aowphol, 2022: 160.

Holotype.

(Figs 3 - 6 ). ZMKU R 01001, adult male from Thailand, Kanchanaburi Province, Si Sawat District, Tha Kradan Subdistrict, Erawan National Park, Tham Phra That Protection Unit (14.39730N, 99.0818E; 747 m elevation), collected 18 November 2021 by Attapol Rujirawan, Siriporn Yodthong, Natee Ampai and Akrachai Aksornneam.

Paratypes.

(Figs 7 , 8 ). Two adult males and two adult females. ZMKU R 01002 (adult female), same collection data as the holotype. ZMKU R 01003 (adult female), same collection data as the holotype, except collected 20 November 2021. ZMKU R 00999-01000 (two adult males) same collection data as the holotype, except collected 26 November 2019 by Attapol Rujirawan, Siriporn Yodthong, Korkhwan Termprayoon and Akrachai Aksornneam.

Diagnosis.

Cnemaspis auriventralis sp. nov. can be distinguished from all other species in the C. siamensis group by having the following combination of morphological and colour pattern characters: SVL 36.7-38.6 mm in adult males (N = 3), 32.9-36.9 mm in adult females (N = 2); eight to ten supralabials; seven to nine infralabials; ventral scales smooth; six or seven precloacal pores in males; 16-17 paravertebral tubercles linearly arranged; tubercles on the lower flanks present; lateral caudal furrows present; no caudal tubercles in the lateral furrows; ventrolateral caudal tubercles present anteriorly; caudal tubercles not encircling tail; subcaudals smooth bearing a single median row of enlarged smooth scales; two postcloacal tubercles on each side; no shield-like subtibial scales; subtibial scales smooth; no enlarged submetatarsal scales; 23-27 subdigital lamellae on the fourth toe; sexually dimorphic in dorsal and ventral colour pattern; prescapular marking absent; gular marking absent; and yellow colouration in life on all ventral surfaces of head, body and tail in adult males.

Description of holotype.

Adult male; SVL 38.0 mm; head oblong in dorsal profile, moderate in size (HL/SVL 0.28), somewhat narrow (HW/SVL 0.19), flat (HD/HL 0.40), distinct from neck; snout moderate (ES/HL 0.42), snout slightly concave in lateral profile; postnasal region concave medially; scales of rostrum round, weakly keeled, raised, larger than similarly-shaped scales on occiput; weak supraorbital ridges; weak frontorostral sulcus; canthus rostralis smoothly rounded; eye large (ED/HL 0.24); extra-brillar fringe scales small in general, but slightly larger anteriorly; pupil round; ear opening oval, taller than wide; rostral concave dorsally, dorsal 80% divided by longitudinal groove; rostral bordered posteriorly by supranasals, one small azygous internasal and nostrils; bordered laterally by first supralabials; 8R/9L (right/left) raised supralabials of similar size, but smallest posteriorly; 8R/8L infralabials, decreasing gradually in size posteriorly; nostrils small, elliptical, orientated dorsolaterally; bordered posteriorly by single, flat, enlarged postnasal scales; mental large, triangular, flat, extending to level of second infralabials, bordered posteriorly by three postmentals, medial postmental smaller than laterals; gular scales smooth, flat, round or oval, juxtaposed; throat scales smooth, raised, round, juxtaposed to subimbricate.

Body slender, elongate (AG/SVL 0.42); small, raised, weakly keeled, dorsal scales generally equal in size throughout body, intermixed with numerous, large, multi-keeled, linearly arranged tubercles; enlarged, multi-keeled, conical tubercles on flanks; tubercles extend from the occiput to base of the tail and continue on tail in whorls; body tubercles slightly smaller anteriorly; 17 paravertebral tubercles; pectoral and abdominal scales smooth, flat, imbricate; abdominal scales larger than pectoral and dorsal scales; seven contiguous, pore-bearing, precloacal scales; precloacal pores round to elongate.

Fore-limbs moderately long, slender; dorsal scales raised, weakly keeled, juxtaposed; ventral scales of brachia smooth, raised, juxtaposed; scales beneath forearm smooth, slightly raised, subimbricate; digits long with an inflected joint; claws recurved; subdigital lamellae unnotched; subdigital lamellae wide throughout length of digits, bearing a larger scale at digital inflections; interdigital webbing absent; fingers increase in length from first to fifth, with fourth and fifth nearly equal in length; relative length of fingers I <II <III <V ≤ IV; total subdigital lamellae on fingers I-V: 12-18-21-25-22 (right), 12-18-22-broken-broken (left). Hind-limbs slightly longer and thicker than fore-limbs; dorsal scales keeled, raised, juxtaposed; ventral scales of thigh and subtibial scales smooth, flat, imbricate; plantar scales smooth, raised, subimbricate; enlarged submetatarsal scales beneath first toes absent; digits elongate with an inflected joint; claws recurved; subdigital lamellae unnotched; lamellae wide throughout length of digits; enlarged scales at digital inflections; interdigital webbing absent; toes increase in length from first to fourth and fifth nearly equal in length; relative length of toes I <II <III <V ≤ IV; total subdigital lamellae on toes I-V: 11-18-22-23-22 (right), 11-17-21-24-21 (left).

Tail original (broken at tip), long, slender, TL = 45.9 mm (TL/SVL 1.21); dorsal, caudal scales arranged in segmented whorls; caudal scales keeled, raised, juxtaposed; mid-dorsal and lateral, caudal furrows present; subcaudals smooth; median row of enlarged subcaudal scales present; paravertebral, dorsolateral and lateral rows of large, keeled, caudal tubercles extend length of tail; ventrolateral rows of tubercles present only anteriorly; caudal tubercle rows do not encircle tail; tubercles absent from lateral caudal furrow; enlarged postcloacal tubercles 2R/2L on lateral surface of hemipenial swellings at base of tail.

Colouration in life.

(Figs 3 - 5 ). Dorsal ground colour of head, nape and fore-limbs grey; dorsal ground colour of trunk and hind-limbs yellowish-grey; dorsal ground colour of tail yellow; top of head bearing small, diffuse, faint, dark and light markings; dark postorbital stripes faint extending to occiput; pair of dark, diffuse, blotches on nape; large, light, irregularly-shaped, vertebral blotches extend from nape to base of tail, continuing on to tail as light yellow caudal bands; small, light, irregularly-shaped blotches in shoulder regions and flanks; limbs mottled with small, diffuse light and dark blotches; digits light grey bearing thin, dark bands; all ventral surfaces of head, body and tail yellow; ventral surfaces of limbs light grey with yellow speckling.

Colouration in preservative.

(Fig. 6 ). Dorsal and lateral surfaces of head, body, limbs and tail darker grey than in life, with some fading of markings. Ventral surfaces of head, body, limbs and tail creamy-white, with minute dark speckling on gular region, limbs and tail regions.

Variation.

Cnemaspis auriventralis sp. nov. shows significant sexual dimorphism in colour pattern. All female paratypes lack yellow colouration on the tail and ventral surfaces. Female paratype ZMKU R 01003 was darker coloured in life than other members of the type series. Two male paratypes ZMKU R 00999-01000 were lighter coloured than the holotype in life. Dark markings on the dorsum of all paratypes are more prominent than the holotype. The female paratypes (ZMKU R 01002-01003) lack precloacal pores and have postcloacal tubercles that are relatively smaller than those in males. One male paratype (ZMKU R 01000) has six (2R/4L) pore-bearing precloacal scales separated by a single scale lacking pore. Variation in morphometric and meristic data amongst specimens in the type series are presented in Table 4 .

Distribution.

This species is known only from the type locality. The type series was collected from a karst formation that is part of the Tenasserim Mountain Range in Erawan National Park, Tha Kradan Subdistrict, Si Sawat District, Kanchanaburi Province, Thailand (Figs 1 , 9 ).

Natural history.

The type locality of Cnemaspis auriventralis sp. nov. is a karst forest at 747 m elevation. The type series was collected in November 2019 at 14:00-14:30 h with temperature 25.4 °C and relative humidity 62.1% and in November 2021 at 16:00-20:00 h with temperature 25.3-26.8 °C and relative humidity 79.9-88.0%. All specimens were found on karst boulders along the nature trail to the Tham (= cave) Phra That. Most were observed clinging upside down to the undersides of large boulders (around 1-3 m2) or in narrow crevices of the boulders. Four individuals (ZMKU R 00999-01002) were found during the daytime (14:00-16:30 h) and one individual (ZMKU R 01003) was found at night (20:30 h). Most observed individuals were found during the daytime and they were active and rapidly escaped from disturbances. The one individual found at night was relatively inactive (slow-moving). At night, the new species was found to co-occur with five other species of gekkonid lizards, Cyrtodactylus monilatus Yodthong, Rujirawan, Stuart, Grismer, Aksornneam, Termprayoon, Ampai & Aowphol, 2022, Cyrtodactylus tigroides Bauer, Sumontha & Pauwels, 2003, Gehyra mutilata (Wiegmann, 1834), Dixonius hangseesom Bauer, Sumontha, Grossmann, Pauwels & Vogel, 2004 and Dixonius siamensis (Boulenger, 1899).

Etymology.

The species epithet auriventrali s is derived from aurum (L.) for gold and ventralis (L.) for venter in reference to the new species having distinct yellow colouration on all ventral surfaces of the head, body and tail in adult males. We propose "Erawan Rock Gecko" for the common English name and “จิ้งจกนิ้วยาวเอราวัณ” (Jing Jok Niew Yao Erawan) for the common Thai name of the new species.

Comparisons.

Cnemaspis auriventralis sp. nov. is distinguishable from all other members of the C. siamensis group by a combination of morphological and colour pattern characteristics (see Table 5 for additional comparisons).

Cnemaspis auriventralis sp. nov. differs from C. adangrawi by having a smaller maximum SVL of 38.6 mm (vs. 44.9 mm); ventral scales smooth (vs. keeled); 16-17 paravertebral tubercles (vs. 23-25); paravertebral tubercles linearly arranged (vs. randomly); tubercles on lower flanks present (vs. absent); caudal tubercles in lateral furrow absent (vs. present); enlarged median subcaudal scales row present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); two postcloacal tubercles on each side in males (vs. one); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellowish colouration only on gular region, abdominal region and caudal region).

Cnemaspis auriventralis sp. nov. differs from C. chanardi by having ventral scales smooth (vs. keeled); 16-17 paravertebral tubercles (vs. 20-30); paravertebral tubercles linearly arranged (vs. randomly); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); two postcloacal tubercles on each side in males (vs. one); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on gular region, belly, underside of hind-limbs and subcaudal region).

Cnemaspis auriventralis sp. nov. is most closely related in mitochondrial DNA to C. huaseesom (Fig. 2 ), but differs in morphology from C. huaseesom by having a smaller maximum SVL of 38.6 mm (vs. 43.5 mm); 16-17 paravertebral tubercles (vs. 18-24); caudal tubercles in lateral furrow absent (vs. present); ventrolateral caudal tubercles anteriorly present (vs. absent); enlarged median subcaudal scales row present (vs. absent); yellow dorsal colouration on fore-limbs in males absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on gular region, throat, pectoral region, underside of fore-limbs and subcaudal region).

Cnemaspis auriventralis sp. nov. differs from C. kamolnorranathi by having 16-17 paravertebral tubercles (vs. 19-24); caudal tubercles in lateral furrow absent (vs. present); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. lacking yellow colouration on ventral surfaces).

Cnemaspis auriventralis sp. nov. differs from C. lineatubercularis by having ventral scales smooth (vs. keeled); 16-17 paravertebral tubercles (vs. 19-21); enlarged median subcaudal scales row present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); two postcloacal tubercles on each side in males (vs. one); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellowish colouration only on anterior gular, abdominal and subcaudal regions).

Cnemaspis auriventralis sp. nov. differs from C. omari by having ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 4); 16-17 paravertebral tubercles (vs. 22-29); ventrolateral caudal tubercles anteriorly present (vs. absent); enlarged median subcaudal scales row present (vs. absent); caudal tubercles not encircling the tail (vs. encircling); two postcloacal tubercles on each side in males (vs. one); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on gular region, belly, underside of hind-limbs, and subcaudal region).

Cnemaspis auriventralis sp. nov. differs from C. phangngaensis by having 7-9 infralabials (vs. 10); ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 4); 16-17 paravertebral tubercles (vs. 22); tubercles on lower flanks present (vs. absent); enlarged median subcaudal scales row present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); subtibial scales smooth (vs. keeled); 23-27 subdigital lamellae on the fourth toe (vs. 29); light or yellowish prescapular crescent absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on anterior gular region, abdomen and subcaudal region).

Cnemaspis auriventralis sp. nov. differs from C. punctatonuchalis by having a smaller maximum SVL of 38.6 mm (vs. 49.6 mm); 6-7 precloacal pores in males (vs. 0); 16-17 paravertebral tubercles (vs. 24-27); 23-27 subdigital lamellae on the fourth toe (vs. 29-31); ocelli on brachium and side of neck in males absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of body and tail in males (vs. orange colouration on throat and subcaudal region).

Cnemaspis auriventralis sp. nov. differs from C. roticanai by having a smaller maximum SVL of 38.6 mm (vs. 47.0 mm); ventral scales smooth (vs. keeled); 16-17 paravertebral tubercles (vs. 25-27); paravertebral tubercles linearly arranged (vs. randomly); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); subtibial scales smooth (vs. keeled); light or yellowish prescapular crescent absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on regenerated tail absent (vs. present).

Cnemaspis auriventralis sp. nov. differs from C. selenolagus by having 7-9 infralabials (vs. 10); paravertebral tubercles linearly arranged (vs. randomly); tubercles on lower flanks present (vs. absent); lateral caudal furrow present (vs. absent); ventrolateral caudal tubercles anteriorly present (vs. absent); enlarged median subcaudal scales row present (vs. absent); caudal tubercles not encircling the tail (vs. encircling); enlarged submetatarsal scales on the first toe absent (vs. present); 23-27 subdigital lamellae on the fourth toe (vs. 22); orange-yellow colouration on anterior 1/2 of body in males absent (vs. present); ocelli on brachium and side of neck in males absent (vs. present); light or yellowish prescapular crescent absent (vs. present); yellow dorsal colouration on fore-limbs in male absent (vs. present); yellow colouration on original tail in males present (vs. absent); and having yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on anterior part of body).

Cnemaspis auriventralis sp. nov. differs from C. siamensis by having ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 0); 16-17 paravertebral tubercles (vs. 19-25); paravertebral tubercles linearly arranged (vs. randomly); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); lineate gular marking absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on gular region, throat and pectoral region).

Cnemaspis auriventralis sp. nov. differs from C. thachanaensis by having ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 0); enlarged median subcaudal scales row present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); two poscloacal tubercles on each side in males (vs. 0); subtibial scales smooth (vs. keeled); lineate gular marking absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellowish-orange colouration only on gular region).

Cnemaspis auriventralis sp. nov. differs from C. vandeventeri by having a smaller maximum SVL of 38.6 (vs. 44.7 mm); ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 4); 16-17 paravertebral tubercles (vs. 25-29); paravertebral tubercles linearly arranged (vs. randomly); tubercles on lower flanks present (vs. absent); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. weakly keeled); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. orange colouration on gular region, throat, pectoral region, underside of limbs, belly and subcaudal region).

Figures

Figure 1. Map illustrating the type locality (yellow star) of Cnemaspis auriventralis sp. nov. at Erawan National Park, Si Sawat District, Kanchanaburi Province, Thailand and the Cnemaspis siamensis group samples used in the molecular analyses (asterisk) given in Table 2. Stars indicate type localities and circles represent additional localities.

Figure 2. The best tree resulting from Maximum Likelihood analysis of 1,327 aligned characters of the mitochondrial NADH dehydrogenase subunit 2 gene and flanking tRNAs of Cnemaspis species. Nodal support is indicated by Ultrafast bootstrap (UFB) values and Bayesian posterior probabilities (BPP) from a separate Bayesian Inference analysis, respectively. GenBank accession numbers and locality data for sequenced samples are provided in Table 2.

Figure 3. Adult male holotype of Cnemaspis auriventralis sp. nov. (ZMKU R 01001) in life.

Figure 4. Adult male holotype of Cnemaspis auriventralis sp. nov. (ZMKU R 01001) immediately after euthanasia. A. Dorsal and ventral views; B. Subcaudal region and C. Precloacal region with precloacal pores (outlined in black).

Figure 5. Adult male holotype of Cnemaspis auriventralis sp. nov. (ZMKU R 01001) immediately after euthanasia. A. Lateral view of head; B. Dorsal and ventral views of head (supranasal and internasal scales in dorsal view and mental, postmental and first infralabial scales in ventral view; outlined in black); C. Palmar view of the right manus; D. Plantar view of the right pes.

Figure 6. Dorsal and ventral views of adult male holotype of Cnemaspis auriventralis sp. nov. (ZMKU R 01001) in preservative.

Figure 7. Adult female paratype of Cnemaspis auriventralis sp. nov. (ZMKU R 01002). A. Dorsolateral view in life; B. Dorsal and ventral views immediately after euthanasia; C. Dorsal and ventral views in preservative.

Figure 8. Cnemaspis auriventralis sp. nov. paratypes in life. A. Adult male ZMKU R 00999; B. Adult male ZMKU R 01000; C. Adult female ZMKU R 01003.

Figure 9. Habitat of Cnemaspis auriventralis sp. nov. at the type locality at Erawan National Park, Si Sawat District, Kanchanaburi Province, Thailand. A. Microhabitat in karst boulder crevice (white arrow); B. Microhabitat on undersides of karst boulder (white arrow).