Cyrtodactylus evanquahi, Wood Jr & Grismer & Muin & Anuar & Oaks & Sites Jr, 2020

Wood Jr, Perry L., Grismer, L. Lee, Muin, Mohd Abdul, Anuar, Shahrul, Oaks, Jamie R. & Sites Jr, Jack W., 2020, A new potentially endangered limestone-associated Bent-toed Gecko of the Cyrtodactylus pulchellus (Squamata: Gekkonidae) complex from northern Peninsular Malaysia, Zootaxa 4751 (3), pp. 437-460 : 448-455

Cyrtodactylus evanquahi sp. nov.

English: Evan Quah’s banded Bent-toed Gecko

Malay: Cicak Jari-bengkok Evan Quah ( Figs. 5 and 6 )

Holotype. Adult male, BYU 53435 collected on 13 August 2016 by Perry L. Wood, Jr. and Evan S. H. Quah from Gunung Baling, Kedah, Peninsular Malaysia (5.684989 N, 100.912590 E; 226 m).

Paratypes. Adult female, BYU 53436 and juvenile BYU 53437 collected on 14 August 2016 by Evan S. H. Quah and Perry L. Wood, Jr. both specimens bear the same collection data as the holotype .

Diagnosis. Cyrtodactylus evanquahi sp. nov. can be differentiated from all other species of Cyrtodactylus by having a combination of the following characters: maximum SVL of approximately 96 mm; nine or 10 supralabials; nine or 10 infralabials; prominent tuberculation on body; no tubercles on ventral surface of forelimbs, gular region, in ventrolateral body folds, or anterior one-third of tail; 31–34 paravertebral tubercles; 18–23 longitudinal tubercle rows; 29–33 ventral scales; 22 or 23 subdigital lamellae on fourth toe; 32–36 femoro-precloacal pores; shallow precloacal groove in males; six or seven dark dorsal body bands; body bands much narrower than interspaces; faint rostral chevron; body bands and nuchal loop edged with a thin white, tubercle-bearing line; dorsum lacking scattered pattern of white tubercles; no banding on base of thigh; 9–11 dark caudal bands on original tail; white caudal bands generally not immaculate; hatchlings and juveniles bearing white tail tips; and adult posterior caudal region white. All these characters are scored across all species of the C. pulchellus complex in Table 5.

TABLE 5. Diagnostic characters differentiating the 17 species of the Cyrtodactylus pulchellus complex. W=weak; M=moderate; S=strong; /=data unavailable. Some information was collected from the following literature ( Grismer & Ahmad 2008; Grismer et al. 2012, 2014d, 2016b; Sumontha et al. 2012; Quah et al. 2019).

TABLE 5. (Continued)

Description of the Holotype. Adult male, 85 mm SVL; head large, moderate in length (HL/SVL 0.29), wide (HW/HL 0.65), slightly flattened (HD/HL 0.39), distinct from neck, triangular in dorsal profile; lores concave anteriorly, inflated posteriorly; frontal and prefrontal regions deeply concave; canthus rostralis rounded anteriorly; snout elongate (ES/HL 0.43), rounded in dorsal profile, laterally constricted; eye large (ED/HL 0.21); ear opening elliptical, taller than wide, moderate in size (EL/HL 0.03), obliquely oriented; eye to ear distance greater than diameter of eye; rostral rectangular, divided dorsally by an inverted Y-shaped furrow, bordered posteriorly by left and right supranasals, and one medial postrostrals (=internasals), bordered laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal and smaller postrostral, posteriorly by two postnasals, ventrally by first supralabial; 9(R, L) rectangular supralabials extending to just beyond upturn of labial margin, tapering abruptly below midpoint of eye; 9(R,L) infralabials tapering in size posteriorly; scales on rostrum and lores weakly raised, larger than granular scales on top of head and occiput, those on posterior portion of canthus rostralis boney frontal ridges bordering orbit confluent with boney, transverse, parietal ridge; dorsal superciliaries elongate, smooth, largest anteriorly; mental triangular, bordered laterally by first infralabials and posteriorly by left and right, rectangular postmentals which contact medially for 70% of their length; single row of slightly enlarged, elongate chinshields extending posteriorly to seventh infralabials; small, granular to flat gular scales grading posteriorly into larger, flat, smooth, imbricate, pectoral and ventral scales.

Body relatively short (AG/SVL 0.43) with well-defined, non-tuberculate, ventrolateral folds; dorsal scales small, granular, interspersed with low, regularly arranged, keeled tubercles, smaller intervening tubercles occasionally present; tubercles extend from top of head to caudal constriction and onto anterior one-fifth of tail; tubercles on occiput and nape small, those on body largest; approximately 18 longitudinal rows of tubercles at midbody; 33 paravertebral tubercles; 33 flat imbricate ventral scales between ventrolateral body folds; ventral scales larger than dorsal scales; precloacal scales large, smooth; shallow precloacal groove.

Forelimbs moderate in stature, relatively short (FL/SVL 0.16); scales on dorsal surfaces of forelimbs, small, juxtaposed, intermixed with large tubercles in close contact with one another; scales of ventral surface of forearm flat, subimbricate, tubercles absent; palmar scales weakly rounded; digits well-developed, inflected at basal, interphalangeal joints; subdigital lamellae rectangular proximal to joint inflection, only slightly expanded distal to inflection; digits more narrow distal to joints; claws well-developed, sheathed by a dorsal and ventral scale; hind limbs more robust than forelimbs, moderate in length (TBL/SVL 0.20), larger tubercles on dorsal surface of legs separated by smaller subimbricate scales; ventral scales of thigh flat, smooth, imbricate, larger than dorsal granular scales; ventral, tibial scales flat, smooth, imbricate; single row of greatly enlarged, flat, rectangular, imbricate, femoroprecloacal scales extend nearly from knee to knee through precloacal region where they are continuous with slightly larger; those on the occiput intermixed with small tubercles; posterior interorbital region tuberculate; large, enlarged, pore-bearing precloacal scales; 36 contiguous, pore-bearing precloacal scales forming an inverted T bearing a shallow, precloacal groove in which 11 pore-bearing scales are found (six on left, five on right); postfemoral scales immediately posterior to enlarged scale row small, nearly granular, forming an abrupt union with postfemoral scales on posteroventral margin of thigh; plantar scales low, slightly raised, slightly round; digits well-developed, inflected at basal, interphalangeal joints; subdigital lamellae proximal to joint inflection rectangular, only slightly expanded distal to inflection; digits more narrow distal to joints; claws well-developed, sheathed by a dorsal and ventral scale; 22(R) 21(L) subdigital lamellae on 4th toe.

Original tail 199 mm in length, 7.2 mm in width at base, tapering to a point; dorsal scales of tail flat, squarish; subcaudal region bearing large median row of transverse scales; shallow caudal furrow; base of the tail bearding hemipenial swellings; three small, postcloacal tubercles on each hemipenial swelling; postcloacal scales smooth, flat, large, imbricate. Coloration in life. Dorsal ground color of head, body, limbs, and base of tail, light brownish grey, immaculate; no V-shaped line on the rostrum; moderate, dark-brown nuchal loop edged anteriorly and posteriorly by thin, whitish cream line bearing tubercles; six dark-brown body bands between nuchal loop and hind limb insertions edged anteriorly and posteriorly by thin whitish cream lines bearing tubercles; body bands slightly thinner than interspaces; no markings on posterior margin of thigh; ventral surface of head, body, and limbs beige, immaculate except for black stipples in each scale; tail bearing eleven dark bands separated by ten, narrower, beige (anteriorly) to white (posteriorly) bands; subcaudal region tan ( Figs 5 and 6 ).

Variation. The paratypes closely resemble the holotype in all aspects of color and pattern except that the female paratype (BYU 53436) has a darker dorsal ground color, two incomplete dark dorsal bands, and nearly immaculate white bands on the tail ( Figs 5 and 6 ). Additional color pattern and morphological differences are listed in Table 5.

Distribution. Cyrtodactylus evanquahi sp. nov. is known only from Gunung Baling, Kedah, Peninsular Malaysia ( Fig. 1 ). It is expected to be found at other limestone forested areas near the Gunung Baling karst formation.

Etymology. The specific epithet honors Dr. Evan S. H. Quah, who suggested the urgency to document the herpetofaunal diversity of Gunung Baling, Kedah, which is under constant threat from two cement companies that are actively mining the limestone. He also participated in the only herpetological survey of the area. Dr. Quah is an extremely productive contributor to the study of herpetology in Malaysia and is a champion for conservation of the region.

Natural History. All specimens were collected at night between 2000–2400 hrs at the type locality in primary limestone forest habitat ( Fig. 7 ). The adult male (BYU 53435) was found on a root at the base of the karst formation. The adult female (BYU 53436) was found on a thin sapling approximately 1.5 m off the ground. The juvenile female (BYU 53437) was found on a sapling close to the karst. None of the specimens were found directly on the karst and all were found on vegetation, so we hypothesize that these are a limestone forest dwelling species and facultative karst-dwellers. The only adult female collected was not gravid so there are no data on the reproductive biology of this species.

TABLE 6 . Characters and measurements of the type series of Cyrtodactylus evanquahi sp. nov. from Gunung Baling , Kedah Peninsular Malaysia. M=male, F=female, J=juvenile, /=data unavailable , R=regenerated, B=broken. W=weak, P=prominent. Other abbreviations are listed in the Materials and Methods.

Comparisons. Cyrtodactylus evanquahi sp. nov. differs from all other species in the C. pulchellus complex by having prominent tuberculation, more dark body bands, and a smaller maximum SVL (Table 5). It is further differentiated from all other species by having a combination of prominent tuberculation on the body; no tubercles on the ventral surface of the forelimbs, gular region, or in the ventrolateral folds; 31–34 paravetebral dorsal tubercles; 18–23 longitudinal rows of tubercles; 29–33 ventral scales; 22–23 subdigital lamellae on the fourth toe; 32–36 fem- oroprecloacl pores; a shallow precloacal groove in males; body bands and nuchal loop edged with a thin white line bearing tubercles; no scattered white sports on the dorsum; six or seven dark body bands thinner than interspaces; 9–11 dark caudal bands on original tail; bands on the original tail separated by not imperfect white caudal bands (Table 4). Additional comparisons between C. evanquahi sp. nov. and other members of the C. pulchellus complex can be found in Table 4.

Within the C. pulchellus complex, C. evanquahi sp. nov. is the sister species to C. pulchellus and can be further differentiated from it by having prominent tuberculation as opposed to moderate–moderate+; shallow precloacal groove in males opposed to a deep groove; having more dark dorsal body bands (six or seven vs. four); having thinner dark body bands; hatchlings and juveniles with white tail tips as opposed to no white tail tips; white caudal bands in adults not immaculate; adults having a posterior caudal region white (Table 5).

Conservation and Threats. Based on the what we know about the limited distribution of this species and the fact that the type locality has cement quarries on either side of it ( Figs. 8–9 ), it is likely that the continued mining of limestone will result in the extinction of this species if this species does not occur in other localities. Gunung Baling is also a popular hiking destination and the increased traffic of tourists also pose a threat to habitat. For example, there have been multiple human induced fires that inflicted considerable damage to the area. We suggest that this species be listed as “Vulnerable” in accordance with the formulaic conservation status assessment criterion of the International Union for Conservation of Nature ( IUCN 2019), based on its small population size and the threat of nearby habitat destruction from mining and quarrying.

Figures

FIGURE 1. Taxon sampling for the Cyrtodactylus pulchellus complex used in this study (excludes C. lekaguli Grismer, Wood, Quah, Anuar, Muin, Sumontha, Ahmad, Bauer, Wangkulangkul, Grismer & Pauwels from the map).

FIGURE 5. Type series of C. evanquahi sp. nov. in life, from Gunung Baling, Kedah, Malaysia. (A) adult male holotype (BYU 53435): (B), adult female paratype (BYU 53436), and (C) juvenile female paratype (BYU 53437).

FIGURE 6. Type series of C. evanquahi sp. nov. from Gunung Baling, Kedah, Malaysia. From left to right: adult male holotype (BYU 53435), middle, adult female paratype (BYU 53436), and juvenile female paratype (BYU 53437).

FIGURE 7. Limestone forest microhabitat at the type locality of C. evanquahi sp. nov., Gunung Baling, Kedah.

FIGURE 8. (A) Image of the limestone mining quarry on the North side of the type locality (Cement quarry 1 in Figure 7). (B) Image of the type locality, Gunung Baling, Kedah. (C) Image of the limestone mining quarry on the south side of the type locality (Cement quarry 2 in Figure 7).

FIGURE 9. Type locality of C. evanquahi sp. nov. (the red circle) showing the extent of the limestone mining on both sides of the type locality. Landsat/Copernicus image was constructed using Imagery 2018 CNES/ Airbus, DigitalGlobe, (Google), in the R package ggmap (Kahle & Wickham 2013).