Cyrtodactylus dayangbuntingensis, Quah & Grismer & Wood & Sah, 2019

Quah, Evan S. H., Grismer, L. Lee, Wood, Perry L. & Sah, Shahrul Anuar Mohd, 2019, The discovery and description of a new species of Bent-toed Gecko of the Cyrtodactylus pulchellus complex (Squamata: Gekkonidae) from the Langkawi Archipelago, Kedah, Peninsular Malaysia, Zootaxa 4668 (1), pp. 51-75 : 58-67

Cyrtodactylus dayangbuntingensis sp. nov.

Suggested common name: Dayang Bunting Island Bent-toed Gecko

Fig. 4–7 .

urn:lsid:zoobank.org:act:403A3EA3-C4E2-4C27-99AF-7D34B1EDDF5A

Holotype ( Fig. 4A ). Adult male, LSUHC 14353 collected on 24 July 2018 at 2030 hrs by Evan S.H. Quah from along a trail to Dayang Bunting Lake , Dayang Bunting Island, Langkawi Archipelago, Kedah, Peninsular Malaysia (6°12’28.1”N 99°47’02.8”E; 18 m elevation).

Paratypes ( Fig. 4B & C ). Adult male, LSUHC 14354 and sub-adult female, LSUHC 14355 bear the same collection data as the holotype .

Diagnosis. Cyrtodactylus dayangbuntingensis sp. nov. can be differentiated from all other species of Cyrtodactylus by having a combination of the following characters: maximum SVL of approximately 99.00 mm; 12–14 supralabials; 10–11 infralabials; weak tuberculation on body; no tubercles on ventral surface of forelimbs, gular region, ventrolateral body folds, or anterior one-third of tail; 35 or 36 paravertebral tubercles; 20–22 longitudinal dorsal tubercle rows; 36–39 ventral scales; 21–23 subdigital lamellae on fourth toe; 26–29 femoroprecloacal pores; deep precloacal groove in males; up to three rows of small to medium-sized postcloacal (hemipenial) tubercles with a (1–3 + 2–4 + 2–4) range of tubercles per row; four dark dorsal body bands; body bands slightly narrower than interspaces; no rostral chevron; body bands and nuchal loop edged by a broken, thin white or yellow line formed by a single row of tubercles; scattered white tubercles present on dorsum; no banding on base of thigh; up to approximately 13 dark caudal bands on original tail; white caudal bands infused with dark pigmentation in adults; and hatchlings and juveniles bearing white tail tips. These characters are scored across all species of the C. pulchellus complex in Table 7 .

Description of holotype. Adult male, 99.00 mm SVL; head large, moderate in length (HL/SVL 0.20), wide (HW/HL 0.94), somewhat flattened (HD/HL 0.56), 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 0.58), rounded in dorsal profile, laterally constricted; eye large (ED/HL 0.32); ear opening elliptical, moderate in size (EL/HL 0.11), 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 postrostral (=internasal), bordered laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal, posteriorly by two postnasals, ventrally by first supralabial; 14(R), 12(L) rectangular supralabials extending to just beyond upturn of labial margin, tapering abruptly posterior to the midpoint of eye; first supralabial largest; 11(R) 10(L) infralabials tapering in size posteriorly; scales of rostrum and lores weakly raised, larger than granular scales on top of head and occiput, those on posterior portion of canthus rostralis slightly larger; scales on occiput intermixed with small tubercles; posterior interorbital region tuberculate; large, bony frontal ridges bordering orbit confluent with a weak, bony, 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 50% of their length; single row of slightly enlarged, elongate chinshields extending posteriorly to the third (left) and fourth (right) 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, weakly 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 20 longitudinal rows of tubercles at midbody; 35 paravertebral tubercles; 37 flat imbricate ventral scales between ventrolateral body folds; ventral scales larger than dorsal scales; precloacal scales large, smooth; deep precloacal groove.

Forelimbs moderate in stature, relatively short (FL/SVL 0.15); scales on dorsal surfaces of forelimbs larger than those of dorsum, juxtaposed, intermixed with large tubercles in near contact with one another; scales of ventral surface of forearm flat, subimbricate, tubercles absent; palmar scales small, weakly rounded; digits well-developed, inflected at basal, interphalangeal joints; subdigital lamellae rectangular proximal to joint inflection, only slightly expanded distal to inflection; digits narrower distal to joints; claws well-developed, sheathed by a dorsal and ventral scale; fourth and fifth digits broken on left forearm; hind limbs more robust than forelimbs, moderate in length (TBL/SVL 0.19), larger tubercles on dorsal surface of legs separated by smaller juxtaposed 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 enlarged, pore-bearing precloacal scales; 29 contiguous, pore-bearing femoroprecloacal scales forming an inverted T bearing a deep, precloacal groove; 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 weakly rounded to flat; digits well developed, inflected at basal, interphalangeal joints; subdigital lamellae proximal to joint inflection rectangular, only slightly expanded distal to inflection; digits narrower distal to joints; claws well-developed, sheathed by a dorsal and ventral scale; 23(R) 22(L) subdigital lamellae on 4th toe.

Tail 133.0 mm in length, last 22.5 mm regenerated, 8.7 mm in width at base, tapering to a point; dorsal scales of tail flat, squarish; subcaudal region bearing large median row of transverse scales; no caudal furrows; base of tail bearing hemipenial swellings; three rows totaling eight [3:(1+3+4)] (R and L) medium-sized postcloacal tubercles on each hemipenial swelling ( Fig. 6A & B ); postcloacal scales smooth, flat, large, imbricate.

Coloration in life ( Fig. 4A ). Ground coloration of the top of head, limbs and dorsum light-brown, immaculate; no V-shaped rostral chevron; wide, dark-brown nuchal loop edged anteriorly and posteriorly by broken, thin light-colored line formed by a single row of white and light-yellow tubercles; four dark-brown body bands between nuchal loop and hind limb insertions edged anteriorly and posteriorly by broken, thin light-colored line formed by a single row of white or cream tubercles; dark-colored body bands slightly narrower than light-colored interspaces; white, cream or light-yellow tubercles scattered on dorsal surfaces of nape, body, limbs and anterior portion of the tail; no markings on posterior margin of thigh; throat, venter and underside of limbs beige, immaculate except for black stipples in each scale; original portion of tail bearing seven dark-colored bands separated by seven, narrower, beige (anteriorly) to white (posteriorly) bands, while tail bands infused with dark-brown pigmentation; regenerated tip of tail dark-brown; subcaudal region tan anteriorly, becoming darker posteriorly.

Coloration in preservative ( Fig 5 ). The overall coloration of the body in preservation is similar to that in life except the colors are faded. The dark body and tail bands are less prominent and yellow colored tubercles fade to off-white.

Variation. Paratypes are similar to the holotype in color pattern and scale counts. The male paratype (LSUHC 14354) has an aberrant row of femoroprecloacal pores, with some of the enlarged femoral scales on both the right and left sides only having dimples in place of pores causing it to have a broken row of femoroprecloacal pores ( Fig. 6D ). However, the dimpled scales were counted as pore-bearing scales fide Grismer et al. (2018a,b; 2019). It also has 2:(3+4)/3:(1+3+2) (R & L) medium-sized, postcloacal hemipenial tubercles on each hemipenial swelling. The regenerated tail is light-grey. The female paratype (LSUHC 14355) had yellow tubercles fringing the borders of the body bands instead of cream or white tubercles ( Fig. 4C ) and the regenerated portion of the tail is grey with a whitish tip. Homologous to the hemipenial tubercles in the males, are two rows, 2:(3+3)/2:(3+2) (R & L) of very small, postcloacal tubercles on each side of the base of tail. All mensural and meristic characters for the type series are presented in Table 6. A photograph of a juvenile indicates it is patterned similar to adults but has less prominent body tuberculation, lighter body ground coloration, the original tail has approximately 13 dark-colored bands, the posterior portion of tail is white, and the light-colored bands on the tail are immaculate ( Fig. 7A ).

Distribution ( Fig. 1 ). Cyrtodactylus dayangbuntingensis sp. nov. is only known from the southwestern corner of Dayang Bunting Island, Langkawi Archipelago, Kedah on the karst outcrops and hills fringing Dayang Bunting Lake. It is expected to range wider on the island in areas with the appropriate karst habitat.

Etymology. The specific epithet dayangbuntingensis is in reference to the type locality of this species on Dayang Bunting Island of the Langkawi Archipelago, Kedah, Peninsular Malaysia.

Natural history. Cyrtodactylus dayangbuntingensis sp. nov. is a karst-associated species that is only found in close proximity of karst outcrops ( Fig. 7B ). The holotype (LUSHC 14353) was found under a karst overhang at night approximately 1 m above the ground while the male paratype (LSUHC 14354) was found approximately 1.5 m above the ground on the trunk of a tree that was growing next to and in contact with a karst wall. The female paratype (LSUHC 14355) was found on the ground under a karst overhang. Another adult specimen was observed hiding in a narrow vertical karst crevice 2 m above the ground. A juvenile ( Fig. 7A ) was photographed on 17 October 2015 and indicates breeding may take place during the latter half of the year. Other species of geckos observed on the karst were Cnemaspis sp. and Gehyra mutilata (ESHQ per. obs.).

Comparison. Cyrtodactylus dayangbuntingensis sp. nov. can be differentiated from all other species of the C. pulchellus complex by having a combination of low, rounded body tubercles; no tubercles on ventral surfaces of forelimbs, gular region or in the ventrolateral body folds; 12–14 supralabials; 35 or 36 paravertebral tubercles; 20–22 longitudinal rows of dorsal tubercles; 36–39 ventral scales; 21–23 subdigital lamellae on the 4 th toe; 26–29 femoroprecloacal pores; a deep precloacal groove; four body bands that are slightly narrower than the width of the interspace; juveniles with white tail tips; white caudal bands of adults infused with dark pigment; and white, cream or light-yellow tubercles scattered on dorsum. Cyrtodactylus dayangbuntingensis sp. nov. has the highest number of postcloacal (hemipenial) tubercle rows of any species within the C. pulchellus complex, with up to three rows with a (1–3 + 2–4 + 2–4) range of tubercles per row ( Fig. 6A,B,C ; Table 7 & 8 ). Other diagnostic characters that separate C. dayangbuntingensis sp. nov. from the other species of the C. pulchellus complex are summarized in Table 7 . Within the C. pulchellus complex, C. dayangbuntingensis sp. nov. is part of the northern karst clade along with C. astrum , C. langkawiensis and C. lekaguli . All four species can be differentiated by differences in a number of their meristic data ( Table 8 ). Cyrtodactylus dayangbuntingensis sp. nov. can be differentiated from C. lekaguli by the presence of scattered white tubercles on the dorsum, fewer femoroprecloacal pores (26–29 versus 33–36), the ratio of the width of dark body bands being narrower than light-colored interspaces (0.75 versus 1.00–2.00), and smaller maximum SVL (99.0 mm versus 103.5 mm). From C. astrum it can be distinguished by having fewer paravertebral tubercles (35–36 versus 40–57), fewer femoroprecloacal pores (26–29 versus 31–38), the dark body bands being narrower than light-colored interspaces (0.75 versus 1.00–2.00) and smaller maximum SVL (99.0 versus 108.1). Cyrtodactylus dayangbuntingensis sp. nov. most closely resembles C. langkawiensis but can be differentiated from it by having more supralabials (12–14 versus 9–12), more infralabials (10–11 versus 8–10), and fewer femoroprecloacal pores (26–29 versus 30 in single male) ( Table 4 , 7 & 8 ). From C. macrotuberculatus , which is also found in the Langkawi Archipelago, C. dayangbuntingensis sp. nov. is differentiated by having weak as opposed to very prominent body tubercles; an absence of tubercles on the gular region, ventral surface of forelimbs, and ventrolateral fold; higher number of ventral scales (36–39 versus 17–28), and the presence of scattered white tubercles on the dorsum.

Figures

FIGURE 1. Location of the type localities of Cyrtodactylus dayangbuntingensis sp. nov., C. langkawiensis, and C. macrotuberculatus in the Langkawi Archipelago, Kedah. Location of the Langkawi Archipelago along the west coast of Peninsular Malaysia inset.

FIGURE 4. Type series of Cyrtodactylus dayangbuntingensis sp. nov. from Dayang Bunting Island, Langkawi archipelago, Kedah. (A) Holotype (LSUHC 14353). (B) Paratype (LSUHC 14354). (C) Paratype (LSUHC 14355). Photographs by Evan Quah.

FIGURE 5. Dorsal (A) and ventral (B) aspects of the preserved type series of Cyrtodactylus dayangbuntingensis sp. nov.. Voucher numbers are in the LSUHC series and LSUHC 14353 is the holotype.

FIGURE 6. Arrangement of postcloacal hemipenial tubercles on right (A) and left (B) side of tail in holotype of Cyrtodactylus dayangbuntingensis sp. nov. (LSUHC 14353). (C) Arrangement of postcloacal hemipenial tubercles in adult male C. macrotuberculatus (LSUHC 9428) from Langkawi Island. (D) Femoroprecloacal scale row and pores in paratype of C. dayangbuntingensis sp. nov. (LSUHC 14354).

FIGURE 7. (A) Juvenile Cyrtodactylus dayangbuntingensis sp. nov. photographed on Dayang Bunting Island, Langkawi ar- chipelago, Kedah. Image courtesy of M.A. Muin. (B) Karst microhabitat of C. dayangbuntingensis sp. nov. on Dayang Bunting Island, Langkawi archipelago, Kedah. Photograph by Evan Quah.

Tables

TABLE 4. Mean uncorrected p-distances (%) calculated for species of the Cyrtodactylus pulchellus complex based on 1442 bp of ND2 and its flanking tRNAs using MEGA v5.2.2 (Tamura et al. 2011). Distances in bold are intraspecific distances, and distances below the diagonal are interspecific distances.

	nov.
	C. dayangbuntingensis sp. C. astrum	C. australotitiwangsaensis	C. bintangrendah C. bintangtinggi C. hidupselamanya C. jelawangensis C. langkawiensis C. lekaguli						C. lenggongensis C. macrotuberculatus C. pulchellus		C. sharkari	C. timur	C. trilatofasciatus
C. dayangbuntingensis sp. nov.	0.0
C. astrum	14.1	1.4
C. australotitiwangsaensis	21.4	22.1	1.0
C. bintangrendah	20.3	21.1	11.0	0.8
C. bintangtinggi	15.6	16.4	7.3	6.8	0.0
C. hidupselamanya	22.0	18.9	21.0	22.6	15.7	0.2
C. jelawangensis	17.2	18.8	16.7	16.2	12.5	15.7	0.0
C. langkawiensis	10.9	16.4	15.1	20.3	15.6	28.2	21.9	0.0
C. lekaguli	12.5	9.6	22.9	21.9	17.2	23.6	15.6	14.1	0.0
C. lenggongensis	20.3	21.1	10.4	0.6	6.3	22.0	15.6	20.3	21.9 0.0
C. macrotuberculatus	19.6	16.0	15.8	15.3	11.6	17.4	14.6	20.7	19.9 14.7	2.7
C. pulchellus	20.3	14.8	15.1	17.8	12.5	18.9	14.1	20.3	18.8 17.2	6.4	0.0
C. sharkari	20.3	19.5	8.9	14.6	10.9	26.7	17.2	14.1	18.8 14.1	14.2	12.5	n/c
C. timur	21.4	22.9	12.5	20.4	16.7	14.7	11.5	18.2	22.9 19.8	21.6	22.4	21.4	1.0
C. trilatofasciatus	20.3	19.5	9.4	14.6	10.9	26.7	17.2	14.6	18.8 14.1	14.2	12.5	0.5	21.9	1.0