Cyrtodactylus hikidai Riyanto, 2012, sp. nov.
Creators: name: Riyanto, Awal
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Gekkonidae
Cyrtodactylus
Cyrtodactylus hikidai

description: Cyrtodactylus hikidai sp. nov.
(Figs. 2 A–C; 3, 4)
Holotype. MZB.Lace.8659, adult male, Mount Ranai, Kecamatan Bunguran Timur, Kabupaten Natuna, Propinsi Kepulauan Riau, Bunguran (Great Natuna) Island, Indonesia (03o57’24.6”N, 108o21’12.4”E; 310 m above sea level), collected 26 October 2011 by A. Riyanto.
Paratypes. MZB.Lace.8650–58, 8660–62 and MZB.Lace.8846, same data as for the holotype, collected 24–26 October 2011 (see Table 1).
Diagnosis. A large Cyrtodactylus with SVL reaching 102.2 mm in adult females, males slightly smaller, up to 100.6 mm, original complete tail 114–151% of SVL; body slender; digits with well-developed claws; a single pair of postmentals in contact posteriorly; 16–20 longitudinal rows of tubercles on dorsum and 24 or 25 paravertebral tubercles; lateral folds present; 22–24 subdigital lamellae on fourth toe; 32–48 ventral scales across belly, smooth, imbricate; enlarged precloacal scales present; precloacal groove present; six pore-bearing scales in deep groove; enlarged femoral scales absent; head with paired white lines extending from the posterior margin of the nostril to the anterior margin of eye, and continuing from posterior margin of eye onto neck, forming a net-like pattern (“triangle”) on occiput.
Etymology. The specific epithet hikidai honors Tsutomu Hikida, one of the world’s authorities on the herpetology of Asia, in recognition of his contribution to our knowledge of the genus Cyrtodactylus.
Description of holotype. An adult male, SVL 98.7 mm, TL 112.3 mm; head moderately long (HL/SVL=0.30) and wide (HW/HL=0.65), somewhat depressed (HH/HL=0.40), distinct from neck, and triangular in dorsal profile; lores weakly inflated, prefrontal region concave, canthus rostralis smoothly rounded; snout moderate (SL/ HL=0.37) and sharply rounded in dorsal profile; eye large (OD/HL=0.26); ear opening oval, small (EarL/ HL=0.10); eye to ear distance greater than diameter of eye (EaEy/OD=1.02); rostral twice as wide as high, incompletely divided by dorsal, Y-shaped rostral groove; nostril bordered anteriorly by rostral, dorsally by an anterior large supranasal and a smaller posterior supranasal, posteriorly by two postnasals, and ventrally by first supralabial; 10 supralabial scales to midpoint of orbit (11 scales on right and 12 left in total); 6 infralabial scales to midpoint of orbit (9 scales to rictus on both left and right sides), first to third scales of series largest; scales of rostrum, lores, top of head, and occiput small and granular, occiput with tubercles; mental triangular, wider (3.7 mm) than deep (1.4 mm), bordered laterally by first infralabial and posteriorly by paired elongate postmentals in contact anteromedially for 30% of their length; gular scales small and granular, grading posteriorly into slightly larger, flatter, throat scales, then into large, flat, imbricate pectoral and ventral scales.
Body relatively elongate (AGL/SVL=0.41) with weak ventrolateral folds; dorsal scales small and granular, interspersed with low, rounded, semiregularly-arranged, non-keeled tubercles; tubercles extend from occiput to anterior portion of tail; occipital tubercles barely discernable, those on nape and anterior of body largest; approximately 20 longitudinal rows of tubercles and 24 paravertebral tubercles; 40 flat, imbricate ventral scales between ventrolateral body folds, ventral scales much larger than dorsal scales; midventral incision in belly from tissue removal; greatly enlarged patch of precloacal scales with a deep, long precloacal groove; scales adjacent to groove largest; six pore-bearing scales present within the groove, pores visible on surface.
Forelimbs short (FaL/SVL=0.16); granular scales of forearms lightly larger than those of body; tubercles present; palmar scales slightly raised; digits well developed, with inflection at basal interphalangeal joints; subdigital lamellae transversely expanded proximal to joint inflections, digits narrow distal to joints; claws well developed, sheathed by a dorsal and ventral scale; count of subdigital lamellae on manus: I(12), II(17), III(21), IV(21), V(18), relative lengths of digits on manus: IV>III>II>V>I.
Hind limbs more robust than forelimbs, tibia relatively short (CrL/SVL 0.20), covered dorsally with flat, granular scales interspersed with larger, flat tubercles; ventral hind limb scales flat, larger than dorsal; enlarged femoral scales absent; digits well developed, subdigital lamellae of pes transversely expanded proximal to inflected joints, digits narrow distal to joints; count of subdigital lamellae on pes: I(13), II(20), III(18), IV(22), V(21), relative length on pes: 4>5>3>2>1; claws well developed, sheathed by a dorsal and ventral scale.
Tail original, relatively long (TL/SVL=1.14), 10.2 mm in width at its base, tapering to a point at terminus; dorsal caudal scales granular with keeled tubercles, more sparsely distributed at the base than on dorsal-most surface; caudal tubercles restricted to the anterior part of tail (along 37.0 mm from base, 1/3 of tail); 2 enlarged post-cloacal spurs on each side of vent; subcaudals imbricate, arranged in several rows of small, narrow rectangular scales followed by enlarged median subcaudal plates variable in size.
Holotype coloration. In life, dorsal ground color of head, neck, trunk, limbs and tail brown; both sides of head with a white line from posterodorsal margin of nostril to anterodorsal margin of eye and continuing from posterodorsal margin of eye to neck, forming an incomplete triangular reticulation on the nape and occiput; iris metallic greenish during the day; five white irregular transverse bars bordered by dark brown between nape and base of tail, between second and third and third and fourth irregular transverse bands there are small, fragmented white bands extending from the lateral folds; irregular white bands on limbs to digits; tail dark brown with seven white bands; ventral surfaces of head, neck, limbs and tail white, palmar and plantar surfaces pale tan.
Variation. Males and females are sexually dimorphic, with females being larger than males, and exhibiting a more shallow precloacal groove. For other detailed measurements and detailed character states for the entire type series see Table 1.
Distribution. Only known from the type locality, Mount Ranai, Bunguran (Great Natuna) Island, Indonesia.
Natural History. All specimens were collected at night between ca. 20h00 and 24h00 in secondary forest on Mount Ranai, between 310 and 330 m above sea level. They were found crawling on trees and on the vertical surfaces of boulders at around 15 to 200 cm from ground. This species is syntopic with the smaller gecko Cnemaspis kendallii, although C. kendallii is diurnal. Based on presence of eggs in adult females, October is within the reproductive season for the new species.
TABLE 1. Mensural and meristic data for the type series of Cyrtodactylus hikidai sp.nov. + = presence of character state, — = absence of character state, and NA= data is unavailable. Invariant characters not listed. Linear measurements in mm. Weight measured on fresh, unfixed specimens.
Specimen numbers MZB.Lace
Comparisons with congeners. As illustrated in Table 2, Cyrtodactylus hikidai sp. nov. can be readily differentiated from the vast majority of Sunda Shelf species except C. consobrinus (Peters) from Sumatra and C. aurensis (Grismer) from Aur Island in the Seribuat Archipelago on the basis of morphology and color pattern. The new species differs from C. consobrinus by the presence of a deep precloacal groove. Furthermore, the new species has a fixed number of precloacal pores (6 versus 6–8), and lacks enlarged femoral scales or pores, as well as the network of white lines on top of the head (Fig. 4, Table 2). Cyrtodactylus hikidai can be distinguished from C. aurensis by the presence of tubercles on the occiput, forelimbs, and hind limbs, fewer precloacal pores (6 versus 7), and apparent greater maximum length (SVL of 102.2 versus 95.0 mm).
Based on body size and color pattern, Cyrtodactylus hikidai appears more closely related to C. aurensis than to C. consobrinus (see Table 2). Cyrtodactylus hikidai and C. aurensis can further be distinguished by color pattern on the occiput. The new species exhibits a white “triangle” on the nape and occiput, versus one short irregular white band in C. aurensis.
Cyrtodactylus hikidai differs from Cyrtodactylus aurensis, C. cavernicolous (Inger & King) and C. pubisulcus (Inger) in having tubercles on the forelimbs. The new species has tubercles on its hind limbs, distinguishing it from C. aurensis. Cyrtodactylus hikidai differs from C. aurensis, C. brevipalmatus (Smith), and C. elok (Dring) in having tubercles on the occiput.
Cyrtodactylus hikidai lacks a series of enlarged femoral scales such as those found in Cyrtodactylus baluensis (Mocquard), C. batucolus (Grismer, Chan, Grismer, Wood & Belabut), C. brevipalmatus, C. consobrinus, C. fumosus (Müller), C. marmoratus (Gray), C. oldhami (Theobald), C. pulchellus (Gray), C. pubisulcus, and C. quadrivirgatus (Taylor).
In having a precloacal groove, Cyrtodactylus hikidai differs from Cyrtodactylus baluensis, C. batucolus, C. brevipalmatus, C. consobrinus, C. elok, C. ingeri (Hikida), C. jarakensis (Grismer, Chan, Grismer, Wood & Belabut), C. lateralis (Werner), C. malayanus (de Rooij), C. matsuii (Hikida), C. oldhami, C. pantiensis (Grismer, Chan, Grismer, Wood & Belabut), C. peguensis (Boulenger), C. quadrivirgatus, C. yoshii (Hikida), and C. seribuatensis (Youmans & Grismer). It differs from C. matsui and C. yoshii in having enlarged precloacal scales.
Cyrtodactylus hikidai has a white reticulate pattern on the head, distinguishing it from Cyrtodactylus brevipalmatus, C. elok, C. fumosus, C. lateralis, C. marmoratus, C. oldhami, C. pubisulcus, C. pulchellus, C. quadrivirgatus, C. sworderi (Smith), C. semenanjungensis (Grismer & Leong), C. stresemanni (Rösler & Glaw), C. tiomanensis (Das & Lim), and C. yoshii. Cyrtodactylus hikidai differs from C. baluensis, C. batucolus, C. brevipalmatus, C. ingeri, C. jarakensis, C. lateralis, C. oldhami, C. pantiensis, C. pubisulcus, C. quadrivirgatus, and C. stresemanni, in having transverse dorsal body banding.
Cyrtodactylus hikidai sp. nov. is the first endemic gekkonid described from Bunguran Island (Great Natuna) and the second species of Cyrtodactylus reported from Bunguran after Leong et al. (2003). I have conducted fieldwork on this island twice, first in August of 2011 in lowland forest and mangrove habitat, and second, in October 2011, on Mount Ranai and in mangrove habitats. Based on this work, it is apparent that C. hikidai is restricted to Mount Ranai. The new species is likely restricted to mountainous forest, as it has not been encountered in mangroves or modified habitats, such as clove and durian plantations. However, future exploration in a variety of habitats in the Natuna Islands is required to confirm this suspicion.
description: Published as part of Riyanto, Awal, 2012, Cyrtodactylus hikidai sp. nov. (Squamata: Gekkonidae): a new bent toed gecko from Mount Ranai, Bunguran island, Indonesia, pp. 22-30 in Zootaxa 3583 on pages 23-28, DOI: 10.5281/zenodo.214909