Gekko smithii sensu stricto herein after referred to as G. smithii unless noted otherwise can be separated from all other species of Gekko in the G. smithii species complex by having the combination of a maximum SVL of 191.1 mm, 11–17 supralabials, 9–14 infralabials, 3–6 internarial scales, 19–26 frontal scales, 4–9 chin scales, 94–137 midbody scales, 17–23 paravertebral tubercles, 8–11 longitudinal rows of tubercles, 23–35 ventral scales, 15–20 1st toe subdigital lamellae, 19–24 4th toe lamellae; 13–15 precloacal pores in males (absent in females); enlarged subcaudal scales; thin, white nuchal band at base of occiput composed of closely spaced spots; thin dark nuchal band contacting the eyes; large white ocelli surrounding dorsal tubercles or bordering them posteriorly in six or seven transverse rows; and a thick dark reticulum to diffuse banded dorsal pattern (Tables 9, 10).

Gecko smithii ranges from southern Thailand south of the Isthmus of Kra from at least Khao Phanom Bencha National Park in Krabi and Khao Nan National Park in Nakhon Si Thammarat Province to the northern border of the Banjaran Titiwangsa in southeastern Thailand and northwestern Peninsular Malaysia. Its range continues southward along the west side of the Banjaran Titiwangsa to at least the state of Selangor but very likely farther as well (Figs 1, 7).

Stoliczka (1870) reports “Gecko Smithii” from Java based on a juvenile specimen (SVL 86.3 mm) specimen sent to him but not collected by him. However, his description of the color pattern is well within the range of variation of both G. smithii and G. gecko. Stoliczka (1870) stated his specimen had 12 longitudinal rows of “small flattened sub-equal granules [=longitudinal rows of dorsal tubercles], slightly varying in size on the posterior part of the body and especially at the sides”. The dorsal tubercles of species in the smithii complex are distinctly raised and sub-conical in adults but less so in juveniles. Furthermore, of the 93 specimens of the smithii complex examined here, only one specimen from Borneo had 12 rows dorsal tubercles. The others ranged from 8–11. Awal Riyanto (pers com. in lit. 2021) says he nor any of his colleagues working in Java have ever seen G. smithii. Photographic material and specimens we have examined from Java cataloged as G. smithii in the Zoological Museum Amsterdam, now officially part of Naturalis Biodiversity Center in Leiden, are G. gecko. We believe reports of G. smithii from Java stem from the possible misidentification of this species by Stoliczka (1870) as no new naturally occurring populations have been reported or observed to our knowledge. The less likely scenario exists, however, that Stoliczka described a juvenile G. albomaculatus from Bangka island, Indonesia as he notes “I have also added a complete description of the rare Gecko smithii, Gray, a specimen of which was sent to me from Java, and that of what appears to be a full grown specimen of Tetragonosoma [Lycodon] effrene, CANT., from the island Banca.” The ambiguity in this sentence could mean these two species were sent to him from Java but were collected on Bangka Island.

Stoliczka (1870) reported Gekko smithii (as Gecko stentor) from the coastal cities of Chittagong, Bangladesh and Akyab (= Sittwe = Sittway, Rakhine [Arakan] State), Myanmar which was followed by Theobald (1876), Annandale (1906), Boulenger (1912), and Taylor (1963). Smith (1935) stated “I do not know of any specimens to prove that this Gecko inhabits Burma, as has been stated.” Ota et al. (1991) examined a specimen (MCZ 3120) putatively from “Burma: Rangoon” (=Myanmar, Yangon). MCZ has no other data on this specimen and the only species of Gekko we have seen in Yangon and throughout all of Myanmar over the last five years of field work has been Gekko gecko. Furthermore, the herpetological surveys in Myanmar by the California Academy of Sciences (www.calacademy.org/research/herpetology/myanmar) which resulted in the collection of over 14,000 specimens, found no Gekko smithii. We do not consider this species as part of the Burmese herpetofauna. However, the type material of Gekko gecko azhari Mertens, 1955 from Barkal, Chittagong Hill Tracts, Bangladesh does bear some resemblance to G. smithii in head shape, gular scales, and dorsal tubercle shape (Rösler 2001). Mahony et al. (2009) reported on 23 additional specimens from throughout the Chittagong Division that they considered G. g. azhari.

The dorsal body tubercles of Gekko smithii from northernmost Peninsular Malaysia and Thailand north of the Kangar-Pattani Line (generally running from Gunung Jerai, Kedah, Peninsular Malaysia to Songkhla, Songkhla, Thailand) are surrounded by a large white ocellus whereas in southern populations, the ocelli are smaller and may only border the tubercles posteriorly (Figs 7, 8). Although the latter creates a general resemblance to G. hulk sp. nov., the small white spots in G. hulk sp. nov., when not confined to the tubercles, tend to border them anteriorly. Although not as adept at substrate matching as G. gecko (see figs 374–378 in Grismer 2011a), considerable variation has been observed wherein some individuals of G. smithii from Penang and Selangor states have very faded dark dorsal markings (Fig. 8F). Although rare, other geckos from Selangor state may resemble east peninsular lineage geckos in lacking a dark nuchal loop and having a darkly speckled dorsum (Fig. 8C). Iris color can also range from turquoise to lime green in the same population (Figs 8A, 8D) and along with ground color (which can vary from yellow to dark gray (Figs 8B, 8E)), is not a diagnostic character (contra Grossmann 2006). See Tables 9 and 10 for variation in morphology.

Figure 8. 

Geographic variation in Gekko smithii (A–G) and G. hulk sp. nov. (H–M). A. Gekko smithii (LSUDPC 12899) from Ulu Yam, Selangor, Peninsular Malaysia. B. Gekko smithii (LSUHC 4959) from Pulau Pangkor, Perak, Peninsular Malaysia. C. Gekko smithii (LSUDPC 12898) from Ulu Yam, Selangor, Peninsular Malaysia. D. Gekko smithii (LSUDPC 12895) from Kota Damansara, Selangor, Peninsular Malaysia. E. Gekko smithii (LSUDPC 12903) from Bukit Panchor, Penang, Peninsular Malaysia. F. Gekko smithii (LSUDPC 12902) from Ulu Yam, Selangor, Peninsular Malaysia. G. Gekko smithii (THNHM 01844) from Phu Pha Phet, Satun, Province, Thailand. H. Gekko hulk sp. nov. (LSUDPC 12912) from Lata Kekabu, Setiu, Terengganu, Peninsular Malaysia. I. Gekko hulk sp. nov. (LSUDPC 8696) from Endau-Rompin, Johor, Peninsular Malaysia. J. Gekko hulk sp. nov. (LSUDPC 12953) from the Hala-Bala Wildlife Sanctuary, Narathiwat Province, Thailand. K. Gekko hulk sp. nov. (LSUHC 5152) from the Tekek-Juara Trail, Pulau Tioman, Pahang, Peninsular Malaysia. L. Gekko hulk sp. nov. (LSUHC 5873) from Kota Tinggi, Peninsular Malaysia. M. Gekko hulk sp. nov. (LSUDPC 12955) from Hutan Lipur Sekayu, Terengganu, Peninsular Malaysia. Photographs by Kurt H. P. Guek (A, C, D, F), L. Lee Grismer (B, K, L), Evan S. H. Quah (E, H), Michael Cota (G, J), M. A. Muin (I) and Syed A. Rizal (M).

Gekko smithii is an arboreal nocturnal species that is well-established in all types of primary and secondary forests. It is particularly well-suited for inhabiting occupied and abandoned human dwellings along forest edges where it is most easily observed. In forested habitats, geckos occur on the trunks of large trees and boulders from where males are commonly heard calling during the day and early in the evening.

Rösler et al. (2011) and Wood et al. (2020a) considered Gekko albofasciolatus a valid species within G. (Gekko). Rösler et al. (2011) provide a detailed history of the taxonomy G. albofaciolatus which is best repeated here in its original form: “In the original description of Gecko albo-fasciolatus (= Gekko albofasciolatus), Günther (1867) only provided a vague type locality Polynesia with a question mark. Smith (1935) subsequently stated ‘type loc. unknown, probably Malay Archipelago.’ Later, Wermuth (1965) wrote ‘Polynesia’ as the type locality with the addition (fide Smith 1935), that the species probably occurs in the Indo-Australian Archipelago. According to Günther (1872), G. smithii occurs in the north of Borneo (Labuan, now Sabah) and G. albofasciolatus in the South (Banjermassin, Martapoura). We herein restrict the type locality of G. albofasciolatus to Banjermassin (= Banjar-masin), Kalimantan, Indonesia. While commenting on G. albofasciolatus, Günther (1872:589) stated that he received three specimens from Dr. Bleeker from Borneo under different names (Platydactylus pentonopus, Platydactylus borneensis, and Hemidactylus zosterophorus). From Günther’s (1872) footnotes it is obvious that he allocated all of Bleeker’s specimens to G. albofasciolatus. Of Bleeker’s species, only Platydactylus borneensis had been recorded from Borneo. The names P. borneënsis (= P. borneensis) and H. zosterophorus were introduced by Bleeker (1857) without formal species descriptions (see also Bleeker 1860). The type locality of Platydactylus borneensis (non Pentadactylus borneensis Günther, 1864 = Aeluroscalabotes felinus Günther, 1864; non Tarentola borneensis Gray, 1845 = Tarentola delalandii Duméril & Bibron, 1836) is ‘Bandjermasin’ and the type locality of Hemidactylus zosterophorus is ‘Padang (ook op Nias)’. In his critical review of Bleeker’s type specimens, Boulenger (1887) did not consider the taxa Platydactylus borneensis and Hemidactylus zosterophorus. According to Bauer (1994), both names are species inquirenda and Kluge (2001) listed them as nomina nuda (see also Rösler 2000). Therefore, the names Platydactylus borneensis Bleeker, 1857 and Hemidactylus zosterophorus Bleeker, 1857, which are according to Günther’s (1872) statements younger, subjective synonyms of Gekko albofasciolatus Günther, 1867, are not available. The same concerns Günther’s (1872) name Platydactylus pentonopus. Boulenger (1885) synonymized G. albofasciolatus with G. smithii (see also Wermuth 1965; Kluge 1991, 1993; Bauer 1994; Rösler 2000). De Rooij (1915) obviously also followed Boulenger (1885), because she listed the distribution of G. albofasciolatus based on Günther (1872) under the species G. smithii. Recently, Kluge (2001) revalidated G. albo-fasciolatus at the specific rank, but Malkmus et al. (2002) and Das (2004) did not consider G. albofasciolatus as part of the Bornean herpetofauna.”

Günther (1867) noted that Gekko albofasciolatus had a reddish-olive dorsum marbled with grayish and a uniformly whitish venter. Specimens with a reddish-olive dorsum with gray marbling also occur in Sabah (Fig. 9E) and preserved material examined from western and eastern Borneo all have uniform whitish venters, although in life, some have faint-yellow marbling which presumably fades after preservation. Günther (1867) also noted his specimen had “a narrow horseshoe-shaped band across the neck, the convexity being directed backwards”. This is clearly in reference to the nuchal band which was not present in specimens we examined or in photographs we acquired (Fig. 9). Contra to Das (2004, 2007), all Bornean specimens we examined had the characteristic dark Y-shaped marking on the head common to G. smithii and geckos of the eastern peninsular lineage (Figs 7, 8, 9). Grossmann (2006) illustrated a specimen from eastern Kalimantan (i.e. eastern Borneo) with a brown vertebral stripe and small white dorsal flecks. All adult Bornean specimens examined herein, have small white flecks and variable degrees of dorsal striping and ground color (Fig. 9). Therefore, dorsal color pattern is not a reliable character separating populations from Borneo west of the Iran Mountains and populations east of the Iran Mountains. Rösler et al. (2011) noted that northern Bornean populations might be different on the basis of Günther’s G. albofasciolatus (eastern Borneo) having 26 rows of ventral scales versus 29–39 in G. smithii s.l. However, specimens examined from northern Borneo (N = 7) have 23–33 scale rows and a specimen examined from eastern Kalimantan at Kelay (Fig. 9C) has 27 scale rows. Therefore, at this point, other than the spotted nuchal band, there are no morphological or color pattern differences between G. albofasciolatus populations east of the Iran Mountains and populations west of the Iran Mountains (i.e. from the Malaysian states of Sarawak and Sabah and the Sultanate of Brunei). The molecular data clearly indicate that the Bornean samples from Sarawak are not conspecific with G. smithii s.s. or any other lineage (Fig. 2). Therefore, the name albofasciolatus, is available for Bornean populations. However, owing to an absence of molecular data from eastern populations, all populations west of the Iran Mountains are referred to as G. cf. albofasciolatus pending the outcome of a molecular analysis. We believe this approach is justified based on the fact that the Banjaran Titiwangsa of Peninsular Malaysia separate G. smithii and the east peninsular lineage and the Iran Mountains may be doing the same with populations from Borneo. Investigations on Bornean populations are currently underway (Grismer et al. unpubl.)

Figure 9. 

Distribution and color pattern variation in Gekko albofasciolatus and G. cf. albofasciolatus in Borneo A. LSUDPC 12916 from Gunung Mulu, Sarawak, East Malaysia. B. LSUDPC 12918 from Gunung Mulu, Sarawak, East Malaysia. C. LSUDPC 12919) from Kelay Subdistrict, Kalimantan, Indonesia. D. LSUDPC 1293 from Kalimantan, Indonesia. E. LSUDPC 12949 from Kinabatangan River, Sabah, East Malaysia. F. LSUDPC 12924 from Lambir, Sarawak, East Malaysia. G. LSUDPC 12925 from Lambir, Sarawak, East Malaysia. H. LSUDPC 12929 from Gunung Gading, Sarawak, East Malaysia. Unannotated circles denote localities of specimens or photographs examined here or verified from other publications as well as vouchered samples in the literature. Photographs by Alan Watson www.alanwatsonfeatherstone.com (A), Wolfgang Grossmann (B, H), C. J. Franklin (C), Mistar Kamsi (D), Chien C. Lee (E), and Nick Baker (F,G).

Gray (1842) described Gecko Smithii from “Prince of Wales’ Island” (= Penang Island, Penang, Peninsular Malaysia). Cantor (1847)—apparently unaware of Gray’s previous description—created the junior synonym, Platydactylus Stentor, by describing additional material from “Pinang” (the Malay and Thai phonetic spelling of Penang) Island. Giebel (1861) described three new species of Platydactylus, one of which was P. albomaculatus from “Insel Bangka” (= Bangka Island, Bangka Belitung Province, Sumatra, Indonesia). Based on the descriptions of Gray (1842) and Cantor (1847), Günther (1864) removed Cantor’s P. Stentor from the genus Platydactylus and placed it in the genus “Gecko”. Günther (1864), however, made no mention of P. albomaculatus, and thus that name remained valid and his taxonomy was followed by several prominent authors of the time (e.g. Boulenger 1889, 1890, 1912; Müller 1895 first report from Sulawesi; Flower 1896, 1899; de Rooij 1915 and Smith 1930). Boettger (1886) synonymized Gecko Stentor Cantor from “Insel Nias” with (Gecko) fasciolatus (sic) Günther (1867). Additionally, Stoliczka’s (1870) description of a specimen from Java as Gecko Smithii was most likely based on a specimen of Gekko gecko. It wasn’t until Smith (1935) stated “Gray’s description of Gekko smithi, brief though it is, cannot well apply to any other Gecko coming from Penang; I therefore reinstate his name, which has priority over stentor.” that Platydactylus Stentor formally became recognized as a junior synonym of G. smithi. Smith (1935) stated that G. smithi ranged throughout the Malay Peninsula as far north as Pattani [Thailand] and the Malay Archipelago. Grossmann and Ulber (1990) reverted to the original spelling of the specific epithet “smithii” following Mertens (1946).

Comparing the short description of the two syntypes of Platydactylus albomaculatus by Giebel (1861) and the slightly more detailed redescription of a lectotype (the larger of the two syntypes) by Müller (1941), we cannot differentiate them from the specimens examined from Sumatra, islands off the west coast of Borneo, or G. smithii. They can be putatively separated from the eastern peninsular lineage by the male having 15 precloacal pores as opposed to 6–13 (n=16) and having dark blotching on the body as opposed to its absence or reduction to fine speckling (Fig. 10G). Müller (1941) noted that the lectotype had a dark-brown horseshoe-shaped band on the back of the head running from eye to eye that was bordered posteriorly by a row of moderately large white blotches. Only some Sumatran specimens have a dark nuchal band and the white blotches are often fused, forming a thin white band that is unique to specimens from Sumatra and its adjacent islands (Fig. 10). Bangka Island is Indonesia’s ninth largest island and lies less than 15 km off the southeastern coast of Sumatra from where G. “smithii” have been reported (e.g. de Rooij 1915; Fig. 10). The seaway between Bangka Island and mainland Sumatra is less than 25 m deep and these landmasses had broad intermittent subaerial connections with one another, Peninsular Malaysia, and Borneo over the last 10 million years (Hall 2013). Nonetheless, lacking sequence data from topotypic material and mainland Sumatra, the possibility exists, however unlikely, that the Bangka Island population is not conspecific with other Sumatran populations. The molecular data clearly indicate that the Nias and Banyak Islands populations are not G. smithii or any other lineage. Therefore, based on current geography and geographic history, we refer to these insular populations and mainland Sumatran populations as G. cf. albomaculatus. Investigations on these populations are currently underway (Grismer et al. unpubl.).

Figure 10. 

Distribution and color pattern variation in Gekko albomaculatus and G. cf. albomaculatus in Sumatra A. LSUDPC 12933 from Gunung Leuser NP, North Sumatra, Sumatra, Indonesia. B. LSUDPC 12934 (JAM 10261) from Pulau Nias, Sumatra, Indonesia. C. LSUDPC 12940 from Andalas University, Sumatra Barat, Sumatra, Indonesia. D. LSUDPC 12944 from Kecamatan Ngambur, Lampung, Sumatra, Indonesia. E. LSUDPC 12952 from Sum, Sumatra, Indonesia. F. LSUDPC 12924 from Sumber Rejio, Bengkuat Belimbing, Sumatra, Indonesia. G. Syntypes of G. albomaculatus from Banka Island, Sumatra, Indonesia. Unannotated circles denote localities of specimens or photographs examined here or verified from other publications as well as vouchered samples in the literature. Photographs by Andrea Molyneaux (A), Jimmy A. McGuire (B), Eric N. Smith (C, E), C. J. Franklin (D), Photo from Creative Commons Attribution Share Alike (F), and Frank Tillack (G).

Adult male LSUHC 6284 from the Tekek-Juara trail on Pulau Tioman, Pahang, Peninsular Malaysia (2.821021°N 104.179596°E; 462 m) collected by Jesse L. Grismer, Perry L. Wood, Jr., and L. Lee Grismer on 2 July 2004.

All paratypes are from Peninsular Malaysia and were collected by various personnel from La Sierra University, Universiti Sains Malaysia, Universiti Kabangsaan Malaysia, and the Department of Wildlife and National Parks Malaysia. Adult female LSUHC 6283 bears the same data as the holotype. Adult females LSUHC 5152 and 5399 from the upper Tekek-Juara trail on Pulau Tioman, Pahang (2.821021°N 104.179596°E; 462 m) collected on 3 March 2003. Adult female LSUHC 7026 from Pulau Tulai, Johor (2.909920°N 104.105315°E; 11 m) collected on 14 September 2004. Adult male LSUHC 5062 from Pulau Tulai, Johor (2.909920°N 104.105315°E; 11 m) collected on 17 August 2002. Adult male LSUHC 7648 from Endau-Rompin, Peta, Visitor center, Johor (2.530818°N 103.414191°E; 42 m) collected on 25 August 2005 by Perry L. Wood, Jr., Kin Onn Chan, and L. Lee Grismer. Adult female LSUHC 7649 and 7651 from Endau-Rompin, Peta, Visitor center, Johor (2.530818°N 103.414191°E; 42 m) collected on 25 August 2005 by Perry L. Wood, Jr., Kin Onn Chan, and L. Lee Grismer. Adult female LSUHC 7694 from Endau-Rompin, Peta, Sungai Semawak, Johor (2.529150°N 103.401173°E; 36 m) collected on 29 August 2005 by Perry L. Wood, Jr., Kin Onn Chan, Norhayati Ahmad, and L. Lee Grismer. Juvenile female LSUHC 10585 from Gunung Ledang, Johor (2.529150°N 103.401173°E; 36 m) collected on 31 May 2008, collector unknown 2008. Juvenile female LSUHC 9959 from Gunung Lambak, (2.029934°N 103.353323°E; 255 m). Juvenile male ZRC 2.6014 from FRIM, Pasoh, Negeri Sembian (2.968545°N 102.297043°E; 255 m) collected on 27 November 2008. Adult male LSUHC 1197 from Sungai Bubu, Terengganu (4.997105°N 102.953106°E; 174 m) collected on 1 September 2009 by L. Lee Grismer and Kin Onn Chan.

Figure 11. 

Type series of Gekko hulk sp. nov. from Peninsular Malaysia.

Gekko hulk sp. nov. can be separated from all other species of Gekko in the G. smithii species complex by having the combination of a maximum SVL of 161.3 mm, 10–15 supralabials, 9–13 infralabilas, 3–5 internarial scales, 13–24 frontal scales, 4–8 chin scales, 84–110 midbody scales, 16–21 paravertebral tubercles, 9–11 longitudinal rows of tubercles, 22–28 ventral scales, 14–19 1st toe subdigital lamellae, 18–24 4th toe lamellae; 6–13 precolacal pores in males (absent in females); subcaudals enlarged; thin, white nuchal band at base of occiput composed of closely spaced spots; thin dark nuchal band absent or faded and never contacting eyes; small white ocelli confined to dorsal tubercles or their anterior margin in six or seven transverse rows; and no thick dark reticulum on body (Tables 9, 10).

Adult male SVL 147.5 mm; head moderate in length (HL/SVL 0.28), width (HW/HL 0.65), somewhat flattened, distinct from neck, triangular in dorsal profile; lores concave slightly anteriorly, weakly inflated posteriorly; prefrontal region concave; canthus rostralis rounded; snout elongate (SE/HL 0.41), rounded in dorsal profile; eye large (OD/HL 0.26), pupil vertical, margins crenulated; ear opening elliptical, obliquely oriented, moderate in size; eye to ear distance slightly less than diameter of eye; rostral rectangular, bordered posteriorly by large left and right supranasals and smaller azygous postrostral, bordered laterally by first supralabials; external nares seated anteriorly in nasal scale bordered anteriorly by rostral, dorsally by large anterior and smaller posterior supranasals, posteriorly by three small postnasals, ventrally by first and second supralabials; five internasals; 12 (R,L) rectangular supralabials, first supralabial slightly larger than second; 12(R) 10(L) infralabials tapering smoothly to angle of jaw; scales of rostrum and lores flat, larger than flat scales on top of head and occiput; scales of occiput intermixed with distinct, small tubercles; superciliaries elongate, largest dorsally; mental not enlarged, subtriangular, bordered laterally by first infralabials and posteriorly by left and right trapezoidal postmentals contacting medially for 60% of their length posterior to mental; one row of slightly enlarged, elongate chin scales extending posteriorly to fifth (R) and sixth (L) infralabial; gular and throat scales small, flat, juxtaposed, grading posteriorly into larger, smooth, imbricate, pectoral scales which grade into larger ventral scales.

Figure 12. 

Holotype of Gekko hulk sp. nov. (LSUHC 6284) from the Tekek-Juara Trail, Pulau Tioman, Pahang, Peninsular Malaysia. A. Top of head. B. Gular region. C. Dorsum. D. Precloacal region and ventral surfaces of the hind limbs and tail. E. Complete dorsal view. F. Complete ventral view.

Body slightly flattened, relatively long (AG/SVL 0.51) with well-defined ventrolateral folds; dorsal scales small, flat, juxtaposed, interspersed with larger, smooth subconical, regularly arranged tubercles; 110 longitudinal rows of scales at midbody; 17 paravertebral tubercles, those at midbody surrounded by 9–12 smaller scales; 10 longitudinal rows of tubercles at midbody; body tubercles extend from occiput onto base of tail forming transverse rows, terminating near end of original tail; smaller tubercles in temporal and postocular regions; 25 longitudinal rows of flat, imbricate, ventral scales much larger than dorsal scales between body folds; and eight large, pore-bearing, precloacal scales.

Forelimbs moderately robust, relatively short (FL/SVL 0.13); large, imbricate scales of upper arm and anterior surface of forearm larger than those on posterior surface which are interspersed with large tubercles; palmar scales flat, subimbricate; digits well-developed, inflected at penultimate interphalangeal joints, arising from digital pad; subdigital lamellae wide, transversely expanded forming digital pad; claws well-developed, claw base sheathed by a dorsal and lateral scale; digit I clawless; hind limbs more robust than forelimbs, moderate in length (CL/SVL 0.16), covered anteriorly by large, flat, imbricate scales, dorsally and posteriorly by much smaller flat, juxtaposed scales interspersed with large, subconical tubercles; ventral scales of hind limbs large, flat, imbricate, abruptly contacting small postfemoral scales; femoral pores absent; plantar scales flat, subimbricate; digits well-developed, inflected at penultimate interphalangeal joints, arising from digital pad; distal subdigital lamellae wide, transversely expanded forming digital pad; 15 transverse lamellae beneath digit I, 19 transverse lamellae beneath digit IV; claws well-developed, claw base sheathed by a dorsal and lateral scale; digit I clawless; small amount of webbing between digits I–IV.

Tail original, 139.0 mm in length, tapering to a point; dorsal scales flat, square, bearing transverse rows of six large, subconical tubercles; tubercle rows separated by six or seven transverse rows of dorsal scales; large, paired, median, transversely expanded subcaudal scales; and base of tail bearing hemipenal swellings, each with two conical postcloacal tubercles.

Ground color of all dorsal surfaces yellowish-brown bearing slightly darker faint mottling; top of head bearing small white spots and dark-colored, diffuse Y-marking; thin white nuchal band composed of closely spaced spots extends from one ear opening to other, edged anteriorly by faint, dark-colored nuchal band running between postocular regions; incomplete series of obliquely aligned, small white spots immediately anterior to forelimb insertions parallel the white nuchal spots; series of five rows of transversely arranged, widely separated, small white spots between limb insertions, another between hind limb insertions; white spots on body generally confined to tubercles or border them anteriorly; limbs bearing incomplete, thin white bands; white spots on base of each digit and one or two more on each digit; venter beige, mottled with faint dark-colored markings, weakest in gular region, most dense in subcaudal region; and center of iris gold, transitioning distally to green then turquoise.

Color pattern variation in Gekko hulk sp. nov. is not as extensive as that in G. smithii. The hue and intensity of the ground color changes from day to night and is generally lighter and less bold during evening hours. The description here is of the daytime coloration. The dorsal ground color in life can be dark brownish green, light-green, tan or yellowish brown. There are no thick, dark-colored reticulations on the dorsum although some specimens have faint, brown markings. The white dorsal spots are small and typically confined to the tubercles although in some specimens they may border the tubercles anteriorly or both. The light-colored caudal bands can vary in both width and boldness. In one specimen from Pulau Tioman (LSUHC 5152; Fig. 8K), the white nuchal spots form a solid band as in G. albomaculatus. The color pattern of hatchlings and juveniles is more boldly marked. Variation in morphology is presented in Tables 11 and 12.