Cnemaspis gituen, Kurita & Kojima & Nishikawa & Grafe, 2025

Cnemaspis gituen sp. nov.

Malay: Cicak bintang

Holotype. Adult male, UBDM.4.00170 collected by T. Kurita on 7 March 2025 from Bukit (= Hill) Patoi ( 4.74895, 115.17654, WGS84; 273 m a.s.l.), Mukim Labu, Temburong District, Brunei Darussalam. GoogleMaps

Paratype. Six adult males and two adult females ( UBDM.4.00171 and KUZ R81879–81885 collected by T. Kurita, Y. Kojima, and K. Nishikawa from the same locality as holotype, on 5, 7, and 8 March 2025. GoogleMaps

Diagnosis. SVL up to 50.8 mm. Supralabials 11–14; infralabials 9–13; internasals 1–2; postmentals 6–10. Supranasals same size as or slightly larger than surrounding granular scales. Head, ventral, forearm, tibial, subcaudal, and dorsal tubercles keeled; 16–20 paravertebral tubercles between limb insertions, not linearly arranged; tubercles on ventrolateral surface of trunk present and clustered on yellow spots. Precloacal scales with round pores 7–10, arranged in a chevron, separated into right and left at midline by 1–2 poreless scales in adult males; no femoral pores. Single pair of postcloacal tubercles. Enlarged submetatarsal scales beneath first toe; 29–35 subdigital lamellae beneath fourth toes. Tubercles present within lateral caudal furrow, at least anterior part; ventrolateral caudal tubercles present anteriorly; single continuous median row of enlarged keeled (unicarinate) subcaudals. Head, trunk, and limb dorsum dark brown in both sexes; spots on flanks distinct yellow in males and pale in females. Original tail honey yellow with diffuse brown blobs and bleached tip in males, and grey and black banding pattern encircling tail except for white tip in females; regenerated tail yellow in males and dark brown in females.

Description of holotype ( Fig. 4 View FIGURE 4 ). Adult male; SVL 47.3 mm. Head moderate in size (HL/SVL 0.29), oblong in dorsal profile (HW/HL 0.62), flat (HD/HL 0.37), distinct from neck (nape width/HW 0.61). Snout short (snout length/HL 0.37); beak concave at middle between snout tip and anterior edges of eyes in lateral profile (beak depth/ HD 0.57), raised at middorsal region, not dented posterior to nostril. Head slightly concave middorsally and convex at orbital edges. Canthus rostralis smoothly rounded. Nostrils round, open dorsolaterally. Scales of rostrum conical, weakly keeled, juxtaposed; occipital area covered with conical scales smaller than those of rostrum, intermixed with tubercles posterior to the level of anterior edge of ear opening. Eye moderate in size (eye diameter/HL 0.17); surface not exceed jaw edge and not visible from the ventral side; pupil round; strongly prominent, pointed extrabrillar fringe scales from anterior to dorsal edge, with largest scales anteriorly. Ear opening oval, oriented dorsoventrally. Rostral rectangular with convex dorsal edge, wider than high in dorsal and lateral views, high enough to cover entire snout tip; bordered by first supralabials, nostrils, granular supranasals, and two internasals; medial longitudinal groove exceeds two thirds of height. Nostrils bordered by rostral, first supralabials, supranasals, and nine/eight postnasals. Supralabials 13/12 and infralabials 11/11, gradually decreasing in size posteriorly. Mental large; Ushaped posterior edge extending to the level of middle or posterior edge of third infralabials. Postmentals 7; slightly raised, smooth, bordered by first infralabials at both ends. Gular scales oval, slightly raised, keeled, juxtaposed, gradually decreasing in size posteriorly. Throat scales almost the same size as gular scales, oval, raised, keeled, slightly imbricate, interspaced with strongly raised yellowish scales on ventrolateral surfaces ( Fig. 5 View FIGURE 5 ).

Body slender, elongate (axilla–groin length/SVL 0.50). Small, smooth or weakly keeled granular scales throughout trunk dorsum, intermixed with keeled conical tubercles more or less randomly arranged, infilled with small amorphous scales between granular scales and tubercles. Multiple, mostly three to five, keels on anterior surface of tubercles. Trunk tubercles dense dorsally, decreasing in number laterally; aggregated in yellow blotches on lateral and ventrolateral surfaces ( Fig. 5 View FIGURE 5 ); less prominent on ventrolateral surfaces; absent on venter; 19/20 paravertebral tubercles. Abdominal scales round, slightly raised, keeled, slightly imbricate anteriorly; longitudinally oval, slightly raised, strongly keeled, imbricate posteriorly. Precloacal scales round or longitudinally oval, slightly raised, keeled, juxtaposed. Precloacal pores round; 4/4 pore-bearing scales arranged in chevron, medially separated by two keeled poreless scales ( Fig. 5 View FIGURE 5 ); no femoral pores. Precloacal depression absent. Postcloacal scales vertically oval, slightly raised, keeled, slightly imbricate. A pair of postcloacal tubercles on lateral surfaces of hemipenal swellings.

Brachium and antebrachium long (brachial length/SVL 0.16, antebrachial length/SVL 0.18); dorsal scales small, round, raised, keeled, slightly imbricate; ventral scales conical, keeled, juxtaposed; keel condition gradually less prominent distally. Palmar scales round, raised, smooth. Fingers long with an inflected joint, increasing in length from first to fourth, with fifth two-thirds of fourth; interdigital webbing weak; subdigital lamellae smooth, almost entirely wide and saddle-shaped, unnotched; lamellae on joint between second and third distal phalanges (base of digit in first finger) distinctively enlarged; subdigital lamellae from first to fifth fingers 15, 23, 28, 30, 22/16, 22, 26, 30, 22; claws recurved, bordered by a keeled dorsal scale and distalmost subdigital lamella. Hind limbs longer (femur length/SVL 0.23; crus length/SVL 0.23) and more robust than forelimbs; dorsal scales conical, keeled, juxtaposed; ventral scales weakly raised, keeled, slightly imbricate proximally; gradually increasing in size and degree of keel distally. Plantar scales round, raised, smooth, slightly imbricate. Toes long with an inflected joint, increasing in length from first to fourth with fifth slightly shorter than fourth; ventral surface covered by subdigital lamellae similar to fingers; subdigital scales from first to fifth toes 12, 19, 25, 32, 26/13, 23, 27, 31, 26; claws recurved, bordered by a weakly keeled dorsal scale and distalmost lamella. One to three palmar and plantar scales which arranged in linear series proximally from enlarged subdigital lamellae at base of first digit wider than surrounding scales.

Tail original, long (tail length/SVL 1.41), segmented. Shallow contiguous middorsal caudal furrow on anterior half of tail; lateral caudal furrow shallow, continues from first to fourth segments. Caudal scales arranged in segmented whorls. Dorsocaudal scales round, weakly raised, weakly keeled, imbricate. Ventrocaudal scales oval vertically, strongly keeled, slightly imbricate, larger and more flattened than dorsocaudals; a single continuous median row of unicarinate, enlarged subcaudals posterior to fifth segment, with 4–5 scales per caudal segment in anterior part of tail, increasing in size and more sharply folded posteriorly ( Fig. 5 View FIGURE 5 ). Conical enlarged caudal tubercles with strong keel arranged on paravertebral row; tubercles on dorsolateral, lateral (in lateral furrow at some segments), and ventrolateral rows anteriorly, smaller than paravertebral row, gradually decreasing in size posteriorly; single ventrolateral tubercles per caudal segment; lateral tubercles in lateral caudal furrows on basal segments; tubercles not encircling tail.

In life, dorsal surface of head, trunk, and limbs dark brown; faint yellow granular scales scattered on snout, lateral sides of occiput, nape, and trunk; black spots scattered from snout to interorbital and brachial regions. Ventral surface of head dark grey; brilliant yellow scales on edge of lower jaw and nape. Supralabials darker than snout with faint yellow blob; infralabials brown. Iris black with dark red edge. Eight black lines radially extending from eye, of which two on posterior edge of eye extend posteriorly, one reaches occiput and another extends to ear opening; longitudinally elongated black spots on lateral surfaces of nape, probably extension of a part of radial eye lines. A single round black spot on occiput middorsum. Nine pairs of amorphous black spots and eight pairs of somewhat round faint yellow spots arranged alternately along paravertebral region from occiput to base of tail. Tuberclecentred brilliant yellow spots on lateral to lower flank between forelimb and hind limb insertions; three rows of large yellow spots, which span a width of four to seven granular scales, arranged somewhat randomly; four to seven yellow spots in each row, partly interspaced with black spots. Dorsal surface of forelimbs and hind limbs brighter than head and trunk, speckled with black spots and faint yellow spots, with transverse black bands on carpus. Ventral surface of trunk and limbs yellowish brown with faint yellow flecks and dark brown blobs. Dorsal surface of digits with black and faint yellow banding pattern. Tail honey yellow, with eight nebulous brown blobs on paravertebral region and with obviously bleached distal portion and black tip. In preservation (formalin), yellow tubercles, spots on the flank, and tail faded to white.

Variation ( Fig. 6 View FIGURE 6 ). The male paratypes are highly similar to the holotype in colouration and pattern, but slightly differ in shape and arrangement of the patterns of dorsal black blotches and lateral yellow spots. Dorsal black blotches are longitudinally elongated in some males ( KUZ R81880–81882 , and 81885). In two males ( UBDM.4.00171 and KUZ R81884 ), lateral yellow spots merge and form short rugged lines. A female ( UBDM.4.00171) has putative pore-bearing precloacal scales, which are concave and faded at the centre, though these are not obvious. Lateral spots are present but faint (almost grey) and inconspicuous in females. The original caudal pattern of females is a grey and black banding encircling the tail except for the tip, which is immaculate white with a small black spot ( UBDM.4.00171). The regenerated tail is yellow with slightly darker dorsum in males, while uniformly dark brown in a female ( KUZ R81884 ). Scales on the regenerated tail are longitudinally oval, flat or slightly raised, keeled, slightly imbricate, and are equal or slightly larger in size than those on original tail; those on the ventral surface are larger than those on the dorsal surface. The brightness of the colouration changes with conditions. Scalation and other meristic characters are described in Table 2 .

Comparisons ( Table 3). Cnemaspis gituen is differentiated from all other Bornean congeners in having patches of aggregated tubercles associated with round yellow spots on the lower flank. In most Bornean species, some individuals possess a few, scattered ventrolateral tubercles, meanwhile those are not clustered together. In addition, this species is distinguished from each of the other Bornean species as follows.

Cnemaspis gituen differs from C. lagang in having distinct tubercles on the trunk ( versus indistinct); prominent median subcaudals ( versus less prominent); and in males, dark brown head ( versus grey), round black paravertebral markings ( versus thin), brilliant yellow round spots on the flank ( versus absent), and honey yellow tail with a bleached distal portion and black tip ( versus immaculate white) in males. The new species is distinguished from C. dringi by having a smaller maximum SVL ( 50.8 mm versus 59.5 mm); more precloacal pores (7–10 versus 5–6); and fewer paravertebral tubercles (16–20 versus 25–27). It is distinct from C. kendallii in having smaller maximum SVL ( versus 59.2 mm); small supranasals same size to or slightly larger than surrounding granular scales ( versus large as about two times wider than surrounding scales); more postmentals (6–10 versus 2–3); precloacal pores ( versus absent); contiguous enlarged mid-subcaudals on the anterior part ( versus discontiguous); non-encircling caudal tubercles ( versus encircling); and darker ground colour of head ( versus yellowish grey), yellow spots on the flank ( versus pale mottling), and honey yellow tail ( versus grey–black banding on the dorsum and an immaculate white portion on the venter). Cnemaspis gituen differs from the members of the nigridia species group in having yellow spots on the flank in males ( versus faint yellow vertical lines). The new species is distinguished from them except for C. sirehensis , which was not directly examined in this study, in having smaller maximum SVL ( versus a range of 52.9 mm in C. paripari to 76.9 mm in C. nigridia ); smaller supranasals ( versus large); fewer paravertebral tubercles ( versus 23 or more); a keeled median row of subcaudals ( versus smooth and flat in C. nigridia , C. leucura , and C. puterisantubongae , and smooth and folded in C. paripari and C. matahari ); and distinctive caudal colouration. It is also differentiated from C. nigridia in having fewer precloacal pores in males ( versus 13–14) and keeled subcaudal rows ( versus smooth or weakly keeled subcaudal rows, gradually increasing in the degree of keel condition laterally); from C. paripari in having internasals ( versus absent), more precloacal pores ( versus 2–5), and fewer poreless scales separating pore-bearing scale rows (1–2 versus 3–6); from C. matahari in having fewer poreless scales between pore-bearing scale rows ( versus 3–4); and from C. leucura in having fewer postcloacal tubercles (1 versus 3–8). Cnemaspis gituen is distinguished from other Southeast Asian congeners by its maximum SVL, aggregated tubercles on the lower flank, number of precloacal pores, size and keel condition of subcaudals, and body and caudal colouration.

Etymology. The gender of the generic name is feminine. The specific epithet gituen is treated as a noun in apposition, derived from the noun “gituen ” in Lun Bawang, an indigenous ethnic group of central northern Borneo, meaning star ( Tuie 1995), which refers to the dark body colouration and distinctive yellow spots on the flank of males as well as the nature of the new species, which is difficult to find in the daytime and easier to see at night (see below).

Distribution. Cnemaspis gituen is known from the type locality: Bukit Patoi, Mukim Labu, Temburong District, Brunei Darussalam ( Fig. 1 View FIGURE 1 ).

Natural History. Cnemaspis gituen occurs on the plateau of Bukit Patoi, at and above the elevation of a rock wall called Batu Bedinding, which is covered by a lowland kerangas forest ( Fig. 7 View FIGURE 7 ). Geckos were found exclusively on the sandstone wall and boulder surfaces, not on trees or logs. The wall is approximately 8 m high, and boulders are about 2–4 m high. In the daytime, a single male was observed on the boulder’s overhanging surface. The gecko was alert, and escaped quickly into the cavity under the boulder ( Fig. 8 View FIGURE 8 , left). At night, geckos appeared on the outer surfaces of boulders and were less sensitive to approach ( Fig. 8 View FIGURE 8 , right). All specimens were collected between 23:00 and 01:00 h. No individuals displayed tail wagging behaviour. Paratype females had two eggs.

Small spiders, wasps, ants, and beetles were found in the faecal samples. Cyrtodactylus baluensis ( Mocquard, 1890) , C. miriensis Davis, Das, Leaché, Karin, Brennan, Jackman, Nashriq, Chan & Bauer, 2021 , Gekko monarchus (Schlegel, 1836 in Duméril & Bibron, 1836), and Gonocephalus bornensis ( Schlegel, 1851) were the squamates found in sympatry with the new species.