Hemidactylus amarasinghei, Sayyed & Khot & Purkayastha, 2025

Hemidactylus amarasinghei sp. nov.

Figs. 2 View FIGURE 2 , 3 View FIGURE 3 , 4 View FIGURE 4 , 5 View FIGURE 5 , 6 View FIGURE 6 and 7 View FIGURE 7

Holotype. Adult male, BNHS 2929 View Materials , collected from under a rock during daytime at Chalkewadi Plateau (17.554166°N, 73.820000°E; alt. 1057.6 m a.s.l.), Satara District, Maharashtra State, India by Amit Sayyed on 01 August 2022. GoogleMaps

Paratypes. Two adult males, BNHS 2930 View Materials , BNHS 2931 View Materials , and an adult female, BNHS 2932 View Materials , collected by Ayaan Sayyed and Masum Sayyed; same data as holotype GoogleMaps .

Diagnosis. A medium-sized gecko of the genus Hemidactylus, SVL up to 54.3 mm (n = 4); having 10–11 supralabials; 9–10 infralabials; scales on snout and canthus rostralis round, juxtaposed, smooth; head dorsum, temporal and occipital region with much smaller scales intermixed with randomly arranged, weakly keeled, conical, enlarged tubercles; rostral divided by a median suture for its entire length; two pairs of well-developed postmentals, the inner pair slightly larger than the outer; canthal region with 18–21 scales; supraciliaries separated by 21–22 scales at mid-orbit; dorsal pholidosis heterogeneous; small, granular scales intermixed with enlarged, regularly arranged, feebly keeled tubercles having 15–16 across the midbody; 28–31 paravertebral tubercles between pelvic and pectoral limb insertion points; midsagittal ventral scales 135–147; mid-body scales 30–31 across the belly between the lowest rows of dorsal scales; males with 7–9 femoral pores (n = 3) on each side, six or seven poreless scales between femoral pores; 7–8 lamellae beneath toe IV; original tail covered above with granular, flattened, smooth scales, intermixed with series of 4–7 much enlarged, keeled, pointed, conical tubercles forming whorls; ventral scales with large, undivided, rectangular subcaudal scales, covering almost entire portion of the tail; median row bordered laterally by one or two rows of large, smooth, imbricate triangular scales; two post-cloacal spurs present on each side.

Comparisons: The species was compared with the members of H. brookii group based on direct specimen examination and from original literature describing species within the group ( Gray 1845; Blanford 1870; Beddome 1870; Murray 1884; Grandison & Soman 1963; Constable 1949; Deraniyagala 1953; Mahony 2009; Giri & Bauer 2008; Bauer et al. 2008; Agarwal et al. 2019, 2020; Mirza & Raju 2017; Lajmi et al. 2020; Adhikari et al. 2022; Khandekar et al. 2023). Hemidactylus amarasinghei sp. nov. can be easily distinguished from all members of the H. brookii group by a combination of the following non-overlapping characters: 7–9 femoral pores on each side versus 10–11 in H. kushmorensis ; 10–14 in H. malcolmsmithi ; 11–17 in H. parvimaculatus ; 10–12 in H. rishivalleyensis Agarwal, Thackeray & Khandekar ; 15 in H. sankariensis Agarwal, Bauer, Giri & Khandekar ; 16–17 in H. srikanthani Adhikari, Achyuthan, Kumar, Khot, Shreeram & Ganesh ; 12–13 in H. brookii sensu stricto; 15–16 in H. xericolus Lajmi, Giri, Singh & Agarwal and 12–13 in H. gleadowi , precloacal pores are present in H. gracilis Blanford , H. reticulatus Beddome , H. sataraensis Giri & Bauer , H. albofasciatus Grandison & Soman and H. imbricatus Bauer, Giri, Greenbaum, Jackman, Dharne & Shouche ; 6–7 poreless scales between femoral pores versus 2–3 in H. kushmorensis ; 9–10 in H. rishivalleyensis ; 8 in H. chipkali Mirza & Raju ; 1–3 in H. malcolmsmithi and H. parvimaculatus ; 4 in H. sankariensis ; a single poreless scale in males of H. brookii sensu stricto and H. xericolus ; no poreless scales in H. quartziticolus Khandekar, Thackeray, Mariappan, Gangalmale, Waghe, Pawar & Agarwal ; enlarged, feebly keeled, conical tubercles on dorsum versus no enlarged tubercles in H. imbricatus ; strongly keeled pointed tubercles in H. gracilis , H. chipkali , H. chikhaldaraensis Agarwal, Bauer, Giri & Khandekar , H. mahonyi Adhikari, Achyuthan, Kumar, Khot, Shreeram & Ganesh , H. murrayi , H. sankariensis , H. treutleri Mahony and H. srikanthani ; 15–16 rows of tubercles on the mid-dorsum versus 6–8 in H. xericolus ; 11–14 in H. flavicaudus Lajmi, Giri, Singh & Agarwal ; 13–14 in H. mahonyi and 19–20 in H. kushmorensis ; 30–31 ventral scale rows across the belly at midbody versus 22–26 in H. flavicaudus and H. xericolus , 26–28 in H. sataraensis and 24–29 in H. quartziticolus ; more than 33 in H. chikhaldaraensis , 32–34 in H. gleadowi , 33–42 in H. kushmorensis , 30–35 in H. rishivalleyensis , 33–35 in H. sankariensis and 37 or 38 in H. srikanthani .

Hemidactylus amarasinghei sp. nov. is morphologically close to H. varadgirii , however, can be distinguished from it by having: parasagittal tubercle rows feebly keeled (versus parasagittal tubercles strongly keeled); 7–9 femoral pores on each side and 6–7 poreless scales between femoral pores versus 9–10 femoral pores on each side separated by four or five poreless scales.

Description of the holotype. A male, in good state of preservation ( Figs. 2A, B View FIGURE 2 ), SVL 42.9 mm, head short (HL/SVL 0.3), moderately wide (HW/HL 0.65), not depressed (HD/HL 0.4), distinctly wider than neck. Loreal region and canthus rostralis slightly inflated. Snout short (ES/HL 0.42), bluntly tapered; scales on the snout, canthus rostralis, forehead, and inter-orbital region heterogeneous, scales on snout and canthus rostralis, round, juxtaposed, smooth, larger than those on forehead and inter-orbital region, scales on canthus rostralis larger than those on snout; head dorsum, temporal and occipital region with much smaller scales intermixed with randomly arranged, weakly keeled, conical, enlarged tubercles; enlarged tubercles on head dorsum, temporal and occipital region much smaller than those on nape and shoulder ( Fig. 3 A View FIGURE 3 ). Eye large (ED/HL 0.27), pupil vertical with crenulated margins; supraciliaries moderate in size, blunt, fairly circular, largest and more prominent anteriorly; ear-opening oval, small (EOD/HL 0.04); eye to ear distance much longer than the diameter of eye (ET/ED 2.11). Rostral much wider (1.7 mm) than high (1.0 mm), divided by a median suture; single, elongated, enlarged supranasal on each side, separated from each other by small, round scales; rostral in contact with supralabial I, nasal, supranasal and internasal; nostrils small, oval; nasal bordered by postnasals, supranasal and rostral; a row of small scales separate the orbit from the supralabials. Mental enlarged, triangular, pointed posteriorly, slightly wider (2.0 mm) than long (1.7 mm); two pairs of postmentals, inner pair larger than outer; scales on throat and gular region small, granular, juxtaposed, smooth, smaller than those on ventral aspect of trunk ( Fig. 3B View FIGURE 3 and 4B View FIGURE 4 ). Supralabials up to angle of jaw 10 on right and 11 on the left side; first and second supralabials roughly same in size and shape; infralabials up to angle of jaw nine on both sides; first and second infralabials equal in size. Canthal region with 21 scales on both sides; supraciliaries separated by 36 scales at mid-orbit.

Body elongated (AG/SVL 0.42); lacking distinct ventrolateral furrow. Dorsal pholidosis heterogeneous; small, granular, round, raised, smooth scales intermixed with enlarged, regularly arranged, feebly keeled enlarged tubercles; enlarged paravertebral tubercles slightly smaller than those on lateral body; few slightly smaller tubercles on lower flanks ( Fig. 4A, C View FIGURE 4 ); 28 dorsal paravertebral tubercles between the limb insertions; 15 longitudinal rows of enlarged tubercles on dorsum. Small, granular scales on nape intermixed with weakly keeled enlarged tubercles, enlarged tubercles on nape, and shoulder slightly smaller than those on dorsum. Scales on ventral surface of neck, chest, manus and pes smooth, cycloid; pectoral and abdominal scales much larger than scales on dorsum, midsagittal ventral scales 147, mid-body ventral scales across the belly 31 ( Fig.4 B View FIGURE 4 ); eight femoral pores on each thigh, six poreless scales between femoral pore series ( Fig. 3D View FIGURE 3 ).

Forelimbs moderately long, slender; dorsal scales of brachium smooth, flattened and subimbricate; scales on forearm smooth, flattened and subimbricate, much smaller than those of brachium, intermixed with enlarged, feebly keeled enlarged tubercles; ventral scales of brachium smooth, rounded, juxtaposed, smaller than those on forearm; ventral scales of forearm, smooth, flattened, imbricate; palmar scales slightly raised, sub circular, juxtaposed; claws strongly curved; dorsal scales of thigh and shank small, granular, smooth intermixed with enlarged, feebly keeled tubercles; ventral scales of thigh and shank flat, cycloid; plantar scales smooth, subimbricate; fore and hind limbs relatively short, forearm short (FAL/SVL 0.12); shank relatively long (TBL/SVL 0.18); all digits of manus and digits I–IV of pes indistinctly webbed at the base; terminal phalanx of all digits curved, arising angularly from distal portion of expanded lamellar pad, measuring at least half the length or more of the associated lamellar pad; Lamellae beneath the digits, right manus 5–6–6–7–7, right pes 5–7–7–7–6 ( Fig. 3E, F View FIGURE 3 ). The relative length of digits, fingers: V (3.1 mm) = IV (3.1 mm)> III (2.8 mm)> II (2.3 mm)> I (1.6 mm); pes: V (2.8 mm)> IV (2.7 mm)> III (2.6 mm)> II (2.5 mm)> I (1.7 mm).

Tail entire and original, somewhat depressed and flat beneath; longer than snout-vent length (TL/SVL 1.1). Dorsal scales at tail base and on the tail are heterogeneous, small, granular and similar in size and shape to those on the mid-body dorsum, intermixed with a series of 4–7 much enlarged, keeled, pointed, conical tubercles forming whorls. Ventral scales at tail base equal in size, smooth, imbricate, slightly larger than mid-body ventral scales; a median row of large, undivided, rectangular, plate-like subcaudal scales covering almost entire underside of tail; median row bordered laterally by one or two rows of large, smooth, imbricate triangular scales; two post-cloacal spurs present on each side of hemipenial bulge ventrally.

Colouration in life ( Fig. 5 View FIGURE 5 ). The overall dorsal aspect of the body is brown with three longitudinal series of dark brown blotches extending from the occiput to the hindlimb insertion; a set of dark brown blotches present on both sides of the lower flank, originating from the postocular stripe, with dimensions smaller than those on the body dorsum. Head overall brown with dark brown scattered markings, small on forehead and snout; supraciliaries pale yellowish-brown; forelimbs brown above with small pale yellowish-brown and dark scales, hind limbs are brown above with irregular, large, dark brown markings; digits brown with irregular pale yellowish-brown and dark spots on the scales. Dorsal aspect of the tail pale yellowish-brown with large darker markings. Venter of the head, body, limbs, and tail whitish-grey.

Colouration in preservative ( Fig. 2 View FIGURE 2 ) In preservative, the dorsum of the body, head, limbs, and tail lightened to a greyish coloration; all markings on dorsal and lateral sides of the head, body, and tail are slightly decolorized but distinctly visible; the ventral side of the head, body, limbs, and tail have become grey.

Variation. Mensural and meristic data for the type series are given in Table 3 View TABLE 3 . There are three male specimens and a female specimen within the type series ranging in SVL from 42.9 mm to 54.3 mm. Infralabials 9–10 among the paratypes. Male paratype BNHS 2930 View Materials has 9 femoral pores on the right thigh and 7 on the left, whereas the other male paratype, BNHS 2931 View Materials , has 8 femoral pores on the right thigh and 9 on the left. The female paratype lacks femoral pores. The post-cloacal spurs on the female paratype were smaller than the holotype and male paratypes.

Etymology. The specific epithet is a noun in the masculine singular genitive case, honouring Dr. A. A. Thasun Amarasinghe, a renowned Indonesian herpetologist (born in Sri Lanka), currently affiliated with the National Research and Innovation Agency (BRIN; the scientific authority of the Government of Indonesia) for his enormous contribution to Asian herpetological research since 2005, especially on the systematics of the gekkonid fauna of South and Southeast Asia.

English name: Amarasinghe’s house gecko.

Natural History ( Fig. 6 View FIGURE 6 ). Individuals of the new species were observed in the daytime (09.00–11.00 hr), and on the ground during the night, actively searching for prey. Currently, Hemidactylus amarasinghei sp. nov. is only known from its type locality. The new species was found to be sympatric with H. sataraensis and the following reptiles were observed in the same vicinity: Ptyas mucosa (Linnaeus) ; Naja naja (Linnaeus) ; Echis carinatus (Schneider) ; Daboia russelii (Shaw & Nodder) ; Calotes versicolor (Daudin) ; Sarada superba Deepak, Zambre, Bhosale & Giri ; Ophisops beddomei (Jerdon) ; Rhabdops aquaticus Giri, Deepak, Captain & Gower ; and Liopeltis calamaria (Günther) .

Distribution ( Fig. 7 View FIGURE 7 ). Currently, Hemidactylus amarasinghei sp. nov. is only known from its type locality, Chalkewadi Plateau (17.554166°N, 73.820000°E; alt. 1057 m a.s.l.), Satara District, Maharashtra State, India. Additional investigation is imperative to elucidate the scope of distribution, trends in population, and the conservation status of the species.