Hemidactylus sirumalaiensis Khandekar & Thackeray & Pawar & Agarwal 2020, sp. nov.
Creators: name: Khandekar, Akshay
name: Thackeray, Tejas
name: Pawar, Swapnil
name: Agarwal, Ishan
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Gekkonidae
Hemidactylus
Hemidactylus sirumalaiensis

description: Hemidactylus sirumalaiensis sp. nov.
(Figures 4–7, 3A; Table 4)
urn:lsid:zoobank.org:act: DD1B5AF6-EB89-4425-B801-0E2B033C902F
Hemidactylus cf. acanthopholis Ganesh et al. 2016
Holotype. NCBS-BH743 (AK 908), adult male, from Sirumalai massif (10.281944° N, 77.994722° E; ca. 580 m asl.), Dindigul district, Tamil Nadu state, India, collected by Akshay Khandekar, Ishan Agarwal and Swapnil Pawar on 16 Oct 2019.
Paratypes. NCBS-BH747 (AK 914), NCBS-BH748 (AK 915), NCBS-BH749 (AK 917), adult males, NCBS-BH744 (AK 909), NCBS-BH746 (AK 911), NCBS-BH750 (AK 922), adult females, NCBS-BH745 (AK 910), juvenile, same collection data as holotype.
Etymology. The specific epithet is a toponym for the Sirumalai Massif, the only known locality of the species.
Suggested Common Name. Sirumalai rock gecko.
Diagnosis. A medium-sized Hemidactylus, SVL <95 mm (n=8). Dorsal pholidosis heterogeneous, comprising subcircular granular scales intermixed with fairly regularly arranged longitudinal rows of enlarged, strongly keeled, pointed tubercles that are heterogeneous in shape and size, extending from occiput to tail; enlarged tubercles smallest on central two parasagittal rows, gradually increasing in size and becoming conical toward flanks, last two rows on flanks smaller and strongly conical; 17 or 18 dorsal tubercle rows at mid-body, 22–26 tubercles in paravertebral rows. Ventrolateral folds indistinct; about 36–38 ventral scale rows at mid-body. Digits with enlarged scansors, lamellae in straight transverse series, all divided except the apical and a few basal that are undivided, nine or 10 lamellae beneath first digit and 11 or 12 beneath fourth digit of manus and pes. Males with 16–18 femoral pores on each side separated by 13–15 poreless scales. Tail with 4–8 much enlarged, strongly keeled, conical tubercles forming whorls; median row of subcaudal plates large, covering almost entire underside of tail; two (rarely 1) subequal postcloacal spurs on each side that are much smaller than dorsal tubercles at mid-body. Dorsal colouration brown with five transversely arranged dark>0<shaped markings running from occiput to sacrum, tail with alternating light and dark bars, limbs with irregular dark bands.
Comparison with members of the prashadi group. Hemidactylus sirumalaiensis sp. nov. can be distinguished from members of the prashadi group on the basis of the following differing or non-overlapping characters: males with 16–18 FP on each side and 13–15 SBFP (versus males with 19 FP and six SBFP in H. aaronbaueri Giri; 19–21 FP and 13 or 14 SBFP in H. acanthopholis; 15–19 FP and 2–4 SBFP in H. depressus; 23–28 FP and 1–3 SBFP in H. graniticolus Agarwal, Giri & Bauer; 22–24 FP and 3–6 SBFP in H. hunae Deraniyagala; 18–21 FP and four SBFP in H. kangerensis Mirza, Bhosale & Patil; 21–25 FP and two or three SBFP in H. kolliensis; 16–19 FP and 5–9 SBFP in H. maculatus Duméril & Bibron; 10–12 FP and 16–18 SBFP in H. paaragowli; 17–20 FP and 1–3 SBFP in H. pieresii Kelaart; 17–20 FP and three SBFP in H. prashadi Smith; 11–15 FP and three SBFP in H. sahgali Mirza, Gowande, Patil, Ambekar & Patel; 17 or 18 FP and five SBFP in H. siva Srinivasulu, Srinivasulu & Kumar; 20–23 FP and 3–6 SBFP in H. sushilduttai Giri, Bauer, Mohapatra, Srinivasulu & Agarwal; 7–9 FP and 1–3 SBFP in H. triedrus (Daudin); 17–22 FP and 10 or 11 SBFP in H. vanam; seven or eight FP and three SBFP in H. whitakeri Mirza, Gowande, Patil, Ambekar & Patel; FP absent, only precloacal pores present in H. scabriceps); 36–38 MVSR (versus 41–43 MVSR in H. aaronbaueri; 28–36 MVSR H. depressus; 40–46 MVSR in H. graniticolus; 28–30 MVSR in H. kangerensis; 32–34 MVSR in H. kolliensis; 28–34 MVSR in H. maculatus;>30 MVSR in H. sahgali; 27–30 MVSR in H. siva; 30–33 MVSR in H. sushilduttai; 30–32 MVSR in H. triedrus; 28–30 MVSR in H. whitakeri); SVL <95 mm (versus SVL up to 128 mm in H. aaronbaueri; SVL up to 108 mm in H. acanthopholis; SVL up to 111 mm in H. graniticolus; SVL up to 118 mm in H. maculatus; SVL up to 128 mm in H. paaragowli; SVL up to 105 mm in H. siva and H. sushilduttai; SVL up to 112 mm in H. vanam).
Description of holotype. The holotype is in good condition except for minor artefacts of preservation: a small missing patch of skin on left side of canthus rostralis, a 4.7 mm long incision in sternal region for tissue collection, a prominent fold of skin (not the lateral fold) from axilla to close to the groin on either side, tail tip bent towards right side (Figure 4A, B). Adult male, SVL 94.2 mm. Head short (HL/SVL 0.25), slightly elongate (HW/HL 0.76), not strongly depressed (HH/HL 0.48), distinct from neck. Loreal region slightly inflated, canthus rostralis indistinct (Figure 5A). Snout short (SE/HL 0.46); slightly longer than twice eye diameter (ED/SE 0.46); scales on snout, canthus rostralis, forehead, and inter-orbital region heterogeneous, mostly granular and conical; scales on the snout and canthus rostralis much larger than those on occiput, forehead and inter-orbital regions (Figure 5A). Eye small (ED/HL 0.21); pupil vertical with crenulated margins; supraciliaries small, mucronate, gradually increasing in size towards front of the orbit (Figure 5C). Ear opening oval (greatest diameter 2.1 mm); eye to ear distance slightly greater than diameter of eye (EE/ED 1.39). Rostral wider than deep (RW/RL 0.68), partially divided dorsally by a weakly developed rostral groove; two enlarged supranasals, separated from each other by single much smaller internasal; single postnasal on each side, slightly larger than supranasal; rostral in contact with nasal scale, supralabial I, internasal and the small scale separating the internasals; nostrils small (0.7 mm), oval; nasal scale surrounded by rostral, internasal, supranasal, postnasal, and supralabial I on either side; three or four rows of scales separate orbit from supralabials on each side. Mental subtriangular; two pairs of well-developed postmentals, the inner pair slightly shorter (3.1 mm) than the mental (3.7 mm), and in strong contact with each other (1.2 mm) below mental, outer pair much shorter (1.8 mm) than the inner pair and separated from each other by inner pair (Figure 5B). Inner postmentals bordered by mental, infralabial I and II, outer postmental and six small gular scales on either side; outer postmentals bordered by infralabial II, inner postmental, and six (right) and seven (left) gular scales increasing in size laterally, two outer-most of which are much enlarged and continues as two rows of enlarged scales below the infralabials; two additional rows of scales below infralabials III to VII are enlarged and weakly imbricate (Figure 5B). Supralabials (on both sides) to mid-orbital position 10, and 12 up to angle of jaw; nine infralabials up to angle of jaw on each side (Figure 5C).
Body relatively stout (BW/SVL 0.21), not elongate (TRL/SVL 0.39), ventrolateral folds indistinct (Figure 6). Dorsal pholidosis heterogeneous, composed of subcircular granular scales intermixed with enlarged, fairly regularly arranged, strongly keeled, pointed tubercles in 17 or 18 longitudinal rows, extending from occiput to tail, that are heterogeneous in shape and size; enlarged tubercles on the two most medial parasagittal rows smaller than rest on dorsum and the rows most broadly spaced from one another, gradually increasing in size and becoming conical towards flanks, last two rows on flanks marginally larger or equal to medial parasagittal rows and strongly conical (Figure 6A); each enlarged tubercle surrounded by a rosette of 9–18 small granules with 1–3 granules between two longitudinally adjacent enlarged tubercles (5–8 between parasagittal rows at mid-body); enlarged tubercles on nape and shoulder smaller and conical, those on occiput and temporal region still smaller, conical (Figure 5A). Ventral scales much larger than dorsal granular scales, smooth, imbricate, slightly larger on precloacal and femoral region than on chest and abdominal region (Figure 6B); mid-body scale rows across belly 36; gular region with small, flattened, granular scales, becoming slightly larger and imbricate on lateral aspect (Figure 5B). Scales on palm and sole smooth, imbricate, subcircular; enlarged tubercles on dorsal aspect of upper arm are similar to last row of enlarged tubercles on dorsum in size, weakly pointed, imbricate, keeled; dorsal aspect of forearm with smaller, granular scales, intermixed with a few enlarged, keeled, conical tubercles, those on anterior aspect are smooth, flat, imbricate; scales on dorsal part of thigh and shank granular, except those on knee flat, imbricate, intermixed with enlarged, keeled, conical tubercles, which are larger on thigh compared to shank; anterior aspect of thigh with flatter scales, posterior aspect with granular scales (Figure 4A, B). Eighteen pores in slightly enlarged row of femoral scales on either side, separated medially by a diastema of 15 poreless scales; (Figure 5D). Fore and hind limbs relatively short, stout; forearm short (FL/SVL 0.15); tibia short (CL/SVL 0.17); digits moderately short, strongly clawed; all digits of manus and digits I–IV of pes indistinctly webbed; terminal phalanx of all digits curved, arising angularly from distal portion of expanded lamellar pad, half or more than half as long as associated toepad; scansors beneath each toe in a straight transverse series, divided except for distal and two to four basal scansors on digit I and one or two in other digits: 9-11-11-11-11 (left manus), 9-11-11-11-11 (right manus; Figure 5E), 9-12-12-12-11 (left pes), 9-12-11-12-11 (right pes; Figure 5F). Relative length of digits (measurements in mm in parentheses): I (6.2) <II (7.3) <V (7.5) <III (7.6) <IV (7.7) (left manus); I (6.2) <II (7.9) <III (8.3) <IV (9.3) <V (9.5) (left pes).
Tail depressed, flat beneath, verticillate, with well-defined median furrow; tail slightly longer than snout-vent length (TL/SVL ratio 1.20) (Figure 4C, D). Dorsal scales at tail base granular, similar in size and shape to those on mid-body dorsum, gradually becoming larger, flatter, pointed, weakly keeled, subimbricate posteriorly, intermixed with series of 4–8 much enlarged, strongly keeled, conical tubercles; eight enlarged tubercles in first segment and six in second and third segments, rest with four enlarged tubercles, lacking tubercles in ventrolateral furrow on either side (Figure 4C). Ventral scales at tail base smooth, imbricate, slightly larger than mid-body ventrals; rest of the tail with large plate-like subcaudal scales (median row) covering almost entire portion of the tail, first two subcaudal scales divided, rest entire, roughly rectangular; median row bordered laterally by one or two rows of large, smooth, imbricate scales (Figure 4D). Two subequal postcloacal spurs on left and a single on right side are much smaller than dorsal tubercles at mid-body (Figure 4B, D).
Colouration in life (Figure 7A). Dorsal ground colour of head, body, limbs, and tail brown. A preorbital light yellow streak flanked by black borders runs from anterior of eye to nostril and continues as a postorbital streak till above tympanum. Labials dark grey with some lighter yellow spots. Head with indistinct dark brown and yellow markings. Dorsal pattern of dark transverse>0<shaped markings, single indistinct band on nape, three bands on back, and one indistinct band on tail base. Tail with 10 light and 10 or 11 dark bands. Dorsum of limbs and digits with irregular dark bands. Ventral surfaces dirty white, with faint pale saffron-yellow speckles, most prominent and mixed with dark markings underside of tail; palm and sole grey.
Variation and additional information from type series. Mensural and meristic data for the type series are given in Table 4. There are three males, three females and a single juvenile ranging in size from 34.6 mm to 91.2 mm. All paratypes resemble the holotype except as follows: 1. Supranasals separated by a large internasal and a single, marginally smaller scale on snout in NCBS-BH745, NCBS-BH744, NCBS-BH746, and NCBS-BH748; 2. number of gular scales bordering inner postmental on each side (five on each side in NCBS-BH747 and, six in NCBS-BH744, NCBS-BH749; five on left and six on right in NCBS-BH748; six on left and seven on right in NCBS-BH750), 3. contact of inner postmental (in contact with infralabial I on each side in NCBS-BH748; in contact with infralabial I on left and infralabials I & II on right in NCBS-BH747), 4. number of gular scales bordering outer postmental on each side (nine on each side in NCBS-BH746; eight in NCBS-BH747; five in NCBS-BH750; six on left and eight on right in NCBS-BH749; seven on left and nine on right in NCBS-BH745 and NCBS-BH748), 5. contact of outer postmental with infralabials (in contact with infralabial II on left and infralabials II & III on right in NCBS-BH744 and NCBS-BH745; in contact with infralabials I & II on left and infralabials I, II & III on right in NCBS-BH748; in contact with infralabials II & III on left and infralabial II on right in NCBS-BH749 and NCBS-BH750; in contact with infralabials I & II on left and infralabials II & III on right in NCBS-BH747). Four para-types— NCBS-BH744, NCBS-BH745, NCBS-BH747 and NCBS-BH748, with original and complete tails, slightly longer than body (TL/ SVL 1.11, 1.12, 1.14 and 1.17 respectively), while in other three paratypes—NCBS-BH749, NCBS-BH750 and NCBS-BH746 with either partially or almost fully regenerated but complete tails, marginally shorter than body (TL/ SVL 0.97, 0.85 and tail almost equal to body 1.01 respectively). All paratypes closely agree with the holotype in colouration except that juvenile specimen NCBS-BH745 has a well-defined dorsal pattern and nine light and 10 dark bands on the tail (Figure 7C); the colouration of the regenerated tail in life is brown and lacks enlarged tubercles.
Distribution and Natural history. Hemidactylus sirumalaiensis sp. nov. is known only from the type locality at elevations of ~ 580 m asl. (Figure 1 left panel). We collected the type series a few hours after the sunset from large rocks and trees along road-cuttings in a deciduous forest patch (Figure 3B). The species often loses patches of skin upon capture and handling, which was also observed in H. vanam (Chaitanya et al. 2018). Sympatric lizards at the type locality include Hemidactylus frenatus, Hemidactylus parvimaculatus, Hemidactylus reticulatus Beddome, Hemidactylus cf. triedrus, Cnemaspis cf. gracilis, Cyrtodactylus (Geckoella) cf. collegalensis, Eutropis carinata (Schneider), Psammophilus cf. blanfordanus, and Calotes versicolor (Daudin).
description: Published as part of Khandekar, Akshay, Thackeray, Tejas, Pawar, Swapnil & Agarwal, Ishan, 2020, A new medium-bodied rupicolous Hemidactylus Goldfuss, 1820 (Squamata Gekkonidae) from the Sirumalai massif, Tamil Nadu, India, pp. 83-100 in Zootaxa 4852 (1) on pages 90-98, DOI: 10.11646/zootaxa.4852.1.4, http://zenodo.org/record/4408297