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

description: Hemidactylus rishivalleyensis sp. nov.
Figures 7–10, 5B; Table 5.
Hemidactylus treutleri, [part] Sreekar et al. 2010; Lajmi et al. 2016
Holotype. NCBS-BH728 (AK 649), adult male, from Cave Rock Hill, Rishi Valley school (13.632° N 78.457° E; ca. 730 m asl.), Chittoor district, Andhra Pradesh state, India, collected by Akshay Khandekar, Ishan Agarwal, Nikhil Gaitonde and Joshua Muyiwa on 12 March 2019.
Paratypes. NCBS-BH731 (AK 650), NCBS-BH732 (AK 651), adult males, NCBS-BH729 (AK 647), NCBS-BH730 (AK 648), NCBS-BH733 (AK 652), NCBS-BH734 (AK 653), NCBS-BH735 (AK 654) adult females, same collection data as holotype.
Etymology. The specific epithet is a toponym for the Rishi Valley, the type locality for the new species.
Suggested Common Name. Rishi Valley rock gecko
Diagnosis. A medium-sized Hemidactylus, SVL to at least 63 mm (n=8). Dorsal pholidosis heterogeneous, composed of subcircular granular scales intermixed with 15 or 16 fairly regularly arranged longitudinal rows of much enlarged, strongly keeled, pointed tubercles that are heterogeneous in shape and size, extending from occiput to tail; 17–22 tubercles in paravertebral rows. Ventrolateral folds indistinct; about 30–35 scale rows across the venter. Digits with enlarged scansors, lamellae in straight transverse series, all divided except the apical and a few basal that are undivided, nine (manus) and nine or ten (pes) lamellae beneath fourth digit and six or seven (manus and pes) beneath first digit. Males with 10–12 femoral pores on each side separated by nine or ten poreless scales. Original tail depressed, scales on dorsal aspect heterogeneous, slightly larger than granular scales on dorsum, granular, intermixed with a longitudinal series of 4–6 much enlarged, strongly pointed, keeled tubercles; single median row of enlarged subcaudal plates covering almost entire tail venter except a single row closest to vent divided, bordered laterally by single row of larger pointed, smooth, imbricate scales; three enlarged postcloacal spurs on both sides, anterior and middle spurs similar to each other in size and shape and marginally smaller than dorsal tubercles; posterior spur largest, at least thrice the size of anterior. Dorsal coloration beige, numerous scattered dark and light blotches on dorsum.
Comparison with members of the brookii group. Based on size, dorsal pholidosis and general colouration, Hemidactylus rishivalleyensis sp. nov. is most similar to H. brookii, H. chipkali Mirza & Raju, H. gleadowi Murray, H. kushmorensis Murray, H. malcolmsmithi Constable, H. murrayi Gleadow, H. parvimaculatus Deraniyagala, H. subtriedroides Annandale, H. varadgirii Chaitanya, Agarwal, Lajmi & Khandekar, H. chikhaldaraensis Agarwal, Giri, Bauer & Khandekar H. sankariensis Agarwal, Giri, Bauer & Khandekar and H. treutleri Mahony but can be diagnosed on the basis of the following combination of characters: 10–12 femoral pores on each side separated by nine or ten poreless scales (opposing character states indicated in parentheses): H. brookii (12–13 femoral pores on each side separated by single poreless scale), H. chipkali (seven femoral pores on each side separated medially by eight poreless scales), H. gleadowi (12–13 femoral pores on each side separated by single poreless scale), H. kushmorensis (10–11 femoral pores on each side separated by 2–3 poreless scales), H. malcolmsmithi (10–14 femoral pores on each side separated by 1–3 poreless scales), H. murrayi (6–8 femoral pores on each side separated by 5–7 poreless scales), H. parvimaculatus (11–17 femoral pores on each side separated by 1–3 poreless scales), H. sankariensis (15 femoral pores on each side separated by four poreless scales), H. subtriedroides (seven femoral pores on each side separated by five or six poreless scales), H. treutleri (seven femoral pores on each side separated by seven poreless scales).
Description of the holotype. The holotype is in good condition except for a small vertical incision on the venter (5.4 mm) for tissue collection (Fig. 7A, B). Adult male, SVL 62.2 mm. Head short (HL/SVL 0.25), slightly elongate (HW/HL 0.75), not strongly depressed (HD/HL 0.44), distinctly larger than neck. Loreal region slightly inflated, canthus rostralis indistinct (Fig. 8A). Snout short (SE/HL 0.44); about two times eye diameter (ED/SE 0.51); scales on snout, canthus rostralis, forehead and inter-orbital region heterogeneous, mostly granular and conical; scales on the snout and canthus rostralis weakly keeled, twice the size of those on occipital, forehead and inter-orbital regions (Fig. 8A). Eye small (ED/HL 0.22); pupil vertical with crenulated margins; supraciliaries small, mucronate, gradually increasing in size towards front of the orbit, those at the anterior end of orbit larger. Ear opening oval (greatest diameter 1.2 mm), a row of large pointed tubercles starting above the ear till anterior border of axilla; eye to ear distance slightly greater than diameter of eye (EE/ED 1.18). Rostral wider than deep (RL/RW 2.0), partially divided dorsally by a weakly developed rostral groove; one supranasal on each side, enlarged and separated by a slightly smaller single internasal and two still smaller scales on snout; single postnasal on each side, approximately similar in size to internasal on each side; rostral in contact with nasal scale, supralabial I, supranasals, and internasal; nostrils small (0.4 mm), oval shaped; nasal surrounded by rostral, supranasal, postnasal and supralabial I on either side; three rows of scales separate orbit from supralabials (Fig. 8C). Mental subtriangular; two well-developed postmentals, the inner pair slightly longer (3.1 mm) than the mental (2.6 mm), and in strong contact with each other (1.4 mm) behind mental, outer pair slightly smaller (2.2 mm) than the inner pair and separated from each other by inner pair and five gular scales (Fig. 8B). Inner postmental bordered by mental, infralabial I, II, outer postmental and two small gular scales on either side; outer postmental bordered by infralabial II, inner postmental and eight gular scales. Infralabials bordered by a single row of enlarged scales; 2–6 rows of scales below infralabials III–VIII are enlarged and weakly imbricate. Nine supralabials up to midorbital position, and 10 up to angle of jaw on each side; nine infralabials up to angle of jaw on each side.
Body relatively stout, not elongate (AGL/SVL 0.43), ventrolateral folds indistinct (Fig. 9A, B). Dorsal pholidosis heterogeneous, comprising sub circular, granular scales intermixed with enlarged, fairly regularly arranged longitudinal rows of 15–17 strongly keeled tubercles that are heterogeneous in shape and size, extending from occiput to tail; a few scattered enlarged tubercles along medial parasagittal rows are smaller, rest of enlarged dorsal tubercles similar in size except last row on flanks which is smaller than adjacent enlarged tubercles, tubercles becoming conical toward flanks,; each enlarged tubercle surrounded by a rosette of 13–15 small granules with 1–3 granules between two longitudinally adjacent enlarged tubercles (4–7 between parasagittal rows at mid-body); enlarged tubercles on nape and shoulder slightly smaller, those on occiput and temporal region still smaller, rounded and conical except a few behind the ear opening are slightly larger and more pronounced (Fig. 7A). Ventral scales larger than dorsal granular scales, smooth, imbricate, slightly larger on precloacal and femoral region than on chest and abdominal region; mid-body scale rows across belly 30–33; gular region with much smaller, flat, subimbricate scales, becoming slightly larger and juxtaposed on anterior aspect (Fig. 9B). Scales on palmar and plantar surfaces granular; scales on dorsal aspect of upper arm and forearm larger than last row of enlarged tubercles on dorsum, flat, weakly pointed, weakly keeled and subimbricate, intermixed with a few scattered enlarged tubercles that are slightly more conical and distinct on forearm; scales on dorsal part of thigh and shank granular, except those on knee flat, imbricate, intermixed with enlarged, conical, rounded, weakly keeled, heavily striated tubercles, which are larger on thigh compared to shank, anterior aspect of thigh with flatter scales, posterior aspect with granular scales. Ten femoral pores on either side separated medially by a diastema of nine poreless scales; pore-bearing scales distinctly larger than other femoral scales (Fig. 8D). Fore and hindlimbs relatively short, stout; forearm short (FL/SVL 0.12); tibia short (CL/SVL 0.15); 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 three basal scansors on digit I and two or three in other digits: 6-8-9-9-9 (left manus), 6-8-9-9-9 (right manus) (Fig. 8E) 6-8-10-10-8 (left pes), 6-8-10-10-8 (right pes) (Fig. 8F). Relative length of digits (measurements in mm in parentheses): IV (4.9)> V (4.6)> III (4.1)> II (3.9)> I (2.7) (right manus); IV (5.3)> V (5.1)> III (4.4)> II (3.7)> I (2.6) (right pes).
Tail entire and original, depressed, flat beneath, verticillate, with well-defined median furrow (Fig. 7C); tail slightly longer than snout vent length (TL/SVL 1.06). Dorsal caudal scales flat, subimbricate, smooth and rounded, larger than granules on dorsum, with a series of 4–6 much enlarged, strongly pointed, keeled tubercles; last row on ventrolateral aspect rounded, smooth and extends ~30 % of tail (Fig. 7C, D). Ventral scales on tail enlarged, imbricate, single median row of enlarged plates covering entire ventral surface except for single divided row nearest the vent, those on tail base small, smooth, flat and imbricate (Fig. 7D). Three enlarged postcloacal spurs on both sides, anterior and middle spurs similar to each other in size and shape and marginally smaller than dorsal tubercles; posterior spur largest, at least thrice the size of anterior and middle ones (Fig. 7D).
Colouration in life (Fig. 10A). Dorsal ground colour of head, body, limbs and tail beige. Two indistinct dark preorbital streaks, one terminating at nostril and the other at supralabials; postorbital streaks not distinct. Labials with fine black spots and yellow streaks. Head, body, limbs and tail with dark brown/ black and off-white blotches; tail with narrow dark, broader brown and still broader light markings, darker markings more defined on posterior two-thirds of tail. Venter off-white; with very fine black speckles on only the lateral edge of the belly and gular region; faintly suffused with yellow on the extreme lateral edge of the belly and throat.
Variation and additional information from type series. Mensural and meristic data for the type series is given in Table 5. There are two male and five female specimens ranging in size from 51.1 mm to 60.2 mm. All paratypes resemble the holotype except as follows: NCBS-BH730 and NCBS-BH732 lacking internasal scales between supranasals two longitudinal internasal scales separate supranasals on snout in NCBS-BH735; four gular scales bordering inner postmental in NCBS-BH733 and NCBS-BH735, three in NCBS-BH730 and NCBS-BH732, seven in NCBS-BH731 and six in NCBS-BH729; inner postmental bordered by infralabial I and small gular scales on left and infralabial I and II on right side in NCBS-BH729. Outer postmentals bordered by 11 gular scales on either side in NCBS-BH734, nine in NCBS-BH729 and NCBS-BH730, eight in NCBS-BH733 and NCBS-BH735, nine on left and 10 on right in NCBS-BH732, 14 on left and 11 on right in NCBS-BH731; outer postmentals bordered by infralabials II & III on left and infralabials II on right in NCBS-BH730 and NCBS-BH733, NCBS-BH731 is not in contact with any infralabials, two gular scales prevents contact between infralabial II on each side. Three paratypes—NCBS-BH730, NCBS-BH734 and NCBS-BH729, with original and complete tails, slightly longer than body (TL/ SVL 1.16, 1.04 respectively) and tail marginally shorter than body (TL/ SVL 0.92) in NCBS-BH729; three paratypes—NCBS-BH731, NCBS-BH732 and NCBS-BH735 with either partially or fully regenerated but complete tails, marginally shorter than body (TL/ SVL 0.77, 0.80 and 0.97 respectively), NCBS-BH733 with incomplete tail (Fig. 5B). All paratypes closely agree with the holotype in colouration except NCBS-BH729 which is slightly darker (Fig. 5B). The colouration of the regenerated tail in life is brown, without any enlarged tubercles (Fig. 5B).
Distribution and Natural history. Hemidactylus rishivalleyensis sp. nov. has only been collected from its type locality, Cave Rock Hill in Rishi Valley School, Chittoor District, Andhra Pradesh, India. The species is also known from three localities within 50–100 km of its type locality based on mitochondrial sequence data: near Kaiwara, Chickballapur District, Karnataka; near Vellore, Vellore District, Tamil Nadu and Yelagiri, Tirupattur District, Tamil Nadu. The species has been observed on granite boulders at night and in crevices in the daytime. The species appears chiefly nocturnal and strongly rupicolous. Sympatric geckos at the type locality include Cnemaspis graniticola, C. rishivalleyensis sp. nov., Hemidactylus giganteus, H. triedrus, H. frenatus, H. leschenaultii.
description: Published as part of Agarwal, Ishan, Thackeray, Tejas & Khandekar, Akshay, 2020, Geckos in the granite: two new geckos (Squamata: Gekkonidae) from rocky, scrub habitats in Rishi Valley, Andhra Pradesh, India, pp. 451-474 in Zootaxa 4838 (4) on pages 464-466, DOI: 10.11646/zootaxa.4838.4.1, http://zenodo.org/record/4486616