Hemidactylus graniticolus, Agarwal, Ishan, Giri, Varad B. & Bauer, Aaron M., 2011

Agarwal, Ishan, Giri, Varad B. & Bauer, Aaron M., 2011, A new cryptic rock-dwelling Hemidactylus (Squamata: Gekkonidae) from south India, Zootaxa 2765, pp. 21-37 : 23-32

Hemidactylus graniticolus sp. nov.

Figs. 1–7

Holotype. Bombay Natural History Society ( BNHS) 1850, adult female; collected from hills near Harohalli, Bangalore Rural District, Karnataka, India (12°40’57.97’’N, 77°29’21.30’’E, 913 m asl) on 9 June 2008. Collected by I. Agarwal, V. Mistry, N. Page and P. Chanchani.

Paratypes. BNHS 1859, adult male, BNHS 1858, adult female and BNHS 1860, juvenile female, collected along with holotype; BNHS 1826, adult female, collected from adjacent hill on 11 November 2007 by I. Agarwal and V. Mistry. BNHS 2016, adult female, collected from near Yercaud, Salem District, Tamil Nadu (11° 45’ 3.02’’ N 78° 11’ 18.78’’ E, 606 m asl) on 5 December 2009 by I. Agarwal and A. D. Roy; BMNH 1946.8.23.70–71 and BMNH 1946.8.23.73–75, four adult females, and BMNH 1946.8.23.72, adult male, collected from Salem District, Tamil Nadu, India by R. H. Beddome; BMNH 1946.8.23.76, adult male, collected from ‘Malabar’, India by R. H. Beddome.

Diagnosis. A large sized Hemidactylus , snout-vent to at least 110.6 mm. Dorsal pholidosis heterogeneous, with 16–18 fairly regularly arranged longitudinal rows of subtrihedral, striated tubercles at midbody ( Fig. 1 ). First supralabial in broad contact with nasal. Two well-developed pairs of postmentals, the inner pair longer than the outer pair and mental, and in broad contact behind the mental. Ventrolateral folds distinct, about 40–46 scale rows across venter. 12–13 enlarged, divided scansors beneath fourth digit and 9–10 (rarely 11) beneath first digit of both manus and pes. 23–28 femoral pores on each side separated by one to three poreless scales in males. Original tail depressed, oval in transverse section with a median dorsal furrow; scales on the tail slightly larger than dorsals of body, striated, imbricate, with a longitudinal series of two enlarged, weakly keeled, striated, flattened tubercles on either side of the median dorsal furrow. Body dorsum with a series of pale saddles from occiput to sacrum, tail with distinct alternating light and dark bands.

Hemidactylus graniticolus sp. nov. may be distinguished from all other Indian and Sri Lankan congeners on the basis of (taxa with differing or non-overlapping character states indicated parenthetically): dorsum with conical, granular, striated scales intermixed with enlarged, fairly regularly arranged, longitudinal rows of 16–18 sub-trihedral, weakly keeled, striated tubercles (dorsum with small granules usually intermixed with scattered, rounded, feebly keeled or conical tubercles in H. frenatus Schlegel ; enlarged dorsal tubercles usually few or sometimes absent in H. leschenaultii Duméril & Bibron ; dorsum with very few enlarged tubercles, more often absent altogether in H. flaviviridis ; small, uniform, granular dorsal scales except along the sides where they may form a single line of larger rounded tubercles in H. garnotii Duméril & Bibron ; no enlarged dorsal tubercles in H. anamallensis (Günther) , H. giganteus Stoliczka , H. platyurus (Schneider) and H. aquilonius McMahan & Zug ; dorsum with uniform, imbricate, scales in H. scabriceps (Annandale) and H. imbricatus (Bauer, Giri, Greenbaum, Jackman, Dharne & Shouche) , 23–28 femoral pores on each side in males (9–13 precloacal pores in H. persicus Anderson ; angular series of 6 precloacal pores in H. porbandarensis Sharma ; 6 precloacal pores in H. gracilis Blanford ; 6-12 precloacal pores in H. reticulatus Beddome ; 7–10 precloacal pores in H. albofasciatus Grandison & Soman ; and 4–6 precloacal pores in H. sataraensis Giri & Bauer , 7–16 femoral pores on each side in H. brookii Gray and parvimaculatus Deraniyagala; 6–14 femoral pores on each side in H. lankae Deraniyagala , H. subtriedrus Jerdon and H. triedrus (Daudin) ; 14 femoral pores in H. treutleri Mahony ; 12–14 femoral pores on each side in H. gujaratensis Giri, Bauer, Vyas & Patil ; 16–19 femoral pores on each side in H. depressus Gray ).

Hemidactylus graniticolus sp. nov. may also be distinguished from all the above mentioned species on the basis of its large size (adult SVL to at least 110.6 mm). The only four Indian and Sri Lanka congeners that grow beyond 100 mm SVL are H. aaronbaueri Giri , H. prashadi , H. maculatus and H. hunae .

H. aaronbaueri can be distinguished from Hemidactylus graniticolus sp. nov. by the presence of 15–19 femoral pores on each side separated by 6 poreless scales in males (vs. 23–28 femoral pores on each side separated by 1–3 poreless scales in males) and 18–20 rows of irregularly arranged, enlarged, rounded and feebly keeled tubercles on dorsum (vs. 16–18 rows of fairly regularly arranged sub-trihedral, weakly keeled, striated tubercles on dorsum). H. prashadi can be distinguished from the new species by the presence of 17–20 femoral pores separated by 3 poreless scales in H. prashadi (vs. 23–28 femoral pores on each side separated by 1–3 poreless scales in males) and lamellae beneath first toe 8 and fourth toe 10 (vs. lamellae beneath first toe 9–11 and fourth toe 12–13).

The new species is similar in size and general appearance to Hemidactylus maculatus , but differs with respect to ( H. maculatus versus H. graniticolus sp. nov.): dorsal pholidosis (back with small juxtaposed, conical, granular scales and large trihedral tubercles arranged in 20 fairly regular longitudinal rows versus back with conical, granular, striated scales intermixed with enlarged, fairly regularly arranged, longitudinal rows of 16–18 sub-trihedral, weakly keeled, striated tubercles ( Fig. 2 )); dorsal pholidosis of tail (small, irregular, more or less pointed, keeled scales and a series of six or eight large, keeled, trihedral tubercles versus small, imbricate, striated scales and a series of four enlarged, keeled and weakly striated and flattened tubercles ( Fig. 3 )); femoral pores in males (16–19 femoral pores on each side with a gap of 5 to 9 scales versus 23–28 femoral pores on each side separated by 1–3 scales ( Fig. 4 )); colouration (brown above with darker spots, dorsal pattern with a series of dark, transverse undulating crossbars versus dorsal pattern with a series of alternating broad pale saddle-markings and narrower, darker, interspaces; no scattered dark spots.

The new species most closely resembles the Sri Lankan Hemidactylus hunae , but differs with respect to ( H. hunae versus H. graniticolus sp. nov.): dorsal pholidosis of tail (a series of six large, keeled, pointed/recurved tubercles, dorsolateral rows largest versus a series of four enlarged, keeled, weakly striated and flattened tubercles, dorsolateral row absent; femoral pores in males (22–24 femoral pores on each side with a gap of 3–6 scales versus 23–28 femoral pores on each side separated by 1–3 scales).

Description. The holotype is generally in good condition with some minor exceptions ( Fig. 1 ). The body shape is somewhat dorsoventrally flattened. A fold of skin is present on the right side of the gular region, running from below the eye to the axilla, an artefact of preservation. The tail is partially regenerated and the tail tip is missing (stored for phylogenetic analysis in the personal collection of IA).

Head short (HL/SVL ratio 0.28), slightly elongate (HW/HL ratio 0.71), not strongly depressed (HH/HL ratio 0.41), distinct from neck ( Fig. 5 A). Loreal region slightly inflated, canthus rostralis not prominent. Snout short (SE/HL ratio 0.43); slightly longer than eye diameter (OD/SE ratio 0.52); scales on snout, canthus rostralis, forehead and between eyes homogenous, juxtaposed, and weakly pointed; scales on snout, canthus rostralis and forehead twice the size of those on the occipital and interorbital region, canthus rostralis with slightly enlarged patch of scales ( Fig. 5 B). Eye small (OD/HL ratio 0.22); pupil vertical with crenulated margins; supraciliaries small, pointed, those at the anterior end of orbit slightly larger. Ear opening oval (greatest diameter 2.5 mm); eye to ear distance slightly greater than diameter of eye (EE/OD ratio 1.22). Rostral wider (4.1 mm) than deep (2.3 mm), incompletely divided dorsally by weakly developed rostral groove; two internasals, enlarged, in contact anteriorly, posteriorly separated by a single scale, one supranasal on each side which is smaller than internasal, one pair of still smaller postnasals; rostral in contact with nostril, supralabial I, and internasal; nostrils large (1.1 mm), circular, each surrounded by supranasal, internasal, rostral, supralabial I and postnasal; 3–4 rows of scales separate orbit from supralabials. Mental triangular, two well developed postmentals, the inner pair slightly longer (4.1 mm) than mental (3.8 mm), and in extensive contact with each other (2.5 mm) behind mental, outer pair about half the size of the inner pair, separated from each other by inner pair ( Fig. 5 C). Inner postmental bordered by mental, infralabial I, outer postmental and three gular scales; outer postmental bordered by infralabials I and II, inner postmental, and 6 gular scales of which the outer 2 are enlarged and continue as a single row of enlarged scales below infralabials. Infralabials bordered by a single row of enlarged scales, about 2 to 8 rows of scales below infralabials III to VIII are enlarged and weakly imbricate. Supralabials (to midorbital position) 9 (right) – 9 (left); supralabials (to angle of jaw) 13 (right) – 12 (left); infralabials (to angle of jaw) 9 (right) – 9 (left).

Body relatively stout, not elongate (TRL/SVL ratio 0.40), with ventrolateral folds without denticulate scales. Dorsal pholidosis heterogeneous, composed of conical, granular, striated scales intermixed with enlarged, fairly regularly arranged, longitudinal rows of 16–18 subtrihedral, weakly keeled, striated tubercles at midbody, extending from occipital region to tail, each enlarged tubercle roughly two to three times longer than adjacent granules, surrounded by rosette of 10–13 small granules, 2–5 granules between two adjacent enlarged tubercles; enlarged tubercles on back smallest on two most medial parasagittal rows, increasing in size toward the flanks, the last row on flank smallest after medial rows; enlarged tubercles more strongly keeled and slightly larger on flanks and close to the tail than on the dorsum; enlarged tubercles on nape, shoulder small and pointed, those on occipital, temporal region still smaller, strongly pointed. Ventral scales larger than dorsal, smooth, imbricate, slightly larger on precloacal and femoral region than on chest and abdominal region; midbody scale rows across belly 42–46; gular region with still smaller, sub-imbricate scales, those on lateral aspect of neck granular, anterior gular scales slightly larger than the rest.

Scales on the palm and sole smooth, imbricate, rounded; scales on dorsal aspect of upper arm larger than granules on dorsum, subimbricate and striated, dorsal aspect of forearm with smaller, striated, conical and granular scales, intermixed with a few enlarged conical tubercles; those on dorsal part of thigh and shank conical, granular, striated, intermixed with enlarged, striated, sub trihedral tubercles, which are numerous on shank compared to anterior aspect of thigh, posterior aspect of thigh lacks enlarged tubercles.

Fore- and hind limbs relatively short, stout; forearm short (FL/SVL ratio 0.14); tibia short (CL/SVL ratio 0.14); 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 straight transverse series, divided except for distal and three to four basal scansors on digit I and one or two in all digits that are single; scansors from proximal most at least twice diameter of palmar scales to distalmost single scansor: 10-13-13-13 -13 (right manus; Fig. 6 A ), 9-13- 13-13 -13 (right pes; Fig. 6 B). Relative length of digits (measurements in mm in parentheses): III (8.9)> IV (8.8) = V (8.8)> II (8.7)> I (7.0) (right manus); II (10.0)> III (9.9)> V (9.6)> IV (9.4)> I (7.6) (right pes).

Tail depressed, flat beneath, verticillate, with well defined median furrow; length of the partially regenerated and slightly broken tail less than snout-vent length (TL/SVL ratio 0.73); tail covered above with small (slightly larger than those on the dorsal granules), posteriorly-pointed, imbricate, striated scales and a series of two enlarged, keeled and weakly striated, posteriorly pointed and flattened tubercles on either side of the median furrow ( Fig. 3 A); ventral scales larger, imbricate, median row (subcaudal plates) slightly broader, about twice as broad as adjacent scales, not extending across width of the tail proximally, but distally they extend almost across the width of the tail. Coloration (in preservative). Dorsum grayish- brown with a vague, pale beige vertebral stripe and a series of narrow, wavy, mid-brown transverse markings defining the edges of somewhat paler saddles (indistinct saddle on occiput, one across shoulders, two between fore- and hindlimb insertions, and one on sacrum). Dorsolateral tubercle rows mostly dark brown, those on flanks predominantly ashy to white. Crown of head with scattered vague mid-brown markings. A cream stripe, bordered above and below by a narrow (one scale wide) dark brown margin, extending from nostril to midorbital rim, through eye, and on to temporal region, confluent with posterior edge of pale occipital marking. Infralabials and posterior supralabials pale, anterior supralabials with scattered dark pigment, anterior three scales darkest. Limbs pale, yellowish-gray with vague irregular dark markings, more distinctly alternating with pale interspaces distally, especially on metapodial and phalangeal segments. Original tail mostly gray-brown with lighter mottling; distal portion of original tail with alternating vague lighter and darker bands. Regenerated portion of tail unmarked. Venter cream with scattered patches of diffusely pigmented scales, particularly under thighs; palms and soles grayish. Ventrolateral surfaces of tail darkly pigmented, with scattered speckling on proximal portions of midventral scutes.

Coloration (in life). In life dorsal markings much more evident, especially in light phase, although vertebral stripe not visible. Saddle-shaped markings ashy with dark brown edges. Interspaces between saddles with diffuse orangey-brown highlights. Tail distinctly banded, with alternating light and dark bands similar to trunk dorsum in colour; darker bands somewhat wider than pale bands. Mottled pattern of limb bases and banding of distal limbs clearly demarcated. In dark phase dorsal colours much less contrasting; paler saddles light brown, darker interspaces a dark, slightly reddish-brown ( Fig. 7 A). Iris marbled greenish-silver suffused with brown-rust veination that is most prominent near the pupil.

Etymology. The species is named for the conspicuous granite rock formations upon which it lives. The specific epithet is a masculine adjective.

Variation and additional information from type series. Mensural data for the type series and additional material is given in Table 1 . There is one male, and four females including a juvenile, ranging in size from 39.2 mm to 110.6 mm. All paratypes resemble the holotype except as follows: internasals separated by two (BNHS 1858) or three (BNHS 1826, 1859, 1860) scales. Range of supralabials is from 12–14 (9–10 below eye) and infralabials is from 9–11. The scales across belly also range from 40–46 in the paratypes. Males have a series of 23–28 femoral pores separated mesially by 1-3 poreless scales (BNHS 1859 – 25/27 pores on left/right side separated by a single poreless scale, BMNH 1946.8.23.72 – 27/28 pores separated by 2 scales, BMNH 1946.8.23.76 – 25/23 pores separated by 3 scales).

Colouration. Adult colouration variation primarily due to relative prominence of the dorsal pattern elements. Light and dark phases physiological so may be seen in the same individual ( Fig. 7 A, B). Juvenile pattern very bold, brighter than in adults, with very sharp edges to dorsal markings ( Fig. 7 C). Light markings on head, edges of dorsal pale saddles, and lateral tubercles pale yellowish. Darker portions of trunk and limbs purplish-brown. Crown distinctly lighter than nape and temporal region. Tail very boldly banded with alternating dark chocolate and ashy (proximal) to white (distal) bands; 10 pale bands from tail base to tip. Venter in dark phase heavily mottled with brown.

Holotype Paratypes

continued. Distribution. Hemidactylus graniticolus is known based on voucher specimens from the following localities ( Fig. 8 ), in Karnataka state: Bangalore Rural District (Harohalli), Ramnagaram District (Ramnagaram); and Tamil Nadu state: Nilgiri District (Masanagudi-Ooty road), Salem District (near Yercaud). This species has also been visually observed in the following localities ( Fig. 8 ), in Andhra Pradesh: Chittoor District (Kangundi); Karnataka: Mysore District (Chamundi Hills, Kollegal); and Tamil Nadu: Vellore District (near Vellore), Villupuram District (near Gingee).

Natural history. The type locality is a rocky hillock in the outskirts of Bangalore, Karanataka, India ( Fig. 9 ). These broken hills are a conspicuous feature of this landscape. Hemidactylus graniticolus appears to be strictly rupicolous, recorded only from boulders. The boulder habitats of this species are both in hills and rocky outcrops in the plains; localities around Bangalore lie on the Mysore plateau and may be above 1000 m asl while localities further south such as in Salem District are as low as 200 m. These areas are characterized by sparse scrub vegetation and few trees or occasionally deciduous forests. The average annual rainfall at the type locality is about 889 mm ( Hegde et al. 2008), and the altitude is 830 m.

The species is active after dark on rock faces and occasionally culverts, in the day they may be found in crevices among boulders. These fast-moving geckos are relatively abundant and widespread within their range, found on even isolated outcrops. H. graniticolus is the most commonly seen gecko at the type locality. These large geckos have fragile skin that is easily damaged by handling. Juveniles have been observed in June.

Sympatric congeners at the type locality include Hemidactylus cf. brookii , H. frenatus , and H. triedrus . The ground-dwelling H. reticulatus occurs in the same habitats at various other localities; and the large rupicolous H. giganteus is sympatric with H. graniticolus at Ramnagaram (Karnataka) and Kangundi (Andhra Pradesh).

Figures

FIGURE 1. Dorsal view of holotype (BNHS 1850, adult female) of Hemidactylus graniticolus sp. nov.

FIGURE 2. Details of dorsal pholidosis. A) Hemidactylus graniticolus sp. nov. holotype BNHS 1850, B) H. hunae type BMNH 1946.8. 23.77, C) H. maculatus BNHS 1836.

FIGURE 3. Dorsal view of tail. A) Hemidactylus graniticolus sp. nov. holotype BNHS 1850, B) H. hunae type BMNH 1946.8. 23.77, C) H. maculatus BNHS 1836.

FIGURE 4. Pericloacal region of adult male Hemidactylus graniticolus sp. nov. (BNHS 1859) showing a series of 25 femoral pores on left and 27 on right side separated mesially by one scale.

FIGURE 5. Head of Hemidactylus graniticolus sp. nov. holotype, BNHS 1850. A) Dorsal view, B) Lateral view, C) Ventral view.

FIGURE 6. A) Ventral view of right manus of Hemidactylus graniticolus sp. nov. holotype, BNHS 1850, B) Ventral view of right pes of H. graniticolus sp. nov. holotype, BNHS 1850.

FIGURE 7. Photographs of Hemidactylus graniticolus sp. nov. in life. A) Adult colouration, light phase (holotype BNHS 1850, adult female), B) Adult colouration, dark phase (specimen not collected), C) juvenile colouration (paratype BNHS 1860, juvenile female). Note the prominent, contrasting patterning in the juvenile, which fades in adult specimens.

FIGURE 8. The known distribution of Hemidactylus graniticolus sp. nov. in South India: 1, near Harohalli, Karnataka (type locality); 2, Ramnagaram, Karnataka; 3, Nilgiri District, Tamil Nadu; 4, near Salem, Tamil Nadu; 5, Kangundi, Andhra Pradesh; 6, Chamundi Hills, Karnataka; 7, near Kollegal, Karnataka; 8, near Vellore, Tamil Nadu, and 9, near Gingee, Tamil Nadu. Triangles indicate localities with voucher specimens, squares represent visual observations.

FIGURE 9. Type locality of Hemidactylus graniticolus sp. nov. near Harohalli, Bangalore Rural District, Karnataka, India. The holotype (BNHS 1850) and paratypes (BNHS 1858 – 1860) were collected among the boulders in this habitat.

Tables

TABLE 1. Measurements (mm) and scale counts for type series of Hemidactylus graniticolus sp. nov. Abbreviations as in Materials and Methods. * indicates tail is incomplete, - measurement not taken.

	BNHS 1850	BNHS 1826	BNHS 1858	BNHS 1859	BNHS 2016
Sex	F	F	F	M	F
SVL	103.8	82.5	101.5	108.5	81.0
TRL	41.4	37.1	42.6	46.6	34.5
BW	23.4	19.6	25.5	23.5	-
CL	14.9	14.3	17.2	17.8	13.1
TL	75.5*	67.2*	105.6	107.8	65.0*
TW	13.5	10.2	13.6	14.6	-
HL	29.0	23.3	27.9	30.6	22.8
HW	20.7	16.8	20.2	21.2	16.8
HH	11.9	8.7	11.9	12.5	10.3
FL	15.0	11.6	14.9	16.0	11.6
OD	6.4	5.2	6.2	5.9	-
NE	9.7	8.1	9.8	10.4	7.6
SE	12.4	9.9	12.1	12.6	9.8
EE	7.8	6.2	7.3	8.2	6.6
EL	2.5	2.4	2.8	3.3	-
IN	2.9	2.5	3.0	2.9	2.4
IO	8.7	8.5	10.7	9.8	9
Lamellae
L Manus	9-11-12-12-11	10-12-12-12-12	11-12-12-14-13	10-12-13-13-12	10-10-12-12-13
R Manus	9-12-12-12-12	10-12-12-12-12	11-12-12-13-13	10-10-13-13-13	10-12-12-12-13
L Pes	9-14-13-12-12	9-13-13-13-12	10-13-13-13-13	10-13-13-13-13	10-13-13-13-13
R Pes	9-13-13-12-12	9-13-13-12-13	10-13-13-13-12	10-13-13-13-13	10-13-12-13-12
Supralabials
L	12 (9)	14 (10)	12 (9)	12 (10)	13 (9)
R	13 (9)	13 (9)	14 (10)	12 (9)	12 (8)
Infralabials
L	9	10	10	9	11
R	10	10	10	10	10