Hemidactylus mahonyi, Adhikari & Achyuthan & Kumar & Khot & Shreeram & Ganesh, 2022

Adhikari, Omkar D., Achyuthan, N. S., Kumar, G. Chethan, Khot, Rahul V., Shreeram, M. V. & Ganesh, S. R., 2022, Two new species of Hemidactylus Goldfuss, 1820 (Squamata: Gekkonidae) from the rocky outcrops of the Deccan plateau, peninsular India, Zootaxa 5129 (2), pp. 227-249 : 234-238

Hemidactylus mahonyi sp. nov.

( Figs. 3‒6 ; Table 3 )

Hemidactylus treutleri — Lajmi et al. 2016, 2019 part

Holotype. BNHS 2598 , adult male, collected by Omkar Adhikari, Ranjit Manakadan, and Vithoba Hegde on 21 March 2019 from Sandur Hills (in Joga Village ; 15.229°N, 76.538°E; 440 m asl), Sandur Taluk, Bellary District, Karnataka State, India.

Paratypes (n=2). BNHS 2597 , adult male and BNHS 2601 , sub-adult male, same collection information as the holotype .

Etymology. Patronym named in genitive singular case, honouring Dr. Stephen Mahony, an Irish herpetologist and a decade-long friend and colleague of the last author, for his significant research contributions on Tropical Asian herpetofauna and, in particular, on the H. brookii group. Suggested English name. Mahony’s Rock Gecko.

Diagnosis. A medium-sized (SVL 51.3–56.1 mm, n=2) species of Hemidactylus inhabiting the Sandur Hills. Dorsal pholidosis composed of sub-circular, flattened granular scales interspersed with enlarged, strongly keeled tubercles that are heterogeneous in size and shape, smallest on the neck gradually increasing in size posteriorly and laterally where they are up to 3–4 times the size of surrounding granular scales, fairly regularly arranged in 13–14 longitudinal rows at mid-body; 24–27 tubercles in paravertebral rows. VS 29–35 scale rows. Digits with enlarged scansors, lamellae in straight transverse series, all divided except the apical and a few basal that are undivided; lamellae beneath digit I: 5–6 (both manus and pes), digit IV: 8–9 (manus) and 8–10 (pes). Males with 7–9 precloacal-femoral pores on each thigh separated by six pore-less pre-cloacal scales. Dorsum yellow to brown ocher in color with numerous scattered dark and light blotches. Two or three post-cloacal spurs; tail dorso-laterally depressed; scales on dorsal aspect of tail heterogeneous, slightly larger than granular scales on dorsum, intermixed with a series of 6–8 enlarged, strongly keeled, pointed tubercles on each whorl.

Comparison. Hemidactylus mahonyi sp. nov. can be easily distinguished from members of the murrayi group based on the following non-overlapping characters (note: comparison with the new species H. srikanthani sp. nov. will follow that species’ description): male with 7–9 PCFP and six SBFP (versus 12–13 PCFP and single SBFP in H. brookii ; 12–13 PCFP and single SBFP in H. cf. gleadowi ; 10–11 PCFP and two or three SBFP in H. cf. kushmorensis ; 10–14 PCFP and one to three SBFP in H. malcolmsmithi ; 11–17 PCFP and one to three SBFP in H. parvimaculatus ; 10–12 PCFP and nine or ten SBFP in H. rishivalleyensis ; 15 PCFP and four SBFP in H. sankariensis ; 11–15 PCFP and three SBFP in H. sahgali ; 17 or 18 PCFP and five SBFP in H. siva ; 15 or 16 PCFP and single SBFP in H. xericolus ; 15–17 PCFP and one or two SBFP in H. flavicaudus ; 16–17 PCFP and seven SBFP in H. srikanthani sp. nov. and 7 or 8 PCFP. 13–14 DTR in Hemidactylus mahonyi sp. nov. (versus 17–18 in H. gleadowi , 19–20 in H. kushmorensis , 16–20 in H. murrayi , 6–8 in H. xericolous , 15 in H. chikhaldaraensis , 15–16 in H. chipkali , 15–20 in H. malcolmsmithi , 15–17 in H. sankariensis , 15 or 16 in H. rishivalleyensis , 16 in H. siva , 15–16 in H. treutleri , 17 or 18 in H. varadgirii , 15 or 16 in H. sahgali , 16 or 17 in H. whitakeri . 19–20 in H. triedrus . Sub-digital lamellae beneath digit I of manus 5–6 in H. mahonyi sp. nov. (versus 7 in H. srikanthani sp. nov.); lamellae beneath digit I of pes 8–10 H. mahonyi sp. nov. (11 lamellae in H. chikhaldaraensis , and 6 in H. sankariensis ). Sub-digital lamellae beneath digit IV of manus 8–9 H. mahonyi sp. nov. (11 in H. chikhaldaraensis ); lamellae beneath digit IV of pes 8 in H. mahonyi sp. nov. (versus 11 in H. chikhaldaraensis , and 9 or 10 in H. rishivalleyensis ). The moderate size (up to 56.1 mm SVL, n=2) of Hemidactylus mahonyi sp. nov. easily distinguishes it from other large sized peninsular Indian congeners: 108 mm in H. acanthopholis ; 111 mm in H. graniticolus ; 95 mm in H. kangerensis ; 80 mm in H. kolliensis ; 78 mm in H. sahgali ; 95 mm in H. sirumalaiensis ; 105 mm in H. siva and H. sushilduttai ; 126 mm in H. tamhiniensis ; 107 mm in H. easai ; 76 mm in H. triedrus ; 112 mm in H. vanam ; 124.4 in H. paaragowli . Additionally, in having a dorsal scalation that is intermixed with large, trihedral, keeled tubercles, H. mahonyi sp. nov. instantly differs from the following species that lack it: H. frenatus , H. leschenaultii , H. giganteus , H. yajurvedi , H. hemchandrai , H. scabriceps , H. reticulatus , H. gracilis , H. sataraensis , H. albofasciatus , H. xericolus and H. flavicaudus .

Description of holotype ( Figs. 3 , 4 ). The holotype specimen is in good condition, moderately flat beneath, distinct ventrolateral folds on both sides of the trunk, distal half of the tail curved towards the right, hemipenis partially everted on both sides. An adult male; head short (HL 13.3% of SVL); slightly broad (HW 60.1% of HL); slightly depressed (HD 36.4% of HL), distinct from neck. Loreal region slightly inflated, interorbital region slightly concave, canthus rostralis rounded; snout relatively long (E-S 14.2% of SVL), longer than horizontal eye diameter (HED 43.6% of E-S). Scales on snout, forehead, canthus rostralis and inter-orbital region rounded, smooth, convex scales on snout larger than those on occipital region; scales on occipital region small, mostly granular, intermixed with comparatively larger, keeled scales. Eyes rounded, small (HED 18% of HL); pupil vertically elliptical with crenulated margins; supraciliaries small, few slightly elongate on anterior of top half of orbit, gradually decreasing in size posteriorly. Ear opening deep, roughly oval (EL 17.9% of E-N); lacking enlarged lobules; E-E1.6 times greater than horizontal diameter of eye. SL, 10/10 (left/right), 8 th SL in mid-orbital position on right side, roughly rectangular in shape, dorsal edge slightly convex; separated from orbit by single row of scales. Rostral rectangular, much wider than deep, partially divided dorsally by a weakly developed rostral groove. Nostril oval shaped; oriented dorsally, touching 1 st SL on either side; two supranasals, slightly larger compared to surrounding scales, separated from each other by a much smaller scale; three post nasals on either side, smaller than supranasal, lower postnasal contacting 1 st SL. IL, 8/8 (left/right); 1 st and 2 nd slightly larger in size, rectangular in shape; 3 rd –8 th IL decreases in size posteriorly and the lower edge are bordered with two rows of enlarged elongated scales. Mental triangular (MW 94.6% ML); two pairs of well-developed postmentals; primary pair in contact with each other (PPMenL 91.9% of ML), bordered by smooth, rounded scales, contacting 1 st and 2 nd IL on both sides; secondary pair comparatively smaller in size to primary pair (SPMenL 93.3% PPMenL and 86.4% of ML) not contacting each other, rounded posteriorly. Tongue narrowly elongate, with a weak median cleft.

Body slightly elongated (A-G 40.9% of SVL), dorsally depressed, stout, distinct ventrolateral folds on both sides. Dorsal pholidosis composed of sub-circular, flattened granular scales interspersed with enlarged, strongly keeled tubercles that are heterogeneous in size and shape, smallest on the neck gradually increasing in size posteriorly and laterally where they are up to 3–4 times the size of surrounding granular scales, fairly regularly arranged in 13–14 almost longitudinal rows at mid-body, extending from posterior part of head to groin; 24 or 25 tubercles in paravertebral scale rows. Ventral scales imbricate, larger than dorsal granular scales, VS 34 or 35; gular region covered in small granular scales about equal in size to dorsal granules, gradually increasing in size posteriorly; forelimbs and hindlimbs covered with enlarged granular scales which are subequal to ventral granular scales; scales on dorsal surface of thighs and shanks are interspersed with enlarged tubercles; largest tubercles being equal in size to mid-dorsal tubercles; pre-anal groove absent; pre-anal depression absent; PCFP, 8/7 (left/right) in number, SBFP, 6; pore-bearing scales are enlarged in size and rhomboidal in shape relative to adjacent scales; SBFP are equivalent to the adjacent scales in size and shape.

Fore and hind limbs relatively short, slender, ventral surfaces of limbs covered with uniform, flattened, subimbricate scales; forearm short, (HUL 17.3% of SVL, RUL (14.6% of SVL); thigh stout, (THL 22.0% of SVL; CL 21.1% of SVL); digits moderately short, flattened, a small curved claw on all digital tips; interdigital webbing absent; distal phalanges elevated; each digit with enlarged scansors, lamellae in straight transverse series, all divided except those on the apical portion of the digit, the distal most scansor and a few basal lamellae that are undivided LRM 5-7-8-8-7, and LRP 5-8-9-8-7; digit lengths (measurements in parentheses): TOLRM III (3.9)> II (3.8)> IV (3.7)> V (3.1)> I (2.9); TOLRP III (5.0)> IV (4.9)> V (3.6)> II (3.2)> I (2.1).

Tail original, complete, TL 58.9 mm; dorso-laterally depressed, oval in cross section; (TL/SVL: 1.2) with somewhat rounded tail tip in dorsal aspect. Post-cloacal hemipeneal bulge distinct; three pairs of post-cloacal spurs, proximal two pairs sub-equal in size, close to the cloaca, three times smaller than the distal most spur pair, each spur comprising of one raised, rounded, dorso-ventrally flattened scale. Scales on dorsal aspect of tail smooth, rounded, slightly larger than granules on dorsum, with a series of eight enlarged, pointed tubercles on the 1 st whorl and six in the rest; tubercles on the 1 st to 6 th whorls keeled, strongly pointed; tubercles on the 7 th to 10 th whorls weakly keeled or smooth, pointed. Ventral scales on post-cloacal region and at proximal part of tail base larger than on rest of dorsal portion of tail, sub-caudal scales smooth traverse the entire tail width on distal two thirds of tail length.

Coloration in life. Overall dorsal body coloration yellow to brown ocher; head, limbs and tail yellow to brown ochre; dorsum of head, body, limbs and tail with dark brown and off-white blotches; anterior snout region including interorbital region more yellowish with light to dark colored scales; labials yellowish to pale brown mottled with finer brownish or blackish spots; entire ventral surface of the body and tail is off-white or soft beige colored; lateral edge of the belly, gular region and tail, ventral surface of the forearms speckled with very fine blackish spots; ventral surface of the hind limb speckled with few and finer blackish spots ( Fig. 3 ).

Coloration in ethanol. Dorsum of body lightened to grayish brown coloration; head coloration marginally darker than body dorsum; coloration on anterior snout and interorbital region with slight dark brown blotches; all markings on dorsal and lateral sides of the body and the head are slightly decolorized but distinctly visible; labials whitish or greyish mottled with brownish speckles; supraorbital region with light black or brown blotch; dorsal side of each toe of manus and pes with one or two pale greyish or whitish patches or bands; lamellae under each digit beige colored. Ventral surface of the head, body and tail off-white, specked with very fine blackish spots extending from mental, post mental scales to lateral edge of gular region, ventral surface of the forearms, ventrolateral edge of the body as well as tail ( Fig. 4 : A‒F).

Variation based on paratypes (n=2; Fig. 5 ). The intraspecific variation in mensural and meristic characters is presented in Table 3 .

Paratype BNHS 2597 has digit II of right manus damaged; tail regenerated, showing vertical discontinuous black steaks on the regenerated portion; tail length marginally shorter than body (TL/SVL 0.9). Paratype BNHS 2601 is an immature male specimen with a dark brown head and dorsum of body; a small vertical incision on the venter 7.1 mm made to extract liver tissue; series of femoral scales that are enlarged and rhomboidal in shape relative to adjacent scales, without bearing any pore; SBFP that are equivalent to the adjacent scales in size and shape; tail detached near the tail base, tail was lost during the collection of specimens.

Distribution and Natural History ( Figs. 1 , 6 ). Hemidactylus mahonyi sp. nov. is known to occur only from the hillocks in and around the type locality Sandur Hills near Joga village, Bellary District, Karnataka, India, at an elevation of ca. 440‒500 m asl. The species was encountered only on the rocky boulders. The species appears to be nocturnal and locally abundant as we encountered>20 active individuals from the dusk through the night (18:00–22:00 hrs) and at dawn (05:00–07:30 hrs) in the winter season. During the day, a few individuals were seen inactive, sheltered under rocks or in crevices. Sympatric geckos encountered during night at the type locality include Hemidactylus siva Srinivasulu, Srinivasulu & Kumar , H. cf. reticulatus , H. cf. giganteus Stoliczka and Cnemaspis adii Srinivasulu, Kumar & Srinivasulu. Other lizards such as Calotes vultuosus (Harlan) , Psammophilus cf. dorsalis (Gray) , Eutropis cf. carinata (Schneider) and, Ophisops cf. jerdoni Blyth and O. leschenaulti (Milne-Edwards) were observed sharing the same rocky habitat during the day. Habitat at the type locality consists of dry evergreen forests, with moist patches near the summit, and thorny scrub hillocks at the foothills ( Madiwalar & Wodeyar 1993).

Figures

FIGURE 1. Map of southern India depicting the type localities of the two new species—black circle (Sandur Hills):Hemidactylus mahonyi sp. nov. and red circle (Devarayana Durga Hills): Hemidactylus srikanthani sp. nov.

FIGURE 3. Holotype of Hemidactylus mahonyi sp. nov. (in life) from Sandur (Joga village), Bellary District, Karnataka, India.

FIGURE 4. Preserved holotype of Hemidactylus mahonyi sp. nov. (BNHS 2598)—A. dorsal view of entire specimen; B. ventral view of entire specimen; C. right side of the head; D. left side of the head; E. ventral view of the head; F. dorsal view of the head; G. lamellae on right manus; H. lamellae on right pes; I. precloacal-femoral pores. [Scale bar: A. & B.: 10 mm; C., D., E. & F.: 5 mm; G. & H.: 2 mm]

FIGURE 5. Paratypes of Hemdiactylus mahonyi sp. nov.—A. dorsal & B. ventral, view of entire specimen (BNHS 2597); C. dorsal & D. ventral, view of entire specimen (BNHS 2601); E. (BNHS 2597) in life; F. (BNHS 2601) in life. [Scale bar: A., B., C. & D.: 10 mm]

FIGURE 6. Habitat at the type locality of Hemidactylus mahonyi sp. nov. Sandur (Joga village), Bellary District, Karnataka, India.