Hemidactylus srikanthani, 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 : 240-244

Hemidactylus srikanthani sp. nov.

( Figs. 7‒10 ; Table 3 )

Holotype. BNHS 2640 , adult male, collected by N. S. Achyuthan and M. V. Shreeram on 21 July 2018, from Devarayana Durga Hills (13.371°N, 77.210°E; 1,060 m asl) in Tumkur district , Karnataka, India.

Paratype. BNHS 2641 , subadult female, same collection information as the holotype .

Etymology. Patronym named in genitive singular case honouring Mr. Srikanthan Vijayraghvan, the father of the second author, for inspiring and supporting the author’s interests in nature conservation and herpetology; and financially supporting the team of authors for herpetological research projects. Suggested English name. Srikanthan’s Rock Gecko.

Diagnosis. A medium-sized (adult SVL 66.6 mm; n=1) species of Hemidactylus inhabiting the Tumkur Hills. Dorsal pholidosis composed of sub-circular, flattened, granular scales interspersed with enlarged, strongly keeled tubercles that are heterogeneous in size and shape, fairly regularly arranged in 14 or 15 longitudinal rows at midbody; 29 or 30 tubercles in paravertebral rows. VS 37 or 38 scale rows. Digits 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; lamellae beneath digit I: 7 (manus) and 7 (pes), digit IV: 9–10 (manus) and 10 (pes). Males with 16–17 precloacal-femoral pores on each thigh separated by seven pore-less scales. Three postcloacal spurs on each side; tail depressed, scales on dorsal aspect of tail heterogeneous, slightly larger than granular scales on dorsum, intermixed with a series of 6 enlarged, strongly pointed, keeled tubercles on each whorl.

Comparison. Hemidactylus srikanthani sp. nov. can be easily distinguished from its peninsular Indian congeners based on the following non-overlapping characters (note: comparison with a new species H. mahonyi sp. nov. will follow its present description): male with 16–17 PCFP and seven SBFP (versus 12–13 PCFP and single SBFP in H. brookii ; 7 PCFP and eight SBFP in H. chipkali ; 12–13 PCFP and single SBFP in H. gleadowi ; 10–11 PCFP and two or three SBFP in H. kushmorensis ; 10–14 PCFP and one to three SBFP in H. malcolmsmithi ; 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 ; 9 or 10 PCFP and four or five SBFP in H. varadgirii ; 7–9 FP and 1–3 SBFP in H. triedrus ; 7 or 8 PCFP and three SBFP in H. whitakeri ; 7–9 PCFP and six SBFP in H. mahonyi sp. nov. and 7 or 8 PCFP and seven SBFP in H. treutleri ). 14–15 DTR in Hemidactylus srikanthani sp. nov. (versus 17–18 in H. gleadowi , 19–20 in H. kushmorensis , 16–20 in H. murrayi , 6–8 in H. xericolous , 16 in H. siva , 17 or 18 in H. varadgirii , 16 or 17 in H. whitakeri . 19–20 in H. triedrus ). Sub-digital lamellae beneath digit I of manus 7 in H. srikanthani sp. nov. (versus 6 lamellae in H. chikhaldaraensis and H. sankariensis , 5–6 in H. parvimaculatus and H. mahonyi sp. nov.); lamellae beneath digit I of pes 9–10 H. srikanthani sp. nov. (11 lamellae in H. chikhaldaraensis , and 6 in H. sankariensis ). Sub-digital lamellae beneath digit IV of manus 9 or 10 in H. srikanthani sp. nov. (versus 11 in H. chikhaldaraensis , and 8 in H. sankariensis ); lamellae beneath digit IV of pes 10 in H. srikanthani sp. nov. (versus 11 in H. chikhaldaraensis , and 7–9 in H. sankariensis ). The moderate size (up to 66.6 mm SVL, n=2) of Hemidactylus srikanthani 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. srikanthani 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. 7 , 8 ). The holotype specimen is in good condition except for a small vertical inscision on the venter 11.2 mm made to extract liver tissue, forms strong ventrolateral folds on both sides of the trunk, distal half of the tail curved towards the left; hemipenis partially everted on both sides—all artefacts of preservation. An adult male; head comparatively shorter than SVL, (HL 31.0% of SVL); slightly broad, (HW 61.8% of HL); slightly depressed, (HD 36.2% of HL), distinct from neck. Loreal region slightly inflated; interorbital region and forehead fairly concave; canthus rostralis rounded; snout comparatively longer, (E-S 12.9% of SVL), longer than horizontal eye diameter (HED 53.4% 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 22.2% 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 19.1% of E-N); lacking enlarged lobules; E-E 1.2 times greater than horizontal diameter of eyes. SL 10/9 (left/right), 8 th SL in mid-orbital position on right side, rectangular, slightly convex above; separated from orbit by one or two rows of scales. Rostral rectangular, partially divided dorsally by a weakly developed rostral groove. Nostril oval shaped, oriented dorsally, contacting with rostral anteriorly; two supranasals, slightly larger compared to surrounding scales, separated from each other by a smaller scale; three post nasals on either side, smaller than supranasal, lower postnasal not in contact with 1 st SL. IL 9/8 (left/right); 1 st and 2 nd slightly larger in size, rectangular in shape; 3 rd –8 th /9 th IL decreases in size posteriorly and the lower edge are bordered with four or five rows of enlarged elongated scales. Mental triangular (MW 90.5% ML); three pairs of well-developed postmentals; primary pair in contact with each other (PPMenL 95.2% of ML), touches 1 st and 2 nd IL; secondary pair marginally smaller to primary pair (SPMenL 95.0% PPMenL and 90.5% of ML), not contacting each other, touches 2 nd IL; outermost pair smaller than both primary and secondary pair, rounded posteriorly; separated from 3 rd IL by single smooth, elongated scale. Tongue narrowly elongate, with a weak median cleft.

Body elongated, (A-G 38.7% of SVL); dorsally depressed, stout. Dorsal pholidosis composed of sub-circular, flattened granular scales that are heterogeneous in size, interspersed enlarged, strongly keeled tubercles that are heterogeneous size and shape, fairly regularly arranged in 14 or 15 longitudinal rows at mid-body extending from posterior part of head to groin; 29–30 tubercles on the paravertebral rows. Ventral scales imbricate, larger than dorsal granular scales, VS 37; 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 17/16 (left/right); SBFP 7; pore-bearing scales are enlarged in size and rhomboidal in shape relative to adjacent scales; SBFP that 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; HUL slightly longer than RUL (HUL 18.3% of SVL, RUL 15.8% of SVL); thigh stout; THL and CL sub-equal, (THL 19.2% of SVL, CL 19.4 % 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 7-9-9-9-9, and LRP 6-9-10-10-10; toe lengths (measurements in parentheses): TOLRM III (5.1)> IV (4.9)> II (4.7)> V (4.4)> I (1.9); TOLRP IV (5.7)> V (5.1)> III (4.5)> II (4.3)> I (2.2).

Tail original, complete; not regenerated, oval in cross section; TL 1.2 times longer than SVL with rounded tip. Post-cloacal hemipeneal bulge distinct; three pairs of post-cloacal spurs, proximal most 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 six enlarged, pointed tubercles on the 1 st whorl and six in next four whorls; tubercles on the 1 st to 5 th whorls keeled, strongly pointed; four weakly keeled, pointed tubercles on 6 th to 9 th whorls and remaining whorls with three small, weakly keeled or smooth, pointed tubercles. Ventral scales on post-cloacal region and at proximal part of tail base larger than on rest of dorsal portion of tail, with a median row of transversely enlarged, smooth sub-caudals covering almost entire tail width on the distal two thirds of the tail length.

Coloration in life. Overall dorsal body coloration light cream to light brown; head, limbs and tail light cream to light brown; dorsum of head, body, limbs and tail with dark brown/ black and off-white blotches; dorsum with a series of saddles forming vague ‘X’ shaped dark brown markings periodically interspaced with white ‘I’ shaped markings. anterior snout region including interorbital region more pinkish with light to dark colored scales; labials pinkish to pale brown mottled with finer brownish or blackish spots; entire ventral surface of the body and tail is off-white or beige colored; lateral edge of the belly, gular region and the tail region banded with dotted dark brown to black markings ventral surface of the forearms speckled with very fine blackish spots; ventral surface of the hind limbs speckled with few and finer dark brown to blackish dots ( Fig. 6 ).

Coloration in ethanol. Dorsum of body lightened to a pale grayish-brown to beige coloration; all markings on dorsal and lateral sides of the body and the head are slightly decolorized but distinctly visible; labials whitish mottled with greyish speckles and blotches; dorsal side of each toe of manus and pes are darker with lighten in color marked with dark brown or blackish patches or bands; lamellae under each digit beige to whitish that are edged with beige colored. Ventral surface of the head, body and tail off-white, specked with very fine blackish spots only on the lateral edges ( Fig. 7 : A‒F).

Variation based on paratype ( Fig. 9 ). The intraspecific variation of mensural and meristic characters is presented in Table 3 .

Distribution and natural history ( Figs. 1 , 10 ). Commonly found on granite rock formations, neighboring human habitations and houses in villages surrounding the type locality, Devarayana Durga Hills (~ 800‒1000 m asl) of Tumkur District, Karnataka State, in Peninsular India. Hemidactylus srikanthani sp. nov. is nocturnal and found alongside H. cf. giganteus . When inactive they often hide in deep rock crevices. The type locality, Devarayana Durga Hills is covered with tropical dry evergreen forests, with a few moist patches at the peak and rocky scrub at the foothills ( Bhaskar & Kushalappa 1995).

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

FIGURE 7. Holotype of Hemidactylus srikanthani sp. nov. (in life) from Devarayana Durga Hills, Tumkur District, Karnataka, India.

FIGURE 8. Preserved holotype of Hemidactylus srikanthani sp. nov. (BNHS 2640)—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 9. Preserved paratype of Hemidactylus srikanthani sp. nov. (BNHS 2641)—A. dorsal view of entire specimen; B. ventral view of entire specimen. [Scale bar: A. & B.: 10 mm.]

FIGURE 10. Habitat at the type locality of Hemidactylus srikanthani sp. nov. Devarayana Durga Hills, Tumkur District, Karnataka, India