Cnemaspis geethaiyerae Agarwal, Thackeray & Khandekar, 2024

Agarwal, Ishan, Thackeray, Tejas & Khandekar, Akshay, 2024, Two new species of South Asian Cnemaspis Strauch, 1887 (Squamata: Gekkonidae) from the southern tip of the Western Ghats, India, Journal of Natural History 58 (41 - 44), pp. 1803-1843 : 1826-1837

Cnemaspis geethaiyerae Agarwal, Thackeray & Khandekar sp. n.

https://zoobank.org/ 0DBBA297-D0A2-4963-8BCD- 27101169 A886

( Figures 9–13 ; Tables 6–8 )

Holotype

NRC-AA-8338 (AK-R 1092), adult male, near Aralvaimozhi (8.24420°N, 77.50831°E; ca. 200 m asl), Kanyakumari District, Tamil Nadu State, India; collected by Akshay Khandekar, Ishan Agarwal, Swapnil Pawar, and team on 5 April 2022.

Paratypes

NRC-AA-8339 (AK-R 1094), NRC-AA-8340 (AK-R 1095), adult males, same data as holotype; NRC-AA-8341 (AK-R 1098), adult male, BNHS 2883 (AK-R 1091), ZSI-R-28778 (AK-R 1097), adult females, near Aralvaimozhi (8.25118°N, 77.51523°E; ca. 170 m asl), Kanyakumari District, same data as holotype .

Etymology

The specific epithet is a latinised eponym honouring Dr Geetha Iyer, entomologist and former biology teacher at Rishi Valley School, Andhra Pradesh, India, for her contributions as a teacher – instrumental in helping many children develop and sustain an interest in nature (including IA in particular), and for her help with our survey work in Kanyakumari District.

Suggested common name

Geetha Iyer’s dwarf gecko.

Diagnosis

A small-sized Cnemaspis, SVL up to 32.0 mm (n = 6). Dorsal pholidosis heterogeneous; weakly keeled granular scales intermixed with regularly arranged rows of enlarged, strongly keeled, conical tubercles; last one or two rows of enlarged tubercles on flank weakly keeled, short and spine-like; 10 (rarely 9, n = 1/6) rows of dorsal tubercles at midbody, 14–17 tubercles in paravertebral rows; ventral scales subequal from chest to vent, smooth, oval or elongate, and subimbricate on pectoral region, becoming slightly larger posteriorly 30–34 scales across belly at midbody, 132–148 longitudinal scales from mental to cloaca; subdigital scansors smooth, unpaired, unnotched; 11–13 lamellae under digit I of manus and 11 or 12 under digit I of pes, 18 or 19 (rarely 17, n = 1/6) lamellae under digit IV of manus and 20–22 (rarely 19, n = 1/6) lamellae under digit IV of pes; males with three or four femoral pores on each thigh, separated medially by 22–28 poreless scales (n = 4/6); tail with enlarged, strongly keeled, and weakly pointed tubercles forming whorls; median row of subcaudals keeled only on tip, slightly enlarged with condition of two or three slightly enlarged scales alternating with an enlarged scale. Dorsum with light blotches including four large in vertebral row and scattered dark markings; a single indistinct black dorsal ocellus on neck, venter off-white with black speckles most prominent under throat; original tail in males with 9–11 faint bands, regenerated tail brown.

Comparison with peninsular Indian congeners

Cnemaspis geethaiyerae sp. n. can be easily distinguished from all 10 other major clades of South Asian Cnemaspis in India as well as C. boiei , C. jerdonii , and C. umashaankeri by a combination of the following differing or non-overlapping characters: males without precloacal pores, three or four femoral pores on each thigh, separated medially by 22–28 poreless scales (vs males without femoral or precloacal pores in C. boiei ; males with only precloacal pores in C. beddomei clade; males with both precloacal and femoral pores in C. umashaankeri , C. bangara clade, C. goaensis clade, C. gracilis clade, C. monticola clade, and C. mysoriensis + adii clade; males with only femoral pores but> 8 in C. jerdonii , C. littoralis clade; males with 5–9 femoral pores on each thigh separated by 12–18 (rarely 19) poreless scales in C. wynadensis clade expect for C. wynadensis which has four or five femoral pores separated by 13–16 poreless scales, and C. kolhapurensis which has a continuous series of precloacal-femoral pores); short spine-like tubercles present on flanks (vs short or distinctly long spine-like tubercles absent on flanks in C. boiei , C. bangara clade, C. beddomei clade, C. indica clade, and C. wynadensis clade); small-sized, SVL of adults <40 mm (vs medium and large-sized, SVL of adults> 40 mm in C. bangara clade; C. beddomei clade except for C. aaronbaueri , C. galaxia , C. nigriventris , C. regalis ; and C. wynadensis clade expect for C. wynadensis ); median row of subcaudals keeled on tip of original tail, slightly enlarged with condition of two or three slightly enlarged scales alternating with an enlarged scale (vs subcaudal types A, B, C, or D in C. girii clade as defined by Khandekar et al. 2024a); not strongly sexually dichromatic (vs distinctly sexually dichromatic in C. beddomei clade, C. goaensis clade, C. gracilis clade, C. littoralis clade, and C. mysoriensis + adii clade).

Cnemaspis geethaiyerae sp. n. is similar genetically to members of the goaensis clade (five species) and morphologically to members of the gracilis clade (14 species) but can be easily distinguished from all by a combination of the following differing or non-overlapping characters: only femoral pores present, precloacal pores absent (vs both femoral and precloacal pores present in C. amboliensis , C. goaensis , C. ranganaensis , C. sakleshpurensis , and C. vijayae of the goaensis clade; and C. agarwali , C. agayagangai , C. fantastica , C. ganeshaiahi , C. gracilis , C. jackieii , C. mundanthuraiensis , C. pachaimalaiensis , C. reticulata , C. rudhira , C. salimalii , C. shevaroyensis , C. thackerayi , and C. triedra of the gracilis clade); median row of subcaudals slightly enlarged with condition of two or three slightly enlarged scales alternating with an enlarged scale (vs median row slightly enlarged in C. amboliensis , C. goaensis , C. ranganaensis , C. sakleshpurensis , and C. vijayae of the goaensis clade; and median row distinctly enlarged in C. agarwali , C. agayagangai , C. fantastica , C. ganeshaiahi , C. gracilis , C. jackieii , C. mundanthuraiensis , C. pachaimalaiensis , C. reticulata , C. rudhira , C. salimalii , C. shevaroyensis , C. thackerayi , and C. triedra of the gracilis clade).

Cnemaspis geethaiyerae sp. n. is morphologically and geographically closest to its sister species Cnemaspis kanyakumariensis sp. n. but can be easily distinguished by having 10 (rarely 9, n = 1/6) rows of dorsal tubercles at midbody (vs 12 rows of dorsal tubercles at midbody); subcaudal scales keeled only on tip of original tail (vs subcaudal scales keeled on posterior one-third portion of original tail); presence of short spine-like tubercles on lower flank (vs distinctly long spine-like tubercles on lower flank; and mean of 18.4 (17–19) TLAMF4 (vs 16.1 (15–19))). Additionally, C. geethaiyerae sp. n. is 10.2 and 2.9% divergent from C. kanyakumariensis sp. n. in uncorrected pairwise ND2 and 16S sequence divergence, respectively ( Table 2 ).

Description of the holotype

Adult male in good state of preservation except tail tip bent towards right, and 1.6 mm long incision on sternum region for tissue collection ( Figure 9 (A–E)). SVL 29.2 mm, head short (HL/SVL 0.27), wide (HW/HL 0.62), not strongly depressed (HD/HL 0.33), distinct from neck. Loreal region marginally inflated, canthus rostralis not distinct. Snout half of head length (ES/HL 0.46), slightly more than two times eye diameter (ES/ED 2.17); scales on snout and canthus rostralis oval to elongate, subequal, smooth, becoming weakly keeled, and weakly conical front on the eye, much larger than those on forehead and interorbital region; scales on forehead similar to those on snout and canthus rostralis except smaller and weakly conical; scales on interorbital region even smaller, granular and smooth to weakly keeled; scales on occipital and temporal region heterogeneous, slightly enlarged, weakly keeled, rounded, and conical tubercles intermixed with smaller, weakly keeled and weakly conical granular scales ( Figure 10 (A)). Eye small (ED/HL 0.21) with round pupil; supraciliaries short, larger anteriorly; six interorbital scale rows across narrowest point of frontal bone; 26 scale rows between left and right supraciliaries at mid-orbit ( Figure 10 (A, C)). Ear-opening deep, oval, small (EL/HL 0.06); eye to ear distance greater than diameter of eye (EE/ED 1.41) ( Figure 10 (C)). Rostral slightly more than two times wider (1.33 mm) than high (0.60 mm), incompletely divided dorsally by a strongly developed rostral groove for more than half of its height; a single enlarged supranasal on each side, slightly larger than postnasals, separated from each other by a slightly smaller and elongate internasal scale; two postnasals, upper postnasal marginally larger than lower; rostral in contact with supralabial I, nostril, internasal, supranasal, and lower postnasal on either side; nostrils oval, surrounded by two postnasals, supranasal, and rostral on either side; two rows of scales separate orbit from supralabials ( Figure 10 (C)). Mental enlarged, subtriangular, slightly wider (1.38 mm) than high (1.19 mm); two pairs of postmentals, inner pair roughly rectangular, much shorter (0.48 mm) than mental, separated from each other below mental by a single enlarged median chin shield; inner pair bordered by mental, infralabial I, outer postmental, enlarged median chin shield and a single enlarged chin shield on either side; outer postmentals roughly hexagonal, even smaller (0.38 mm) than inner pair, bordered by inner postmentals, infralabial I and II, and three enlarged chin shields on either side; four enlarged gular scales between left and right outer postmentals; all chin scales bordering postmentals smooth, flattened, roughly hexagonal or circular, juxtaposed, subequal and much smaller than outermost postmentals; scales on rest of throat even smaller, roughly hexagonal or circular, juxtaposed, subequal ( Figure 10 (B)). Infralabials bordered below by a row or two of slightly enlarged, much elongated scales, decreasing in size posteriorly. Ten supralabials up to angle of jaw and seven on left and eight on right side at midorbital position; supralabial I largest, rest of the series gradually decreasing in size posteriorly; eight infralabials up to angle of jaw on either side and six on left and seven on right side at midorbital position; infralabial I largest, gradually decreasing in size posteriorly ( Figure 10 (C)).

Body relatively slender (BW/AGL 0.31), trunk half of SVL (AGL/SVL 0.51) without ventrolateral folds; short and conical spine-like tubercles on flank present ( Figure 11 (A–C)). Dorsal pholidosis heterogeneous; weakly keeled granular scales intermixed with regularly arranged rows of enlarged, strongly keeled, conical tubercles; tubercles in approximately 9 or 10 longitudinal rows at midbody including short and conical spine-like tubercles at lower flank; 14 tubercles in paravertebral rows ( Figure 11 (A,C)). Ventral scales much larger than granular scales on dorsum, subequal from chest to vent, smooth, oval or elongate, and subimbricate on pectoral region, becoming slightly larger posteriorly; midbody scale rows across belly 32; 142 scales from mental to anterior border of cloaca ( Figure 11 (B)). Scales on base of neck similar to those on belly except much smaller; gular region with much smaller, smooth, flattened, roughly hexagonal, juxtaposed, and subequal; those bordering postmentals enlarged ( Figure 10 (B)). Three femoral pores on each thigh, separated medially by 28 poreless scales ( Figure 10 (D)).

Scales on palms and soles small, smooth, oval or subcircular, and flattened; scales on dorsal aspects of limbs heterogeneous in size; upper arm with scales slightly larger than granular scales on body dorsum, weakly keeled, and subimbricate; scales on lower arm even smaller, weakly keeled and subimbricate; scales on thigh and much larger than granular scales on body dorsum, weakly keeled, and subimbricate; posterolateral aspect of thigh with small, weakly keeled to smooth granular scales ( Figure 9 (A)). Ventral aspect of forelimbs with small, smooth, subimbricate scales, larger on lower arm than upper arm; ventral aspect of hindlimb with enlarged, smooth, flattened, subimbricate scales, slightly larger than body ventrals ( Figure 9 (B)). Forelimbs and hindlimbs moderately long, slender (LAL/SVL 0.16; CL/SVL 0.18); digits long, with strong, recurved claw, distinctly inflected, distal portions laterally compressed conspicuously. Digits with unpaired lamellae, separated into a basal and narrower distal series by single enlarged lamella at inflection; basal lamellae series: (2-5-6-6-5 right manus, Figure 10 (E); 2-7-7-9-6 right pes, Figure 10 (F)), (2-6- 6-6-5 left manus, 2-6-7-8-5 left pes); distal lamellae series: (10–11-13-13-11 right manus, Figure 10 (E); 10-11-14-13-12 right pes, Figure 10 (F)), (11-11-14-13-11 left manus, 10 - 11- 14-14-13 left pes). Relative length of digits (measurements in mm in parentheses): IV (2.9) = III (2.9)> II (2.8)> V (2.7)> I (1.9) (right manus); IV (3.9)> V (3.3) = III (3.3)> II (2.9)> I (2.1) (right pes).

Tail original, entire, subcylindrical, slender, marginally longer than snout-vent length (TL/SVL 1.07; Figure 9 (C–E)). Dorsal scales on tail base weakly keeled, granular, similar in size and shape to granular scales on midbody dorsum, gradually becoming larger, flattened, imbricate posteriorly, intermixed with enlarged, strongly keeled, weakly pointed, conical tubercles; enlarged tubercles on the tail forming whorls; six tubercles each on first nine whorls, 2–4 tubercles afterwards ( Figure 9 (C)). Scales on ventral aspect of tail much larger than those on dorsal aspect, subimbricate, smooth except for tip which are keeled; median series slightly larger than rest, with condition of two or three slightly enlarged scales alternating with an enlarged scale; scales on tail base slightly larger than those on midbody ventrals, smooth, imbricate; a single enlarged, weakly keeled, and conical postcloacal spur on each side ( Figure 9 (D)).

Colouration in life ( Figure 12 (A))

Dorsum of head, body, limbs and tail base light brown with numerous pale blotches and scattered smaller dark markings. Head with pale blotches and alternating light and dark bands on labials. A faint preorbital streak from eye to nostril, two dark brown postorbital streaks terminating anterior to forelimb insertions and one suborbital streak extending onto throat. A faint, single dark ocellus on neck. Dorsum with five large, pale vertebral blotches from neck of which the two at tail base most prominent, interspersed with scattered light and dark markings on rest of dorsum and flank. Dorsum of limbs more muted than back, thigh with few darker markings, digits with alternating dark and light bands. Tail with nine alternating dark brown bands. Venter off-white with black speckles, most prominent under throat.

Variation and additional information from the paratype series

Mensural, meristic and additional character state data for the type series are given in Tables 6–8 . There are three adult males and two adult females, ranging in size from 30.3 to 32.1 mm ( Figure 13 ). All paratypes resemble the holotype except as follows: two enlarged chin scales separate inner postmentals below mental in NRC-AA-8341; inner postmental bordered by mental, infralabial I, outer postmental, in all paratypes, additionally, bordered by median chin shields and three chin scales on either side in NRC-AA-8339, by two median chin shields and a single chin scale on either side in NRC-AA-8341. Outer postmental bordered by inner postmental, infralabials I and II in all paratypes, additionally bordered by four chin scales on either side in NRC-AA-8339, bordered by three chin scales on left and four on right side in NRC-AA-8340 and NRC-AA-8341; outer postmental separated from each other medially by three enlarged chin scales in NRC-AA-8339, NRC-AA-8340, BNHS 2883, and ZSI-R-28778. ZSI-R-28778 with original and complete tails, slightly longer than body (TL/SVL 1.11); two paratypes – NRC-AA-8339 and NRC-AA-8340 – with regenerated but complete tails, marginally shorter than body (TL/SVL 0.92 and 0.90, respectively); half of the tail broken and missing in NRC-AA-8341; and tail completely broken and missing in BNHS 2883 ( Figure 13 (A)). Hemipenis fully everted in all three male paratypes ( Figure 13 (B)). Colouration of paratypes similar to holotype except some individuals with more dark markings, 9–11 bands on original tail, and regenerated tail uniform light brown, lacking bands; colouration on original tail in juvenile (uncollected) yellowish green ( Figures 12 (B,C); 13(B)).

Distribution and natural history

Cnemaspis geethaiyerae sp. n. is known only from two locations ~ 1 km apart on a small hill, near Aralvaimozhi, Kanyakumari District, Tamil Nadu, at elevations of 170–200 m asl, ~8 and 17 km, respectively, straight-line distance from the known localities of C. kanyakumariensis sp. n. ( Figure 1 ). The habitat where the new species was found is characterised by dry thorny forest or sparse deciduous forest dominated by granulite boulders ( Figure 8 (B)). We surveyed the hill on only one day during the late afternoon until night (3.30–8.30pm) and observed the new species active on boulders in large numbers and on temple walls about 1–2 m above the ground in well-shaded areas (n => 25). At night, the species was observed resting exposed on rocks without any movement (n => 10). Sympatric lizards encountered at the type locality include Hemidactylus hegdei , H. parvimaculatus , H. cf. whitakeri , Hemidactylus cf. frenatus , Cyrtodactylus (Geckoella) aravindi , Eutropis carinata , Calotes versicolor , and Psammophilus cf. blanfordanus .

Figures

Figure 1. (A) Elevation map showing localities of the new species (stars, grey fill: Cnemaspis geethaiyerae sp. n., white fill: Cnemaspis kanyakumariensis sp. n.) and all other sampling locations in Kanyakumari District and Tirunelveli District (yellow crosses, indicating the absence of the kanyakumariensis clade); black lines indicate state boundaries, and grey dotted lines are district boundaries, with district names marked. (B) Inset map of peninsular India showing location of main map with the Western Ghats boundary shaded and the Palghat Gap (PG) marked; maximum likelihood phylogeny of South Asian Cnemaspis based on (C) ND2, (D) 16S. Clades collapsed (see Table 1 for species composition), numbers at nodes indicate bootstrap support> 60% and posterior probability> 0.95.

Figure 8. General view at type localities showing dry thorny forest dominated by granulite boulders. (A) Cnemaspis kanyakumariensis sp. n., and (B) C. geethaiyerae sp. n.

Figure 9. Cnemaspis geethaiyerae sp. n. (holotype, NRC-AA-8338). (A) Dorsal view of body; (B) Ventral view of body; (C) Dorsal view of tail; (D) Ventral view of tail; (E) Lateral view of tail. Scale bars: 10 mm. Photographs by Akshay Khandekar.

Figure 10. Cnemaspis geethaiyerae sp. n. (holotype,NRC-AA-8338).(A) Dorsal view of head; (B) Ventral view of head; (C) Lateral view of head,right side; (D) View of femoral region showing femoral pores, (E) Ventral view of right manus, (F) Ventral view of right pes. Scale bars: 5 mm. Photographs by Akshay Khandekar.

Figure 11. Cnemaspis geethaiyerae sp. n. (holotype, NRC-AA-8338). (A) Dorsal view of midbody; (B) Ventral view of midbody; (C) Lateral view of midbody. Scale bars: 5 mm. Photographs by Akshay Khandekar.

Figure 12. Cnemaspis geethaiyerae sp. n., in life. (A) Adult male (holotype, NRC-AA-8338), (B) Adult female (paratype, ZSI-R-28778), and juvenile (uncollected). Photographs by Akshay Khandekar.

Figure 13. Paratype series of Cnemaspis geethaiyerae sp. n. From left to right, NRC-AA-8339–NRC-AA- 8341, BNHS 2883, and ZSI-R-28778: (A) Dorsal view, and (B) Ventral view. Scale bars: 10 mm. Photographs by Akshay Khandekar.