Cnemaspis kanyakumariensis 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 : 1813-1824

Cnemaspis kanyakumariensis Agarwal, Thackeray & Khandekar sp. n.

http://www.zoobank.org/ urn:lsid:zoobank.org:pub:83F905FD-BA36-4C86-B975-8CCCF9DB248E

( Figures 3–7 ; Tables 3–5 )

Holotype

NRC-AA-8334 (AK-R 1073), adult male, Kadukkarai (8.30224°N, 77.46255°E; ca. 80 m asl), Kanyakumari District, Tamil Nadu State, India; collected by Akshay Khandekar, Ishan Agarwal, Swapnil Pawar and team on 5 April 2022.

Paratypes

BNHS 2881 (AK-R 1078), adult male, ZSI-R-28777 (AK-R 1074), adult female, same data as holotype; NRC-AA-8335 (AK-R 1046), NRC-AA-8336 (AK-R 1053), adult males, BNHS 2882 (AK-R 1045), adult female, from near Valli Chunai (8.25560°N, 77.35272°E; ca. 200 m asl), Thuckalay , Kanyakumari District, same collection data as holotype except collected on 3 April 2022; NRC-AA-8337 (AK-R 1055), adult male, ZSI-R-28776 (AK-R 1056), adult female, from Valli Chunai (8.25842°N, 77.37250°E; ca. 600 m asl), Thuckalay, Kanyakumari District, same collection data as holotype except collected on 4 April 2022 .

Etymology

The specific epithet is a toponym for Kanyakumari District of Tamil Nadu State, to which the new species is endemic.

Suggested common name

Kanyakumari dwarf gecko.

Diagnosis

A small-sized Cnemaspis, SVL up to 33.0 mm (n = 8). 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, long and spine-like; 12 rows of dorsal tubercles at midbody, 12–17 tubercles in paravertebral rows; ventral scales subequal from chest to vent, smooth, oval or elongate, and subimbricate on pectoral region, becoming slightly larger posteriorly; 30–35 scales across belly at midbody, 128–138 longitudinal scales from mental to cloaca; subdigital scansors smooth, unpaired, unnotched; 11–13 lamellae under digit I of manus and 10–12 under digit I of pes, 15–17 (rarely 19 n = 1/8) lamellae under digit IV of manus and 18–22 lamellae under digit IV of pes; males with 3–5 femoral pores on each thigh, separated medially by 22–28 poreless scales (n = 5); tail with enlarged, strongly keeled, and pointed tubercles forming whorls; median row of subcaudals keeled on posterior one-third portion of tail, slightly enlarged with condition of two or three slightly enlarged scales alternating with an enlarged scale. Dorsum with diffuse light blotches including some in a vertebral row and numerous dark blotches; single black dorsal ocellus on neck; venter off-white with black speckles forming longitudinal lines on throat; original tail with 9–11 dark bands, regenerated tail grey.

Comparisons with peninsular Indian congeners

Cnemaspis kanyakumariensis 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, 3–5 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 (Beddome, 1870) 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); spine-like tubercles present on flanks (vs 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 Sayyed, Grismer, Campbell and Dileepkumar, 2019 , C. galaxia Pal, Mirza, Dsouza and Shanker, 2021 , C. nigriventris Pal, Mirza, Dsouza and Shanker, 2021 , C. regalis Pal, Mirza, Dsouza and Shanker, 2021 , and C. wynadensis clade expect for C. wynadensis ); median row of subcaudals keeled on posterior one-third portion of 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 kanyakumariensis sp. n. is sister to the other divergent lineage from Kanyakumari which is described below, and otherwise genetically closest 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 Sayyed, Pyron and Dileepkumar, 2018 , C. goaensis , C. ranganaensis , C. sakleshpurensis Khandekar, Thackeray and Agarwal, 2022 , and C. vijayae Khandekar, Thackeray and Agarwal, 2022 of the goaensis clade; and C. agarwali Khandekar, 2019 , C. agayagangai Agarwal, Thackeray and Khandekar, 2022 , C. fantastica Agarwal, Thackeray and Khandekar, 2022 , C. ganeshaiahi , C. gracilis , C. jackieii Pal, Mirza, Dsouza and Shanker, 2021 , C. mundanthuraiensis Khandekar, Thackeray and Agarwal, 2022 , C. pachaimalaiensis Agarwal, Thackeray and Khandekar, 2022 , C. reticulata , C. rudhira Agarwal, Thackeray and Khandekar, 2022 , C. salimalii Agarwal, Thackeray and Khandekar, 2022 , C. shevaroyensis Khandekar, Gaitonde and Agarwal, 2019 , C. thackerayi Khandekar, Gaitonde and Agarwal, 2019 , 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 kanyakumariensis sp. n. is diagnosed against the other new species as part of its description below.

Description of the holotype

Adult male in good state of preservation except tail slightly bent towards right from the base, hemipenes are fully everted, and 3.6 mm long incision on sternum region for tissue collection ( Figure 3 (A–E)). SVL 29.2 mm, head short (HL/SVL 0.26), wide (HW/HL 0.64), not strongly depressed (HD/HL 0.39), distinct from neck. Loreal region marginally inflated, canthus rostralis not distinct. Snout half of head length (ES/HL 0.5), slightly more than two times eye diameter (ES/ED 2.11); scales on snout and canthus rostralis subcircular to oval, subequal, smooth anteriorly, becoming weakly keeled, and weakly conical posteriorly; 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, smooth, rounded, and conical tubercles intermixed with smaller, weakly keeled and weakly conical granular scales ( Figure 4 (A)). Eye small (ED/HL 0.23) with round pupil; supraciliaries short, larger anteriorly; six interorbital scale rows across narrowest point of frontal bone; 27 scale rows between left and right supraciliaries at mid-orbit ( Figure 4 (A,C)). Ear opening deep, oval, small (EL/HL 0.09); eye to ear distance greater than diameter of eye (EE/ED 1.33) ( Figure 4 (C)). Rostral slightly more than two times wider (1.35 mm) than high (0.63 mm), incompletely divided dorsally by a strongly developed rostral groove and internasal scale for more than half of its height; a single enlarged supranasal on each side, slightly larger than postnasals, separated from each other by a similar sized 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 4 (C)). Mental enlarged, subtriangular, slightly wider (1.60 mm) than high (1.16 mm); two pairs of postmentals, inner pair roughly rectangular, much shorter (0.46 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 subcircular, even smaller (0.40 mm) than inner pair, bordered by inner postmentals, infralabial I and II, and four enlarged chin shields on left and three on right side; three enlarged gular scales between left and right outer postmentals; all chin scales bordering postmentals smooth, flattened, roughly hexagonal, subequal and much smaller than outermost postmentals; scales on rest of throat even smaller, smooth, flattened, roughly hexagonal, and subequal ( Figure 4 (B)). Infralabials bordered below by a row or two of slightly enlarged, much elongated scales, decreasing in size posteriorly. Ten supralabials on left and nine on right side up to angle of jaw and eight at midorbital position on either side; supralabial I largest, rest of the series gradually decreasing in size posteriorly; nine 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 4 (C)).

Body relatively slender (BW/AGL 0.34), trunk half of SVL (AGL/SVL 0.50), without ventrolateral folds; long and conical, spine-like tubercles on flank present ( Figure 5 (A–C)). Dorsal pholidosis heterogeneous;weakly keeled granular scales intermixed with regularly arranged rows of enlarged, strongly keeled, conical tubercles; tubercles in approximately 12 longitudinal rows at midbody including long and conical spine-like tubercles at lower flank; 15 (left) and 13 (right) tubercles in paravertebral rows ( Figure 5 (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 34; 137 scales from mental to anterior border of cloaca ( Figure 5 (B)). Scales on base of neck similar to those on belly except much smaller; gular region with much smaller, smooth, flattened, roughly hexagonal,and subequal; those bordering postmentals enlarged ( Figure 4 (B)). Three femoral pores on each thigh, separated medially by 28 poreless scales ( Figure 4 (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 3 (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 3 (B)). Forelimbs and hindlimbs moderately long, slender (LAL/SVL 0.16; CL/SVL 0.17); 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: (2-4-4-5-4 right manus, 1-5-5-6-5 right pes), (2-4-5-4-5 left manus, Figure 4 (E); 2-5-6-6-5 left pes, Figure 4 (F)); distal lamellae series: (9–10-12-10-9 right manus, 8-9-12-12-10 right pes), (9–10-12-11-9 left manus, Figure 4 (E); 8-9-12-12-11 left pes, Figure 4 (F)). Relative length of digits (measurements in mm in parentheses): IV (2.4) = III (2.4)> V (2.2)> II (2.0)> I (1.6) (left manus); IV (3.4)> V (3.2) = III (3.2)> II (2.9)> I (1.6) (left pes).

Tail original except tip (4.5 mm) which is regenerated, entire, subcylindrical, slender, slightly longer than snout-vent length (TL/SVL 1.21; Figure 3 (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, distinctly pointed, conical tubercles; enlarged tubercles on the tail forming whorls; six tubercles each on first 10 whorls, 2–4 tubercles afterwards ( Figure 3 (C,E)). Scales on ventral aspect of tail much larger than those on dorsal aspect, subimbricate, smooth except for posterior one-third 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 3 (D)).

Colouration in life ( Figure 6 (A))

Dorsum of head, body, limbs and tail base light brown with numerous pale blotches and smaller dark markings. Head with some dark markings on parietal and occiput with 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 single black ocellus with a fine margin of orangish scales on neck. Dorsum with five pale vertebral blotches from neck to tail base, interspersed with smaller dark brown spots on rest of dorsum and flank. Dorsum of limbs more muted than back, thigh with darker markings, digits with alternating dark and light bands. Tail with eight alternating dark brown bands, regenerated tip uniform grey. Venter off-white, with black speckles under throat forming two longitudinal markings.

Variation and additional information from the paratype series

Mensural, meristic and additional character state data for the type series are given in Tables 3–5 . There are four adult males and three adult females, ranging in size from 27.7 to 33.0 mm ( Figure 7 ). All paratypes resemble the holotype except as follows: internasal absent, supranasals in contact with each other behind rostral in ZSI-R-28776. Outer postmental bordered by inner postmental, infralabials I and II in all types and additionally bordered by four chin scales on either side in NRC-AA-8335, NRC-AA-8336, and bordered by three chin scales on either side in BNHS 2882; outer postmental separated from each other medially by four enlarged chin scales in ZSI-R-28777. Three paratypes – NRC-AA-8336, ZSI-R-28776, and BNHS 2881 – with original and complete tails, slightly longer than body (TL/SVL 1.14, 1.15, and 1.13 respectively); NRC-AA-8337 with tail complete with only tip regenerated, marginally longer than body (TL/SVL 1.09); almost entire tail broken and missing in BNHS 2882 and ZSI-R-28777. Colouration of paratypes similar to holotype, 9–11 bands on original tail in NRC-AA-8336, ZSI-R-28776, and BNHS 2881; regenerated tail brown, lacking bands ( Figure 7 (A)). Left forelimb is damaged from the base in BNHS 2881; hemipenis is fully everted in NRC-AA-8335 ( Figure 7 (B)).

Distribution and natural history

Cnemaspis kanyakumariensis sp. n. is known from two closely spaced hills ~ 12 km straight-line distance apart (Kadukkarai and Thuckalay, Kanyakumari District, Tamil Nadu) at elevations of 80–600 m asl ( Figure 1 ). The habitats where the new species was found are characterised by dry thorn scrub or sparse deciduous forest dominated by granulite boulders. We surveyed the type locality on one day from late afternoon until night (~3.30–8.30pm) and the paratype locality on only one afternoon (~12.00–5.00pm). The new species seems to be diurnal/crepuscular, scansorial, and locally abundant. At collection sites, many individuals (n =>20) were observed active during the late afternoon to evening (16.00–.30pm) about 1 or 2 m above the ground on granulite boulders in well-shaded areas ( Figure 8 (A)); and a few individuals were seen resting near rock crevices at night (7.00–8.30pm). Sympatric lizards encountered at the type locality include Hemidactylus hegdei Pal and Mirza, 2022 ; H. parvimaculatus Deraniyagala, 1953 ; Hemidactylus cf. frenatus ; Cyrtodactylus (Geckoella) aravindi Narayanan et al. (2022) ; Eutropis carinata (Schneider, 1801) ; Calotes versicolor (Daudin, 1802) ; 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 3. Cnemaspis kanyakumariensis sp. n. (holotype, NRC-AA-8334). (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 4. Cnemaspis kanyakumariensis sp. n. (holotype, NRC-AA-8334). (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 left manus; (F) Ventral view of left pes. Scale bars: 5 mm. Photographs by Akshay Khandekar.

Figure 5. Cnemaspis kanyakumariensis sp. n. (holotype, NRC-AA-8334). (A) Dorsal view of midbody,(B) Ventral view of midbody, (C) Lateral view of midbody. Scale bars: 5 mm. Photographs by Akshay Khandekar.

Figure 6. Cnemaspis kanyakumariensis sp. n., in life. (A) Adult male (holotype, NRC-AA-8334), (B) Adult female (paratype, ZSI-R-28776). Photographs by Akshay Khandekar (A) and Ishan Agarwal (B).

Figure 7. Paratype series of Cnemaspis kanyakumariensis sp. n. From left to right, NRC-AA-8335–NRC- AA-8337, BNHS 2881, BNHS 2883, ZSI-R-28776, and ZSI-R-28777. (A) Dorsal view, and (B) Ventral view. Scale bars: 10 mm. Photographs by Akshay Khandekar.

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.