Cnemaspis azhagu, Khandekar & Thackeray & Agarwal, 2022

Khandekar, Akshay, Thackeray, Tejas & Agarwal, Ishan, 2022, Three more novel species of South Asian Cnemaspis Strauch, 1887 (Squamata, Gekkonidae) from Kalakad Mundanthurai Tiger Reserve, Tamil Nadu, India, Vertebrate Zoology 72, pp. 385-422 : 385

Cnemaspis azhagu sp. nov.

(Figs 3 , 4 , 5 , 6 , 7 , 8

Holotype.

NRC-AA-1170 (AK-R 678), adult male, from Thirukurungudi forest range (8.4069°N, 77.5485°E; ca. 200 m asl.), Kalakad Mundanthurai Tiger Reserve, Tirunelveli district, Tamil Nadu state, India; collected by Akshay Khandekar and team on 06 May 2021.

Paratypes.

NRC-AA-1171 (AK-R 670), NRC-AA-1172 (AK-R 671), NRC-AA-1174 (AK-R 673), BNHS 2818 (AK-R 674), BNHS 2819 (AK-R 675), BNHS 2820 (AK-R 676), adult males; BNHS 2821 (AK-R 677), adult female; NRC-AA-1173 (AK-R 672), subadult female. AK-R 670 and AK-R 671 collected from the same locality as holotype; AK-R 673, AK-R 674, and AK-R 675 collected from 8.4049°N, 77.5376°E, ca. 280 m asl.; AK-R 676, AK-R 677, and AK-R 672 collected from 8.4142°N, 77.5323°E, ca. 400 m asl.; all localities from Thirukurungudi forest range, Kalakad Mundanthurai Tiger Reserve, Tirunelveli district, Tamil Nadu state, India; same collectors as holotype except collected on 07 May 2021.

Etymology.

The specific epithet, Cnemaspis azhagu (a-lha-gu, also sometimes transliterated as alaku), is the Tamil word for beauty (அழகு) and is used as a noun in apposition for this beautiful new species.

Suggested Common Name.

Thirukurungudi dwarf gecko.

Diagnosis.

A small-sized Cnemaspis , snout to vent length less than 38 mm (n =9). Dorsal pholidosis heterogeneous; smooth granular scales intermixed with a fairly regularly arranged row of enlarged, weakly keeled, conical tubercles on either side of flank; granular scales gradually increasing in size towards each flank, largest on mid-flank; spine-like scales absent on the flank; two (rarely three, n =1/9) rows of dorsal tubercles at mid-body, enlarged tubercles in paravertebral region absent (rarely a few present, n =2/9); ventral scales subcircular, smooth, subimbricate, and subequal from chest to vent, 34-44 scales across belly at mid-body, 151-171 longitudinal scales from mental to cloaca; subdigital scansors smooth, some divided and others entire; 13-16 lamellae under digit I of manus and 12-14 lamellae under digit I of pes, 20-25 lamellae under digit IV of manus and 24-27 lamellae under digit IV of pes; males (n =7/9) with a continuous series of 6-8 precloacal pores (n = 5/7), rarely divided medially by a single poreless scale (n =2/7), femoral pores absent; tail with enlarged, weakly keeled, pointed, and weakly conical tubercles forming four whorls only on anterior third; followed by a row of three paravertebral tubercles on either side; rest of tail without enlarged tubercles; a median row of subcaudals smooth, regularly arranged with condition of two slightly larger scales alternating with a large divided scale. Males with ochre head and grey body, females more uniform brown; single central black ocellus on occiput flanked by lighter markings, collar formed by thick black spots/streak flanked posteriorly by white band just anterior to forelimb insertions; tail without strong markings; iris red with light orange ring surrounding pupil.

Comparison with members of C. beddomei clade.

Cnemaspis azhagu sp. nov. is a member of the Cnemaspis beddomei clade and can be easily distinguished from all 13 members of the clade by a combination of the following differing or non-overlapping characters: two (rarely three) rows of dorsal tubercles at mid-body (versus 8-10 rows of dorsal tubercles at mid-body in C. aaronbaueri ; 10-12 in C. beddomei (Theobald, 1876), eight in C. galaxia ; 16-18 in C. nairi ; 13 or 14 in C. nigriventris Pal, Mirza, Dsouza and Shanker, 2021; 12-14 in C. nimbus Pal, Mirza, Dsouza and Shanker, 2021; and C. ornata (Beddome, 1870); 7-9 in C. regalis ; 8-10 in C. rubraoculus Pal, Mirza, Dsouza and Shanker, 2021; 19-22 in C. smaug Pal, Mirza, Dsouza and Shanker, 2021; and 14-15 in C. wallaceii Pal, Mirza, Dsouza and Shanker, 2021); paravertebral tubercle rows absent (versus paravertebral tubercle rows present in C. aaronbaueri , C. beddomei , C. galaxia , C. nairi , C. nigriventris , C. nimbus , C. maculicollis , C. ornata , C. regalis , C. rubraoculus , C. smaug , and C. wallaceii ); A small-sized Cnemaspis SVL 38 mm (versus medium-sized Cnemaspis SVL 40-50 mm: C. nairi ; C. nimbus ; C. ornata ; C. rubraoculus ; and C. wallaceii ; large-sized Cnemaspis SVL>50 mm: C. anamudiensis Cyriac, Johny, Umesh and Palot, 2018; C. beddomei ; C. maculicollis Cyriac, Johny, Umesh and Palot, 2018; and C. smaug ); 151-171 longitudinal ventral scales from mental to cloaca (versus 135-140 longitudinal ventral scales from mental to cloaca in C. aaronbaueri , 143-147 in C. nairi , 134-141 in C. nimbus , 148-154 in C. regalis , 122-133 in C. rubraoculus , and 142-150 in C. smaug ); 34-44 ventral scales across belly at mid-body (versus 31-33 ventral scales across belly at mid-body in C. aaronbaueri , 30-34 in C. beddomei and C. smaug , 27-31 in C. galaxia , 32-33 in C. nairi , 26-27 in C. nimbus , and 28-29 in C. wallaceii ); 24-27 lamellae under digit IV of pes (versus 20-22 lamellae under digit IV of pes in C. anamudiensis , 21-23 in C. beddomei , 23-24 in C. maculicollis , 22 or 23 in C. nimbus and C. wallaceii , 28-31 in C. ornata , 18 or 19 in C. rubraoculus , 20-22 in C. smaug ).

Description of the holotype.

Adult male in good state of preservation except head marginally bent towards left and tail tip towards right (Fig. 3A, B ); SVL 37.5 mm, head short (HL/SVL 0.25), wide (HW/HL 0.64), not strongly depressed (HD/HL 0.42), distinct from neck. Loreal region marginally inflated, canthus rostralis indistinct. Snout half of head length (ES/HL 0.48), ~2.5 times eye diameter (ES/ED 2.47); scales on snout and canthus rostralis subcircular, subequal, smooth, much larger than those on forehead and interorbital region; scales on forehead similar to those on snout and canthus rostralis except much smaller and weakly conical; scales on interorbital region, occipital, and temporal region even smaller, granular (Fig. 4A ). Eye small (ED/HL 0.19); with round pupil; supraciliaries short, larger anteriorly; nine interorbital scale rows across narrowest point of frontal bone; 29-31 scale rows between left and right supraciliaries at mid-orbit (Fig. 4A ). Ear-opening deep, oval, small (EL/HL 0.04); eye to ear distance greater than diameter of eye (EE/ED 1.47) (Fig. 4C ). Rostral slightly more than twice as wide (1.8 mm) as high (0.8 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 upper postnasal and strongly in contact with each other on snout; rostral in contact with supralabial I, nostril, and supranasal on either side; nostrils oval, surrounded by two postnasals, supranasal, rostral and supralabial I on either side; a single row of scales separate orbit from supralabials (Fig. 4C ). Mental enlarged, subtriangular, marginally wider (2.1 mm) than high (1.9 mm); two pairs of postmentals, inner pair roughly rectangular, shorter (1.0 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 and two enlarged chin shields on either side; outer postmentals roughly rectangular, half the size (0.5 mm) than inner pair, bordered by inner postmentals, infralabial I and II, and four enlarged chin shields on either side; five enlarged gular scales between left and right outer postmentals; all chin scales bordering postmentals flat, subcircular, smooth, and smaller than outermost postmentals, except the one separating inner pair (median) below mental as large as outer postmentals; scales on rest of throat granular, small, smooth (Fig. 4B ). Infralabials bordered below by a row or two of slightly enlarged, much elongated scales, decreasing in size posteriorly. Eight supralabials up to angle of jaw and six at midorbital position on each side; supralabial I largest, gradually decreasing in size posteriorly; seven infralabials up to angle of jaw, six at midorbital position on left and five on right side; infralabial I largest, gradually decreasing in size posteriorly (Fig. 4C ).

Body relatively slender (BW/AGL 0.44), trunk less than half of SVL (AGL/SVL 0.40) without ventrolateral folds and spine-like scales on flank (Fig. 5B, C ). Dorsal pholidosis heterogeneous; smooth granular scales intermixed with a fairly regularly arranged row of enlarged, weakly keeled, conical tubercles on either side of flank; granular scales gradually increasing in size towards each flank, largest on mid-flank; granular scales on occiput and nape slightly smaller than paravertebral granules (Fig. 5A ). Ventral scales much larger than granular scales on dorsum, subcircular, smooth, subimbricate, subequal from chest to vent; scales on precloacal region and on last two or three rows on femur distinctly enlarged; mid-body scale rows across belly 40; 159 scales from mental to anterior border of cloaca (Fig. 3B ). Scales on base of neck similar to those on belly, marginally smaller; gular region with much smaller, smooth, granular scales, those bordering postmentals enlarged, smooth, subcircular, and flattened (Fig. 4B ). A continuous series of six precloacal pores, femoral pores absent (Fig. 4D ). Scales on palm and soles granular, smooth, rounded, and flattened; scales on dorsal aspects of limbs heterogeneous in shape and size; mixture of small granules, slightly larger than body dorsum and flattened, smooth (few weakly keeled), subimbricate scales which are twice the size of granules on the body dorsum, largest on anterolateral aspect of the hands and feet; posterolateral aspect of limbs with small granular scales; ventral aspect of forelimbs with small granular scales, slightly larger on lower arm than upper arm; ventral aspect of hindlimb with enlarged, smooth, flattened, subimbricate scales, much larger than body ventrals (Fig. 3A, B ).

Forelimbs and hindlimbs slightly long, slender (LAL/SVL 0.15); (CL/SVL 0.18); digits long, with a strong, recurved claw, distinctly inflected, distal portions laterally compressed conspicuously. Digits with both paired and unpaired lamellae, separated into a basal and narrower distal series by single enlarged lamella at inflection; 1-7 most basal paired on basal series and 1-5 paired lamellae above the inflection; basal lamellae series: (2-6-6-6-4 right manus, 2-7-7-8-4 right pes), (2-6-6-6-4 left manus, Fig. 4E ; 2 - 7-7 - 8 - 4 left pes, Fig. 4F ); distal lamellae series: (13-14-16-15-14 right manus, 12-14-17-17-18 right pes), (13-14-17-15-15 left manus, Fig. 4E ; 11 - 14 - 18 - 17-17 left pes, Fig. 4F ). Relative length of digits (measurements in mm in parentheses): IV (4.1)> III (3.7)> V (3.5)> II (3.3)> I (2.1) (left manus); IV (4.6)> V (4.2) = III (4.2)> II (3.4)> I (1.9) (left pes).

Tail original, entire, subcylindrical, slender, slightly longer than snout-vent length (TL/SVL 1.30; Fig. 3C-E ). Dorsal pholidosis on tail heterogeneous; small, smooth, subcircular, flattened, subimbricate scales intermixed on anterior one third portion with enlarged, weakly keeled, and weakly conical tubercles forming four whorls; eight tubercles on first whorl, six tubercles on second, five tubercles on third and four tubercles on fourth; followed by a row of three paravertebral tubercles on either side; rest of the tail lacking enlarged tubercles (Fig. 3C, E ). Scales on tail venter much larger than those on dorsal aspect, smooth, roughly subcircular, flattened, sub-imbricate; median series slightly larger than rest, regularly arranged with condition of two slightly larger scales alternating with a large divided scale (Fig. 3D ). Scales on tail base slightly smaller, smooth, imbricate; a single enlarged, smooth, subcircular, and weakly conical postcloacal spur on each side (Fig. 3D, E ).

Colouration in life (Fig. 6A).

Dorsal ground colour of body, limbs and tail grey; entire head and region anterior to forelimb insertions ochre. Indistinct light preorbital streak runs from nostril to orbit; three light postorbital streaks, uppermost terminating in parietal region, middle at occiput and lowermost continuing until ear opening. A single large central black ocellus on occiput enclosed within a U-shaped light marking and in between uppermost and middle postorbital streaks; a single smaller black ocellus on the right side anterior to forelimb insertions; an incomplete collar at anterior edge of forelimb insertions consisting of a pair of dark blotches flanked posteriorly by a narrower white band on centre of back and small black spot flanked by white band at anterior base of forelimb insertion. Five white spots on vertebral region between forelimbs and tail base, scattered white spots of similar or smaller size on dorsum and femur, larger irregular black blotches scattered on dorsolateral aspect of back (two on left side and one on right). Original tail with indistinct lighter bands, digits with numerous light grey bands. Ventral surfaces of body, limbs and tail light grey with some scattered darker scales especially in centre of belly, throat and underside of neck ochre with scattered darker scales. Pupil black, iris reddish with a light orange ring lining pupil.

Variation and additional information from type series.

Mensural, meristic and additional character state data for the type series is given in Tables 3 , 4 & 5 respectively. There are six adult males, an adult female and a subadult female ranging in size from 27.4-38.3 mm (Fig. 7 ). All paratypes resemble the holotype except as follows: a single internasal scale between supranasals on snout in BNHS 2819. Upper postmentals bordered by infralabial I on right and infralabials I & II on left in BNHS 2818, upper postmental bordered by infralabials I & II on either side in BNHS 2819. Outer postmental bordered by infralabials I & II on right and infralabial II on left in BNHS 2818, outer postmental bordered by infralabial II on either side in BNHS 2819; outer postmental bordered by four enlarged chin scales on right and three on left side in BNHS 2818; outer postmental bordered by three enlarged chin scales on right and five on left side in BNHS 2820. Three paratypes - NRC-AA-1174, BNHS 2819, and BNHS 2821 with original and complete tails, slightly longer than body (TL/SVL 1.29 and 1.39 respectively), partial tail detached from the body in BNHS 2821; NRC-AA-1171, NRC-AA-1172, BNHS 2818 and BNHS 2820 with partially regenerated but complete tails, slightly longer than body (TL/SVL 1.13, 1.20, 1.33, and 1.10 respectively); NRC-AA-1174 with complete but fully renegaded tail, marginally longer than body (TL/SVL 1.09). Sub-adult female (NRC-AA-1173) with damaged skin around the neck; four paratype males (NRC-AA-1174, BNHS 2818, BNHS 2819, and BNHS 2820) with partially or fully everted hemipenis. The new species is strongly sexually dimorphic in colour pattern (Fig. 6A, B ), both female paratypes (NRC-AA-1173, BNHS 2821) brown with a slightly lighter head, ventrally dirty white with faint ochre on the edge of throat base; collar more complete in all paratypes except damaged in NRC-AA-1173; 1-4 dark ocelli on each side of back; head with numerous lighter lines in all paratypes except for BNHS 2821 (Fig. 7 ).

Distribution and natural history.

Cnemaspis azhagu sp. nov. is currently known only from around its type locality (Thirukurungudi forest range ca. 200-400 m asl.), Kalakad Mundanthurai Tiger Reserve, Tirunelveli district, Tamil Nadu (Fig. 1 ). Individuals of the new species were observed active during the daytime (morning to afternoon, 0930-1300 hrs) on rocks (<2 m high from the base) inside dry deciduous forest patches (Fig. 8A-C ). A large number of individuals (n =>30) were observed at all three locations indicating high abundance. The species moved inside rock crevices rapidly when approached. The holotype and two paratypes were collected during the day from rock crevices, while the rest of the type series were collected at night-time (1930-2100 hrs) from the other two closely spaced localities. All the paratypes collected at night were observed inactive, located openly on the rocks and did not try to escape when approached. Hemidactylus cf. acanthopholis and H. cf. frenatus were the only two gecko species we found sympatric with the new species.

Figures

Figure 1. Elevation map of southern Kerala and Tamil Nadu showing the distribution of all known Cnemaspis species from the region: circles, Cnemaspis beddomei clade; squares, Cnemaspis gracilis clade; triangle, Cnemaspis littoralis clade; pentagon, Cnemaspis australis clade.

Figure 2. Maximum likelihood (ML) phylogeny of South Asian Cnemaspis based on the mitochondrial ND 2 gene. Bootstrap support> 70 shown at nodes; Cnemaspis beddomei, Cnemaspis gracilis and Cnemaspis littoralis clades marked by text. Roman numerals indicate other broad clades: I, Cnemaspis australis; II, Cnemaspis mysoriensis; III, Cnemaspis goaensis; IV, girii; V, Cnemaspis bangara; VI, Cnemaspis indica; VII, Cnemaspis podihuna; VIII, Cnemaspis assamensis; IX, Cnemaspis wynadensis. Top left inset is a 16 S ML phylogeny of the Cnemaspis littoralis clade (outgroups not shown).

Figure 3. Cnemaspis azhagu sp. nov. (holotype, NRC-AA- 1170): A dorsal aspect of body, B ventral aspect of body, C dorsal aspect of tail, D ventral aspect of tail, and E lateral aspect of tail. Scale bars 10 mm; photos by Akshay Khandekar and Satpal Gangalmale.

Figure 4. Cnemaspis azhagu sp. nov. (holotype, NRC-AA- 1170): A dorsal aspect of head, B ventral aspect of head, C lateral aspect of right side head, D aspect of cloacal region showing precloacal pores, E ventral aspect of left manus, and F ventral aspect of left pes. Scale bars 5 mm; photos by Akshay Khandekar and Satpal Gangalmale.

Figure 5. Cnemaspis azhagu sp. nov. (holotype, NRC-AA- 1170): A dorsal aspect of mid-body, B ventral aspect of mid-body, and C right side lateral aspect of mid-body. Scale bars 5 mm; photos by Akshay Khandekar and Satpal Gangalmale.

Figure 6. Colouration in life of Cnemaspis azhagu sp. nov.: A adult male (holotype, NRC-AA- 1170), and B adult female (paratype, BNHS 2821). Photos by Akshay Khandekar and Satpal Gangalmale.

Figure 7. Paratype series of Cnemaspis azhagu sp. nov. from left to right, NRC-AA- 1171, NRC-AA- 1172, NRC-AA- 1173, NRC-AA- 1174, BNHS 2818, BNHS 2819, BNHS 2820, and BNHS 2821. Scale bar 10 mm; photo by Akshay Khandekar and Satpal Gangalmale.

Figure 8. Habitat at the type locality of Cnemaspis azhagu sp. nov.: A general habitat showing the dry scrub forest dominated by rocks, and B & C microhabitat showing the rock and its base from where the type series were collected. Photos by Akshay Khandekar.

Figure 11. Cnemaspis mundanthuraiensis sp. nov. (holotype, NRC-AA- 1175): A dorsal aspect of mid-body, B ventral aspect of mid-body, and C right side lateral aspect of mid-body. Scale bars 5 mm; photos by Akshay Khandekar and Satpal Gangalmale.

Figure 14. Habitat at the type locality of Cnemaspis mundanthuraiensis sp. nov.: A general habitat showing the moist deciduous forest dominated by rocks, and B & C microhabitat showing the rock and its base from where the type series were collected. Photos by Akshay Khandekar.

Figure 17. Cnemaspis kalakadensis sp. nov. (holotype, NRC-AA- 1180): A dorsal aspect of mid-body, B ventral aspect of mid-body, and C right side lateral aspect of mid-body. Scale bars 5 mm; photos by Akshay Khandekar and Satpal Gangalmale.

Figure 18. Colouration in life of Cnemaspis kalakadensis sp. nov.: A adult male (holotype, NRC-AA- 1180), and B adult female (paratype, BNHS 2828). Photos by Akshay Khandekar and Satpal Gangalmale.