Cnemaspis nilagirica Manamendra-Arachchi, Batuwita & Pethiyagoda, 2007

Cyriac, Vivek Philip, Johny, Alex, Umesh, Pavukandy & Palot, Muhamed Jafer, 2019, Rediscovery of Cnemaspis nilagirica Manamendra-Arachchi, Batuwita and Pethiyagoda, 2007 (Squamata: Gekkonidae) from Kerala, India with notes on morphology and distribution, Zootaxa 4586 (1), pp. 98-108 : 99-104

Cnemaspis nilagirica Manamendra-Arachchi, Batuwita & Pethiyagoda, 2007

Holotype: BMNH 74.4 .29.729, an adult female of SVL 42.1 mm; collected from the “Nilgiries” ( Nilgiri Hills , Tamil Nadu, India).

Referred material: ZSI / WGRC /IR. V/2710, an adult male of SVL 40.5 mm and ZSI / WGRC /IR. V/2714, an adult female of SVL 47.0 mm; collected from under a fallen log near Sispara (11.19717°N, 076.43117°E) at an elevation of 1728 m ASL in Silent Valley National Park on 13 February 2015 by Vivek Philip Cyriac . ZSI / WGRC / IR. V/2711, an adult male of SVL 38.4 mm; collected on 3 May 2013 on a tree in Thudukki range (11.134792°N, 76.522514°E) at an elevation of 1600m ASL of Silent Valley National Park, Palakkad District, Kerala by Vivek Philip Cyriac and P. K. Umesh . ZSI / WGRC /IR. V/2712, an adult female of SVL 42.7 mm; collected from the same locality as ZSI / WGRC /IR. V/2711, from a network of roots adjoining a stream on 3 May 2013 by Vivek Philip Cyriac and P.K. Umesh . ZSI / WGRC /IR. V/2713, an adult male of SVL 39.8 mm; collected from under rock near Sispara (11.20050°N, 076.43577°E) at an elevation of 1937m ASL, Silent Valley National Park on 14 February 2015 by Vivek Philip Cyriac

Diagnosis: Cnemaspis nilagirica may be diagnosed from all other congeners by the following set of characters. Maximum snout-vent length 47.0 mm. Mid-dorsal scales homogenous with spine-like tubercles present on flanks. Ventral scales of neck weakly keeled. Ventral scales of the pectoral and abdominal region are distinctly keeled and imbricate. Pre-cloacal scales are smooth and imbricate. Nasals surrounded by three scales—supranasal, one postnasal and rostral. Supralabials to the angle of jaw 7–8, infralabials 6–8. Subdigital lamellae under manus IV ranges between 15 and 18; under pes IV between 17 and 19. Dorsal scales of tail homogenous and granular. Subcaudals are enlarged, uniform and smooth. Males have 4–6 femoral pores and no pre-cloacal pores. Prominent orange spots present on the sides of the head and neck. Both males and females have a bright orange abdomen.

Cnemaspis nilagirica differs from all other congeners by the following characters: the presence of small, scattered spine-like tubercles present on flanks (versus absence of spine-like tubercles on the flanks in C. beddomei (Theobald) , C. nairi Inger, Marx & Koshy , C. adii Srinivasulu, Kumar & Srinivasulu , C. otai Das & Bauer , C. sisparensis (Theobald) , C. wynadensis (Beddome) , C. anaikattiensis Mukherjee, Bhupathy & Nixon , C. indica (Gray) , C. yercaudensis Das & Bauer , C. giri Mirza, Pal, Bhosale & Sanap , C. australis , C. limayei Sayyed, Pyron & Dileepkumar , C. ajijae Sayyed, Pyron & Dileepkumar , C. mahabali Sayyed, Pyron & Dileepkumar ); dorsal scales homogenous (versus dorsal scales heterogeneous in C. indraneildasii Bauer , C. heteropholis Bauer , C. gracilis (Beddome) , C. ornata (Beddome) , C. andersonii (Annandale) , C. beddomei , C. yercaudensis , C. wicksii (Stoliczka) , C. girii , C. kottiyoorensis Cyriac and Umesh , C. monticola , C. australis and C. goaensis Sharma ; C. limayei , C. ajijae , C. amboliensis Sayyed, Pyron & Dileepkumar , C. mahabali ); median series of subcaudals enlarged, hexagonal (versus median series of subcaudals not enlarged in C. gracilis ); ventral scales of gular, pectoral and abdomen region keeled (versus ventral scales smooth in C. beddomei , C. mysoriensis (Jerdon) , C. jerdonii (Theobald) , C. nairi , C. otai , C. yercaudensis , C. sisparensis , C. anaikattiensis , C. wynadensis , C. heteropholis , C. kolhapurensis Giri, Bauer & Gaikwad , C. indica , C. gracilis , C. littoralis (Jerdon) , C. giri , C. adii , C. flaviventralis Sayyed, Pyron & Dahanukar , C. anamudiensis Cyriac, Johny, Umesh & Palot , and C. maculicolis Cyriac, Johny, Umesh & Palot , C. limayei , C. ajijae , C. amboliensis , C. mahabali ; pectoral and abdomen scales smooth in C. monticola , C. goaensis , C.wicksii ); presence of 4 femoral pores (versus a continuous series of 24–28 precloacal-femoral pores in C. kolhapurensis ; absence of femoral pores in males in C. boiei (Gray) .

Description of male specimen: ZSI/WGRC/IR. V/2710 is an adult male of SVL 40.5 mm; head short (HL 26.0 % of SVL), broad (HW 66.5 % of HL), depressed (HD 41.4 % of HL), distinct from neck. Snout moderately long (ES 46.0% of HL). Scales on snout weakly keeled, larger than those on forehead and interorbital region. Eye relatively small (ED 23.0% of HL); pupils round; extra-brillar fringe scales small, larger anteriorly. Scales on interorbitals and supercilium smooth. The tympanum is small (TD 7.8% of HL), longer than broad. Rostral broader than long, almost completely divided by a median rostral groove. Two supranasals separated from each other by an internasal scale; nasal not in contact with the first labial; nostril circular, surrounded by a single postnasal, a supranasal and the rostral. Mental scale sub-triangular and broader than rostral. Three pairs of postmentals, first pair largest and separated from each other by an intermediate chin shield. Frst post mental surrounded by five scales—mental, first infralabial, second postmental and two chin shields. Supralabials to angle of jaw, seven on the right and eight on the left; infralabials to angle of jaw seven on each side. Gular scales granular. Ventral scales of neck weakly keeled. Lateral sides of neck with few small projecting spine-like tubercles.

Body slender (TW 17.0 % of SVL), elongate (AG 42.8 % of SVL). Mid-dorsal scales are homogenous, granular, few carinate. Flanks have five small, sub-conical, spine-like tubercles. Ventral scales larger than dorsal scales. Pectoral and abdominal scales are keeled and imbricate. Pre-cloacal scales smooth, imbricate and subcircular.

Forelimbs moderately long (UAL 11.0 % of SVL, LAL 15.2% of SVL). Hindlimbs long, femur longer than tibia (FEL 17.7 % of SVL, TBL 16.9 % of SVL). Dorsal scales of forelimb and hindlimb keeled. Dorsal scales of manus and pes keeled. Ventral scales of forelimb weakly keeled and that of hindlimb, keeled. Femoral pores, four on the right and five on the left femur. No pre-cloacal pores. Subdigital lamellae entire, a few fragmented; lamellae on the basal phalanges, enlarged. Interdigital webbing is absent. Subdigital lamellae on finger I: 11; finger II: 15; finger III: 17; finger IV: 18; finger V: 15; toe I: 13; toe II: 16; toe III: 19; toe IV: 20; toe V: 17. Relative length of digits, fingers: IV (5.02mm)> III (4.6mm)>II (4.19mm)> V (3.9mm)> I (3.3 mm); toes: IV (6.6 mm)> III (5.8 mm)> V (5.2mm)> II (5.2 mm)> I (3.9 mm).

The original tail is subcylindrical, swollen at the base and longer than SVL (TL 131.0 % of SVL). Dorsal scales of tail homogenous, granular, with four slightly enlarged tubercles on either side. Ventral scales larger than dorsal scales; median subcaudals enlarged, subpentagonal, uniform, smooth. A post-cloacal spur present on either side of the base of the tail.

Colouration in preservative. Head grayish brown, with two whitish lines extending from the posterior of the eye to the sides of the head; sides of head and neck with three to four whitish spots. Gular scales grayish black. Dorsum grayish brown with a vertebral series of black edged light spots; sides mottled with light and dark markings. Tail grayish brown above, whitish below.

Colouration in life. Head brown with dark brown mottling and two dark-edged streaks extending from the posterior corner of the eye to the sides of the head. Lateral sides of the head and neck have several orange-yellow spots. Ventral side of the head and neck dark gray except for the mental, postmentals and a few infralabials are orange-yellow. Dorsum grayish brown with a vertebral series of black-edged light elongated spots. Flanks grayish brown having six to seven orange-yellow spots. Dorsal side of forelimbs and hindlimbs grayish brown with darker markings and few scattered orange-yellow patches. Ventral side of the body, forelimbs and hindlimbs bright orange-yellow with patches of grey towards the margins. Dorsal side of tail brown with darker irregular transverse bars; ventral side orange-yellow at the base and fading to a dull white colour towards the tip.

Variation: Variation in the pholidosis of this species is summarized in Table 1 . Supralabials range between 7 and 8 with the ZSI/WGRC/IR. V/2710 having 7 on the right side and 8 on the left. There is considerable variation in the number of lamellae on the manus which ranges from 10–12 on manus I, 13–15 on manus II, 16–17 on manus III, 15–18 on manus IV and 14–15 on manus V; pes which ranges from 10–13 on pes I, 13–16 on pes II, 17–19 on pes III, 18–20 on pes IV and 13–17 on pes V. Femoral pores range from 4–6 with ZSI/WGRC/IR. V/2711 having 4 and 5 on the right and left respectively and ZSI/WGRC/IR. V/2713 having 5 and 6 on the right and left respectively.

Distribution: At present this species is only known from high elevation (between 1702–1937m ASL) evergreen forests of Silent Valley National Park, Palakkad District, Kerala, which is located just above the Palghat Gap in the northern part of the Southern Western Ghats. Since Silent Valley is continuous with Mukurthi Tiger Reserve of the Nilgiris of Tamil Nadu, it is possible that the range of this species may extend to parts of Tamil Nadu.

Natural History Cnemaspis nilagirica is a forest species and found only in thick evergreen forests at high elevations between 1700m and 1950m asl in the Nilgiri Hills. All individuals of this species were observed close to the ground either beneath fallen logs and rocks or at the base of trees, indicating that this species is primarily terrestrial but may also have arboreal habits. Like many other members of this genus, C. nilagirica appears to be a diurnal species as individuals were observed active during the day. Several clusters of eggs were found in rock crevices from where individuals were collected suggesting communal oviposition in this species. There is no sexual dichromatism within this species and both males and females possess the characteristic dark grey gular region and the orange-yellow colour on the abdomen and tail ventrally.