Cnemaspis nilgala, Karunarathna & Bauer & Silva & Surasinghe & Somaratna & Madawala & Gabadage & Botejue & Henkanaththegedara & Ukuwela, 2019

Karunarathna, Suranjan, Bauer, Aaron M., Silva, Anslem De, Surasinghe, Thilina, Somaratna, Lankani, Madawala, Majintha, Gabadage, Dinesh, Botejue, Madhava, Henkanaththegedara, Sujan & Ukuwela, Kanishka D. B., 2019, Description of a new species of the genus Cnemaspis Strauch, 1887 (Reptilia: Squamata: Gekkonidae) from the Nilgala Savannah forest, Uva Province of Sri Lanka, Zootaxa 4545 (3), pp. 389-407 : 393-401

publication ID	https://doi.org/ 10.11646/zootaxa.4545.3.4
publication LSID	lsid:zoobank.org:pub:D7F2BB9B-B6D6-40F0-82DF-733C6E65520E
DOI	https://doi.org/10.5281/zenodo.5940674
persistent identifier	https://treatment.plazi.org/id/03CB8789-5E17-FFEB-FF26-0CF1FC6B8A7D
treatment provided by	Plazi
scientific name	Cnemaspis nilgala
status	sp. nov.

Treatment

Cnemaspis nilgala sp. nov.

( Figures 2–3 View FIGURE 2 View FIGURE 3 ; Tables 1–4)

Holotype. 2018.07.01.NH, Adult male, 32.9 mm SVL ( Figure 2 View FIGURE 2 ), collected from rock cave in Serawa , Bibila , Monaragala District, Uva Province, Sri Lanka (7.264075 N, 81.356997 E, elevation 260 m a.s.l. WGS1984+-) collected on 6 November 2002 by Aaron M. Bauer & Anslem de Silva. GoogleMaps

Paratypes. NMSL 2018.06.01.NH, Adult female, 31.5 mm SVL, collected from rockcave in Pitakumbura , Bibila, Monaragala District, Uva Province, Sri Lanka (7.264069 N, 81.359025 E, elevation 275 m a.s.l. WGS1984+-), collected on 6 November 2002 by Aaron M. Bauer & Anslem de Silva; 2018.06.02.NH, Adult male, 31.1 mm GoogleMaps SVL ( Figure 3 View FIGURE 3 ) and 2018.06.03.NH, Adult male, 31.7 mm SVL, collected from rockcave in Yakunhela , Bibila, Monaragala District, Uva Province, Sri Lanka (7.200950 N, 81.329731 E, elevation 282 m a.s.l.), collected on 25 June 2018 by Suranjan Karunarathna GoogleMaps .

Diagnosis. Cnemaspis nilgala sp. nov., can be readily distinguished from its peninsular Indian and Sri Lankan congeners by a combination of the following morphological and meristic characteristics and color pattern: maximum SVL 32.9 mm; dorsum with homogeneous, unkeeled granular scales; internasal present; ventral scales smooth, venter subimbricate; two enlarged postmentals including median chin scale; each postmental bounded by 6–7 posterior postmental scales including medial chin scale; chin, throat, gular, pectoral and abdominal scales smooth; 17–19 ventral scales across midbody; 4 very weakly developed tubercles on posterior flank; 179–187 paravertebral granules linearly arranged; precloacal pores absent in males, 7–9 femoral pores on each side separated by 14–15 unporedfemoro-precloacal scales, 5–6 enlarged femoral scales; 122–129 ventral scales; subcaudals smooth, median row enlarged, in an irregular series of subhexagonal scales, subequal in width; 7–8 supralabials; 6–7infralabials; 17–18 subdigital lamellae on fourth digit of pes.

The new species most closely resembles Sri Lankan congeners in the C. podihuna clade ( Agarwal et al., 2017): C. alwisi , C. gemunu Bauer, de Silva, Greenbaum & Jackman , C. kandambyi Batuwita & Udugampala , C. molligodai Wickramasinghe & Munindradasa , C. phillipsi Manamendra-Arachchi, Batuwita & Pethiyagoda , C. podihuna , C. punctata Manamendra-Arachchi, Batuwita & Pethiyagoda , C. rajakarunai , C. rammalensis Vidanapathirana, Rajeev, Wickramasinghe, Fernando & Wickramasinghe , and C. scalpensis Ferguson (systematic position confirmed based on presence of enlarged subcaudals, and hexagonal or subhexagonal-shaped scales on the tail). Of these similar species, the new species differs from C. kandambyi , C. molligodai and C. podihuna from the absence (versus presence) of precloacal pores. It can be diagnosed from C. alwisi , C. punctata and C. rajakarunai , respectively, by the presence of 122–129 (versus 146–152, 131–135 and146–186) ventral scales, by having fewer unpored femoro-precloacal scales ranging from 14–15 (versus 18–19, 24–26 and 20–22), by the presence of 7–8 (versus 8–10, 7–10 and 9–11) supralabials, body relatively short, relatively smaller SVL of 31.5–32.9 mm (versus 37.8–39.9 mm, 35.2–37.1 and 36.2–40.1) ( Table 3). The new species also differs from C. gemunu , C. phillipsi , C. rammalensis and C. scalpensis , respectively, by the presence of fewer femoral pores ranging from 7–9 (versus 11– 14, 15–16, 15 and 13–15). The new species further differs from C. phillipsi , C. rammalensis and C. scalpensis , respectively, by the presence of 17–19 (versus 21–25, 28 and 21–23) fewer belly scales across the ventral at midbody and from C. gemunu by the presence of 17–19 (versus 13–16) more ventral scales across the mid body.

Description of Holotype. An adult male, 32.9 mm SVL. Head relatively short (HL 28.2% of SVL, HL 60.6% of TRL), narrow (HW 16.0% of SVL, HW 56.8% of HL), depressed (HD 8.5% of SVL, HD 30.0% of HL) and distinct from neck ( Table 3). Snout relatively long (ES 70.1% of HW, ES 39.8% of HL), less than twice the length of eye diameter (ED 53.5% of ES), more than half length of jaw (ES 66.1% JL), snout slightly concave in lateral view; eye relatively small (ED 21.3% HL), larger than the ear (EL 33.8% ED), pupil rounded; orbit length equals to eye-to-ear distance (OD 100.1% EE) and to the length of IV digit in manus (OD 99.2% DLM IV); supraocular ridges are not prominent or absent; ear opening very small (EL 7.2% HL), deep, taller than wide, larger than nostrils, smaller than eyes; two rows of scales separates orbit from supralabials; interorbital gap is narrow (IO 11.1% of SN), subequal to snout to nostril length (IO 107.3% of HL); eye to nostril distance greater than the eye to ear distance (EN 81.3% of EE); granules on snout very smooth, larger than those on interorbital and occipital regions; canthus rostralis nearly absent, 12, smoothly round scales from eye to nostril; scales of the interorbital region ovular and smooth; tubercles absent both on the sides of the neck and around the ear ( Tables 4). Unkeeled, rounded, juxtaposed scales present on the chin and throat raised, smooth, small; unkeeled, imbricate scales on the gular and pectoral regions, and the abdomen. Rostral scale wider than long, 4/5 partially divided by a medial groove, in contact with first supralabial. Nostrils separated by two enlarged supranasals with a single internasal ( Figure 2 View FIGURE 2 ); no enlarged scales behind the supranasals. Nostrils oval, dorsolaterally orientated; nostrils not in contact with first supralabial. Two postnasals smooth, larger than nostrils, the lower one partially in contact with first supralabial. Mental sub-rhomboid in shape, as wide as long, posteriorly in contact with two enlarged postmentals (smaller than mental, and lager than chin scale); postmentals in contact medially and bordered posteriorly with seven unkeeled posterior-postmental scales (smaller than postmentals), in contact with the 1 st and 2 nd infralabials; ventral scales smaller than posterior-postmentals. Supralabials 7/7, infralabials 7/7, becoming smaller towards the gape ( Figure 3 View FIGURE 3 ). Ear opening oval vertically, backward slanted (EL, 0.67 mm), 19 scales between anterior margin of the ear opening and the posterior margin of the eye. Body slender, relatively short (AG 46.6% of SVL). Middorsal granules homogeneous, 179 paravertebral granules; 122 midventral scales, smooth; 78 midbody scales; four very weakly developed tubercles on the flanks; ventro-lateral scales enlarged; pectoral and abdominal scales smooth, subimbricate to imbricate towards precloacal region, abdominal scales slightly larger than dorsals; 17 belly scales across ventral; smooth scales around vent and base of tail, subimbricate; no pore-bearing precloacal scales or precloacal depressions; 8 and 7 femoral pores on left and right sides, respectively; 14 unpored femoroprecloacal scales in between pores in each side; 5 enlarged femoral scales ( Figure 2 View FIGURE 2 ).

Forelimbs moderately long, slender (LAL 16.4% of SVL, UAL 13.7% of SVL); hind limbs long, tibia relatively shorter than the femur (TBL 19.5% of SVL, FEL 21.7% of SVL). Dorsal, anterior, ventral and posterior surfaces of upper arm with unkeeled and less imbricate scales, scales of the anterior surface twice larger than those of the other parts; ventral scales unkeeled. Scales on dorsal, ventral and tail less imbricate. Dorsal and anterior surfaces of lower arm with unkeeled and less imbricate scales, ventral and posterior surfaces with keeled scales those are less imbricate. Scales on dorsal surface of the thigh less keeled and granular, imbricate scales on the anterior, posterior and ventral surfaces, scales on the anterior and ventral surfaces are twice the size than those of the other parts. Dorsal, anterior, ventral and posterior surfaces of tibia with unkeeled and less imbricate scales, scales of the ventral surface twice larger than those of the other parts, dorsal and posterior surfaces with unkeeled homogeneous granules.

Dorsal and ventral scales on the manus and the pes with unkeeled granules. Dorsal surface of digits with granular scales. Digits elongate and slender with an inflected joint, all bearing slightly recurved claws. Subdigital lamellae entire (except the divided lamellae at first interphalangial joint), unnotched; subdigital lamellae on manus: digit I, 11, digit II, 13, digit III, 15, digit IV, 17, digit V, 15; subdigital lamellae on pes: digit I, 11, digit II, 13, digit III, 15, digit IV, 17, digit V, 13; interdigital webbing absent; relative length of digits of manus: IV (2.6 mm)>V (2.1 mm)> III (2.0 mm)> II (1.8 mm)> I (1.5 mm); relative length of digits of pes IV (3.3 mm)> V (2.9 mm)> III (2.7 mm)> II (2.3 mm)> I (1.3 mm). Regenerated tail of holotype shorter than the snout-vent length (86.3% of SVL); tail base greatly swollen (TBW 3.4), homogeneous scales on the dorsal aspect of the tail directed backwards, no spine-like tubercles at the base of tail; tail with 4–5 enlarged flattened obtuse scales forming whorls; a small postcloacal spur on each side, dorso-ventrally flattened and narrow ( Figure 3 View FIGURE 3 ); subcaudals smooth and are arranged into an irregular subhexagonal median series.

forest, Sri Lanka.

Color in life. The color of the head, body and limbs on the dorsal side generally vary from light grey to brown with small black and white spots on the entire dorsum, paired black paravertebral blotches can be seen; an oblique black line is present in between the eye and the nostrils on either side, and dirty white lines are present in the occipital area; there is a narrow ‘V’ shaped, pale grey patch on the occipital area with scattered cream white spots. Two distinct black spots on the dorsolateral surfaces of the shoulders; tail is dirty golden-brown on the dorsum, 7– 9 faded cream white cross-bands present along the tail; three straight, dark brown postorbital stripes extend from eyes downward and backwards ( Figure 3 View FIGURE 3 ); the pupil is circular and black with the surrounding scales being yellowish brown in color; supralabials are cream white and spotted, and infralabaials are bright yellow with dusted with black; chin, throat, gular and lower shoulder scales are bright orange-yellow without dark spots; pectoral, abdomen and cloacal scales cream white without dark spots; post-cloacal spur and subcaudal scales pale orangeyellow; limbs have white patches; manus and pes with black and white stripe arrangement.

Color of preserved specimens. Dorsally dark brown with pale colored, dark paravertebral blotches distinct; Ventral surface cream colored with some scales on thigh, tail base and arms with dark brown margins. Color patterns in preservative not similar to that in life, all the dark marking fades, with the dorsal background color becoming slightly darker; chin, throat, gular and lower shoulder scales are cream color without dark spots ( Figure 2 View FIGURE 2 ).

Variation. The SVL of adult specimens in the type series (n =4) size ranges from 31.5 to 32.9 mm; number of supralabials 7–8, and number of infralabials 6–7; number of interorbital scales 29–31; number of supraciliaries above the eye is between 13–17; number of canthul scales 10–12; number of scales from eye to tympanum 17–21; number of lamellae on digit I of the manus is between 11–12, number of lamellae on digit II of manus is between 13–14; number of lamellae on digit III of manus is between 1 5–16; number of ventral scales 122–129; number of belly scales across ventral 17–19; number of midbody scales 71–78; number of lamellae on digit I of pes is between 11–12; number of lamellae on digit II of pes is between 13–15; number of lamellae on digit IV of pes is between 17–18; number of lamellae on digit V of pes is between 13–14, and number of paravertebral granules 179– 187 ( Table 3–4).

Etymology. The species name is an eponym ( nilgala ) for the region it inhabits, the Nilgala savannah forest in Sri Lanka (7.133333– 7.233333 N and 81.266667– 81.335400 E), formed here as a noun in apposition.

Suggested vernacular names. The vernacular names suggested for the species are: Nilgala diva-sari huna (in Sinhala), Nilgala pahal-palli (in Tamil), Nilgala day gecko (in English).

Remarks. The records of Cnemaspis alwisi from Nilgala forest and vicinity (7.133333– 7.233333 N and 81.266667– 81.335400 E) by Karunarathna & Amarasinghe (2011) refer to Cnemaspis nilgala sp. nov.

Distribution and habitat. The Nilgala savannah forest (NSF) is a savannah dominated forest approximately 12,432 ha in size, situated in the lower plains of the Uva Province, Monaragala District (intermediate bioclimatic zone) in the eastern part of Sri Lanka ( Figure 4 View FIGURE 4 ). The NSF approximately lies between 7.133333– 7.233333 N and 81.266667– 81.335400 E. Different parts of the NSF are under the protection of both the Department of Wildlife Conservation and Forest Department, although the statutory protection status remains uncertain ( Goonewardene et al. 2003; Karunarathna et al. 2013; Kumara et al. 2017). The mean annual rainfall varies between 1500 and 2000 mm, received mainly during the north-east monsoon (October– January) (de Silva et al. 2004). The mean annual temperature of the area is 28–31°C, and its elevation range is 220– 570 m. The major vegetation of NSF can be classified as dry monsoon grassland (savannah), although the area around Nilgala is mostly lowland tropical dry mixed evergreen forests ( Gunatileke & Gunatileke 1990). Furthermore, four other secondary vegetation categories were identified within NSF: savannah grasslands, deciduous seasonal forests ( Figure 5 View FIGURE 5 ), anthropogenically modified vegetation (e.g. croplands and home gardens) and degraded lands predominantly covered by thorny weeds ( Karunarathna & Amarasinghe 2011). So far, this species is only recorded from rock outcrops with prehistoric granite caves of the type similar to those that have been subjected been subjected to historical (since stone-age until the colonial period) human occupancy ( Goonewardene et al. 2003). It is likely that this species occurs throughout the NSF and nearby habitats, but aggregated in these relatively undisturbed granite caves.

Autecology. Cnemaspis nilgala sp. nov. was scarce in and around NSF. Our survey revealed only 3 (±1) geckos per man-hour (approximately a total surveyed area of 25 km 2). This species was restricted to rock outcrops (2 locations, 7 individuals) and granite caves embedded in forested areas, and ascended up to 4 m along vertical surfaces (4 locations, 21 individuals) ( Figure 5 View FIGURE 5 ). These habitats were relatively moist and cool in comparison to the cave exterior where temperature of the rock surface of the cave interior varied between 27.5–28.2 ˚C. Inside the caves, the light intensity and the humidity were 0–582 Lux and 82–96%, respectively. The geckos were active during the day time (0700–1700 h) and, when disturbed, sought refuge in the crevices of the rocky outcrops. The new species was sympatric (at both local habitat and the microsite) with several other micro-endemic cavedwelling geckos ( Calodactylodes illingworthorum Deraniyagala , Cnemaspis sp., Cyrtodactylus sp., Hemidactylus depressus Gray , H. frenatus Duméril and Bibron , H. hunae Deraniyagala , H. triedrus (Daudin) , H. parvimaculatus Deraniyagala ). During the survey, across six distinct locations ( Figure 4 View FIGURE 4 ), we documented 14 females, nine males, five juveniles, and 63 unhatched eggs (likely belong to the new species given their proximity to the habitats of adults) deposited in six different communal egg laying sites within an extent of ca. 40km 2 area. From July to September (2016), hatchlings, juveniles and gravid females carrying one or two eggs were observed. Older and newly laid eggs were observed on granite rock crevices, typically laid in pairs. The eggs were pure white in color almost spherical in shape (mean diameter 5.16 ± 0.02 mm (n =26)), with a slightly flattened side attached to the rocky substrate.

Conservation status. Application of the IUCN Red List criteria indicates that C. nilgala sp. nov. is Critically Endangered due to having an area of occupancy (AOO) <10km 2 (six locations, 4.7 km 2 in total assuming a 500 m radius around the georeferenced location) and an extent of occurrence (EOO) <100 km 2 (32.43 km 2) in the lower elevations of Uva Province [applicable criterion is B2-b (iii)]. Further, the characteristic habitats of this species, monsoon-influenced savannah grasslands embedded with rock outcrops and granite rock caves, are not spatially extensive in the intermediate zone of Sri Lanka, which suggests that the habitat area suitable for this species is small. See the map ( Figure 4 View FIGURE 4 ) for distribution data of C. nilgala sp. nov.