Dravidogecko janakiae, Chaitanya & Giri & Deepak & Datta-Roy & Karanth, 2019

Chaitanya, R., Giri, Varad B., Deepak, V., Datta-Roy, Aniruddha & Karanth, Praveen, 2019, Diversification in the mountains: a generic reappraisal of the Western Ghats endemic gecko genus Dravidogecko Smith, 1933 (Squamata: Gekkonidae) with descriptions of six new species, Zootaxa 4688 (1), pp. 1-56 : 34-37

Dravidogecko janakiae sp. nov.

( Figs 12 A–D, 13E, 15C; Table 8 )

Hemidactylus anamallensis: Bauer & Russell, 1995

Hemidactylus anamallensis [non Gecko anamallensis Günther, 1875 ]— Bansal & Karanth, 2013

Dravidogecko anamallensis: Smith, 1933

Dravidogecko anamallensis [non Gecko anamallensis Günther, 1875 ]— Radhakrishnan, 1999.

Holotyp e. BNHS 2356 , an adult male, Munnar town (10.1436 °N, 77.0927 °E; ca. 1900 m asl.), Idukki District , Kerala, collected by Jafer Palot and RC on 28 th May, 2016 .

Paratypes. Details of collection same as the holotype. BNHS 2358 , BNHS 2359 and ZSIK 2989 —adult males; BNHS 2357 , BNHS 2360 and ZSIK 2988 —adult females .

Type locality. Munnar town, Idukki District, Tamil Nadu.

Summarized description and diagnosis. Snout-vent length up to 52.0 mm (n=8); two pairs of well-developed postmentals, inner pair longer than the outer and never in contact with infralabial II; ventral scales counted at midbody, 24–30; precloacofemoral pores, 35 or 36 (n=4); subdigital lamellae under digit IV of manus, 7–9 and under digit IV of pes, 9–11; supralabials 8–11 and infralabials, 8–10 on each side.

Dravidogecko janakiae sp. nov. can be distinguished from other congeners based on the following characters: Number of precloacofemoral pores (PcFP 35 or 36 versus 45 or 46 in D. anamallensis , 52–56 in D. septentrionalis sp. nov., 36–38 in D. meghamalaiensis sp. nov., 42 or 43 in D. douglasadamsi sp. nov., 48 in D. smithi sp. nov. & 38–40 in D. tholpalli sp. nov.); first pair of postmentals much longer than the second (2PML/1PML 0.47–0.70 versus only slightly longer, 0.82–0.96 in D. meghamalaiensis sp. nov.).

Genetic divergence (p-distance). Dravidogecko janakiae sp. nov. exhibits 0.2% intraspecific variation, while it is 10.1% –21.5% divergent from all other congeners ( Table 9 ).

Description of holotype. The holotype is in good condition ( Fig 12A ). The hemipenis is partially everted and is visible on both sides when viewed dorsally. Body dorsoventrally flattened, tail entire. Second and fifth toes on each hindlimb curved upwards, an artefact of preservation. Adult male, SVL 48.4 mm. Head short (HL/SVL 0.26), slightly elongate (HW/HL0.68), slightly depressed (HH/HW 0.55), distinct from neck. Loreal region slightly inflated, canthus rostralis indistinct ( Fig 12C ). Snout short (SE/HL 0.37), longer than orbital diameter (OD/SE 0.61); scales on snout, canthus rostralis, inter-orbital region, forehead, occipital and nuchal regions granular and rounded with those on the snout and canthus rostralis being larger ( Fig 12B ). Eye small (OD/HL 0.22); pupil vertical with crenulated margins; supraciliaries small, rounded, directed outwards, increasing in size anteriorly. Ear opening elliptical (longer diameter 0.6 mm); eye to ear distance longer than diameter of eye (EE/OD 1.26). Rostral wider than deep (RL/RW 0.42), with a distinct rostral groove extending halfway through the scale medially; two large internasals, separated by a smaller, subequal scale, all in broad contact with rostral; two postnasals on either side, slightly smaller than the internasals, the lower in contact with supralabial I; rostral in contact with nasal, supralabial I, internasals and the smaller scale separating the internasals; nostrils smaller than lower postnasal, roughly circular with nasal pad visible posteriorly; nasal surrounded by internasal, rostral, two postnasals and supralabial I (barely touching) on either side; 2 or 3 rows of scales separate orbit from supralabials at mid-orbital position. Supralabials roughly rectangular, increasing in length anteriorly. Supralabials (to midorbital position) 8 (right), 7 (left); supra- labials (to angle of jaw) 10 (right), 9 (left); infralabials (to angle of jaw) 9 (right), 9 (left). Mental triangular; two pairs of smaller postmentals, the inner pair shorter (0.7 mm) than the mental (1.1 mm), and barely in contact with each other (0.2 mm) behind mental; outer pair distinctly shorter (0.4 mm) than the inner pair, separated from each other by four gular scales that are smaller than postmentals ( Fig 12D ). Inner postmentals bordered by mental, infralabial I, outer postmentals and three smaller gular scales; outer postmentals bordered by infralabials I and II, inner postmentals, and smaller gular scales of dissimilar sizes, four on the right and five on the left sides. Body relatively slender, elongate (TRL/SVL 0.46). Dorsal pholidosis composed of small, rounded granules that are juxtaposed in arrangement throughout; Ventral scales larger than dorsals, largely homogeneous in shape and size, smooth, flat, weakly pointed and sub-imbricate; gular region with smaller, granular, juxtaposed scales, anteriormost gular scales visibly larger, flatter; scales on sacral and femoral regions larger than those on chest; precloacal scales larger than scales on femoral region; midbody scale rows across belly 24 or 25; Non-lamellar scales in the palmar and plantar regions heterogeneous in size, flat, rounded and juxtaposed on palm and sole; scales on dorsal aspect of upper arm larger than granules on dorsum, flat, weakly pointed, sub-imbricate and smooth; dorsal aspect of forearm with smaller, sub-imbricate scales intermixed with a few rounded granules around the elbow; scales on dorsal aspect of hand and digits larger than those on forearm, flat, weakly pointed and imbricate; scales on anterior aspect of thigh large, flat, imbricate and weakly pointed; rest of the dorsal scales on hindlimb smaller, granular and rounded. Scales on dorsal aspect of foot larger than those on shank, flat, weakly pointed and imbricate.

Forearm (FL/SVL 0.12) and tibia short (CL/SVL 0.14); digits moderately short with relatively long terminal phalanges, strongly clawed; all digits of manus and digits I–IV of pes indistinctly webbed; terminal phalanx of all digits curved, arising angularly from distal portion of expanded lamellar pad, more than half as long as associated toepad; scansors beneath each toe undivided throughout, in a straight transverse series: 6-7-8-9-7 (left manus), 5-7- 8-9-6 (right manus), 6-9-8-11 -7 (left pes), 5-7-8-9-6 (right pes). Relative length of digits (measurements in mm in parentheses): IV (4.5)> III (4.3)> II (4.0)> V (3.4)> I (2.9) (left manus); IV (5.0)> III (4.7)> V (4.2)> II (3.8)> I (2.8) (left pes).

Hemipenes partially everted, followed by six or seven rows of flat, weakly pointed, imbricate scales in the pygal region. Tail entire, rounded at the base, flat beneath, tapering posteriorly, covered above uniformly with round, smooth, flat, sub-imbricate scales that become slightly larger laterally; subcaudal scales larger, with an undivided median series of enlarged scales. An uninterrupted series of 35 precloacofemoral pores that are only faintly visible towards the knee ( Fig 13E ).

Variation in paratypes. Internasals separated by two smaller scales in BNHS 2357 , BNHS 2359 , BNHS 2360 and ZSIK 2989 . Inner postmentals bordered posteriorly by two gular scales in BNHS 2357 and ZSIK 2989 , by four gulars in BNHS 2358 , BNHS 2359 , BNHS 2360 and ZSIK 2988 . Inner postmentals bordered laterally by a smaller, flat scale in BNHS 2357 , BNHS 2359 and ZSIK 2989 . Outer postmentals bordered by three gulars in BNHS 2359 (L) and ZSIK 2988 (R) and five in BNHS 2357 (L) , BNHS 2359 (R) , BNHS 2360 (R) and ZSIK 2989 (R,L) . Outer postmentals not in contact with infralabials in BNHS 2357 and BNHS 2359 and in contact only with infralabial I in ZSIK 2988 (R) and ZSIK 2989 (R,L) . Other morphological variations are listed in Table 8 .

Colour in preservative. Dorsum predominantly dull brown mottled with darker, discontinuous streaks from the snout to the base of tail ( Fig 12A ). Similar mottling faintly visible on dorsal aspect of limbs. Neck with a dark, longitudinal streak, flanked on either side by 2 discontinuous lines emanating from the eye upto the forearm insertion. Inter-orbital region with a single, dark boomerang shaped blotch. Labials as dark as rest of the head with a faint, pattern-less scattering of darker spots on each one. Supralabials bordered by a dark, roughly triangular streak from nostril to eye. Limbs no different from rest of the dorsum. Tail of similar ground colour to dorsum with alternating pale-dark longitudinal bands, the first pair of which is roughly saddle-shaped. Ventral region uniformly cream coloured. Ventral surface of tail pale, with scattered mid-brown speckling in the anterior half and alternating pale-dark bands in the distal half.

Colouration (in life) (based on photographs of an uncollected topotype). Dorsal markings distinct in life ( Fig 15C ). Dorsum creamish with darker mottling and streaks throughout. Head dorsum ground colour, with three distinctly paler patches anterior and posterior to the eye and just above the ear opening. Labials with dark yellow spots. Snout with a mottling of dark and yellow spots. A dark streak emanating from above the third supralabial to eye, continues posteriorly up to posterior-lateral part of head. A dark discontinuous streak originating at the ear opening, continues beyond the forelimb insertion. A dark longitudinal streak at the mid-occipital region, that is flanked by two dark curves. Eight dark blotches along the vertebral region from the neck to the sacrum. Limbs of ground colour with dark blotches scattered irregularly. Anterior portion of tail ground colour, with three distinct dark spots in the vertebral region. Tail regenerated, distinctly banded with alternating light and dark portions. Iris marbled, golden, suffused with prominent dark-brown venation; pupil black with crenulated margins.

Etymology. The specific epithet is an eponym honouring Kerala-born Janaki Ammal, the first Indian woman to obtain a doctorate in Botany in 1931. She obtained a PhD degree in an age when most Indian women were barely allowed a high school education because of prevailing social mores, and made seminal contributions to her fields of cytogenetics and phytogeography.

Suggested Common name. Janaki’s Dravidogecko .

Distribution. Dravidogecko janakiae sp. nov. is presently restricted in distribution to the northern outskirts of Munnar town in Idukki District, Kerala. The habitat is composed of southern west-coast evergreen forests and southern tropical moist deciduous forests ( Champion & Seth 1968). These habitats are at an altitude of 2000–2200 m asl and receive an average annual rainfall of ~ 3600 mm.

Habitat and natural history. The type-series was collected from tree trunks and buildings surrounded by mixed forests composed of evergreen and deciduous trees in the outskirts of Munnar town. Munnar falls under the Alleppey-Mangalore rainfall regime and receives upto 5000 mm of rainfall annually, spread over 144 days ( Pascal 1982). Two species of Cnemaspis and one species of Hemidactylus were found in sympatry with Dravidogecko in the region.

Figures

FIGURE 12. Holotype of D. janakiae sp. nov. A) Full-body dorsal B) Head dorsal C) Head lateral D) Head ventral. Scale bar = 10 mm.

FIGURE 13. Cloacal region showing precloacofemoral pores (indicated by black dots) in the congeners of Dravidogecko. A) D. anamallensis B) D. douglasadamsi sp. nov. C) D. smithi sp. nov. D) D. meghamalaiensis sp. nov. E) D. janakiae sp. nov. F) D. septentrionalis sp. nov. G) D. tholpalli sp. nov. Scale bar = 10 mm

FIGURE 15. A) Dravidogecko smithi sp. nov. (BNHS 2350) from Ponmudi, Tiruvananthapuram, Kerala B) Dravidogecko tholpalli sp. nov. (uncollected specimen) from Kodaikanal town, Dindigul, Tamil Nadu C) Dravidogecko janakiae sp. nov. (uncollected specimen) from Munnar, Idukki, Tamil Nadu.