Dravidogecko anamallensis ( Günther, 1875 )

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 : 14-16

Dravidogecko anamallensis ( Günther, 1875)

( Figs 4A, 4B , 6 A–D, 13A; Table 5 )

Gecko anamallensis: Günther, 1875 .

Hoplodactylus anamallensis: Boulenger, 1885

Hoplodactylus anamallensis —Annandale, 1905 ; etc.

Hoplodactylus anamallensis [non Gecko anamallensis Günther, 1875 ] — Boulenger, 1885 [partim]; Boulenger, 1890 [partim]; Boettger, 1893.

Dravidogecko anamallensis: Smith, 1933

Dravidogecko anamallensis — Mirza & Sanap, 2014 ;

Dravidogecko anamallensis [non Gecko anamallensis Günther, 1875 ] — Smith, 1935 [partim]; Kluge, 1991; Murthy, 1993; Radhakrishnan, 1999; Sharma, 2002 [partim]; Palot, 2015; etc.

Hemidactylus anamallensis: Bauer & Russell, 1995

Hemidactylus anamallensis — Giri & Bauer, 2008 , Aengals et al., 2010; Venugopal, 2010; Agarwal, Giri & Bauer, 2011; Mahony, 2011; Ganesh & Chandramouli, 2013; Venkatraman, Chattopadhyay & Subramanian, 2013; Srinivasulu & Srinivasulu, 2015; etc.

Hemidactylus anamallensis [non Gecko anamallensis Günther, 1875 ] — Johnsingh, 2001; Ganesh, 2010 [partim]; Chandramouli SR & Ganesh SR, 2010; Philip, Arjun & Joy, 2011; Srinivasulu, Srinivasulu & Molur, 2014 [partim]; etc.

Holotype. By monotypy, BMNH 1946.8 .23.61, an adult male collected by Colonel Richard Henry Beddome from the “ Anamallay mountains ”.

Type locality. “ Anamallay ” mountains, restricted to Valparai town in Coimbatore district, Tamil Nadu, herein.

Referred specimens (Topotypes). ZSIK 2969 and ZSIK 2970 , adult females, Valparai town (10.3263°N, 76.9551°E; ca. 1100 m asl.), Coimbatore District , Tamil Nadu, collected by R. Venkitesan, RC and ADR on 10 th December, 2016 .

Summarized description and diagnosis. Snout-vent length up to 54 mm (n=3); rostral groove indistinct; two pairs of well-developed postmentals, inner pair much longer than the mental and outer postmentals, in strong contact behind the mental, bordered by infralabial I, mental, outer postmentals and 2 or 3 gular scales; ventral scales counted at midbody, 25–28; precloacofemoral pores, 45 or 46 (n=2); subdigital lamellae under digit IV of manus, 8–10 and under digit IV of pes, 11 or 12; supralabials, 9–12 and infralabials, 7 or 8 on each side.

Dravidogecko anamallensis can be distinguished easily from other congeners by the presence of 45 or 46 precloacofemoral pores and a pair of distinctly longer postmentals (longer than mentals ML /1PML 0.74–0.81).

Genetic divergence (p-distance). Dravidogecko anamallensis exhibits 2% intraspecific variation for the mitochondrial ND2 gene ( Table 9 ).

Redescription of holotype. The holotype is curved towards the left when viewed dorsally, first two fingers of each forelimb stretched out from the rest towards the body, a minor laceration at the hindlimb insertion and a transverse laceration at the base of the tail—all possibly artefacts of preservation ( Fig 6A ). Tail regenerated with a bifid tip, possibly an abnormality. Adult male, SVL 44.8 mm. Head short ( HL / SVL 0.27), slightly elongate ( HW / HL 0.70), slightly depressed ( HH / HW 0.57), distinct from neck. Loreal region slightly inflated, canthus rostralis indistinct ( Fig 6C ). Snout short ( SE / HL 0.41), longer than orbital diameter ( OD / SE 0.47); 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 6B ). Eye small ( OD / HL 0.19); pupil vertical with crenulated margins; supraciliaries small, rounded, directed outwards, increasing marginally in size anteriorly. Ear opening elliptical (longer diameter 1.7 mm); eye to ear distance longer than diameter of eye ( EE / OD 1.54 ). Rostral wider than deep ( RL / RW 0.36), rostral groove indistinct; two large, roughly circular internasals, separated by a smaller 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 in nasal, about the size of the lower postnasal, roughly circular with nasal pad visible posteriorly, surrounded by internasal, rostral, two postnasals and supralabial I on either side; 2–4 rows of scales separate orbit from supra- labials around mid-orbital position. Supralabials roughly rectangular, increasing in length anteriorly. Supralabials (to midorbital position) 8 (right), 8 (left); supralabials (to angle of jaw) 11 (right), 12 (left); infralabials (to angle of jaw) 8 (right), 8 (left). Mental triangular; two pairs of postmentals, both longer than the mental, the inner pair much longer (1.6 mm) than the mental (1.2 mm), and in strong contact with each other (1.2 mm) behind mental, outer pair marginally longer than mental (1.4 mm), separated from each other by three gular scales that are smaller than postmentals ( Fig 6D ). Inner postmentals bordered by mental, infralabial I, outer postmentals and three smaller gular scales that separate the outer postmentals; outer postmental on both sides bordered by infralabials I and II, inner postmental, and four smaller gular scales of dissimilar sizes. Outer postmental on right appears to be medially divided .

Body dorsoventrally flattened, relatively slender, elongate (TRL/SVL 0.47). Dorsal pholidosis homogenous, composed of small, rounded granules throughout, becoming slightly larger at the lateral aspects; Ventral scales larger than dorsals, largely homogeneous in shape increasing marginally in size posteriorly, smooth, flat, weakly pointed and sub-imbricate; gular region with smaller, granular scales, anterior-most gular scales visibly larger, flatter; scales on sacral and femoral regions larger than those on chest; precloacal scales largest; midbody scale rows across belly 25 or 26; Non-lamellar scales in the palmar and plantar regions heterogeneous in size, flat, rounded, juxtaposed on palm and sub-imbricate on sole; scales on dorsal aspect of upper arm much 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, sub-imbricate and weakly pointed; rest of the dorsal scales on hindlimb smaller, granular and rounded. Scales on dorsal aspect of feet and toes larger than those on shank, flat, weakly pointed and imbricate.

Forearm (FL/SVL 0.12) and tibia short (CL/SVL 0.15); digits moderately short with relatively long terminal phalanges, strongly clawed; 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: 6-7-8-8-7 (left manus), 5-8-8-8-7 (right manus), 6-9-9-12 -7 (left pes), 6-9-7-11 -7 (right pes).

Tail regenerated, rounded at the base, flat beneath, tapering posteriorly, covered above uniformly with round, smooth, flat, sub-imbricate scales that become slightly larger laterally; Pygal portion of tail with 11 or 12 rows of flat, weakly pointed, sub-imbricate scales; subsequent subcaudal scales larger, with an undivided median series of enlarged scales extending to tail tip. Tail tip bifid. An uninterrupted series of 45 precloacofemoral pores that are indistinct towards the knee ( Fig 13A ).

Variation in referred specimens (Topotypes). The referred specimens ZSIK 2969 and ZSIK 2970 differ from the holotype as follows: Inner postmentals bordered posteriorly by 2 gular scales and outer postmentals bordered by 5 gulars in ZSIK 2969 and 3 gulars in ZSIK 2970 on either side. Other morphological variations are listed in Table 5 . An uncollected male topotype was observed to have 46 femoral pores ( Fig 4B ).

Colour in preservative. Dorsum uniformly brown, darker mottling faintly visible from the snout to the base of tail ( Fig 6A ). Neck with a dark, discontinuous longitudinal streak, flanked at the break by two dark lines at a 45° angle. A slightly darker discontinuous line emanates from the eye, following the lateral aspect of head and extending just beyond the forearm insertion. Inter-orbital region with a scattering of dark spots, with a distinct dark blotch bordering the supraciliary region on either side. Labials of similar color as the rest of the head with a faint, patternless scattering of darker spots bordering each labial. A dark, roughly rectangular streak emanates from eye up to the nostril. Limbs no different from rest of the dorsum. Tail of similar ground colour to dorsum, the regenerated portion with a scattering of slightly darker streaks throughout. Ventral region creamy with a scattering of dark spots on each ventral scale. Ventral surface of tail uniformly pale.

Colouration (in life) (based on photographs of an uncollected topotype). Dorsal markings distinct in life ( Fig 4A ). Dorsum creamish with darker streaks throughout. Head dorsum ground colour, snout with a mottling of dark and yellow spots. A dark streak emanating from above the first supralabial to eye, continues posteriorly up to the forelimb insertion. Yellow blotches on the labials and supraciliaries. Forehead ground colour, with a roughly inverted ‘V’ shaped pattern emerging from between the eyes which is followed posteriorly by two dark spots. Seven irregular, dark streaks from the forelimb insertion to the sacral region, flanked on either side by dark spots. Limbs of ground colour with dark spots scattered irregularly. Anterior portion of tail ground colour, with three distinct, dark spots in the vertebral region. Posterior portion of tail, 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 adjectival toponym referring to the Anaimalai Hills in the southern Western Ghats from which Col. Beddome collected the holotype of this species.

Suggested Common name. Anaimalai Dravidogecko .

Distribution. Previously reported from various localities in Kerala and Tamil Nadu ( Boulenger 1885; Smith 1935; Murthy 1993; Johnsingh 2001; Philip et al. 2011), Dravidogecko anamallensis is restricted in distribution herein, to the Valparai Plateau in Coimbatore District, Tamil Nadu. Its occurrence in other regions of the Anaimalai Hills requires verification.

Habitat and natural history. The Valparai Plateau is dominated by monoculture plantations such as tea, coffee and Eucalyptus that are sparsely interspersed with natural evergreen and riparian fragments. The natural vegetation in the region is classified as mid-elevation tropical wet evergreen forest of the Cullenia-Mesua-Palaquium type ( Pascal 1988). Specimens of Dravidogecko anamallensis were chiefly found in abandoned buildings that were amidst natural vegetation. Other geckos in sympatry with them were a species each of the genera Cnemaspis and Hemidactylus .

Taxonomic notes. Günther (1875) described Gecko anamallensis based on a single specimen in the BMNH, collected by Col. Beddome from the “ Anamallay ” mountains. He did not explicitly state the gender of the specimen, but mentioned a lack of femoral or preanal pores, alluding to a female specimen. Boulenger (1885) noted that the type specimen was female and reported many other non-types from “Tinnevelly” while providing a general description of his Hoplodactylus anamallensis based on all these specimens. However, the only specimen from “ Anamallay ”, BMNH 1946.8.23.61, demarcated as the name bearing type for Dravidogecko anamallensis was examined by DV and ascertained to be a male with 45 precloacofemoral pores and distinctly elongate postmentals. Recently observed samples from Valparai in the Anaimalai Hills also conform to these diagnostic characters ( Fig 4B , Table 5 ), eliminating doubt that the specimen BMNH 1946.8.23.61 was indeed from “Anamallay” and therefore must be the original name bearing type. Günther possibly misidentified the gender of the type specimen which then got promulgated and has clearly been accepted unequivocally by later workers. The other specimens (BMNH 82.5.22.79–82) from “Tinnevelly” are herein considered topotypes of D. douglasadamsi sp. nov. (described below).

Figures

FIGURE 4. A) In-situ photograph of an uncollected specimen of D. anamallensis B) Cloacal region showing precloacofemoral pores in an uncollected specimen of D. anamallensis C) Undivided lamellae on the right manus of D. septentrionalis sp. nov.

FIGURE 6. Holotype of D. anamallensis. 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