Hemidactylus vanam CHAITANYA, LAJMI & GIRI, 2018
Can you confirm these amateur observations of Hemidactylus vanam?
|Higher Taxa||Gekkonidae, Gekkota, Sauria, Squamata (lizards: geckos)|
|Common Names||E: Meghamalai Rock Gecko|
|Synonym||Hemidactylus vanam CHAITANYA, LAJMI & GIRI 2018|
Hemidactylus maculatus — BHUPATHY & SATHISKUMAR 2013
Hemidactylus vanam — AMARASINGHE et al. 2021
|Distribution||India (Tamil Nadu)|
Type locality: en-route to the High Wavy Mountains, Tamil Nadu, India (9.7808°N; 77.4427°E, 610 m asl)
|Reproduction||oviparous (manual imputation, fide Zimin et al. 2022)|
|Types||Holotype: NCBS AU158, adult male; collected on 21 November 2016. Collected by R. Chaitanya, Akshay Khandekar and Vanasundara Pandian. Paratypes. NCBS AU159, sub-adult female, NCBS AU160, NCBS AU161, adult females; ESV106, ESV107, adult males, ESV108, adult female; BNHS 2328 sub-adult female, BNHS 2329 adult female; ZSI/WGRC/IR/V.NO 2634, adult male, ZSI/WGRC/IR/V.NO 2635, adult female. Collection data same as holotype; ZSI/WGRC/IR/V.NO 2635, collected near Suruli falls, Theni district (9.6563° N; 77.3061° E, 430 m asl).|
|Diagnosis||Diagnosis: A large sized Hemidactylus, SVL averaging 88.24 ± 16 mm to a maximum of at least 112.2 mm (n=9). Dorsal pholidosis heterogeneous, composed of roughly circular, striated, granular scales intermixed with much enlarged, fairly regularly arranged longitudinal rows of 17–19 strongly keeled, striated tubercles that are heterogeneous in shape and size, extending from occipital region to tail (Fig. 1); enlarged tubercles on the two most medial parasagittal rows are small, flat, strongly keeled and rounded gradually increasing in size and becoming conical towards flanks, last two to three rows on flanks are smaller and strongly conical. Two well-developed pairs of postmentals, inner pair much larger than the outer and in broad contact with each other behind the mental. Ventrolateral folds distinct. About 34–40 scale rows across the venter. All digits with enlarged scansors, lamellae in straight transverse series, all divided except the apical and a few basal that are undivided, 10–12 (manus and pes) lamellae beneath fourth digit and 9–10 (manus) and 8–9 (pes) beneath first digit. Femoral pores on each side 17– 22, separated by 10–11 poreless scales in males. Dorsal coloration pale-brown with transversely arranged saddleshaped markings running from the occiput to the sacrum that are of a darker shade. The large size (up to 112.2 mm SVL) of Hemidactylus vanam sp. nov. can be used to easily diagnose it from most other congeners from the Indian subcontinent and Southeast Asia, including H. garnotii Duméril & Bibron, H. platyurus (Schneider), H. aquilonius McMahan & Zug, H. scabriceps (Annandale), H. imbricatus Bauer, Giri, Greenbaum, Jackman, Dharne & Shouche, H. gracilis Blanford, H. reticulatus Beddome, H. albofasciatus Grandison & Soman, H. sataraensis Giri & Bauer, H. brookii Gray, H. gujaratensis Giri, Bauer, Vyas & Patil, H. frenatus Schlegel, H. persicus Anderson, H. robustus Heyden, H. parvimaculatus Deraniyagala, H. treutleri Mahony, H. gleadowi Murray, H. kushmorensis Murray, H. murrayi Gleadow, H. chipkali Mirza & Raju, H. triedrus (Daudin), H. subtriedrus Jerdon, H. lankae Deraniyagala, H. depressus Gray, H. pieresii Kelaart, H. leschenaultii Duméril & Bibron, and H. flaviviridis Rüppel all of which reach maximum sizes of up to 90 mm SVL. Hemidactylus vanam sp. nov. shares its large adult size (adult SVL upto 112.2 mm) only with H. giganteus Stoliczka, H. aaronbaueri Giri, H. yajurvedi Murthy, Bauer, Agarwal, Lajmi & Giri, H. hemchandrai Dandge & Tiple, H. prashadi Smith, H. hunae Deraniyagala, H. graniticolus Agarwal, Giri & Bauer, H. maculatus Duméril & Bibron, H. acanthopholis, H. kangerensis Mirza, Bhosale & Patil and H. sushilduttai Giri, Bauer, Mohapatra, Srinivasulu & Agarwal. Hemidactylus giganteus differs from H. vanam sp. nov. in the complete absence of enlarged dorsal tubercles while H. aaronbaueri, H. yajurvedi and H. hemachandrai have slightly enlarged, rounded, weakly-keeled tubercles at midbody. Hemidactylus prashadi, H. hunae, H. graniticolus H. kangerensis and H. sushilduttai differ from the new species in dorsal pholidosis, number of femoral pores and the number of poreless scales separating them (differing character states indicated in parenthesis): Hemidactylus prashadi (weakly keeled, sub-trihedral, slightly enlarged dorsal tubercles arranged in 14–16 rows; 17–20 femoral pores separated by 3 poreless scales), H. hunae (keeled, sub-trihedral, slightly enlarged dorsal tubercles arranged in 16– 20 rows; 22–24 femoral pores separated by 3–6 poreless scales), H. graniticolus (keeled, sub-trihedral, slightly enlarged dorsal tubercles arranged in 16–18 rows; 23–28 femoral pores separated by 1–3 poreless scales), H. kangerensis (keeled, trihedral, enlarged dorsal tubercles arranged in 18–20 rows; 18–21 femoral pores separated by four poreless scales), H. sushilduttai (keeled, trihedral, enlarged dorsal tubercles arranged in 16–17 rows; 19–24 femoral pores separated by four poreless scales. Based on size, dorsal pholidosis and general colouration, Hemidactylus vanam sp. nov. is most similar to H. maculatus and H. acanthopholis but can be diagnosed on the basis of the following combination of characters: dorsal pholidosis, femoral pores and the number of poreless scales separating them (differing character states indicated in parenthesis): H. maculatus (enlarged tubercles trihedral throughout, parasagittal rows slightly smaller; 16–19 femoral pores separated by 5–9 poreless scales), H. acanthopholis (enlarged tubercles trihedral, parasagittal rows slightly smaller, last few rows on flanks, slightly conical; 19–21 femoral pores separated by 13–14 poreless scales) (Fig. 6). Additionally, H. vanam sp. nov. can be diagnosed from H. maculatus and H. acanthopholis by the presence of a dense aggregation of enlarged, strongly conical, striated tubercles on dorsal aspect of thigh (enlarged tubercles on dorsal aspect of thigh sparse in H. maculatus and H. acanthopholis) (Fig. 3; Chaitanya et al. 2018).|
|Comment||Habitat: rupicolous; occasionally found on the higher branches of trees that surround rocky boulders; rock crevices during the day.|
Behavior: These strictly nocturnal geckos are seen occupying rock crevices during the day when they are easily disturbed by human presence.
Sympatry: Psammophilus cf. dorsalis, Cnemaspis sp. and Hemidactylus cf. triedrus.
|Etymology||The specific epithet is a noun in apposition honouring Vanam (pronounced vʌnʌm), a nongovernmental organization based in Theni District, Tamil Nadu, India, for carrying out exemplary conservation work in the region. Their unwavering support has been vitally important to our work in the Meghamalai Wildlife Sanctuary.|