Research Article |
Corresponding author: Ishan Agarwal ( ishan.agarwal@gmail.com ) Academic editor: Uwe Fritz
© 2023 Ishan Agarwal, Tejas Thackeray, Akshay Khandekar.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Agarwal I, Thackeray T, Khandekar A (2023) Two new spotted species of the Cyrtodactylus (Geckoella) collegalensis (Beddome, 1870) complex from the south-eastern coast of India (Reptilia: Squamata). Vertebrate Zoology 73: 475-498. https://doi.org/10.3897/vz.73.e102602
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We describe two new spotted species of ground-dwelling gecko of the genus Cyrtodactylus (Geckoella) from southeastern India in an integrative taxonomic framework. The new species are recovered as sister taxa within the C. collegalensis species complex, with 13.0–16.7% uncorrected mitochondrial sequence divergence from the other eight members of the C. collegalensis complex and 10.4% from one another. The new species are morphologically diagnosed by a spotted dorsal pattern of four pairs of spots (occasionally fused into figure 8-shaped markings) from the banded species C. aravindi, C. speciosus, C. rishivalleyensis and C. yakhuna; and from the spotted species with three or fewer pairs of spots in C. collegalensis and C. srilekhae; and from C. chengodumalaensis by the absence of any enlarged dorsal scales and from C. varadgirii by the absence of a patch of enlarged roughly hexagonal scales on the canthus rostralis and beneath the angle of the lower jaw. The two new species can only be differentiated from each other based on slight differences in body size, relative body width and other statistically significant, size-corrected morphometric characters. These are among the first endemic lizards from Tropical Dry Evergreen habitats along the southeast coast of India.
Cryptic species, endemic species, integrative taxonomy, mitochondrial DNA, southern India, taxonomy
Peninsular India is an incredibly biodiverse landscape, encompassing part of the Western Ghats-Sri Lanka Biodiversity Hotspot. Besides the unique geological history of the Indian plate (
The genus Cyrtodactylus is the most diverse gekkonid and third most diverse vertebrate genus, including over 340 species distributed from the Western Himalayas through South and Southeast Asia to the Western Pacific (
Phylogenetic relationships within Geckoella are well understood, the Sri Lankan C. triedrus (Günther, 1864) complex forming the sister taxon to the remaining species; which are split into a wet zone subclade that includes the C. albofasciatus (Boulenger, 1885) and C. deccanensis (Günther, 1864) complexes; and a dry zone subclade which includes C. jeyporensis (Beddome, 1878) as the sister taxon to the C. nebulosus (Beddome, 1870) complex; and the C. collegalensis (Beddome, 1870) complex with seven species in India and one in Sri Lanka (
Map showing localities sampled for phylogenetic analyses of members of the Cyrtodactylus (Geckoella) collegalensis complex in southern India and Sri Lanka (C. varadgirii is not shown), stars represent the type localities of the two new species. Light blue, C. irulaorum sp. nov.; dark blue, C. relictus sp. nov.; light green, C. aravindi; brown, C. chengodumalaensis; white fill, C. collegalensis; black, C. speciosus; dark green, C. srilekhae; yellow, C. rishivalleyensis; grey fill, C. yakhuna.
Specimens were collected by hand and photographed with a Nikon D300 SLR camera with a 60 mm macro lens and external flashes, followed by euthanasia with an overdose of halothane/ isoflurane. Liver or tail samples were collected in molecular grade ethanol and subsequently stored at –20 °C. Specimens were fixed in 4% formaldehyde for ~24 hours to a few weeks, subsequently rinsed in water and transferred to 70% ethanol for long-term storage. Specimens are deposited in the museum and research collection facility at the National Centre for Biological Sciences, Bengaluru (NCBS/NRC).
We extracted genomic DNA from liver/tail-tips using the Qiagen DNeasy kit and amplified and sequenced the mitochondrial gene ND2 (1038 base pairs, bp) using the primers MetF1 (L4437) and H5540 (
List of sequences used in this study with museum number, locality and GenBank accession number. Museum and voucher abbreviations: ADS = Anselm de Silva field series; BNHS = Bombay Natural History Society, Mumbai; CES/ESV = Centre for Ecological Sciences, Bangalore; DMSSK = D.M.S. Suranjan Karunarathna field series; IAG = Ishan Agarwal field series; JB = John Boone private collection; NCBS/ NRC = National Centre for Biological Sciences, Bangalore; ZSI = Zoological Survey of India, Kolkata.
Species | Museum No. | Locality | GenBank Accession Numbers | |
---|---|---|---|---|
C. aravindi | ZSI-R 28275 | India: Tamil Nadu, Kanyakumari district, Nagercoil | OP131039 | collegalensis complex |
C. chengodumalaensis | NRC-AA-1163 (CES09/1410) | India: Kerala, Thrissur District, Mannuthy | OP271668 | |
C. chengodumalaensis | NRC-AA-1166 (CES09/1411) | India: Kerala, Thrissur District, Mannuthy | OP271669 | |
C. chengodumalaensis | BNHS 2812 (CES09/1412) | India: Kerala, Calicut District, Narayamkulam | OP271670 | |
C. chengodumalaensis | NRC-AA-1161 (CES09/1449) | India: Kerala, Malappuram District, Kumaragiri Estate | OP271671 | |
C. chengodumalaensis | BNHS 2817 (AK665) | India: Kerala, Palakkad District, Cheeni Paara | OP271672 | |
C. collegalensis | CES09/1403 | India: Tamil Nadu, Salem District, Mettur Taluk | KX632365 | |
C. collegalensis | CES09/1442 | India: Karnataka, Chamarajanagar District, Male Mahadeshwar Hills | KX632362 | |
C. collegalensis | CES09/1443 | India: Karnataka, Chamarajanagar District, Kollegal Taluk | KX632363 | |
C. collegalensis | CES09/1444 | India: Karnataka, Chamarajanagar District, MM Hills | KM878627 | |
C. collegalensis | CES09/1463 | India: Karnataka, Chamarajanagar District, MM Hills | KX632364 | |
C. irulaorum sp. nov. | CES09/1363 | India: Tamil Nadu, Villupuram District, near Vallam RF | OQ674252 | |
C. irulaorum sp. nov. | CES09/1365 | India: Tamil Nadu, Villupuram District, near Vallam RF | OQ674252 | |
C. irulaorum sp. nov. | NRC-AA-1266 (CES09/1438) | India: Tamil Nadu, Villupuram District, near Vallam RF | OQ674252 | |
C. irulaorum sp. nov. | NRC-AA-1270 (CES09/1441) | India: Tamil Nadu, Villupuram District, near Vallam RF | OQ674253 | |
C. irulaorum sp. nov. | NRC-AA-1271 (IAG 193) | India: Tamil Nadu, Tiruvallur District, near Thervoy Kandigai | OQ674254 | |
C. relictus sp. nov. | NRC-AA-1275 (CES09/1470) | India: Andhra Pradesh, Chittoor District, Kambakkam Durg | OQ674255 | |
C. relictus sp. nov. | NRC-AA-1276 (CES09/1471) | India: Andhra Pradesh, Nellore District, near Penchalakona | OQ674256 | |
C. relictus sp. nov. | NRC-AA-1274 (CES09/1472) | India: Andhra Pradesh, Nellore District, near Penchalakona | OQ674257 | |
C. rishivalleyensis | ESV 104 (CES09/1245) | India: Andhra Pradesh, Chittoor District | KX698080 | |
C. rishivalleyensis | ESV 103 (CES09/1452) | India: Andhra Pradesh, Chittoor District | KX698081 | |
C. cf. speciosus | CES09/1405 | India: Tamil Nadu, Coimbatore District, Coimbatore North Taluk | KM878623 | |
C. cf. speciosus | CES09/1249 | India: Tamil Nadu, Salem District, below Yercaud | KM878629 | |
C. srilekhae | ESV 101 (CES09/1432) | India: Karnataka, Bengaluru Rural District | KX698082 | |
C. srilekhae | ESV 102 (CES09/1461) | India: Karnataka, Bengaluru Rural District | KX698083 | |
C. srilekhae | CES09/1536 | India: Karnataka, Tumkur District, Devarayandurga | KX698084 | |
C. varadgirii | BNHS 1848 | India: Maharashtra, Mumbai | KX632366 | |
C. varadgirii | BNHS 1849 | India: Maharashtra, Mumbai | KX632367 | |
C. varadgirii | BNHS 2099 | India: Gujarat, Navsari District, Vansda | KX632368 | |
C. varadgirii | CES09/1381 | India: Gujarat, Navsari District, Chikhli | KM878612 | |
C. varadgirii | CES09/1433 | India: Gujarat, Navsari District, Kangvai | KX632369 | |
C. yakhuna | DMSSK 159 | Sri Lanka: Polonnaruwa District, Giritale Forest | MW713942 | |
C. albofasciatus | CES09/1109 | India: Karnataka, Chikmagalur District, Kudremukh | KM878626 | Geckoella |
C. albofasciatus | CES09/1117 | India: Karnataka, Shimoga District, Nagavalli | KM878625 | |
C. cf. albofasciatus | CES09/1391 | India: Maharashtra, Kolhapur District, Patgaon | KM878610 | |
C. cf. albofasciatus | CES09/1418 | India: Goa, North Goa District, Chorla Ghat | KM878611 | |
C. cf. albofasciatus | JB7 | India: captive (from Indian stock) | JX440521 | |
C. deccanensis | CES09/1112 | India: Maharashtra, Satara District, Bhairavgad | KM878615 | |
C. deccanensis | CES09/1243 | India: Maharashtra, Thane District, Malshej Ghat | KM878614 | |
C. deccanensis | CES09/1380 | India: Maharashtra, Nashik District, Amboli | KM878613 | |
C. cf. deccanensis | CES09/1396 | India: Maharashtra, Kolhapur District, Panhala | KM878628 | |
C. jeyporensis | CES09/1206 | India: Orissa, Koraput District, Deomali | KM878617 | |
C. jeyporensis | CES09/1356 | India: Andhra Pradesh, Visakhapatnam District, Araku Valley | KM878616 | |
C. nebulosus | CES09/1351 | India: Andhra Pradesh, Visakhapatnam District, Narsipatnam | KM878618 | |
C. cf. nebulosus | CES09/1118 | India: Orissa, Mayurbhanj District, Baripada | KM878620 | |
C. cf. nebulosus | CES09/1119 | India: Orissa, Mayurbhanj District, Tikarpada | KM878619 | |
C. cf. nebulosus | CES09/1205 | India: Orissa, Koraput District, Gupteswar | KM878621 | |
C. cf. nebulosus | CES09/1374 | India: Madhya Pradesh, Anuppur District, Amarkantak | KM878622 | |
C. punctatus | DMSSK 180 | Sri Lanka: Matale District, Knuckles | MW713941 | |
C. triedrus | DMSSK 011 | Sri Lanka: Kandy District, Dunumadalawa Forest | MW713937 | |
C. vedda | ADS35 | Sri Lanka: Yakkunehela | JX440522 | |
Cyrtodactylus fraenatus | DMSSK 046 | Sri Lanka: Kandy District, Gannoruwa | MW713940 | fraenatus group |
Cyrtodactylus soba | DMSSK 124 | Sri Lanka: Matale District, Knuckles | MW713938 |
Uncorrected p-distance between members of the C. collegalensis complex was calculated in MEGA 5.2 using the pairwise deletion option (Table
Uncorrected pairwise genetic distance (mitochondrial ND2 gene, 1038 nt) between species of the Cyrtodactylus (Geckoella) collegalensis complex. Along diagonal, range of variation within species with multiple samples.
Species | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
1 | C. irulaorum sp. nov. | 0.0–0.6 | ||||||||
2 | C. relictus sp. nov. | 10.4 | 0.7–1.6 | |||||||
3 | C. aravindi | 13.2 | 13.7 | - | ||||||
4 | C. chengodumalaensis | 14.2 | 14.8 | 10.5 | 0.1–1.3 | |||||
5 | C. collegalensis | 16.7 | 16.6 | 14.7 | 14.5 | 0.0–4.7 | ||||
6 | C. rishivalleyensis | 15.6 | 14.6 | 12.0 | 11.7 | 13.4 | 0.6 | |||
7 | C. cf. speciosus | 15.2 | 14.7 | 12.8 | 13.0 | 14.4 | 12.0 | 6.4 | ||
8 | C. srilekhae | 16.0 | 15.4 | 12.1 | 12.3 | 14.1 | 8.7 | 11.3 | 0.8–1.0 | |
9 | C. varadgirii | 13.0 | 13.7 | 11.8 | 13.6 | 14.3 | 11.0 | 13.8 | 12.4 | 0.1–1.6 |
10 | C. yakhuna | 13.7 | 15.0 | 10.5 | 10.0 | 13.8 | 11.9 | 12.8 | 11.8 | 11.4 |
We conducted partitioned BI in MrBayes using the best-fit models and parameters estimated in PartitionFinder 2. The analysis had two parallel runs and four chains each (one cold and three hot) and was run for 2,000,000 generations sampling every 200 generations. Convergence was determined based on the standard deviation of split frequencies (<<0.01) and the first 25% of trees were discarded as burn-in. A Maximum Clade Credibility tree was generated using TreeAnnotator 1.10.4 (
Our phylogeny and dataset overlap almost entirely with a recently published phylogeny that used a distance-based and two tree-based methods for species delimitation (
A total of eight and three specimens of each new species were used for morphological data and comparisons were made with all species of the Cyrtodactylus collegalensis complex based on material in the collections of the
Natural History Museum, London (
We recorded colour pattern elements following
As preliminary data demonstrated the two new species described herein were easily diagnosable in colour pattern from all known species of the collegalensis complex, but not from each other (see results), we conducted detailed morphological analyses for only the two new species. Analyses were conducted in R 4.1.3 (
Our dataset overlaps closely with recently published phylogenies for the group (
Maximum likelihood phylogeny of the Cyrtodactylus (Geckoella) collegalensis complex with inset showing PCA plots for the three data treatments: A allometric, B raw and C ratios. Other members of the triedrus group are not shown. Posterior probability (≥0.98)/ ML bootstrap support (≥70) for RaXML/ IQTree shown at nodes. Note that sequences for CES09/1363 and CES09/1365 are identical to NRC-AA-1266 and are not shown in the tree (Table
The lowest genetic divergence between described members of the collegalensis complex is at 8.7% between Cyrtodactylus (Geckoella) srilekhae and C. rishivalleyensis. Employing this cut-off recovered 11 species — C. aravindi, C. collegalensis, C. chengodumalaensis, C. rishivalleyensis, C. cf. speciosus (two lineages), C. srilekhae, C. varadgirii, C. yakhuna and one unnamed lineage each from southeast coastal regions of Andhra Pradesh and Tamil Nadu.
The PCAs using raw data and size corrected data were qualitatively very similar and showed the two putative species separated across PC1 (Fig.
The two lineages from the southeast coast are genetically divergent from one another and reciprocally monophyletic, besides being separated in multivariate morphological space with significantly different values for traits using different analytical methods. Below, we formally describe Cyrtodactylus (Geckoella) irulaorum sp. nov. and C. relictus sp. nov. based on morphological data.
NRC-AA-1266 (CES09/1438), adult male, from a farm near Vallam Reserve Forest (12.6920°N, 80.0263°E; ca. 55 m asl.), Kancheepuram District, Tamil Nadu, India, collected by Ishan Agarwal on 10th April 2013.
NRC-AA-1267 (CES09/1437), NRC-AA-1268 (CES09/1439), NRC-AA-1269 (CES09/1440), NRC-AA-1270 (CES09/1441), adult males, same collection data as holotype; NRC-AA-1272 (AK 105), NRC-AA-1273 (AK 106), adult females, same collection data as holotype except collected by Ishan Agarwal, Akshay Khandekar, R. Chaitanya and Caleb Daniel on 11th November 2017; NRC-AA-1271 (IAG 193), adult female, from Thervoy Kandigai (13.3713°N, 79.9791°E; ca. 30 m asl.), Tiruvallur District, Tamil Nadu, India, collected by R. Chaitanya on date 14th December 2015.
The specific epithet is a patronym in honour of the Irula tribe, an indigenous Dravidian group who are expert snake trackers and catchers. Romulus Whitaker, whose farm the type series was collected at, has worked closely with the Irulas for decades and helped them set up a venom extraction cooperative in 1978. The Irula Snake Catchers’ Industrial Cooperative Society is the largest contributor to antivenom production in India.
Irula Geckoella.
A small-sized Cyrtodactylus (Geckoella), snout to vent length up to 51 mm (n = 8); tail shorter than SVL. Dorsal pholidosis on trunk homogeneous; covered with smooth, subcircular, weakly conical granular scales; scales on occiput and nape slightly smaller and more rounded than those on body dorsum, scales on flank slightly larger than those on dorsum; ventral scales much larger than dorsal scales, smooth, somewhat elongate, subimbricate, subequal from chest to vent; femoral and precloacal pores absent; enlarged precloacal or femoral scales absent, no precloacal groove; four pairs of dark rounded spots from behind occiput to hindlimb insertions, spots occasionally fused along mid-vertebral line forming horizontal figure 8-shaped marking; post-occipital collar broken into a pair of spots.
The diagnostic characters listed above for Cyrtodactylus (Geckoella) irulaorum sp. nov. easily differentiate the new species from all other Cyrtodactylus and Cyrtodactylus (Geckoella) apart from members of the collegalensis complex. Cyrtodactylus (Geckoella) irulaorum sp. nov. can be differentiated from the other members of the complex by its dorsal colour pattern of four pairs of dark spots from behind occiput to hindlimb insertions (spots may be fused centrally forming horizontal figure 8-shaped markings) from C. aravindi (a single dark broad band and one or two single dark spots on dorsum), C. collegalensis (three pairs of dark spots that may be fused forming horizontal figure 8-shaped markings), C. rishivalleyensis (two broad dark bands on dorsum), C. srilekhae (three rows of irregular dark blotches), C. speciosus (two broad dark bands on dorsum) and the Sri Lankan species C. yakhuna (one or two broad dark bands or spots on dorsum in both subspecies). The new species is most similar in colour pattern to C. chengodumalaensis and C. varadgirii (4–6 pairs of dark spots on dorsum) but can be distinguished by the absence of a few, enlarged dorsal tubercles on the dorsum (versus the presence of these tubercles in C. chengodumalaensis) and by the absence of a patch of enlarged roughly hexagonal scales on the canthus rostralis and beneath the angle of the lower jaw (versus the presence of these enlarged scales in C. varadgirii). Cyrtodactylus (Geckoella) irulaorum sp. nov. is closely allied to Cyrtodactylus (Geckoella) relictus sp. nov. and is diagnosed as part of the species description below.
Adult male in good state of preservation except head slightly bent towards left and tail significantly bent towards right side, and a 5.7 mm vertical incision in the sternal region for liver tissue collection (Fig.
Body relatively slender (BW/AGL 0.41), trunk less than half of SVL (AGL/SVL 0.43) without ventrolateral folds. Dorsal pholidosis on trunk homogeneous; covered with smooth, subcircular, weakly conical granular scales; 20 dorsal midbody scale rows across trunk contained within one eye diameter (Fig.
Scales on palm and soles granular, smooth, rounded; scales on dorsal aspects of limbs heterogeneous in shape and size; mixture of small, granules similar to dorsum and many smooth flattened and imbricate scales which are much larger than granules on the body dorsum, largest on anterior aspect of the hands and feet; lateral and ventral aspects of limbs with small granular scales (Fig.
Tail original, circular in cross section with indistinct median dorsal furrow, relatively thick, tapering gradually to tip, unsegmented, slightly shorter than snout-vent length (TL/SVL ratio 0.78). Scales on dorsal aspect of tail base similar to body dorsum; scales on dorsal aspect of tail large flat, subcircular, smooth, and imbricate, becoming slightly larger towards the lateral aspect, largest on ventral side, but not forming median row of transversely enlarged subcaudal scales. Three small, smooth, subequal, conical postcloacal spurs on left side and two on right side of tail base; prominent hemipenal swelling, flap of skin covering cloacal aperture. Tail slightly constricted at the base (Fig.
Dorsal ground colour light tan, four pairs of dark brown spots from behind occiput to hindlimb insertions and a smaller darker pair above tail base. Spots on the left side of the body in the first and second pair fused, other pairs except the fourth separated mid-vertebrally, second pair of spots slightly larger than the rest and first smallest. Spots edged by black on the outer 1–5 rows of scales, finest along flanks and absent in fused portion of fourth set of spots. Flank with only a few scattered fine black spots. Tail dorsum similar in ground colour to body dorsum except slightly suffused with yellow; a dark small pair of spots on tail base and six indistinct darker crossbars reducing in size toward tail-tip, anteriorly forming black edged brown bands. Dorsum of limbs similar in colour to trunk with a few scattered black spots, digits with indistinct mottling. Post-occipital collar formed of two fused brown spots edged with black and a finer light border forming a horizontally 8-shaped marking. Central spots on post-occipital collar roughly subequal to smallest dorsal blotches. Crown of the same shade as trunk with a few small scattered black spots, and seven dark brown markings that have a darker border flanked by a finer light border; a pre-frontal spot that is shorter than two interorbital spots which are similar in length to the longer part of the (broken) interparietal streak and two parietal spots. Brille similar in colour to light scales on crown. Postocular streak runs from posterior edge of eye to just beyond tympanum, separated from dorsolateral markings of collar and first pair of dorsal spots on neck or just meeting above tympanum (L/R); preocular streak extends till nostril. All head markings separated from each other. Labials with dark streaks, a few unmarked scales finely spotted with black. A fine dark streak from below anterior edge of ear opening extends onto start of the forearm. Ventral aspects dirty white with few spots on the lateral edge of the belly and numerous thick streaks and spots on infralabials and gular region; ventral aspect of tail many-coloured with dark with few scattered light streaks.
Mensural and meristic data for the type series is given in Table
Measurements (mm) and meristic data for the type series of the two new species described herein. Abbreviations are listed in Materials and Methods except for * = tail incomplete or regenerated; L and R = left and right; M = male; F = female.
Species | Cyrtodactylus (Geckoella) irulaorum sp. nov. | Cyrtodactylus (Geckoella) relictus sp. nov. | |||||||||
Type | Holotype | Paratypes | Holotype | Paratypes | |||||||
Museum number | NRC-AA-1266 | NRC-AA-1267 | NRC-AA-1268 | NRC-AA-1269 | NRC-AA-1270 | NRC-AA-1271 | NRC-AA-1272 | NRC-AA-1273 | NRC-AA-1274 | NRC-AA-1275 | NRC-AA-1276 |
Sex | M | M | M | M | M | F | F | F | M | F | F |
SVL | 41.5 | 41.7 | 43.4 | 41.5 | 39.8 | 40.8 | 48.2 | 50.5 | 49.1 | 52.7 | 52.7 |
TL | 32.7 | 18.5* | 12.8* | 22.0* | 30.7 | 33.4 | 35.1 | 29.3* | 35.1 | 22.3* | 22.0* |
TW | 4.4 | 4.3 | 4.6 | 4.4 | 4.2 | 3.1 | 3.5 | 3.5 | 5.2 | 4.8 | 4.3 |
LAL | 5.6 | 5.8 | 6.1 | 5.9 | 5.9 | 5.1 | 7.2 | 7.3 | 6.6 | 7.2 | 7.2 |
CL | 6.9 | 6.8 | 7.2 | 7.0 | 6.9 | 7.0 | 8.0 | 8.5 | 8.1 | 8.5 | 8.5 |
AGL | 18.1 | 18.1 | 18.2 | 18.0 | 16.8 | 16.7 | 21.8 | 22.9 | 20.1 | 22.8 | 23.5 |
BH | 3.3 | 4.8 | 4.3 | 3.7 | 3.5 | 3.4 | 4.1 | 4.7 | 3.6 | 4.7 | 7.2 |
BW | 7.6 | 7.0 | 7.6 | 7.8 | 6.9 | 6.7 | 6.9 | 7.1 | 11.3 | 11.3 | 10.6 |
HL | 10.3 | 10.5 | 11.5 | 10.5 | 10.1 | 10.1 | 12.5 | 13.0 | 12.5 | 14.3 | 13.7 |
HW | 7.3 | 6..8 | 7.9 | 7.4 | 6.9 | 7.3 | 8.4 | 8.6 | 8.9 | 9.5 | 9.8 |
HD | 4.8 | 4.3 | 4.9 | 4.7 | 4.5 | 4.5 | 5.8 | 5.5 | 5.7 | 6.6 | 6.6 |
ED | 2.8 | 2.7 | 3.0 | 2.7 | 2.5 | 2.6 | 3.0 | 3.0 | 3.0 | 3.6 | 3.4 |
EE | 3.0 | 3.0 | 3.6 | 3.4 | 3.4 | 3.2 | 3.9 | 4.1 | 3.8 | 4.2 | 4.1 |
EL | 1.3 | 1.0 | 1.4 | 1.0 | 0.9 | 1.0 | 1.5 | 1.2 | 1.1 | 1.1 | 0.9 |
ES | 4.6 | 4.5 | 5.3 | 4.8 | 4.6 | 4.6 | 5.9 | 5.5 | 5.7 | 6.1 | 6.0 |
EN | 3.5 | 3.4 | 3.9 | 3.4 | 3.4 | 3.3 | 4.5 | 4.2 | 4.1 | 4.4 | 4.3 |
IN | 1.6 | 1.6 | 1.8 | 1.7 | 1.6 | 1.5 | 1.9 | 1.9 | 1.9 | 1.9 | 2.1 |
IO | 2.0 | 1.9 | 2.0 | 2.0 | 2.0 | 1.9 | 2.3 | 2.3 | 2.3 | 2.6 | 2.7 |
SL L&R | 12&10 | 9&10 | 9&10 | 10&10 | 10&10 | 9&10 | 10&10 | 9&10 | 10&10 | 8&10 | 11&9 |
IL L&R | 9&9 | 8&9 | 9&8 | 9&8 | 8&8 | 9&9 | 8&8 | 8&8 | 8&8 | 8&8 | 8&8 |
SL M L&R | 8&7 | 6&7 | 7&7 | 7&7 | 7&7 | 7&7 | 7&7 | 6&7 | 7&7 | 6&6 | 7&7 |
IL M L&R | 6&6 | 6&6 | 6&5 | 6&5 | 5&5 | 6&6 | 6&6 | 6&6 | 6&6 | 5&5 | 5&6 |
DLamF1 L&R | 7&7 | 7&7 | 7&7 | 6&7 | 7&7 | 6&7 | 7&7 | 6&7 | 8&8 | 6&6 | 7&7 |
BLamF1 L&R | 5&5 | 2&3 | 4&5 | 3&3 | 3&3 | 3&2 | 3&3 | 5&3 | 5&4 | 3&4 | 3&2 |
DLamF4 L&R | 7&7 | 7&7 | 7&6 | 8&7 | 7&6 | 8&7 | 7&7 | 7&7 | 6&6 | 6&6 | 9&7 |
BLamF4 L&R | 6&6 | 6&6 | 5&6 | 5&5 | 5&5 | 6&6 | 6&5 | 5&5 | 6&6 | 5&5 | 3&5 |
DLamT1 L&R | 8&7 | 7&7 | 6&7 | 8&7 | 8&7 | 8&8 | 8&7 | 8&7 | 8&8 | 8&8 | 8&7 |
BLamT1 L&R | 3&3 | 4&3 | 3&5 | 3&3 | 3&2 | 3&3 | 2&2 | 2&3 | 4&4 | 3&2 | 3&3 |
DLamT4 L&R | 8&9 | 9&8 | 8&8 | 9&9 | 7&7 | 9&9 | 9&9 | 8&9 | 8&9 | 7&7 | 8&8 |
BLamT4 L&R | 7&8 | 7&7 | 8&7 | 8&8 | 7&7 | 8&8 | 9&8 | 9&8 | 10&9 | 7&8 | 8&6 |
PCT L&R | 3&2 | 3&3 | 2&2 | 3&2 | 3&3 | 2&2 | 2&2 | 3&3 | 3&3 | 2&1 | 3&3 |
Selected morphometric, meristic and colour pattern characters of the two new species. Mean (range) presented for morphometric characters and ratios; median (range) presented for meristic characters (* indicates all unique values) from the right side of specimens.
Character | Cyrtodactylus (Geckoella) irulaorum sp. nov. | Cyrtodactylus (Geckoella) relictus sp. nov. |
SVL | 43.4 (39.8–50.5) | 51.5 (49.1–52.7) |
LAL | 6.1 (5.1–7.3) | 7.0 (6.6–7.2) |
CL | 7.3 (6.8–8.5) | 8.4 (8.1–8.5) |
AGL | 18.8 (16.7–22.9) | 22.1 (20.1–23.5) |
BW | 7.2 (6.7–7.8) | 11.1 (10.6–11.3) |
BW/ SVL | 0.167 (0.141–0.188) | 0.215 (0.201–0.230) |
HL | 11.1 (10.1–13.0) | 13.5 (12.5–14.3) |
HW | 7.6 (6.8–8.6) | 9.4 (8.9–9.8) |
HW/ SVL | 0.175 (0.163–0.182) | 0.182 (0.180–0.186) |
ES | 5.0 (4.5–5.9) | 5.9 (5.7–6.1) |
SL | 10 (10) | 10 (9–10) |
IL | 8 (8–9) | 8 (8) |
SL M | 7 (7) | 7 (6–7) |
IL M | 6 (5–6) | 6 (5–6) |
TLam F1* | 10 (9–12) | *(9–12) |
TLam F4 | 12 (11–13) | 12 (11-12) |
TLam T1 | 10 (9–12) | 10 (10–12) |
TLam T4* | 17 (14–17) | *(14–18) |
Dorsum banded/spotted (B/S) | S | S |
Pairs of dark markings on dorsum | 4 (often fused on midline) | 4 (separate or just in contact on midline) |
First pair spots and postocular streak | Separate or fused | Fused |
Spots on flank present | Dots | Dots (1/ 3 specimens) |
Collar | Pair of spots just in contact | Pair of spots/ fused (2/3 specimens) |
Cyrtodactylus (Geckoella) irulaorum sp. nov. is known from only two localities 75 km apart at elevations below ~60 m (Fig.
Habitat photos at type locality of Cyrtodactylus (Geckoella) irulaorum sp. nov.: A farm at base of the hill, from where the holotype and a few paratypes were collected; B a general view from the hill located behind farm, showing the tropical dry evergreen forests. Photos by Akshay Khandekar.
NRC-AA-1274 (CES09/1472), adult male, from near Ubbalamadagu waterfalls, Kambakkam Durg (13.6100°N, 79.8431°E; ca. 120 m asl.), Tirupati District, Andhra Pradesh, India, collected by Ishan Agarwal and team on 18th March 2014.
NRC-AA-1275 (CES09/1470), NRC-AA-1276 (CES09/1471), adult females, from near Penchalakona (14.3266°N, 79.4219°E; ca. 170 m asl.), Nellore District, Andhra Pradesh, India, collected by Ishan Agarwal and team on 17th March 2014.
The specific epithet is from the Latin relictus; which refers to an organism or species that has survived from an earlier period with different environmental conditions. Peninsular India was covered by wet forests and has gradually become more arid since at least the Miocene (
Relict Geckoella.
A small-sized Cyrtodactylus (Geckoella), snout to vent length up to 53 mm (n = 3); tail shorter than SVL. Dorsal pholidosis on trunk homogeneous; covered with smooth, subcircular, weakly conical granular scales; scales on occiput and nape slightly smaller and rounded than those on body dorsum, scales on flank slightly larger than those on dorsum; ventral scales much larger than scales on dorsum, smooth, subcircular, subimbricate, subequal from chest to vent; absence of femoral and precloacal pores; absence of enlarged precloacal or femoral scales, no precloacal groove; four pairs of dark rounded spots from occiput to hindlimb insertions, spots rarely just in contact along mid-vertebral line; post-occipital collar broken into a pair of spots (1/3) or forming a U-shaped band (2/3).
The diagnostic characters listed above for Cyrtodactylus (Geckoella) relictus sp. nov. easily differentiate the new species from all other Cyrtodactylus and Cyrtodactylus (Geckoella) apart from members of the collegalensis complex. Cyrtodactylus (Geckoella) relictus sp. nov. can be differentiated from the other members of the collegalensis complex by its dorsal colour pattern of four pairs of dark spots from behind occiput to hindlimb insertions (first pair fused with postocular streak on either side, spots may be just in contact centrally) from C. aravindi (a single dark broad band and one or two single dark spots on dorsum), C. collegalensis (three pairs of dark spots that may be fused forming horizontal figure 8-shaped markings), C. rishivalleyensis (two broad dark bands on dorsum), C. srilekhae (three rows of irregular dark blotches), C. speciosus (two broad dark bands on dorsum) and the Sri Lankan species C. yakhuna (one or two broad dark bands or spots on dorsum in both subspecies). The new species is most similar in colour pattern to C. chengodumalaensis, Cyrtodactylus (Geckoella) irulaorum sp. nov. and C. varadgirii (which all have 4–6 pairs of dark spots on dorsum); but can be distinguished by the absence of a few, enlarged dorsal tubercles on the dorsum (versus the presence of these tubercles in C. chengodumalaensis), its SVL up to 52.7 mm (versus SVL up to 47.6 mm in C. chengodumalaensis) and by the absence of a patch of enlarged roughly hexagonal scales on the canthus rostralis and beneath the angle of the lower jaw (versus the presence of these enlarged scales in C. varadgirii).
Cyrtodactylus (Geckoella) relictus sp. nov. overlaps in colour pattern with C. irulaorum sp. nov. almost completely, except that the first pair of spots is fused with the postocular streak in C. relictus sp. nov. (versus postocular streak usually separated from first pair of spots in C. irulaorum sp. nov.). The two species occupy distinct positions in multivariate morphospace (Fig.
Adult male in good state of preservation except a 4.7 mm vertical incision in the sternal region for liver tissue collection (Fig.
Body somewhat slender (BW/AGL 0.56), trunk less than half of SVL (AGL/SVL 0.40) without ventrolateral folds. Dorsal pholidosis on trunk homogeneous; covered with smooth, subcircular, weakly conical granular scales; 17 dorsal midbody scale rows across trunk contained within one eye diameter (Fig.
Fore-limbs and hind-limbs slightly long, slender (LAL/SVL 0.13; CL/SVL 0.16); digits short, slender, with a strong, recurved claw, moderately inflected, distal portions laterally compressed. Series of unpaired lamellae on basal portion of digits except one or two which on some digits are paired, separated from narrower distal lamellae by a single large lamella at the inflection, unpaired except one or two which are divided; basal lamellae series: (4-5-6-6-6 right manus, Fig.
Tail original, circular in cross section with indistinct median dorsal furrow, relatively thick, tapering gradually to tip, unsegmented, slightly shorter than snout-vent length (TL/SVL ratio 0.71). Scales on dorsal aspect of tail base similar to body dorsum except marginally larger; scales on dorsal aspect of tail large flat, subcircular, smooth, and imbricate, becoming slightly larger towards lateral aspect, largest on ventral side, but not forming median row of transversely enlarged subcaudal scales. Three small, smooth, subequal, conical postcloacal spurs on each side of tail base; prominent hemipenal swelling, flap of skin covering cloacal aperture. Tail slightly constricted at the base (Fig.
Dorsal ground colour faded light tan, four pairs of dark brown spots from behind occiput to hindlimb insertions. All spots separated except those forming first pair fused with postocular streak on either side; edged by black on the outer 1–5 rows of scales, finest along flanks; anterior two pairs of spots largest. Flank with scattered fine black spots. Tail dorsum similar in ground colour to body dorsum except slightly suffused with yellow; a dark small pair of spots on tail base and eight indistinct black edged brown crossbars reducing in size toward tail-tip. Dorsum of limbs and digits similar in colour to trunk with scattered black spots. Post-occipital collar formed of two brown spots edged with black and a finer light border. Spots on post-occipital collar smaller than the smallest dorsal blotches. Crown slightly darker than trunk with a few small scattered black spots, and seven dark brown markings that have a darker border flanked by a finer light border; a pre-frontal spot that is longer than two interorbital spots and similar in length to the longer part of the (broken) interparietal streak and two parietal spots. Brille similar in colour to light scales on crown. Postocular streak extends from posterior edge of eye through tympanum and fuses with first pair of spots on the neck, separated from dorsolateral markings of collar; preocular streak extends till nostril. All head markings separated from each other except post-occipital and parietal spots fused on right. Labials with dark streaks, a few unmarked scales finely spotted with black. A fine dark streak extends from angle of jaw onto start of forearm, discontinuous until below anterior edge of ear opening. Ventral aspects dirty white with scattered spots on the lateral edge of the belly and numerous grey streaks and spots on infralabials and gular region; ventral aspect of tail many-coloured with indistinct dark reticulations.
Mensural and meristic data for the type series is given in Table
Cyrtodactylus (Geckoella) relictus sp. nov. is known from only two localities about 90 km apart and at elevations of 120 m and 170 m (Fig.
Cyrtodactylus (Geckoella) irulaorum sp. nov. and Cyrtodactylus relictus sp. nov. are the 9th and 10th species of the Cyrtodactylus (Geckoella) collegalensis complex to be described from peninsular India. Apart from C. varadgirii, the known species of the complex are associated with hilly landscapes in southern India. The two new species extend the range of the Cyrtodactylus (Geckoella) collegalensis complex north and east into the Velikonda range. These are the first records of the group from south-eastern India and it remains to be seen how much further north the C. collegalensis complex is distributed. We surveyed Andhra Pradesh in 2014, but these were the only members of the Cyrtodactylus (Geckoella) collegalensis complex we collected, besides C. rishivalleyensis; with the most southern confirmed records of C. nebulosus Beddome about 275 km N-NE of the Velikonda range (Agarwal unpubl. data).
Interestingly, though both new species are both distributed at low elevations (<180 m), they occur within just 30 km of one another and are 10.0–11.5% divergent in mitochondrial sequence data; while each species occurs at two localities 75–90 km apart with ≤ 1.2% divergence. There are no obvious geographic barriers between the known range of the two new species, and Cyrtodactylus (Geckoella) relictus sp. nov. is found associated with riparian and tropical dry evergreen forests at the base of larger mountains while C. irulaorum sp. nov. is found in areas of little relief with tropical dry evergreen scrubland and forest. Cyrtodactylus (Geckoella) rishivalleyensis also occurs within ~50 and ~75 km of the new species, though the former is only known from elevations above 1,000 m (
Tropical dry evergreen forests (TDFs) are a unique ecoregion restricted to lowland pockets along the east coast in India and covering much of the Sri Lankan lowlands (
The Cyrtodactylus (Geckoella) collegalensis complex has seen the most new species discovery within Indian Geckoella, with seven of the nine Indian species described since 2016 (
We are thankful to the Andhra Pradesh Forest Department for collection permits (Rc. No: 34822/2012/WL-3). R. Chaitanya, Aniruddha Datta-Roy, Caleb Daniel, V. Deepak, Tarun Khichi, Aparna Lajmi, and Prudhvi Raj helped with fieldwork. Praveen Karanth provided lab support at CES; Tarun Karmakar and Yeshwanth HM (NCBS field station and museum facility, Bengaluru) helped with specimen registration. Partial funding came from the Ministry of Environment and Forests to Praveen Karanth and a Rufford Foundation Small Grant to Aparna Lajmi (15328-1). We thank Romulus Whitaker and Janaki Lenin for hosting us at their farm and Gerry Martin for collecting the first specimen. We thank Karanth Lab (A. Datta-Roy, A. Lajmi, V. Deepak) for providing habitat photos of the relict Geckoella. We thank Evan Quah, Harshil Patel and Kanishka Ukuwela for their detailed reviews.
Material examined
Museum and institutional abbreviations given in the Materials and methods except for: Akshay Khandekar field series (AK-R).
Cyrtodactylus (Geckoella) aravindi: AK-R 682, AK-R 683, AK-R 1007– AK-R 1011, adult males and females, from Thirukurungudi, Tirunelveli District, Tamil Nadu, India.
Cyrtodactylus (Geckoella) chengodumalaensis: holotype, NRC-AA-1161, adult male, from Kumaragiri Estate, Malappuram District, Kerala, India; paratypes;
Cyrtodactylus (Geckoella) collegalensis: holotype,
Cyrtodactylus (Geckoella) speciosus: AK-R 2689–2693, adult males and females, from near Erode, Erode District, Tamil Nadu, India.
Cyrtodactylus cf. speciosus: CES09/1405–1408, from near Coimbatore, Coimbatore District, Tamil Nadu, India.
Cyrtodactylus (Geckoella) srilekhae: holotype, NCBS AQ740, adult male, near Thathaguni, Bangalore Urban District; paratypes, ESV 101, adult male,
Cyrtodactylus (Geckoella) rishivalleyensis: holotype, NCBS AQ742, adult female, Horsley Hills, Chittoor District, Andhra Pradesh; paratypes; NCBS AQ744, NCBS AQ743, adult males, ESV 103,
Cyrtodactylus (Geckoella) varadgirii: holotype, NCBS AQ475, adult male, from Ulhasnagar, Thane District, Maharashtra, India; paratypes, NCBS AQ191, adult male, same locality as holotype; CES09/1381, adult male, from Chikhli, Navsari District, Gujarat; CES/09/1368, adult male, Chandrapur District, Maharashtra; CES09/1536, adult male and CES09/1537, adult female, from Amravati District, Maharashtra;