Calotes versicolor (Daudin, 1802)

Pal, Saunak, Vijayakumar, S. P., Shanker, Kartik, Jayarajan, Aditi & Deepak, V., 2018, A systematic revision of Calotes Cuvier, 1817 (Squamata: Agamidae) from the Western Ghats adds two genera and reveals two new species, Zootaxa 4482 (3), pp. 401-450 : 421-423

Calotes versicolor (Daudin, 1802)

Original description. Daudin, 1802. Hist. Nat., Rept. iii, 1802: 395, xliv.

Taxonomic comments. Calotes versicolor was described in 1802 by Daudin, based on specimens at MNHN. There is no mention of a precise locality or even a type specimen. Later Smith (Smith 1935) and other workers designated the type-locality to populations from Pondicherry on the east coast of India, Chennai (Madras), and Kolkata (Calcutta) ( Zug et al. 2006). The specimen MNHN 2548, collected from Pondicherry by Leschenault, cannot be a syntype of C. versicolor Daudin 1802 , because Leschenault visited Pondicherry only after 1816 ( Amarasinghe et al. 2009). Amarasinghe et al (2009) clarified that MNHN 2548 collected from Pondicherry by Leschenault is the syntype of Agama tiedemanni Kuhl, 1820 . Gowande et al (2016) synonymized Calotes tiedemanni and designated a neotype from Pondicherry without any comparison with the syntype of Calotes tiedemanni . This neotype designation was recently invalidated ( Chaitanya et al. 2017).

Currently, Calotes versicolor is the most widely distributed species of the genus Calotes . Many researchers have mentioned the high level of morphological variation in this species across different populations and some have even considered it to be a species complex ( Zug et al. 2006). Recently two new species were described from dry zone populations of C. versicolor from Myanmar based on DNA sequence and morphological analysis ( Zug et al. 2006). In our phylogenetic analyses, the southern Western Ghats population forms a distant cluster within the C. versicolor clade ( Fig. 1 ). The studied specimens also show 0–5% genetic divergence across their distribution. This shows that the Indian population might also be a species complex (see Gowande, 2016). A phylogeographic study with thorough sampling across its range and a rigorous comparison of the available type materials for the existing species and subspecies is necessary to resolve the complexity in this species. Since we did not study any historical type materials of Calotes versicolor or the synonyms, we consider the populations in this study as Calotes cf. versicolor . The diagnosis is based on specimens collected from the Southern Western Ghats only and used to separate Calotes cf. versicolor from other distinct species.

Diagnosis and comparison. A medium to large sized Calotes (SVL up to 99.4 mm) characterized by the posterodorsal orientation of lateral scales; antehumeral fold absent; 38-44 midbody scale rows; nuchal and dorsal crest well developed, continuous, extending till the start of tail in males; two well separated supratympanic spines; dorsal and lateral scales large, more or less distinctly keeled, ventral scales strongly keeled, mucronate; paired postmentals, first pair separated by 1–2 median scales; 15–22 subdigital lamellae under fourth finger, 21–25 subdigital lamellae under fourth toe; 10–12 supralabials and 9–11 infralabials; uniform, light brown or greyish above, juveniles and females with darker cross bars or blotches on lateral side, often with paired lighter dorsolateral stripes, gular pouch brick red and overall body reddish in breeding males.

From other members of Smith’s C. versicolor group ( C. nemoricola , C. grandisquamis , C. calotes , C. minor , C. maria , C. jerdoni , C. emma and C. mystaceus ) C. cf. versicolor can be distinguished by a combination of the following characters: smaller body size: adult SVL 73.8–99.4 mm, n=9 (vs. C. nemoricola , adult SVL 112–134.8 mm, n=7, n=5; and C. grandisquamis , adult SVL 110.0– 136.5 mm, n=5); 38–44 midbody scale rows (vs. 27–35 in C. grandisquamis ; 30–35 in C. calotes , n=3; 36–43 in C. nemoricola ; 58–63 in C. maria ; 45–57 in C. jerdoni ; 49– 65 in C. emma ; 48–58 in C. mystaceus and 48–60 in C. minor ); crescent-shaped patch of granular scales in front of the shoulder absent (vs. present in C. nemoricola , C. grandisquamis , C. emma , C. mystaceus and C. jerdoni ); nuchal and dorsal crest well developed, composed of almost equal spines (vs. nuchal spines much longer, dorsal crest reduced in C. nemoricola and C. maria ; nuchal spines much longer than dorsal spines in C. grandisquamis , C. calotes and C. emma ); two well separated supratympanic spines (vs. row of 3–4 compressed supratympanic spines in C. nemoricola and C. grandisquamis ; 8–9 compressed spines in C. calotes ; two parallel rows of compressed supratympanic scales in C. maria and C. jerdoni ; single well developed postorbital spine in C. emma ). Calotes cf. versicolor can be distinguished from its other Sri Lankan congeners based on posterodorsal orientation of lateral scales and absence of oblique fold or pit in front of the shoulder.

Description. Based on specimen CESL 182. A large sized adult male (SVL 99.4 mm), morphometric and meristic data are summarised in Appendix 2 & 3. General habitus moderately compressed. Head moderate (HL/ SVL ratio 0.22), slightly elongate (HW/HL ratio 0.95), maximum height slightly less than maximum width; snout pointed; rostral broader than high; nostrils in single nasal shield which is separated from rostral by two scales; mental shield narrower than rostral; two postmentals, first pair separated from each other by two small scales; genials keeled; gular sac small, composed of strongly keeled scales, slightly smaller than genials; scales on top of snout smooth except median row, which is keeled; scales on top of head heterogenous in size and shape, keeled; supraorbital scales keeled; canthus-rostralis and supraciliary edge sharp; two separated spines on posterior end of head, the anterior much longer, closer to the nuchal crest, posterior above tympanum; orbit diameter 87% of distance between anterior border of orbit and snout tip; tympanum exposed, its greatest diameter 42% of horizontal diameter of orbit; slightly keeled, scales between tympanum and orbit smooth, slightly enlarged; posterior region of jaws swollen; supralabials 11/10; infralabials 10/10.

Nuchal and dorsal crest well developed, continuous; nuchal crest composed of 11 long, conical spines, the first being the smallest; dorsal crest composed of 33 curved spines till above the vent, slightly smaller than the nuchal spines; 36 longitudinal scale rows around midbody; dorsal and lateral scales sub-triangular, keeled, oriented postero-dorsally; ventrals strongly keeled, mucronate, smaller than dorsal and lateral scales.

Limbs slender and covered with strongly keeled scales, similar to laterals, forming parallel longitudinal rows; scales under thighs weakly keeled; length of hindlimb ca. 75 % SVL; relative length of fingers 4>3>2>5>1, third and fourth finger almost equal; relative lengths of toes 4>3>5>2>1; fourth toe much longer than fifth finger; 21 subdigital lamellae under fourth finger; 25 subdigital lamellae under fourth toe; subdigital lamellae with sharp keels, bicarinate; slender, swollen at the base; dorsal and ventral tail scales mucronate, strongly keeled; tail broken, incomplete; tail length 90 mm.

Colouration. In life: dorsum and head uniform, greyish-brown with irregular darker patches towards the flank; each lateral scale with a darker blackish spot towards the base, followed by lighter grey edges; head laterally paler, whitish towards the cheeks; a small, thin darker stripe from posterior corner of the eye till end of orbit; legs with irregular dark crossbars; a black coloured patch above the shoulder, near throat; tympanum pale grey with many small black spots, ventral uniformly lighter, pale grey; tail with alternating dark and light bands. Representative image showing live colouration ( Fig. 4b ). In preservative: colouration mostly similar to that in life, except overall paler.

Variation and secondary sexual characteristics. Meristic and morphometric data of four adult male and four adult female specimens are given in Appendix 2 & 3. The examined specimens agree with each other in general morphology and scalation. All the examined female specimens (CESL 0 48, CESL 163, CESL 306 and BNHM 374) have much smaller nuchal and dorsal spines compared to the males and lack a gular sac.

Distribution. Calotes cf. versicolor is common in the Western Ghats at elevations between 70 m to 1250 m M.S.L. (See Appendix 1 for details).

Ecology and natural history. Calotes cf. versicolor is a diurnal lizard, semi-arboreal to arboreal in habit, and so far, has been recorded mostly in scrub, deciduous forests and plantations. Individuals were mostly seen perching on shrubs, hedges, gardens and along compound walls of houses in villages along forests. C. cf. versicolor has often been found within plantations and prefers open patches to forested areas. During this study, it was never recorded from primary evergreen forests. In some sites, they might occur syntopically in the same habitat as M. rouxii comb. nov. but tend to be restricted to forest edges.

Figures

FIGURE 1. Pruned ML phylogeny of Draconinae showing the relationship of Calotes and its sister clades Monilesaurus, Psammophilus and Microauris. Western Ghats endemics are marked in red, Sri Lankan endemics in dark blue, Indo-Burmese species in light blue and species endemic to India excluding North-east and North West are marked in green, and other wide spread species are marked black. Dark circles indicate bootstrap support>75 and light circles indicate bootstrap support <75. Insert photo: representative species of the four genera endemic to Peninsular India.

FIGURE 4. Lateral photograph showing live coloration of A. adult female C. calotes and B. adult male C. cf. versicolor.