Sitana gokakensis, Deepak & Khandekar & Chaitanya & Karanth, 2018

Deepak, V., Khandekar, Akshay, Chaitanya, R. & Karanth, Praveen, 2018, Descriptions of two new endemic and cryptic species of Sitana Cuvier, 1829 from peninsular India, Zootaxa 4434 (2), pp. 327-365 : 336-343

Sitana gokakensis sp. nov.

Fig. 7–9 & 11 ; Table 3 & 4; Appendix 7 & 8

Holotype. BNHS 2490 , adult male ( Fig. 7 & 8A ) from Gokak plateau, Belagavi district, Karnataka, India (16.18618°N, 74.75952°E), 255 m elevation, collected on 0 8.08.2013 by V. Deepak and Aparna Lajmi .

Paratypes. BNHS 2491, adult female ( Fig. 9b ; Appendix 7b) collected by V. Deepak and Aparna Lajmi; CES 141136, an adult male (Appendix 7a) collected by V. Deepak and Kunal Arekar on 12.5.15; both same collection data as holotype.

Diagnosis. A large sized Sitana with a maximum SVL of 53.1 mm, distinguished from its congeners by the following combination of characters: 1) dewlap feebly serrated without bright orange patches in breeding males (vs well serrated with bright orange patches in breeding males in S. ponticeriana , S. visiri , S. marudhamneydhal and S. devakai ); 2) dewlap extending beyond forearm insertion (vs not extending in S. sivalensis , S. schleichi and S. fusca ); 3) four prominent enlarged non spine like scales bordering occipital region (vs enlarged spine like scales in S. spinaecephalus ); 4) dewlap large sized extending up to 55% of trunk (vs up to 44 % of trunk in S. laticeps in southern most population which appears to be an outlier for the species; up to 29% of trunk in remaining population ( Fig. 10 ) and vs up to 42% of trunk in Sitana sp1 ( Fig. 10 ); 5) body size (male & females averaged) relatively large (SVL: mean 48.8 +/- 3.6 SE; range 42.4–53.1; n=14) vs (body size relatively small in S. laticeps SVL: mean 47.8 +/- 3.2 SE; range 40.7– 54.6; n=63 and in S. sp1 SVL: mean 46.2 +/- 3.2 SE; range 38.9–54.1; n=31 and S. spinaecephalus SVL: mean 47.3 +/- 3.7 SE; range 39.5– 56.6; n=25). It has to be noted here that the southernmost population of S. laticeps appears to have some relatively large bodied individuals (SVL: mean 50.1 +/- 4.2 SE; range 45.2–54.6; n=6) but need a larger sample size to further confirm.

Description of holotype. The holotype is in good condition; hemipenis partially everted, exposed and seen on both sides when viewed dorsally ( Fig. 7a ). Tail entire, curved slightly towards the right; loose folds of skin on the dorsum and a small incision of 4mm to extricate tissue, are artefacts of preservation. An adult male, SVL 51.2 mm. Head relatively long (HL/SVL ratio 0.29), wide (HW/HL ratio 0.70), not depressed (HH/HL ratio 0.51), distinct from neck. Snout short (SE/HL ratio 0.39), longer than diameter of orbit (OD/SE ratio 0.73), obtusely pointed in profile when viewed dorsally ( Fig. 7c ); rostral much wider than high, contacted laterally on either side by first supralabial, a prenasal and dorsally by two smaller, keeled scales ( Fig. 7e ). Canthus rostralis and supraciliary edge, sharp. Nostril roughly circular, laterally positioned and placed in the centre of a large, undivided nasal. Nasal scale bordered by eight scales on either side: one supranasal, three postnasals, one prenasal, the last two scales form a series of enlarged scales bordering the supralabials and a small scale separates them from the first supralabial. Ten supralabials on the right side (11 on left side), first slightly higher than others, broader than long, roughly rectangular, rest more elongate, weakly keeled, bordered above by a row of slightly smaller, rectangular, weakly keeled scales, which start at posterior margin of first supralabial, decreasing in size posteriorly and terminating after the posterior margin of orbit. Twelve infralabials on the right side (13 on left), first slightly smaller, the rest elongate, keeled increasing in size posteriorly. Loreal region concave, with scales of heterogeneous shape and size. Canthals enlarged, overlapping, slightly protruding on supraorbital ridge laterally. Eye large (ED/HL ratio 0.27); pupil rounded, covered under the eyelids; eyelids covered with scales that are heterogeneous in shape and size; larger scales on the upper eyelids, keeled, elongate and bluntly pointed, rest smooth; supraciliaries longer than broad. Orbital scales small but not granular. Scales on postorbital and temporal region, heterogeneous, sub- imbricate, strongly keeled, directed backward and upwards. Tympanum naked. Scales on dorsal surface of snout, forehead, interorbital and occipital region highly heterogeneous in size, shape, mostly elongate, strongly keeled longitudinally ( Fig. 7c ); scales on snout large in size, those on forehead slightly larger, interorbital region largest; occipital region with much smaller imbricate scales relative to other dorsal head scales; four relatively enlarged scales on a transverse row in the occiput region; nine scales anterior and 14 scales posterior of eyelids in the interorbital region; supraorbital scales along the supraciliary edge elongate, keeled, decreasing in size posteriorly, following curvature of orbit. Parietals larger than surrounding scales, longer than broad, tricarinate, separated from each other by two inter-parietal scales; anterior large, roughly triangular, tricarinate; posterior roughly pentagonal, bicarinate, with distinctly visible pineal eye. Parietals and the posterior inter-parietal part of a series of nine large, strongly keeled scales traversing the forehead. Mental shield narrower than rostral, roughly pentagonal, pointed posteriorly, a pair of roughly hexagonal postmentals, slightly shorter than mental, completely divided by a smaller gular scale ( Fig. 7d ); scales on the gular region homogenous in shape, those behind mental smooth, increasing in size and carination posteriorly. Dewlap large (DEWL/SVL ratio 0.69), extends posteriorly over 55% of trunk, extending much beyond axilla ( Fig. 7b ); about nine rows of anterior dewlap scales smaller, elongate, pointed, keeled; remainder of scales much enlarged, keeled, pointed, gradually increasing in size towards margin; single marginal row largest with lanceolate scales. Enlarged scales on dewlap in 23 rows. Nuchal and dorsal crest absent ( Fig. 7a ). Scales on nuchal region smaller, less than half the size of those on interorbital region, imbricate, strongly keeled. Body slender, 60 rows of scales around midbody; vertebral scale row with 46 scales, vertebral scale row partially paired and alternating. Five enlarged dorsal scale rows, on either side of the vertebral scale row (except in 3 places the five rows on either side are in contact with each other), the 5 dorsal scale rows starts from back of neck until groin, sub equal in size and shape, imbricate, pointed, keeled, directed backwards forming regularly arranged longitudinal rows; scales on flanks heterogeneous in size, shape, smaller than those on back, pointed, keeled, upper rows directed backwards and upwards, lower rows backwards and downwards; ventral scales subimbricate, keeled, homogenous in size and shape, arranged in 101 rows. Fore and hindlimbs relatively slender, tibia short (CL/SVL ratio 0.33); digits moderately long, ending in strong, elongate, slightly recurved claw; inter-digital webbing absent; subdigital lamellae entire, bi-mucronate, 22 subdigital lamellae on toe IV including claw sheath; relative length of right fingers 3> 4> 2> 5> 1, right toes 4> 3> 2> 1. Fore and hindlimbs covered above and below with regularly arranged, enlarged, pointed, strongly keeled, scales. Tail long (TL/SVL ratio 2.35), entire, base swollen, uniformly covered with similar sized, keeled, pointed, regularly arranged, backwardly directed imbricate scales; subcaudal scales keeled, weakly pointed near base, becoming pointed posteriorly.

Colour of holotype in life. Head darker than body, dorsum of the torso dark brown, darker compared to flank and tail ( Fig. 7a ) . Neck region with blue and dark pink colouration . Iris yellow in colour, tympanum cream coloured. Dorsum with five black blotches the one on neck darker . Flank region brick red colour with mottled dark brown patches. Enlarged scales on the flank and thigh cream in colour . Belly off white in colour with brown speckles on most scales. Forelimbs and hindlimbs dark brown suffused with red on dorsal side, cream patch on the back of thigh extending to the saccaral region and pale on the ventral side . Lower jaws cream mostly , dark blue colouration starts from the mentum (on 7–8 horizontal scale rows ( Fig. 7d ) and extends along midline of dewlap . Dewlap white, each scale on dewlap with clustered brown speckles.

Colour of holotype in preservative. Head dark brown, darker than the body—with scattered blue patches on the neck. Two broken black stripes start below the eye approximately in the middle directed downwards that broaden and end after the forearm insertion. Tympanum cream coloured, slightly lighter than the surrounding scales with small light brown speckles. Dorsum dark brown with two black blotches on the neck; 3 broad , dark brown bars at the tail base and multiple smaller bars found throughout the tail. The five enlarged rows of scales on the dorsum flanking the vertebral scale rows dark brown coloured, a pale brown broken white stripe starting from neck bordering enlarged scale row on the dorsum ends near the tail base , upper 3 /4th of the flanks dark brown with mixed light brown scales, the lower end of flanks paler. Venter mottled with brown on off white scales. Brown bars present on the dorsal side of limbs. Tail with dark brown bands throughout. Enlarged scales on dewlap with dark brown/black spots, mottled, with some scales having dark brown/black spots with a white spot in the center . Throat region on either side of the enlarged scale on dewlap off white with bluish dark gray /black speckles and the dark blue colouration on the throat is prominent 5 scales after the mentum and its surrounding scales, the rest are faint bluish gray.

Variation in paratypes. The two paratypes agree with the holotype in overall scalation with some exceptions. CES 141136 has 101 ventral scales and 32 belly ventral scales, 58 mid-body scales, 49 dorsal scales, one less infralabial on each side and one additional supralabial on the left. The female BNHS 2491 agrees with the holotype in overall scalation except that it lacks a dewlap, and has 67 ventral scales, one less infralabial on each side. CES 141136 differs in colouration from the holotype in having a light brown dorsum (an artefact of preservation), four distinct dark brown patches on the dorsum the first one darker. No blue patches on the neck . The stripe below the eye, indistinguishable compared to the surrounding scale, only a short light brown stripe ends near the forearm insertion. Blue line on the dewlap/throat darker than the holotype. Broad bands are present throughout the tail. BNHS 2491 differs in colouration from the holotype in having head colouration similar to body, three rhomboidal/ oval patterns on the dorsum, pale white stripe on the dorsum absent. Head brown with patches of brick red and grey (likely due to shedding scales), no blue patches on the neck. Throat region pale white in colour with dark black spots and speckles. One rhomboidal marking on the dorsum of tail base.

Variation in live colouration. Most of the male specimens collected during this study matched with the

holotype in live colouration. There were some specimens which were different from the rest which we describe

herein. Three out of the ten breeding males were found with blue colouration on the upper eyelids. Seven out of the ten males observed in-situ had mostly dark pink and tinge of blue on the nuchal region. The fifth scale on the enlarged scale rows flanking vertebral scales on the dorsum was bordered with continuous cream coloured/reddish stripe starting from neck till the vent (e.g, see Fig. 9 a,b,d ), in some individuals these stripes were broken. The rhomboidal patch on the neck was single in many individuals but the 5 rhomboid patches on the dorsum were separated by a cream line on the vertebral region (e.g, see Fig. 9c ). One of the adult males had blue colouration on the tail which became prominent immediately after euthanization (Appendix 8).

Hemipenial morphology. Four samples were examined (CES 141136 – 141139). Hemipenis bilobed, relatively small, longer than wide and shallowly forked. Sulcus spermaticus bifurcated and the fork continues onto the apical lobes ( Fig. 11a ). Sulcal lips raised and papillate, sulcus smooth originating from the side of the base. Apex with small serrated row of calyces and the sulcal region of apex nude ( Fig. 11d ), medial projection absent. Ornamentation is differentiated and combination of flounces and calyces observed. Papillae present between the apical lobes. Apical regions on the lobes of sulcal side calyces are serrated and continuous; calyces are relatively larger and non-serrated at the base of the lobes ( Fig. 11a,b ). Calyces are deep regular pits on the asulcal side and become shallow at basal region ( Fig. 11b ). Ridges between the calyces are thin and show micro-ornamentation which are scalloped. Flounces present, eight to ten in number, all prominent on the asulcal side ( Fig. 11B,C ).

Etymology. The specific epithet is an adjectival toponym and refers to the Gokak plateau of Belagavi district in Karnataka, to which this species is endemic.

Suggested common name. Gokak fan-throated lizard.

Distribution. Sitana gokakensis sp. nov. is endemic to Gokak plateau in Belagavi district, Karnataka ( Fig. 1 ). The samples collected from north and south outside this plateau (Nipani, Ramdurga, Bagalkot) were of S. laticeps . The Ghataprabha is a rocky river and a potential geographical barrier for this species.

Habitat and natural history. Sitana gokakensis sp. nov. is only known from the open rocky habitat in Gokak plateau ( Fig. 12 ). Gokak hills receives 820 mm of average annual rainfall. The habitat is xeric and is dominated by thorny and dwarf succulent species (Malpure et al. 2016). The recently described Euphorbia gokakensis Yadav,

Malpure, Chandore, 2016 is endemic to this plateau which is found alongside other succulents such as E. antiquorum L., E. caducifolia Haines and Opuntia elatior Mill. and non-succulents like Mundulea sericea (Willd.) A.Chev. (Malpure et al. 2016). Ophisops sp and Hemidactylus murrayi Gleadow, 1887 are the two sympatric lizards found in this plateau. Breeding males were recorded during May and August months.

Figures

FIGURE 1. Map showing sampling localities where we found different Sitana spp. during this study. Rivers and hills referred in this study are labelled. Locality where the two new species were collected are marked in red (S. gokakensis sp. nov.) and blue (S. thondalu sp. nov.). Localities referred in table 1.

FIGURE 7. Holotype of Sitana gokakensis sp. nov. (BNHS 2490) from Gokak, Karnataka. (A) full body dorsal (B) flank region (C) dorsal view of head (D) lateral view of head. Scale bar:10 mm.

FIGURE 8. Sitana gokakensis sp. nov. colouration in life. A. Holotype (BNHS 2490) in life, B. another adult male collected during 2016 from the type locality.

FIGURE 9. Sitana gokakensis sp. nov. colouration in life. A. An adult male from type locality, B. paratype BNHS 2491, C & D. two different uncollected adult females from the type locality.

FIGURE 10. Box plot showing proportion of dewlap in trunk. Note red circle highlighing the southern most population (Bagalkot & Tummargudi) of S. laticeps which have relatively larger dewlaps compared to all other populations.

FIGURE 11. Hemipenis of Sitana gokakensis sp. nov. (CES 141136): (A) sulcal view; (B) asulcal view; C) lateral view; (D) apical view. Scale bar:10 mm.

FIGURE 12. Habitat of Sitana gokakensis sp. nov. at the type locality, Gokak, Karnataka.