Sitana bahiri, Thasun Amarasinghe, A. A., Ineich, Ivan, Suranjan Karunarathna, D. M. S., Botejue, W. Madhava S. & Campbell, Patrick D., 2015

Thasun Amarasinghe, A. A., Ineich, Ivan, Suranjan Karunarathna, D. M. S., Botejue, W. Madhava S. & Campbell, Patrick D., 2015, Two new species of the genus Sitana Cuvier, 1829 (Reptilia: Agamidae) from Sri Lanka, including a taxonomic revision of the Indian Sitana species, Zootaxa 3915 (1), pp. 67-98 : 70-76

Sitana bahiri sp. nov. Amarasinghe, Ineich & Karunarathna

( Figs. 1–3 ; Tables 1–3 )

Litana Ponticereana [sic]— Kelaart (1854) [partim].

Sitana ponticeriana — Smith (1935) [partim]; Taylor (1957) [partim]; Wermuth (1967) [partim]; Manamendra-Arachchi & Liyanage (1994) [partim]; Erdelen (1998) [partim]; Das & de Silva (2005) [partim]; de Silva (2006) [partim]; Somaweera & Somaweera (2009) [partim]; Manthey (2010) [partim].

Sitana ponticeriana ponticeriana — Deraniyagala (1953) [partim].

Sitana ponticertiana [sic]— Bahir & Surasinghe (2005) [partim].

Holotype. Male, WHT 1434A, SVL 45.0 mm, collected at Block 1, Yala National Park, Sri Lanka (6°22′N, 81°31′E), alt. 5 m, by D. Gabadage, 27 May 1995.

Paratypes. Males, WHT 7377, WHT 0206C–D, respective SVL 40.5 mm, 50.0 mm, and 48.8 mm, collected at Bundala National Park, Sri Lanka (6o11′N, 81o16′E), alt. 5 m, by A. Silva & K. Maduwage, 19 August 2006; Male, WHT 0 619, SVL 44.7 mm, collected at Weligatta-Bundala, Sri Lanka, by D. Gabadage, 27 May 1995; Male, ZMH R06344, SVL 43.3 mm, collected in S.E. Sri Lanka, gift from Nat. Mus. Basel, collector Sarasin, 13 December 1904; Females, WHT 195A–B, respective SVL 46.8 mm and 46.9 mm, collected at Mahapelessa, Kirinda, Sri Lanka (6°23′N, 81°31′E), alt. 5 m, by D. Gabadage, 9 January 1993; Females, WHT 0206A–B, respective SVL 44.1 mm and 43.6 mm, collected at Bundala National Park, Sri Lanka, by D. Gabadage, 27 May 1995; Subadult male, WHT 1434B, SVL 32.9 mm, collected at Block 1, Yala National Park, Sri Lanka (6°22′N, 81°31′E), alt. 5 m, by D. Gabadage, 27 May 1995; Subadult female, WHT 1434C, SVL 34.0 mm, collected at Block 1, Yala National Park, Sri Lanka (6°22′N, 81°31′E), alt. 5 m, by D. Gabadage, 27 May 1995.

Diagnosis for adult males. Sitana bahiri sp. nov. differs from all congeners by having the following characters: S. devakai sp. nov. (see below): shorter throat-fan ADW 28.3–29.2% of AG (vs. long, ADW 29.9–32.5% of AG), midbody scale number 49–56 (vs. 57–59), ventral scale number 87–89 (vs. 100–108), abdominal scales bluntly pointed (vs. pointed), unequal and irregular lateral scales with intermediate enlarged scales (vs. equal and regular lateral scales with intermediate enlarged scales), breeding-males with bleached orange colour patch (vs. bright red colour patch); S. deccanensis : smaller SVL 40.0–50.0 mm (vs. large SVL, above 60.0 mm), longer snout ES 54.7–57.4% of HW (vs. shorter, ES 53.1–53.4% of HW), shorter throat-fan ADW 28.3–29.2% of AG (vs. longer, ADW 50.3–60.2% of AG), shorter femur FEL 70.6–75.3% of TBL (vs. longer, FEL 79.7–82.9% of TBL), longer foot FOL 158.9–159.8 of HL (vs. shorter, FOL 131.9–144.6% of HL), supralabial number 7–8 (vs. 12), midbody scale number 49–56 (vs. 66–70), subdigital lamellae number on toe III 14–17 (vs. 13), subdigital lamellae number on toe IV 23–26 (vs. 19–23), enlarged scales above the tympanum present (vs. absent), unequal and irregular lateral scales with intermediate enlarged scales (vs. equal and regular lateral scales without enlarged scales), breeding-males with bleached orange colour patch (vs. bright red patch extending to vent), a single pale stripe from snout up to the shoulder (vs. 3–4 bright stripes from snout and behind the eye up to the shoulders); S. ponticeriana : snout shorter ES 54.7–57.4% of HW (vs. longer, ES 61.5–68.1% of HW), throatfan shorter ADW 28.3–29.2% of AG (vs. longer, ADW 31.1–54.7% of AG), femur shorter FEL 70.6–75.3% of TBL (vs. longer, FEL 80.0–84.8% of TBL), number of ventral scales 87–89 (vs. 65–69), breeding-males with bleached orange colour patch (vs. bright red colour patch); Sitana sivalensis complex: throat-fan extending up to the chest (vs. not extending to the level of the axilla), foot longer FOL 158.9–159.8 of HL (vs. shorter, FOL 120.0–144.3% of HL).

Description. (based on holotype, WHT 1434A). An adult male, 45.0 mm SVL; head moderately large (HL 28.7% of SVL), elongate (HW 60.6% of HL), narrow (HW 17.4% of SVL), distinct from neck; snout short (ES 57.4% of HW); snout length greater than eye diameter (ED 75.0% of ES); interorbital distance broad (IO 14.9% of HL); eye large (ED 26.1% of HL); pupil rounded; ear-opening shallow, its greatest diameter being dorsoventrally, ear-opening with enlarged unkeeled scales anteriorly but not posteriorly, tympanum smaller than orbit ( TYD 35.3% of ED); no spines above the tympanum but an enlarged keeled scale above, separated from the tympanum by two smaller rows of scales; diameter of eyes greater than eye to ear distance (ED 117.0% of TYE); forehead concave; scales on snout keeled, smaller in size than those of the occipital region; scales on interorbital and supercilium area strongly keeled; no nuchal or dorsal crest; rostral scale width greater than height, ventro-posteriorly in contact with the first supralabial, in contact posteriorly with the prenasal and three postrostral scales which are unequal in size; two supranasals on each side, two postnasals among all approximately of equal size and one prenasal; nostril rounded and located in the middle of an undivided nasal plate; two postnasals border the nasal, the upper one larger; canthus rostralis and superciliary edges sharp; parietal plate lozenge shaped (anterior sides shorter than posterior sides) including a grey-blue coloured “pineal eye”, parietal plate larger than adjacent plates. Mental pentagonal, its width and length approximately equal, posteriolaterally in contact with two enlarged postmentals separated by a smaller scale preventing contact between them; each postmental pair bordered posteriorly by three (left side) and four (right side) smooth scales including the medial scale, but exclusive of infralabial. Throat-fan small, its posterior scales not extending to mid venter (DWL 56.3% of SVL, ADW 29.1% of AG), margin of the anterior part of the throat-fan covered with smooth, overlapping, bluntly pointed scales, posterior part (from the middle of the throat to the midventer) with elongate, lanceolate bluntly pointed, keeled scales; throat scales elongate, smooth and overlapping; three scale rows separate orbit from supralabials; supralabials 7 (6th located in mid orbit position); infralabials 8, decreasing in size towards gape; scales on the throat-fan smooth but adjacent ventral scales keeled and mucronate, overlapping.

Body slender (AG 44.8% of SVL); mid dorsal scales enlarged, equal, keeled, not elongate with pointed dorsal scales at midbody, keels straight, forming longitudinal, continuous parallel ridges; scales on dorsum at midbody larger in size than those of venter at the same level; lateral body scales unequal, irregular, keeled, mucronate, smaller than dorsals and with randomly distributed enlarged and mucronate keeled scales; upper dorsolateral scales directed upwards and backwards, dorsoventral ones directed downwards and backwards; 48 scales around midbody; pectoral scales enlarged, elongate and keeled; abdominal scales not enlarged, keeled, and bluntlypointed; ventral keels forming regular and parallel continuous ridges; no preanal or femoral pores. Ventrals, 87.

Upper arm shorter than lower arm (UAL 16.5% of SVL; LAL 18.8% of SVL); femur shorter than tibia (FEL 25.2% of SVL; TBL 35.6% of SVL; FEL 70.6% of TBL). Dorsal scales on fore and hind limbs enlarged, elongate, keeled, overlapping, and mucronate; ventral scales on upper and lower arm enlarged, keeled, overlapping, and bluntly ended; scales on dorsal and ventral surface of thigh slightly keeled, overlapping and bluntly ended; keels on dorsal and ventral arm and foot forming a series of continuous parallel ridges. Digits elongate, slender, all bearing slightly recurved claws; claws are sharp and elongate; subdigital lamellae entire and tri-mucronate, subdigital lamellae on the toe III, 16 and toe IV, 25; inter-digital webbing absent; relative length of fingers 3> 4> 5> 2> 1, and toes 4> 3> 2> 1.

Tail incomplete (broken); tail base swollen, ventral scales on tail base rounded and keeled; dorsal scales on tail keeled, elongate, overlapping, directed backwards, keels forming continuous parallel ridges; tail with subcaudals on median row not enlarged, keeled, and overlapping.

Colour in preserved specimen. Dorsum dark brown with a darker brown patch on the neck but no rhomboid markings on the back. Light coloured blotches on lateral sides of the body, white coloured, incomplete cross bars on the tail beginning just behind the hind limbs, broken tail with seven cross bars. A persian blue stripe starts from mental and continues up to middle of dewlap along mid ventral line. Dark brown blotches on the lateral throat while venter, labials and tympanum are white in colour.

Colour in life. Based on the specimen in Fig. 2 (not collected). Dorsal surfaces of head and back cream to light greyish brown with five black-edged rhomboidal spots, the back is bordered on each side with a dark brownish band, along the middle of the back with a light vertebral line separating them. Upper and lower lips light buff cream with dark markings. A buff light cream streak from the nasal across the tympanum to the forelimb; pupil black. Iris black with its outer rim golden. A brownish-black patch on anterior part of interorbital. Anterior part of the throat-fan is persian blue and cream. A bleached orange diffuse patch at the middle of the throat-fan on a cream coloured background. Upper arm with one, lower arm with three, thigh with two and tibia with three indistinct buff cream bands. Vague, light patches on flank and lateral body. Middle of throat dark blue. Tail with 16 light crossbands. Three buff cross-bands on fingers and three or four on toes. Ventral scales buff cream. See the following corresponding figures in Manthey (2010: 154): RA04169-4 (Pottuvil), RA04170-4 (Ampara).

Variation in male paratypes. Rostral scale in contact posteriorly with postrostral scales in WHT 7377; eight supralabials in male paratypes (WHT 7377, 0206C–D, 0 619, 1434B, and ZMH R06344); seven infralabials in WHT1434B; 52 and 56 scales around the midbody in WHT7377 and WHT1434B respectively; subdigital lamellae on the toe III, 17 and 14 respectively, on toe IV, 26 and 23 respectively. Ventrals respectively 89 and 86.

Description of female. (Based on paratype WHT195A). An adult female, 46.9 mm SVL; head moderately large (HL 27.3% of SVL), elongate (HW 65.2% of HL), narrow (HW 17.8% of SVL), distinct from neck; snout short (ES 51.8% of HW); snout length greater than eye diameter (ED 75.9% of ES); interorbital distance broad (IO 16.4% of HL); eye large (ED 26.4% of HL); pupil rounded; ear-opening shallow, its greatest diameter dorsoventrally, ear-opening with enlarged unkeeled scales anteriorly but not posteriorly, tympanum smaller than orbit ( TYD 39.6% of ED); no spines above the tympanum but an enlarged keeled scale above the tympanum separated from the tympanum by two smaller scale rows; diameter of eye greater than eye to ear distance (ED 111.9% of TYE); forehead concave; scales on snout keeled, smaller in size than those of the occipital region; scales on interorbital and supercilium area keeled; no nuchal or dorsal crest; rostral scale width greater than height, ventro-posteriorly in contact with the first supralabial, in contact posteriorly with the prenasals and three postrostral scales unequal in size; two supranasals around nostrils on each side, nostril rounded located in the middle of an undivided nasal plate; canthus rostralis and superciliary edges sharp; parietal plate lozenge shaped (anterior sides shorter than posterior sides) including a grey-blue coloured “pineal eye”, parietal plate larger than adjacent plates. Mental pentagonal, approximately equal in length and width, posteriolateraly in contact with two enlarged postmentals separated by a smaller scale with no contact between them. Throat-fan absent; throat scales elongate, smooth and overlapping; three scale rows separate orbit from supralabials; supralabials 7 (6th situated in mid orbit position); infralabials 9, decreasing in size towards gape; gular scales keeled.

Body slender (AG 45.4% of SVL); mid dorsal scales equal sized, keeled, not elongate with pointed dorsal scales at midbody, keels straight, forming longitudinal, continuous parallel ridges; scales on dorsum at midbody of similar size than those of venter at same level; lateral body scales unequal, irregular, keeled, mucronate, short, similar in size to dorsals and with randomly distributed, enlarged, rounded, keeled scales; upper dorsolateral scales directed upwards and backwards, dorsoventral ones directed downwards and backwards; 57 scales around the midbody; pectoral scales enlarged, keeled, mucronate and weakly overlapping; abdominal scales elongate and pointed; ventral keels forming regular and parallel continuous ridges; no preanal or femoral pores. Ventrals, 88.

Upper arm shorter than lower arm (UAL 13.3% of SVL; LAL 16.7% of SVL); femur shorter than tibia (FEL 25.3% of SVL; TBL 31.0% of SVL; FEL 81.5% of TBL). Dorsal scales on fore and hind limbs enlarged, elongate, keeled, overlapping, and mucronate; ventral scales on upper and lower arm not enlarged, keeled, overlapping, and bluntly ended; scales on dorsal and ventral surface of thigh slightly keeled, overlapping and bluntly ended; keels on dorsal and ventral arm and foot forming a series of continuous parallel ridges. Digits elongate, slender, all bearing slightly recurved claws; claws are sharp and elongate; subdigital lamellae entire and tri-mucronate, 14 subdigital lamellae on the toe III, and 24 on toe IV; inter-digital webbing absent; relative length of fingers 3> 4> 5> 2> 1, and toes 4> 3> 2> 1.

Tail incomplete (broken); tail base swollen, ventral scales on tail base rounded and keeled; dorsal scales on tail keeled, elongate, overlapping, directed backwards, keels forming continuous parallel ridges; tail with subcaudals on median row not enlarged, slightly keeled, overlapping.

Etymology. The species epithet is an eponym Latinised in the genitive singular, honouring Mohomed Mujythaba Bahir for his generous friendship, and remarkable contributions to Sri Lankan herpetology, carcinology and biodiversity conservation. Currently he spends his valuable time promoting science, biodiversity and conservation to the general public, especially the younger generation. Suggested English name: Bahir’s Fanthroated Lizard; Sinhala (local) name: Bahirgë Theli Katussa; French name: Sitane de Bahir.

Distribution. See map Fig. 9 . Drier coastal areas in south-eastern Sri Lanka, sometimes recorded within the country at a distance of ~ 20 km from the nearest beach (e.g. Tissamaharama).

Natural history. We observed live specimens in warm, lowland habitats but the species was most abundant in the drier coastal areas ( Fig. 10 ), under open scrub jungles on dusty or sandy ground in the dry zone or drier parts of the intermediate zone. S. bahiri sp. nov. has never been recorded from the wet zone or its adjacent habitats. Most of its habitats were covered with tree species such as Manilkara hexandra (Sapotaceae) , Drypetes sepiaria (Euphorbiaceae) , and some shrubs such as Salvadora persica (Salvadoraceae) , Dodonaea viscosa (Sapindaceae) , Spinifex littoreus (Poaceae) , Ziziphus oenopila (Rhamnaceae) , Catunaregam spinosa (Rubiaceae) , Ipomoea asarifolia (Convolvulaceae) , Spermacoce hispida (Rubiaceae) , Gisekia pharnaceoides (Molluginaceae) , Tephrosia purpurea (Fabaceae) , and Portulaca oleracea (Portulacaceae) .

Sitana bahiri sp. nov. is a diurnal lizard fully adapted to harsh terrestrial habits such as dry sandy coasts. In the morning, around 0700–0800 h it mostly lies on rocks, fallen logs or shrubs, and as it warms up, it becomes active and begins its search for food. In the middle of the day, when it is hottest, it tends to hide inside small shrubs. We observed some individuals digging small sand pits near the root of the shrub in order to escape the heat. There is an annual temperature of between 30 o C and 35 o C (mean 32 o C), while the humidity varies between around 40–50% (mean 45%).

Sitana bahiri sp. nov. is a highly territorial animal and shows similar territorial behaviour pattern to Otocryptis (see Karunarathna & Amarasinghe 2008). Before combat (attacking stage) and prior to mating, they extend and stretch their throat-fans very quickly (about 4–6 times per second). Simultaneously, they swivel their heads and open their dark blue coloured mouths in a threat pose to their male opponents. During combat (struggling stage), they mostly use their hind limbs to kick at their opponent. Most often the territorial fighting involved a certain amount of harsh savagery (savaging stage), and the animals often end up with wounded body parts, with particular damage to the face, limbs and posterior body parts.

They mostly feed on ground dwelling insects, but have also been observed predating on airborne dragonflies, butterflies, and caterpillars. Their diet also includes tiny terrestrial crabs. During the night, they sleep on the sandy floor, lower branches or on the roots of shrubs. Eutropis carinata (grass skink), Calotes versicolor (garden lizard), Lycodon aulicus (wolf snake), Coelognathus helena (trinket snake), Varanus bengalensis (land monitor), Herpestes brachyurus (brown mongoose), Acridotheres tristis (common myna), and several birds of prey are observed as their major predators. Egg laying occurs from August to October and they lay 4– 6 eggs per clutch in a nest dug in cool habitats under shrubs.

Conservation status. The result of the application to the IUCN Red List (2013) criteria B2-b (iii) indicates that S. bahiri sp. nov. is Vulnerable (VU). It is restricted to an area of occupancy (AOO) <650 km 2 (7 spotting sites) with an extent of occurrence (EOO) <8,500 km 2 in the south-east dry zone within different forested areas. In April 2004, we conducted a 5x 100m belt transect search along the coast, which was ~75% covered with Spinifex littorus ( Fig. 10 ), 44 S. bahiri specimens (12 males and 32 females) were recorded. Among them 13 were juveniles and subadults. The same location was surveyed again in April 2008 using a 5x 100m belt transect, this time Spinifex littorus cover was reduced to ~10% and only 6 specimens (1 male and 5 females) were recorded. This density has shown a definite decrease due to the Indian Ocean Sumatra–Andaman earthquake and the subsequent tsunami which followed (it flushed away 1–2 km of the land) in December 2004.

Figures

FIGURE 1. Sitana bahiri sp. nov. holotype (WHT 1434 A) (A) dorsal view of head; (B) lateral view of head; (C) ventral view of head; (D) ventral view of thigh and tail base (photo: M. C. De Silva); (E) Sitana bahiri sp. nov. live breeding male (not collected) with expanded throat-fan at Kumana National Park, Sri Lanka (photo: H. Matarage in 2011).

FIGURE 2. Sitana bahiri sp. nov. live breeding male (not collected) with contracted throat-fan at Kirinda, Sri Lanka (photo: A. A. T. Amarasinghe in 2005).

FIGURE 3. Sitana bahiri sp. nov. (A) lateral body scales of holotype male (WHT 1434 A); (B) pectoral scales and (C) abdominal scales of paratype female (WHT 0195 A); Sitana devakai sp. nov. (D) lateral body scales of holotype male (WHT 0111 E); (E) pectoral scales and (F) abdominal scales of paratype female (WHT 0111 C) (illustrated by A. A. T. Amarasinghe).

FIGURE 9. Distribution map of S. ponticeriana (yellow), S. deccanensis (green), Sitana cf. devakai (purple), S. cf. ponticeriana (orange), Sitana sivalensis complex (grey), S. bahiri sp. nov. (blue); S. devakai sp. nov. (black); and S. ponticeriana mucronata (red). Holotype locality of each Sri Lankan species marked with squares.

FIGURE 10. Habitat of Sitana bahiri sp. nov. (A) dry coastal area in Palatupana, Kirinda, Sri Lanka; (B) coast covered with Spinifex littorus (photo: A. A. T. Amarasinghe); habitat of Sitana devakai sp. nov. (C) dry warm sandy area in Puttalam, Sri Lanka; (D) area covered with Abelmoschus angulosus (photo: D. M. S. S. Karunarathna).