Current status of Calotes liocephalus Günther , 1872 ( Reptilia : Agamidae ) of Sri Lanka

Author Details: A.A. THASUN AMARASINGHE, the chairman of the Taprobanica Nature Conservation Society is a Sri Lankan herpetologist. He is the editor-in-chief of the Taprobanica journal, is an editorial board member of Herpetotropicos, and a member of CSG/SSC/IUCN; currently involved in biodiversity conservation projects in Sri Lanka. D.M.S. SURANJAN KARUNARATHNA, an instructor of the reptile study group in Young Zoologists’ Association of Sri Lanka and currently works as a project assistant for the IUCN, Sri Lanka. Also, he is a member of CSG/SSC/IUCN. DINESH E. GABADAGE, the secretary of the Taprobanica Nature Conservation Society is a field biologist working on Sri Lankan herpetofauna and promoting conservation awareness of the value of biodiversity among Sri Lankans.

Seven species of Calotes occur in Sri Lanka.

MATERIALS AND METHODS
The examined holotype is at the Natural History Museum, London, UK (BMNH) and others are with the Wildlife Heritage Trust of Sri Lanka, Colombo, Sri Lanka (WHT).Diagnoses and descriptions are based on morphology.The locality record for each species includes WHT specimen data, published information and our observations during the past decade.
All measurements were taken with dial calipers to the nearest 0.1mm.Scale counts: SUP -Supralabials were counted from the first scale anterior to that at the angle of gape, not including the median scale (when present); INF -infralabials were counted from the first scale posterior to mental, to the angle of gape; DS -dorsal spines were counted from the first spine to the last of mid-dorsal row; CR -canthus rostralis (counted from rostral scale along scale row passing over nostril to posterior end of supraciliary ridge); MDS -mid dorsal scales (counted from scale behind the rostral to the posterior margin of the thigh); MBS -mid body scales were counted from center of the mid-dorsal row forwards and downwards across ventrals (this count is unreliable, by the unequal size and uneven arrangement of the lateral scales); MVS -mid ventral scales were counted from the first scale posterior to mental, to the last scale anterior to vent; SAT -Spines around tympanum were counted from the first spine to the last above tympanum.
External measurements (in mm): SVL -snoutvent length (distance between tip of snout to anterior margin of vent); HL -head length (distance between posterior edge of mandible and tip of snout); HW -head width (maximum width of head); DHL -dorsal head length (distance between posterior edge of cephalic bone and tip of snout); NFE -nostril front eye length (distance between anterior most point of orbit and middle of nostril); UAL -upper-arm length (distance between axilla and angle of elbow); LAL -lower-arm length (distance from elbow to wrist with both upper arm and palm flexed); FL -finger length (distance between tip of claw and the nearest fork); FEL -femur length (distance between groin and knee); TBL -tibia length (distance between knee and heel, with both tibia and tarsus flexed); TL -toe length (distance between tip of claw and nearest fork); AGaxillagroin length (distance between axilla and groin); SAsnoutaxilla length (distance between tip of snout and axilla); TAL -tail length (measured from anterior margin of vent to tail tip); PAL -palm length (taken from posterior most margin of palm and tip of longest finger); FOL -foot length (distance between heel and tip of longest toe, with both foot and tibia flexed); TBW -width of tail base (greatest width of the tail base); IOW -inter orbital width (minimum distance between the upper margins of orbits); ED -eye diameter (horizontal diameter of orbit); SFE -snoutfront eye length (distance between anterior most point of orbit and tip of snout); SBEsnoutback eye length (distance between posterior most point of orbit and tip of snout); SFT -snoutfront tympanum length (distance between anterior most point of tympanum and tip of snout); TD -Tympanum diameter (minimum distance between the inner margins of tympanum).
Diagnosis: Head without spines or rarely a rudimentary spine above the tympanum; dorsinuchal crest poorly developed; lateral scales directed backwards and downwards.
Description: [Based on Holotype and WHT collection: (Images 1-2; Figs.1-3) the range of morphometric data for holotype and WHT specimen shown at the end of the description].Head without spines or rarely a rudimentary spine above ear, an oblique fold in front of shoulder, lower jaw rather short.Canthus rostralis not very prominent, its outline straight.Six scales from eye to nostril.Tympanum about half size of the orbit.Supraocular scales enlarged.Dorsinuchal crest poorly developed and the spines strongest on head, low on neck and rudimentary on body, scales on sides point backwards and downwards; dorsal scales smaller, feebly keeled, about as large as the ventrals; gular sac undeveloped; gular scales as large as or larger than the ventrals; faintly carinate.Body compressed; Body scales faintly carinate; Ventrals strongly carinate.Limbs moderate; third and fourth fingers equal or fourth finger a little longer than the third.Relative length of fingers; 1<5<2<3<4.Fourth toe distinctly longer than the third.Relative length of toes; 1<2<5<3<4.Hind limb reaches to the eye or nearly as far.In a fully-grown male the head is larger and tail is markedly swollen at the base, with Distribution and habitat: Calotes liocephalus appears to be rare and has been recorded only from the forests of the Knuckles Range (from 800-1850 m) and Peak Wilderness (from 800-2000 m) and this species is endemic to Sri Lanka.This species is largely arboreal and its diet comprises of young leaves, buds, insects and worms (de Silva et al. 2005).
Hemipenis morphology: The hemipenis of Calotes liocephalus (Image 5) is well developed.The pedicel is slightly shorter than the head; below the head, it is broadened out in to two shallowly concave shoulders; there are no spines.The head is quadrangular, shallowly divided longitudinally into four lobes, two being slightly larger.Surface of the head is reticulatedly pitted, the pits being larger on the outside, diminishing in size towards the divisions between the lobes.
Nest hole and eggs: A female dug a hole in the ground 92.6mm deep and 79.1mm in diameter.3-8 eggs were deposited in June.The bottom of the hole is conical and is dug at 45 0 angle.The eggs were white and elliptic, with a mean length of 14.8mm and 8.6mm width (n=8).While laying eggs C. liocephalus places the posterior part of its body inside the hole (Fig. 4) and it does not lift the posterior part of the body to lay eggs.Its entire body curls inside the hole, bending the anterior part of its body to look around (see Amarasinghe & Karunarathna 2008).
Other behaviour: This species is active during daytime, largely arboreal and sometimes on trees 5m above ground level.

DISCUSSION
According to Manamendra-Arachchi et al. (2006) the lowlands (elevation ~500m) of the Mahaweli River, which separates the Dumbara Hills (= Knuckles Hills) from the Central Mountains, appears to have served as a barrier to the dispersion of highland species.According to Günther (1872) the holotype of Calotes liocephalus (BMNH 1946.8.11.33), was collected from Peradeniya District presumably, Peradeniya (alt.~500m) in the Kandy District.However, Peradeniya is on the margin of the Knuckles and Central Hills and the Mahaweli River flows across Peradeniya.If the report is correct, C. liocephalus was once distributed throughout the low elevations of Central and Knuckles Mountains.We could not locate any Calotes liocephalus specimen in Peradeniya.Two isolated populations in the Central Hills and Knuckles Region occur and these have not been compared critically (Fig. 5).Therefore, a morphological and morphometric analysis of the two isolated C. liocephalus populations is needed.If the Knuckles population is a distinct morphospecies, its range would be restricted to the Knuckles massif and it would be at risk of extinction before it is even named.

Figure 5 .
Figure 5. Distribution of C. liocephalus populations -Central-hill population; -Knuckles population, -Type locality , Snakes and other Reptiles of Sri Lanka.