Ptychozoon kaengkrachanense, Sumontha, Montri, Pauwels, Olivier S. G., Kunya, Kirati, Ruksue, Chaiwat Limlikhitaksorn Sirichai, Taokratok, Apirat, Ansermet, Michel & Chanhome, Lawan, 2012

Sumontha, Montri, Pauwels, Olivier S. G., Kunya, Kirati, Ruksue, Chaiwat Limlikhitaksorn Sirichai, Taokratok, Apirat, Ansermet, Michel & Chanhome, Lawan, 2012, A new species of Parachute Gecko (Squamata: Gekkonidae: genus Ptychozoon) from Kaeng Krachan National Park, western Thailand, Zootaxa 3513, pp. 68-78 : 69-78

Ptychozoon kaengkrachanense sp. nov.

Figures 1–5 .

Holotype. Adult female PSUZC-RT 2012.1 (formerly Montri Sumontha (MS) field number 541) from Khao Phanernthung (coordinates UTM UPS ca. 47 p0539530 1417468 = 12°49'18.8"N 099°21'51.4"E; altitude ca. 970 m asl), Kaeng Krachan National Park, Amphoe (= District) Kaeng Krachan, Phetchaburi Province, western Thailand. Collected 15 March 2012 by S. Ruksue, P. Chamted and A. Limsuwan.

Paratypes. Adult female QSMI 1169 (formerly MS 545) and adult males PSUZC-RT 2012.2 (formerly MS 542), same locality and collector as holotype. KZM 0 10 (formerly MS 543) from Amphoe Kaeng Krachan, Phetchaburi Province, western Thailand. Collected 15 June 2011 by K. Kunya.

Diagnosis. Ptychozoon kaengkrachanense sp. nov. is a medium-sized Ptychozoon species, reaching an apparent maximum SVL of at least 86 mm. It differs from all known Ptychozoon species by having three dark dorsal chevrons between limbs insertions, homogeneous dorsal scalation without enlarged scales, original tail without long terminal flap, supranasals widely in contact, a continuous series of 14–19 enlarged precloacofemoral scales, bearing 13–17 pores in males (pores absent in females), the absence of predigital notch in the preantebrachial cutaneous expansion and the presence of cutaneous expansions on sides of head. The main morphological and coloration characters of all Ptychozoon species are shown in Table 2.

Description of holotype ( Figures 1–4 ). Body depressed dorsoventrally, relatively stout, somewhat elongate (AG/SVL 0.48). Head short (HL/SVL 0.26), wide (HW/SVL 0.21), depressed (HD/HL 0.42), distinct from neck. Snout rounded at tip. Interorbital region flat. Rostral scale large, rectangular, without dorsomedian groove; rostral width 3.9 mm; rostral depth 2.4 mm. Rostral in contact with 2 supranasals, nostrils and supralabial I. Supralabials 9 (left) / 10 (right), supralabial XIII in mid-orbital position; 9 infralabials on each side. Mental subtriangular, wider than deep, bordered laterally by infralabials I and posteriorly by left and right paired postmentals which contact medially for about 70% of their length. Postmentals subrectangular, slightly longer than mental. One row of slightly enlarged sublabials extending along all infralabials. Nostril rounded, oriented laterally, surrounded by rostral, supralabial I, two postnasals and supranasal. Supranasals trapezoidal, in broad contact with each other. Eye diameter shorter than snout length and subequal to eye-ear distance. Scales on snout and forehead small, rounded, smooth; scales on snout larger than those on occipital region. No ridge of tubercles along mandibles. Eyes large (ED/HL 0.28). Pupil vertically elliptical, with crenelated edges. Supraciliaries elongated, anterior ones lacking spines, posteriormost ones showing minute spines. Auricular opening rounded, lacking enlarged lobes; tympanum deeply sunken. Infra-auricular cutaneous expansion a broad round flap, measuring 3.4 mm at its widest point, with subimbricate hexagonal to round scales dorsally and minute scales ventrally, forming a second, much smaller lobe, tapering into nuchal region. Entire anterior and posterior margins of forelimbs, entire posterior margins of hindlimbs and distal half of anterior margins of hindlimbs (along tibia) with wide cutaneous expansions. Limb expansions with minute scales ventrally and moderately enlarged scales dorsally. Pre- and postantebrachial expansions very reduced near base of digits I and V of manus; digits I and V of manus showing no external cutaneous expansion. No predigital notch in preantebrachial cutaneous expansion. Axilla-groin cutaneous expansion measuring 6.9 mm at midpoint of body with enlarged, imbricate, rectangular scales dorsally and minute scales ventrally; 10–12 enlarged dorsal scales on each side of axilla-groin expansion at midbody. Pretibial expansion a single rounded lobe, beginning at knee, extending distally but not reaching pes. Posttibial expansion not continuous with fringe of digit V of pes.

Chin scales small, rounded, posteriorly abruptly increasing in size and imbricating in the gular area, grading into ventral scales. Dorsal scales at midbody minute, rounded, much smaller than the imbricate, flat, ventrals. Smooth, imbricate ventrals in 24 transverse rows between the flanks which show minute rounded scales below the base of the axilla-groin cutaneous expansion; ventrals gradually decreasing in size laterally.

Scales on manus and pes smooth, rounded. Scales on inner- and outer surfaces of fore- and hind limbs smooth. Precloacal depression or groove absent. Eighteen enlarged precloacofemoral scales in a continuous angular series, lacking pores. Forelimbs moderately short, stout. Forearm short; hind limbs relatively short; tibia short (TBL/SVL 0.16). Digits relatively short, dorsoventrally compressed, all clawed except the inner digit. Claws recurved. Distal phalanges not elevated. Subdigital scansors subrectangular, entire, unnotched. Basal subdigital lamellae broad. Lamellae numbering on manus I (10), II (15), III (15), IV (18) and V (14), and on pes I (12), II (16), III (16), IV (17) and V (14). Inner surface between fingers and toes extensively webbed.

Tail original, flattened, nearly identical to SVL. Two median rows of transversely widened subcaudals; subcaudals smooth. Scales on postanal region and at proximal part of tail base smaller than on rest of tail. Terminal tail flap narrow, very short. Width of tail and lateral lobes progressively decreasing posteriorly; 25 tail lobes on the left side, 24 on the right side. The angling of the caudal lobes is strong.

Measurements and meristic counts taken on the holotype are shown in Table 1 .

Coloration in life. Background color of dorsum light gray with three dark irregular bicolored chevrons (anterior chevron part dark gray with irregular black pigmentation, posterior part black). First chevron beginning at posterior edge of orbit, extending posteriorly beyond forelimbs insertion. Second chevron above midbody and third just before hind limbs insertion. Upper surface of limbs light gray, irregularly barred with black. Upper surfaces of manus and pes light gray with irregular dark pigmentation. One irregular, elongate, dark patch on nape. Dark transverse bar above anterior part of orbits. One reduced, simplified, chevron just posterior to hind limb insertion. Tail encircled by five dark rings. Background color of tail lighter posteriorly. Undersurface of hand cream with scattered dark pigmentation. Belly cream with scattered dark pigmentation increasing posteriorly. Undersurfaces of limbs cream with scattered dark pigmentation, more intense on hind limbs. Underside of manus and pes dark gray. Upper surface of axilla-groin cutaneous expansion light gray with irregular dark pigmentation; underside cream with little, scattered, dark pigmentation.

Variation. Measurements and meristic counts taken on the paratypes are provided in Table 1 . precloacofemoral pores are present in adult males and absent in females. The postcloacal hemipenial bulge is distinct in males. Males possess a single round, flat postcloacal spur on each side of the cloaca. All paratypes have partly regenerated tails, exhibiting fusion of the lateral lobes into a long terminal flap, narrower than the anterior part of tail. The banded pattern of the original tail is absent in the regenerated portion. Males have a more contrasting and darker pigmentation on the throat and belly than females. Besides the type-series, six adults, not collected, were closely observed at the type-locality; all had three dark dorsal chevrons between limbs insertions and a similar dorsal coloration, and their SVL were within the range observed in our type-series. Juveniles are unknown.

Holotype Paratype Paratype Paratype Distribution. Due to the proximity of the type locality to Myanmar (16 airline km), and the environmental homogeneity in the intervening area, there is a very strong possibility that it also occurs in the latter country. Other areas that may support populations of the new species include the mountainous, forested areas in Ratchaburi Province and in northern Prachuap Khiri Khan Province, which are contiguous with those of Kaeng Krachan National Park.

Natural history. Individuals of the new species are commonly observed in wooden houses and man-made structures at the type locality. They rest under the roof during daytime, and hunt insects at night on walls, sometimes around neon lights. Up to seven individuals have been observed hunting insects attracted by light on the same wall. On the same wooden buildings and at the same time we observed Cyrtodactylus brevipalmatus (Smith) , Hemidactylus platyurus (Schneider) and Gehyra mutilata (Wiegmann) . Many Ptychozoon lionotum were observed in nearby wooden man-made structures in the park ( Pauwels & Chan-ard 2006; unpubl. obs.), although not in strict syntopy with P. kaengkrachanense sp. nov.

Etymology. The specific epithet is a reference to Kaeng Krachan National Park and Kaeng Krachan District, Phetchaburi Province (the type locality of the new species). We suggest the following common names: Took-kay bin Kaeng Krachan ( Thai), Kaeng Krachan Parachute Gecko (English) , Gecko planant de Kaeng Krachan (French).

Brown et al. 1997; Brown 1999; Das & Vijayakumar 2009; Kunya et al. 2011). A slash indicates “not applicable.”

Character/species P. horsfieldii P. intermedium P. k u h l i P. lionotum P. nicobarense P. rhacophorus P. trinotaterra P.kaengkrachanense

sp. nov.

Maximal known 73.9 99.8 107.8 98.6 100.3 64.5 71.3 86.0

SVL

Disposition of dorsal Absent 0– 10 2–6 Absent 4 irregular 6–10 rows, 0–1 Absent

tubercles irregular straight rows scattered mediodorsal rows rows row

Seven Ptychozoon species are currently recognized ( Brown 1999; Brown et al. 1997, 2012; Das & Vijayakumar 2009; Kunya et al. 2011): P. horsfieldii Gray from Borneo, P. intermedium Taylor from the Philippines, P. kuhli Stejneger , distributed from southern Thailand and Sumatra eastwards to Sulawesi (potentially including several undescribed species according to Brown et al. 2012), P. lionotum , which occurs in Cambodia, Myanmar, Thailand and peninsular Malaysia, P. nicobarense Das & Vijayakumar, 2009 from the Indian Nicobar Islands, P. rhacophorus Boulenger, 1899 from Borneo and P. trinotaterra Brown, 1999 from eastern Thailand and central Vietnam.

So far, only three Ptychozoon species were known to possess only three dark dorsal chevrons between limbs insertions: P. intermedium from the Philippines, P. nicobarense from the Nicobar Archipelago and P. trinotaterra from eastern Thailand and central Vietnam ( Brown 1999; Das & Vijayakumar 2009; Kunya et al. 2011). The tail shape (tapering, lobe angling, minute distal flap, and lack of lobe fusion) and overall appearance of P. kaengkrachanense sp. nov. suggest a close relationship with P. intermedium and P. horsfieldii , which were shown in a recent molecular phylogenetic analysis to be closely related to each other and quite distinct from the P. k u h l i - P. lionotum - P. trinotaterra clade ( Brown et al. 2012).

Ptychozoon kaengkrachanense sp. nov. can be readily distinguished from P. horsfieldii by lacking separated enlarged femoral scales (versus 8–11 enlarged femoral scales + 10–11 enlarged precloacals in P. horsfieldii ), by having supranasals in contact, by having three dark chevrons between limb insertions (versus four in P. h o r s f i e l d i i), by the absence of rounded nuchal markings (present in P. horsfieldii ) and by a greater SVL (86.0 mm in P. kaengkrachanense sp. nov. versus 73.9 mm in P. horsfieldii ). It differs from P. intermedium by lacking separated enlarged femoral scales (versus 12–19 enlarged femoral scales + 8–12 enlarged precloacals in P. intermedium ), by lacking enlarged tubercular dorsal scales (versus 0–10 irregular rows of enlarged dorsal scales in P. intermedium ; only one out of 25 P. intermedium specimens examined by Brown et al. 1997 lacked enlarged dorsal scale rows) and by a smaller SVL (86.0 mm, versus 99.8 mm in P. intermedium ); both species also differ in dorsal color pattern: the dark dorsal chevrons show a double posterior point in P. kaengkrachanense sp. nov. and a single point in P. intermedium , and the posterior extremity of the nuchal chevron of P. kaengrachanense sp. nov. is pointed while it is straight in P. intermedium (see description and figures in Brown et al. 1997). P. kaengkrachanense sp. nov. differs from P. k u hl i by the absence of dorsal tubercles (versus 2–6 straight tubercle rows in P. k u h l i), by having three dorsal dark chevrons between limbs insertions (versus four), by lacking fusion of distal tail lobes into a long terminal flap in original tail and by a smaller SVL (86.0 mm in P. kaengkrachanense sp. nov. versus 107.8 mm in P. kuhli ). Ptychozoon kaengkrachanense sp. nov. can be distinguished from P. lionotum by its possession of three dark dorsal chevrons between limbs insertions (versus four), by lacking a predigital notch in preantebrachial cutaneous expansion, and by lacking fusion of distal tail lobes into a long terminal flap in original tail. It differs from P. nicobarense by having very visible and contrasting dorsal chevrons (versus three indistinct chevrons in P. nicobarense ), lacking a tan vertebral stripe, lacking enlarged dorsal tubercles (versus four irregular rows of enlarged tubercular dorsal scales in P. nicobarense ), lacking fusion of distal tail lobes into a long terminal flap in original tail, and by a smaller SVL (86.0 mm in P. kaengkrachanense sp. nov. versus 100.3 mm in P. nicobarense ). It differs from P. rhacophorus by lacking enlarged dorsal tubercles, by having supranasals in contact, by having 3 dorsal dark chevrons between limbs insertions (versus. chevrons absent in P. rhacophorus ), by having cutaneous expansions on sides of head (versus absent) and by a larger size (maximal known SVL 86.0 and 64.5 mm, respectively). Ptychozoon kaengkrachanense sp. nov. can be easily distinguished from P. trinotaterra by the absence of fusion of distal tail lobes into a long terminal flap in original tail; by having black dorsal chevrons with more posterior projections in Ptychozoon kaengkrachanense sp. nov. than in the simpler W-shaped chevrons of P. trinotaterra (see Kunya et al. 2011); and apparently by reaching a larger body size (maximal known SVL 86.0 and 71.3 mm, respectively).

Ptychozoon kaengkrachanense sp. nov. is the 5th species of this genus recorded from Thailand, along with P. horsfieldii , P. kuhli , P. lionotum and P. trinotaterra ( Brown 1999; Kunya et al. 2011). It is the only Ptychozoon species endemic to Thailand. It is the 68th reptile species recorded from Kaeng Krachan National Park, which was already known to house the richest herpetofauna of all protected areas of Thailand ( Pauwels & Chan-ard 2006; Pauwels et al. 2009), and it thus reinforces the exceptional value of the park in terms of biodiversity and its conservation.

Figures

FIGURE 1. Preserved type series of Ptychozoon kaengkrachanense sp. nov. Photo by M. Sumontha.

FIGURE 2 A – B. Dorsal and ventral views of the preserved holotype of Ptychozoon kaengkrachanense sp. nov. (PSUZC-RT 2012.1). Photo by M. Sumontha.

FIGURE 3 A – C. Head of the holotype of Ptychozoon kaengkrachanense sp. nov. (PSUZC-RT 2012.1). Photo by M. Sumontha.

FIGURE 4. Ventral view of hindlimbs of the preserved adult male paratype of Ptychozoon kaengkrachanense sp. nov. [PSUZC-RT 2012.2] Photo by M. Sumontha.

FIGURE 5. Adult female Ptychozoon kaengkrachanense sp. nov. (not collected) on a wooden house in Khao Phanern Thung, Kaeng Krachan National Park. Photo by M. Sumontha. s

Tables

TABLE 1. Meristic, morphometrical (in mm) and pattern data for the type series of Ptychozoon kaengkrachanense sp. nov. Paired meristic characters are given left / right. Abbreviations provided in Material and methods section.

PSUZC-RT 2012.1	QSMI 1169	PSUZC-RT 2012.2	KZM 0 10
Sex Female	Female	Male	Male
Supralabials 9/10	9/9	9/8	9/10
Infralabials 9/9	8/8	9/9	9/9
Interorbital scales 35	34	35	37
Supranasals in contact Yes	Yes	Yes	Yes
No. of ventral scale 24 rows	24	25	25
Enlarged 18 precloacofemoral scales (no separated femoral scales)	19	19	14
precloacofemoral 0 pores Lamellae under 4th toe 17 of pes	0 16	17 17	13 15
Predigital notch in No preantebrachial cutaneous expansion	No	No	No
No. of lateral tail lobes 25/24 Black dorsal chevrons 3 between limbs insertions	17/17 (tail partly regenerated) 3	9/10 (tail partly regenerated) 3 (4th one above hind limbs insertion)	13/13 (tail partly regenerated) 3
SVL 79.5	78.5	86.0	78.0
AG 38.2	37.4	40.4	35.7
TL 79.8	73.8 (of which original part 56.4)	66.2 (of which original part 32.1)	69.7 (of which original part 44.0)
TW 7.2	6.8	10.9	8.4
HL 20.9	20.0	21.6	20.6
HW 16.9	15.4	17.5	16.0
HD 8.7	8.0	10.6	10.0
ED 5.8	5.8	7.1	6.7
EAO 6.5	5.9	6.9	6.5
EN 6.1	5.8	6.5	5.9
ES 8.7	8.5	9.0	8.4
AOW 1.5	1.6	1.3	1.2
IN 3.5	3.1	4.0	3.2
IO 3.7	3.5	4.3	3.7
FL 8.4	7.5	8.1	7.6
TBL 13.1	12.2	14.5	12.8