Hemiphyllodactylus bokor, Neang & Samorn & Hun & Henson & Stuart, 2024

Neang, Thy, Samorn, Vireak, Hun, Seiha, Henson, Adam & Stuart, Bryan L., 2024, Review of the Slender Geckos (Squamata: Gekkonidae: Hemiphyllodactylus) of the Cardamom Mountains of southwestern Cambodia, with descriptions of two new species and one country record, Zootaxa 5537 (3), pp. 377-394 : 382-385

Hemiphyllodactylus bokor sp. nov.

Fig. 3

Holotype. NCSM 98991 (field tag BLS 13164 ), adult male, Cambodia, Kampot Province, Teuk Chou District, Preah Monivong Bokor National Park , 10.62368ºN, 104.02650ºE, 1,073 m elev., coll. 01 October 2017 by Neang Thy, Samorn Vireak, and Bryan L. Stuart.

Paratype. CBC 03119 (field tag BLS 13108 ), adult female, same data as holotype except 10.65436ºN, 104.06080ºE, 926 m elev., coll. 26 September 2017 . NCSM 98992 (field tag BLS 17599 ), adult female, same data as holotype except 10.65927ºN, 104.05169ºE, 921 m elev., coll. 27 June 2018 .

Diagnosis. A bisexual species of Hemiphyllodactylus having the unique combination of maximum SVL 39.0 mm; chin scales eight; intersupranasal scales three; circumnasal scales five; supralabial scales 9–11; infralabial scales 8–11; dorsal scales within one diameter of eye 23–24; ventral scales within one diameter of eye 15–16; SubdigLam FI 3–4; SubdigLam FII–V 4554; SubdigLam FTot 18; Subdig TI 3–4; SubdigLam TII–V 4555; SubditLam TTot 19; PreCloFem Pores in males 15, continuous; and cloacal spurs 2–3 on each side.

Description of holotype. Adult male with SVL 35.9 mm; head triangular in dorsal profile, distinct from neck, HL 9.2 mm, longer than width, HW 6.4 mm, slightly depressed, HD 4.0 mm; snout relatively rounded in dorsal profile, SnEyeD 3.7 mm, 40% HL; eye rounded, relatively moderate in size, EyeD 2.5 mm; ear oval, EarDH 1.0 mm, EarDV 0.6 mm; Eye-EarD 3.0 mm, slightly larger than EyeD. Rostral subrectangular with median notch dorsally, 1.8 mm in width, 0.8 mm in depth, in contact with first supralabials laterally, with supranasals and intersupranasals dorsally; supranasals two, similar in size, separated by intersupranasals; intersupranasals three, much smaller than supranasals; circumnasal scales five; external nares in contact with rostral anteriorly, supralabials ventrally, supranasals dorsally, postnasals posteriorly; postnasal scales two; lore oblique dorsally; canthus rostralis rounded, slightly depressed anteriorly; frontal region slightly concave; supralabials 11R/11L, subrectangular, tapering posteriorly, first the largest, 11 th the smallest; infralabials 11R/11L, subrectangular, tapering posteriorly, first the largest, 11 th the smallest. Scales on top of head, nuchal region small, rounded, granular, homogenous; scales on supraocular regions similar to those on rostrum, strongly granular, slightly larger than those on top of head; mental relatively small, triangular, 0.8 mm in width, 0.5 mm in length, in contact with infralabial laterally, two chin scales posteriorly; chin scales eight, the two postmentals largest, enlarged relative to surrounding scales.

Body small, elongated, depressed ventrally, TrunkL 17.4 mm, 48% of SVL; dorsal scales within one diameter of eye transversely across mid-dorsum 23, small, granular, lacking enlarged emerging tubercles; scales on flanks similar in size to those on dorsum; ventral scales within one diameter of eye 16, smooth, imbricate; ventrolateral fold absent; enlarged precloacal and femoral scales 16, continuous, bearing 15 pores, the last one on the right femur poreless; postcloacal spurs on lateral tail base three on each side; hemipenial swelling present. Forelimb relatively short, bearing five fingers with strongly curved claws, on tip of free terminal phalanx, except first finger vestigial, cone-shaped; Fingers II–V with expanded pads; enlarged subdigital lamellae wider than long, on Finger I 4R/4L; proximal subdigital lamellae on Fingers II–V undivided, angular, with U-shape distal subdigital lamellae divided, distal lamellae formula of Fingers II–V 4554 on each side, total lamellae on Fingers II–V 18; scales on forearm and fingers flat, slightly imbricate dorsally and ventrally; scales on palmar region flat, subimbricate; hindlimb longer, more robust than forelimb, with larger, flat, dorsally juxtaposed, scales, those on anterior thigh larger than those on posterior thigh; scales on plantar region flat, subimbricate; hemipenial sheath present; hindlimb bearing five toes with unsheathed claws except first toe vestigial, cone-shaped, distal portion of toes strongly curved, terminal joint free; enlarged subdigital lamellae on Toe I 4R/4L; proximal subdigital lamellae on Toes II–V undivided, angular, with U-shape distal subdigital lamellae divided, distal lamellae formular on Toes II–V 4555 on each side, total lamellae on Toes II–V 19; tail short, TaL 21.1. mm, regenerated, depressed, tapering posteriorly; dorsal caudal region with small scales anteriorly similar to those on body, larger scales posteriorly; subcaudal scales not enlarged, homogenous, slightly larger than those on lateral caudal scales ( Table 1).

Coloration of holotype in life. Dorsal ground color of head, dorsum, flanks, limbs grey-brown with irregular, variable, dark brown grey markings, more distinct on vertebral region; rostrum dark brown; supralabials and infralabials with dark brown spots; dark brown stripe from nostril through eye to level of rear of mandible; indistinct, light grey vertebral line present; flanks with light brown irregularly netting with dark brown blotches variable in size and shape; dark brown crossbars on limbs; orangish postsacral chevron marking, complete across sacrum; orangish color on posterior and ventral surface of thigh and hemipenial sheath; tail light brown with elongated dark brown markings.

Coloration of holotype in preservative. Body light brown with small dark spots on scales and between scales on head, rostrum, body, flanks, and tail; chin, throat, venter, limbs, palmar and plantar surfaces whitish with dark brown spots on scales and between scales; enlarged precloacal and femoral scales white; hemipenial sheath white; dorsal surface of tail base dark brown with light brown V-shaped marking; dark brown on dorsal caudal and caudal scales.

Variation. Morphometric and meristic characters of the type series are presented in Table 1. Paratype CBC 03119 has 24 dorsal scales within one diameter of the eye (vs. 23 in the holotype). Both paratypes have 15 ventral scales (vs. 16 in the holotype). Females lack precloacal and femoral pores.

Distribution and natural history. The new species is currently known only from 921–1,073 m elevation at Preah Monivong Bokor National Park in Teuk Chou District, Kampot Province, Cambodia. The holotype male was collected in a crevice under a balancing top-boulder on a large outcrop at the edge of the escarpment ( Fig. 3 ) during the day (1311 hr) in light rain. Paratype female CBC 03119 was found at night (1935 hr) on a palm frond 0.5 m above the ground in semi-evergreen forest. Paratype female NCSM 98992 was found at night (2003 hr) on the exterior concrete wall of the ruins of a French colonial house near Popokvil Waterfall in montane shrub forest.

Etymology. The specific epithet bokor is an invariable noun in apposition in reference to the type locality in Preah Monivong Bokor National Park, Kampot Province, Cambodia. The suggested common name is Bokor Slender Gecko (English).

Comparisons. Hemiphyllodactylus bokor sp. nov. is phylogenetically related to other species from the southern Indochinese peninsula, specifically H. indosobrinus from southern Laos, the Phnom Samkos taxon, H. flaviventris from eastern Thailand, and H. cattien and H. dalatensis from southern Vietnam, as well as a clade of six species from India, specifically H. arakuensis , H. aurantiacus , H. goaensis , H. jnana , H. kolliensis , and H. minimus .

Hemiphyllodactylus bokor sp. nov. is the sister taxon to H. indosobrinus ( Fig. 2 ), but differs by having chin scales nine (vs. eight in H. indosobrinus ), supralabials 9–11 (vs. 15 in H. indosobrinus ), infralabials 8–11 (vs. 12 in H. indosobrinus ), dorsal scales 23–24 (vs. 30 in H. indosobrinus ), ventral scales 15–16 (vs. 11 in H. indosobrinus ), and number of precloacal and femoral pores 15 (vs. 18 in H. indosobrinus ).

Hemiphyllodactylus bokor sp. nov. differs from the Phnom Samkos taxon (below) by having smaller body size, with maximum SVL 39.0 mm (vs. 45.9 mm in the Phnom Samkos taxon), circumnasals five (vs. four in the Phnom Samkos taxon), intersupranasals three (vs. two in Phnom Samkos taxon), ventral scales within one diameter of eye 15–16 (vs. 9–10 in the Phnom Samkos taxon), and precloacal and femoral pores present and continuous (vs. absent in the Phnom Samkos taxon).

Hemiphyllodactylus bokor sp. nov. differs from H. flaviventris by having dorsal scales within one diameter of eye 23–24 (vs. 18 in H. flaviventris ), ventral scales 15–16 (vs. 8–10 in H. flaviventris ), subdigital lamellae on Finger I 3–4 (vs. five in H. flaviventris ), subdigital lamellae on Toe I 3–4 (vs. five in H. flaviventris ), subdigital lamellae on Fingers II–IV 4554 (vs. 4444 in H. flaviventris ); and number of precloacal and femoral pores 15 (vs. 19–20 in H. flaviventris ).

Hemiphyllodactylus bokor sp. nov. differs from H. cattien by having larger body size, with maximum SVL 39.0 mm (vs. 35.1 mm in H. cattien ), chin scales eight (vs. seven in H. cattien ), dorsal scales within one diameter of eye 23–24 (vs. 20 in H. cattien ), ventral scales 15–16 (vs. 11 in H. cattien ), subdigital lamellae on Finger I 3–4 (vs. five in H. cattien ), subdigital lamellae on Toe I 3–4 (vs. six in H. cattien ), number of precloacal and femoral pores 15 (vs. 19 in H. cattien ), and cloacal spurs 2–3 (vs. one in H. cattien ).

Hemiphyllodactylus bokor sp. nov. differs from H. dalatensis by having smaller body size, with maximum SVL 39.0 mm (vs. 45.9 mm in H. dalatensis ), circumnasal scales five (vs. three in H. dalatensis ), dorsal scales within one diameter of eye 23–24 (vs. 16 in H. dalatensis ), ventral scales 15–16 (vs. 8–9 in H. dalatensis ), subdigital lamellae on Toes II–V 4555 (vs. 5666R/5665L in H. dalatensis ), and precloacal and femoral pores 15 (vs. 23–25 in H. dalatensis ).

Hemiphyllodactylus bokor sp. nov. readily differs from its six Indian relatives H. arakuensis , H. aurantiacus , H. goaensis , H. jnana , H. kolliensis , and H. minimus by having dorsal scales within one diameter of eye 23–24 (vs. 13–16 in H. arakuensis , 11–17 in H. aurantiacus , 16–18 in H. goaensis , 16–20 in H. jnana , 16 in H. kolliensis , and 15–18 in H. minimus ); SubdigLam FII–V 4554 (vs. 2222 in H. arakuensis , 222(3)2(3) in H. aurantiacus , 2222 in H. goaensis , 2222 in H. jnana , 2222 in H. kolliensis , and 2222 in H. minimus ); SubdigLam FTot 18 (vs. 11–12 in H. arakuensis , eight in H. aurantiacus , 10–11 in H. goaensis , eight in H. jnana , eight in H. kolliensis , and 10–11 in H. minimus ); SubdigLam TII–V 4555 (vs. 2(3) 333 in H. arakuensis , 22(3)2(3) in H. aurantiacus , 2(3)2(3) 33 in H. goaensis , 2222 in H. jnana , 2222 in H. kolliensis , and 233(2) 3 in H. minimus ); and SubdigLam TTot 19 (vs. 11–12 in H. arakuensis , 9–12 in H. aurantiacus , 10–11 in H. goaensis , eight in H. jnana , eight in H. kolliensis , and 10–11 in H. minimus ).

Although not phylogenetically closely related to H. yunnanensis ( Fig. 2 ), populations from the Cardamom Mountains have been previously referred in the literature to that species (e.g., Zug 2010). Hemiphyllodactylus bokor sp. nov. differs from H. yunnanensis by having smaller body size, maximum SVL 39.0 mm (vs. 49.3 mm in H. yunnanensis ), circumnasal scales five (vs. 2–4 in H. yunnanensis ), ventral scales 15–16 (vs. 6–12 in H. yunnanensis ), SubdigLam FII–V 4554 (vs. 3333 in H. yunnanensis ), and SubdigLam TII–V 4555 (vs. 3444 in H. yunnanensis ).

Figures

FIGURE 2. Fifty percent majority-rule consensus phylogram resulting from partitioned Bayesian analysis of 1,042 characters of the coding region of the mitochondrial ND2 gene from Hemiphyllodactylus geckos and the outgroups Lepidodactylus lugubris, Dixonius siamensis, and Gehyra pilbara (not shown). Numbers at nodes are Bayesian posterior probabilities (left) and bootstrap values ≥ 50 from a separate maximum likelihood analysis (right). Species names are followed by GenBank accession numbers in parentheses. Illustrated from top to bottom (not to scale) are photographs in life of the holotype of Hemiphyllodactylus bokor sp. nov. (NCSM 98991), the holotype of Hemiphyllodactylus samkos sp. nov. (CBC 01693), and Hemiphyllodactylus typus (CBC 03120).

FIGURE 3. Holotype of Hemiphyllodactylus bokor sp. nov. (NCSM 98991) in life (A) and in preservative with views of dorsum (B), venter (C), subdigital lamellae of hands (D), and subdigital lamellae of feet and femoral pores (E). Microhabitat at the type locality of Hemiphyllodactylus bokor sp. nov. at Preah Monivong Bokor National Park, Teuk Chou District, Kampot Province, Cambodia (F).