Hemiphyllodactylus hongkongensis Sung, Lee, NG, Zhang & Yang, 2018

Li, Xiang-Yi, Lin, Shi-Shi, Zeng, Zhao-Chi, Sun, Yan-Jun & Wang, Jian, 2023, Expanded description of Hemiphyllodactylus hongkongensis (Squamata, Gekkonidae), Herpetozoa 36, pp. 225-232 : 225

Hemiphyllodactylus hongkongensis Sung, Lee, NG, Zhang & Yang, 2018

Fig. 3 Hong Kong Slender Gecko / xiāng gǎng bàn yè zhǐ hǔ (香港半叶趾虎)

Chresonymy.

Hemiphyllodactylus sp. - Chan et al. 2018.

Examined materials.

GEP r024, adult male, and GEP r025-026, adult females, collected by Jian Wang and Zhao-Chi Zeng from Mt. Fenghuang (26°54'33.61"N, 116°36'26.51"E; ca. 1180 m a.s.l.), Chaozhou City, Guangdong Province, China . GEP r032, adult male, collected by Jian Wang and Zhao-Chi Zeng from Mt. Lianhua (23°4'3.51"N, 115°14'14.39"E; ca. 870 m a.s.l.), Huizhou City, Guangdong Province, China .

Description of new specimens.

Morphometric data are listed in Tables 1 , 2 . Head triangular in dorsal profile, depressed, distinct from neck; lores and interorbital regions flat; rostrum relatively long (NarEye/HeadL 0.27-0.33); prefrontal region flat; canthus rostralis smoothly rounded, snout moderate, rounded in dorsal profile; eye large (EyeD/HeadL 0.22-0.24, EyeD/NarEye 0.80-0.84); ear opening oval, small; eye to ear distance greater than diameter of eye; rostral wider than high, bordered posteriorly by large supranasals; 1-3 internasals in contact with rostral anteriorly; circumnasals 3-4; supralabials 10-13; infralabials 9-12; dorsal superciliaries flat, rectangular, imbricate; mental triangular, bordered laterally by first infralabials and posteriorly by two (GEP r024-026) or three (GEP r032) large postmentals; gular scales triangular small, granular, grading posteriorly into slightly larger, subimbricate, throat and pectoral scales which grade into slightly larger, subimbricate ventrals.

Body slender and small, dorsoventrally compressed, ventrolateral folds absent; dorsal scales small, granular, 18-20 scales contained within one eye diameter; ventral scales, flat, subimbricate, larger than dorsal scales, 10-13 scales contained within one eye diameter; in males, 23-24 pore-bearing scales extending from midway between the knee and hind limb insertion of one leg to the other.

Forelimbs short, robust in stature, covered with granular scales dorsally and with slightly larger, flat, subimbricate scales ventrally; palmar scales flat, imbricate; all digits except digit I well developed; digit I vestigial, clawless; distal, subdigital lamellae of digits II-V undivided, angular and fan-shaped; lamellae proximal to these transversely expanded; lamellar formula of digits II-V 3-4-4(5)-4 on both hands; 4-5 transversely expanded lamellae on digit I; claws on digits II-V well-developed, unsheathed; distal portions of digits strongly curved, terminal joint free, arising from central portion of lamellar pad. Hind limbs short, more robust than forelimbs, covered with slightly pointed, juxtaposed scales dorsally and by larger, flat subimbricate scales ventrally; all digits except digit I well-developed; digit I vestigial, clawless; distal, subdigital lamellae of digits II-V undivided, angular and fan-shaped; lamellae proximal to these transversely expanded; lamellar formula of digits II-V 4-4(5)-4(5)-4(5); 4-5 transversely expanded lamellae on digit I; claws on digits II-V well-developed, unsheathed; distal portions of digits strongly curved, terminal joint free, arising from central portion of lamellar pad; posterior section of tail broken, round in cross-section; all caudal scales flat, subimbricate, not forming distinct caudal segments.

Coloration of new specimens in life.

Dorsal surface of head, body, and limbs pale-brown, densely mottled with irregular darker markings; a dark brown preorbital tripe extending from external nares to anterior corner of eye; a dark brown postorbital tripe through extending from posterior corner of eye to just anterior of forelimb insertion on body; limbs and digits with irregularly shaped dark markings; ventral head, body and limbs unicolor beige; dorsal tail olive-brown, with several irregularly shaped dark markings and gray-white mottling, ventral tail unicolor gray-brown.

Coloration of new specimens in preservative.

Dorsal surface of head, body, limbs and tail dorsal dark brown, irregular darker markings more distinct; ventral head, body and limbs gray-brown; pre- and postorbital tripes, irregularly shaped dark markings on limbs and digits, dark markings on dorsal tail more distinct; gray-white mottling on dorsal tail absent; ventral tail unicolor dark brown.

Sexual dimorphism.

Males possess a pair of hemipenis and 23-25 precloacal and femoral pores; gravid females harbor two calcareous eggs.

Revision of diagnostic characters.

(1) 5-6 chin scales in the unique combination, (2) manual lamellar formula 3-3(4)-4(5)-4, (3) pedal lamellar formula 3(4)-4(5)-4(5)-4(5), (4) 23-25 continuous femoral and precloacal pores, (5) 12-20 dorsal scales contained in diameter of eye, (6) 9-13 ventral scales contained in diameter of eye.

Distribution and ecology.

Hemiphyllodactylus hongkongensis is currently known at low altitude from Aberdeen Country Park (ca. 120 m a.s.l.) and Po Toi Island (ca. 50 m a.s.l.), Hong Kong SAR, China, and Mt. Lianhua (ca. 870 m a.s.l.) and Mt. Fenghuang (ca. 1180 m a.s.l.) in eastern Guangdong Province, China. However, the taxonomic status of Hemiphyllodactylus populations from Shek Kwu Chau and Pokfulam Country Park in Hong Kong SAR, China still remained further confirmation (Karsen et al. 1998; Sung et al. 2018; Zug, 2010).

Hemiphyllodactylus hongkongensis is a forest dwelling species which can be found among the bark of large trees, abandoned buildings and rock crevices (Chan et al. 2008). Both newly discovered populations are found in the forest area at high altitude above ca. 800 m a.s.l.. Specimens from Mt. Lianhua are collected on the wall of an abandoned house, while those from Mt. Fenghuang are collected on the bare rocks. This species is oviparous so that each adult female including uncaptured individuals harbors two mature calcareous eggs during surveys on February (Mt. Lianhua) and July (Mt. Fenghuang).

Figures

Figure 3. Life aspect of Hemiphyllodactylus hongkongensis A. Male (GEP r 032) and B. Female (uncaptured) from Mt. Lianhua, Huizhou City, Guangdong Province, China. Photos by Jian Wang.