Philautus hosii ( Boulenger, 1895 )

Dehling, J. Maximilian & Das, Indraneil, 2020, Taxonomic re-evaluation of the enigmatic Polypedates chlorophthalmus Das, 2005 (Anura: Rhacophoridae) from Gunung Murud, Sarawak, Malaysia (Borneo), a junior synonym of Philautus hosii (Boulenger, 1895), Raffles Bulletin of Zoology 68, pp. 319-325 : 320-324

Philautus hosii ( Boulenger, 1895)

Rhacophorus hosii Boulenger, 1895: 169 .

Rhacophorus buergeri hosii Wolf, 1936: 170 .

Rhacophorus hosi Inger, 1954: 385 .

Rhacophorus hosei Inger, 1966: 304 .

Philautus hosei Liem, 1970: 68 .

Philautus hosii Inger, 1985: 529 .

Polypedates chlorophthalmus Das, 2005: 266 . – new synonymy.

Description of ZRC 1.11531 (holotype of Polypedates chlorophthalmus Das, 2005 ). Character states in the original description (D) that differ from the results of the re-examination are given in square brackets.

Adult female ( Fig. 1 ); body large, SVL 59.9 mm [D: 62.1], body moderately slender with narrow waist, widest posterior to head; head large (HL/SVL 0.39), slightly longer than wide (HW/HL 0.93) [D: slightly broader than long (HW/HL 1.04)]; snout elongate and long (SL/HL 0.45), subacuminate in dorsal view, rounded in lateral view, slightly projecting beyond lower jaw [D: not exceeding level of mandible] in lateral view, wider than long (SL/EE 0.91) ( Fig. 2 ); canthus rostralis distinct, slightly concave ( Fig. 2 ); loreal region almost vertical, slightly concave ( Fig. 2 ); nostrils oval, directed anterolaterally, situated close to tip of snout (EN/NS 2.55, EN/SL 0.72 [D: 0.74]), separated from each other by distance much smaller than distance between eye and nostril (NN/EN 0.64 [D: 0.72]) ( Fig. 2 ); eyes directed anterolaterally, protruding, moderately large (ED/HL 0.31); pupil horizontal; eye diameter shorter than snout length (ED/ SL 0.70), and subequal to eye-to-nostril distance (ED/EN 0.98 [D: larger, ED/EN 1.07); interorbital distance slightly greater than upper eyelid (IO/EW 1.05 [D: interorbital distance greater than upper eyelid width, IO/EW 2.22]) and wider than internarial distance (IO/NN 1.38) ( Fig. 2 ); skin of forehead free, not co-ossified to nasal, sphenethmoid or frontoparietal elements of cranium; pineal ocellus present; tympanum distinct, oval, its vertical diameter greater than horizontal diameter, half diameter of eye (TD/ED 0.51), separated from eye by about half its diameter (ET/TD 0.54) ( Fig. 2 ); mouth extends to level of centre of tympanum [D: to posterior corner of eye]; upper jaw with dentition; teeth on premaxilla larger than those on maxilla; choanae elongate, located far anterolaterally at margins of roof of mouth ( Fig. 3 ); vomerine teeth in two highly elevated, large, broad, posteromedially directed ridges at anterior edge of choanae, separated from each other by about one-fourth length of individual ridge ( Fig. 3 ); mandibular symphysis weakly thickened to bony knob; tongue subtriangular, bifid apically, lacking median lingual process, free distally for about one-third its length.

Dorsal side of trunk, head, and limbs shagreened [D: dorsum, including upper eyelids and upper surfaces of limbs smooth] ( Fig. 1 ); supratympanic fold distinct, curved, running from posterior corner of eye to level of forelimb insertion ( Fig. 2 ); ventral side of head and limbs smooth, abdomen and postaxial sides of thighs areolate ( Fig. 1 ).

Forelimbs moderately thick [D: short and thick]; hand large (HND/SVL 0.34); fingers long and slender, lacking webbing ( Fig. 3 ); relative length of fingers: I <II <IV <III; tips of fingers enlarged into broad oval disks, each with circummarginal groove; subarticular tubercles prominent, rounded, numbering one on Fingers I and II, two on Fingers III and IV [D: one on first, second and fourth fingers, two on third finger] ( Fig. 3 ); proximal tubercles on Fingers III and IV smaller than distal tubercles and tubercles on Fingers I and II ( Fig. 3 ); thenar tubercle small, about one-third length of metacarpal of Finger I in palmar view, oval, low; inner and outer palmar tubercle subequal in shape and size to thenar tubercle, on proximal part of metacarpals of Fingers III and IV [D: palmar tubercles indistinct] ( Fig. 3 ); supernumerary small tubercles present on metacarpals.

Hindlimbs long and slender (LEG /SVL 1.96); tibiofibula long (TFL/SVL 0.62), longer than thigh (TFL/THL 1.10); heels without flap, fold, or calcar, overlapping each other considerably when knees flexed and thighs held perpendicularly to median plane [D: meeting each other and overlapping slightly]; foot large (FOT/SVL 0.52), shorter than tibiofibula (FOT/TFL 0.84); toes long and slender, relative length I <II <V <III <IV; tips of toes enlarged into broad oval disks, each with circummarginal groove, smaller than disks on fingers; subarticular tubercles well developed, rounded, prominent, numbering one on Toes I and II, two on Toes III and V, and three on Toe IV ( Fig. 3 ); distal subarticular tubercles on Toes III–V and tubercles on Toes I and II slightly larger than proximal tubercles on Toes III and V and penultimate tubercle on Toe IV ( Fig. 3 ); proximal tubercle on Toe IV smaller than all other subarticular tubercles and less distinct; pedal webbing formula I 1.5/2 II 1+/2+ III 1+/2+ IV 2/1+ V [D: I 2- /2 II 1+/2 III 1+/2 IV 2/1.25 V] ( Fig. 3 ); narrow dermal flap on postaxial side of Toe V from proximal end of metatarsus to disk; inner metatarsal tubercle very prominent and elongate, large, about length of Metatarsal I ( Fig. 3 ); outer metatarsal tubercle absent.

Colouration in preservative. Dorsum greyish light brown; large, dark grey, V-shaped pattern in scapular region; light brown labial region barred with darker spots; dorsal side of limbs light brown with faint dark crossbars; webbing pale

grey; ventral side of trunk and limbs cream-coloured; head, throat, and breast with marked medium brown mottling; abdomen with widely separated small brown dots; preaxial and postaxial sides of limbs with greyish brown mottling; digits of limbs yellowish grey.

We compared the female holotype of Polypedates chlorophthalmus (ZRC 1.11531) in detail to a female Philautus hosii (SMNS 13628), collected near Camp 5 in Gunung Mulu National Park, Sarawak, at ca. 100 m a.s.l. ( Figs. 1–3 ; Table 1). The two specimens are nearly identical in general appearance ( Fig. 1 ), shape of snout ( Fig. 2 ), hands and feet, extent of toe webbing ( Fig. 2 ), presence and shape of hand and foot tubercles ( Fig. 3 ), size and shape of vomerine teeth ( Fig. 3 ), dorsal and ventral colouration and pattern ( Fig. 1 ), and body proportions ( Table 1). We therefore conclude that the two specimens are conspecific. Iris colouration is variable in Philautus hosii and some recently collected specimens exhibit a greenish-coloured iris, instead of the more typical golden iris ( Fig. 4 ).

Figures

Fig. 1. A, dorsal view and C, ventral view of the holotype of Polypedates chlorophthalmus Das, 2005 from Gunung Murud, Sarawak, Malaysia (adult female ZRC 1.11531). B, dorsal view and D, ventral view of an adult female Philautus hosii from Gunung Mulu National Park, Sarawak, Malaysia (SMNS 13628).

Fig. 2. Lateral view of the head of the holotype of A, Polypedates chlorophthalmus (ZRC 1.11531) and B, an adult female Philautus hosii (SMNS 13628). Dorsal view of the head of the holotype of C, Polypedates chlorophthalmus (ZRC 1.11531) and D, an adult female Philautus hosii (SMNS 13628).

Fig. 3. Palmar view of the right manus of the holotype of A, Polypedates chlorophthalmus (ZRC 1.11531) and B, an adult female Philautus hosii (SMNS 13628). Plantar view of the left foot of the holotype of C, Polypedates chlorophthalmus (ZRC 1.11531) and D, an adult female Philautus hosii (SMNS 13628). Ventral view of the roof of the mouth of the holotype of E, Polypedates chlorophthalmus (ZRC 1.11531) and F, an adult female Philautus hosii (SMNS 13628), showing shape of choanae and vomer processes and teeth.

Fig. 4. A, holotype ofPolypedates chlorophthalmus (ZRC 1.11531) from Gunung Murud, Sarawak, Malaysia, in life.B, adult malePhilautus hosii (NMBE 1060413) from 950 m a.s.l. at Gunung Gading, Sarawak, Malaysia, in life. C, lateral view of the head of an adult female Philautus hosii (SMNS 13628) from Gunung Mulu National Park, Sarawak, Malaysia, in life. D, dorsolateral view of SMNS 13628, in life.