Polypedates pseudotilophus, Matsui & Hamidy & Kuraishi, 2014

Matsui, Masafumi, Hamidy, Amir & Kuraishi, Norihiro, 2014, A New Species of Polypedates from Sumatra, Indonesia (Amphibia: Anura), Species Diversity 19 (1), pp. 1-7 : 3-6

Polypedates pseudotilophus sp. nov.

( Figs 3–6 )

Rhacophorus otilophus: Van Kampen 1905: 705 ; 1923: 245 (part); Inger 1966: 329 (part).

Polypedates otilophus: Riyanto et al. 2009: 218 (part).

Etymology. The specific name is derived from the Greek prefix “ pseudo -”, meaning lying or false, and “ otilophus ”, alluding to the fact that the new species has long been treated as though it were Polypedates otilophus .

Diagnosis. Large-sized species of Polypedates , with adult male SVL 60–70 mm and adult female SVL 90–93 mm, with sharp triangular bony process at commissure of jaws, and serrated bony crest projecting above tympanum. Very similar to P. otilophus , but with much lower supratympanic ridge; dorsum with solid, dark hourglass figure beginning at interorbital and ending at sacrum.

Holotype. MZB Amp 16304, male, from Bengkulu, Kepahiang , Merigi, Batu Ampar, southern Sumatra, Indonesia (03°30′46″S, 102°32′53″E, alt. 712 m asl), collected on 18 July 2010 by A. Hamidy and Nurrahim.

Paratype. Sumatra, Indonesia ( Fig. 1 ): MZB Amp 3477 (male) from Rata Agung, Bukit Barisan Selatan National Park , Lampung, collected on 11 March 1998 by Andiek ; MZB Amp 3457 (male) from Rata Agung , Bukit Barisan Selatan National Park , Lampung, collected on 11 March 1998 by Andiek ; MZB Amp 3467 (female) from Dirgahayu Rimba , Bukit Barisan Selatan National Park , Bengkulu, collected in July to August 1997 by Andiek ; MZB Amp 3819 (male) from Soraya , Gunung Leuser National Park , Aceh, collected on 20 April 1999 by D. T. Iskandar; MZB Amp 4221 (female) from Bintuhan, Bukit Barisan Selatan National Park, Bengkulu, collected on 26 August 1999 by Alfad; MZB Amp 4222 (male) from Bintuhan, Bukit Barisan Selatan National Park, Bengkulu, collected on 7 August 1999 by Alfad; MZB Amp 14609 (female) from Linau , Bukit Barisan Selatan National Park , Bengkulu, collected on 29 September 2005 by A. Ul Hasanah; MZB Amp 14857 (male) from Sipurak, Kerinci Seblat National Park, West Sumatra, collected on 6 March 2005 by H. Kurniati; MZB Amp 16303 (male) from Bengkulu, Bengkulu Tengah , collected on 19 July 2010 by A. Hamidy and Nurrahim; MZB Amp 22215 (male) from Gunung Tanggamus, Tanggamus , Lampung, collected in June 2013 by E. Wostl, W. Trilaksono, and G. Barranza; MZB Amp 22944 (female) from Rata Agung, Bukit Barisan Selatan National Park, Lampung, collected on 11 March 1998 by Andiek .

Referred Specimens. Three tadpoles, collection data same as for holotype.

Description of holotype. SVL 67.5 mm; body robust ( Figs 3 , 4A, B ); head triangular, slightly broader (HW 25.9 mm, 38.4% SVL) than long (HL 24.9 mm. 36.7% SVL); snout (SL 12.3 mm, 18.2% SVL) longer than eye (EL 9.8 mm, 14.5% SVL), rounded in profile, slightly pointed at tip and projecting over lower jaw; canthus distinct; lore slightly oblique, slightly concave; nostril slightly protuberant, much nearer to tip of snout than to eye (N-EL 7.0 mm, 10.3% SVL); internarial distance (IND 5.3 mm, 7.9% SVL) much smaller than interorbital (IOD 8.2 mm, 12.2% SVL); latter slightly narrower than eyelid (UEW 8.6 mm, 12.7% SVL); pineal spot absent; eye large, protuberant, pupil horizontal; tympanum distinct, circular, diameter (TD 4.5 mm, 6.7% SVL) slightly smaller than half eye diameter and separated from eye (T-EL 1.9 mm, 2.8% SVL) by two-fifths of tympanum diameter; vomerine teeth in oblique groups between anterior halves of choanae, groups closer to choanae than to each other; bilateral round openings into median subgular vocal sac near jaw commissures; tongue deeply notched posteriorly.

Forelimb ( Fig. 5A ) slender, long (FLL 43.3 mm, 64.2% SVL); relative finger length I<II<IV<III; length of first finger (1FL 7.9 mm, 11.7% SVL) shorter than length of eye; tips of all fingers expanded into large disks with circummarginal and transverse ventral grooves; disk of third finger (3FDW 3.9 mm, 5.8% SVL) narrower than tympanum; rudimentary basal web between fingers ( Fig. 5 ); subarticular tubercles rounded, formula 1, 1, 2, 2; other indistinct subarticular tubercles present; supernumerary tubercles absent on metacarpals; prepollex prominent, oval; flat, inner palmar tubercle (IPTL 4.4 mm, 6.5% SVL) and indistinct, round outer palmar tubercle (OPTL 3.3 mm, 4.8% SVL) present; grayish, velvety nuptial pad covering dorsal and medial surfaces of first finger from wrist to level of subarticular tubercle and also circular area on dorsal surface of second finger.

Hindlimb ( Fig. 5B ) slender, short (HLL 103.8 mm, 153.8%SVL), about 2.4 times length of forelimb; thigh (30.9 mm, 45.8% SVL) shorter than tibia (TL 34.2 mm, 50.7% SVL), heels overlapping when limbs held at right angles to body; tibiotarsal articulation of adpressed limb reaching point between eye and nostril; foot (27.2 mm, 40.3% SVL) shorter than tibia; relative length of toes I<II<III<V<IV; tips of toes expanded into round disks with distinct circummarginal grooves, smaller than those of outer fingers (4TDW 3.0 mm, 4.4% SVL); toes poorly webbed, toe webbing formula I 2-2¼ II 1½-3 III 1¾-3 IV 3-2 V ( Fig. 5 ); subarticular tubercles distinct, rounded, formula 1, 1, 2, 3, 2; supernumerary tubercles absent; low, oval inner metatarsal tubercle (IMTL 2.2 mm, 3.3% SVL) present, about one-fourth length of first toe (1TOEL 8.1 mm, 12.0% SVL), but no outer metatarsal tubercle evident.

Dorsum nearly smooth, with scattered non-spinose tubercles; skin of head co-ossified with roof of skull; a low, serrated bony ridge projecting from eye above tympanum, posteriorly running as dorsolateral fold and ending at anterior one-third of flank; blunt triangular bony process at commissure of jaws; flank wrinkled; underside of chin and chest smooth, abdomen and thigh coarsely granular; very narrow, smooth-edged fringe of skin along forearm ending as a small, triangular dermal appendage at elbow; triangular dermal appendage present at tibiotarsal articulation; two pairs of enlarged, white tubercles below vent.

Color. Color in life pale brown above with large, brown hourglass marking between anterior part of each eye and sacral region ( Figs 3 , 4A ); narrow brown dorsolateral streak continuing to bony ridge; forearm and tibia with three wide pale brown bars dorsally; thigh with seven narrow black bars dorsally; body dirty white below, dusted gray on chin and thigh ( Fig. 4B ). In alcohol dorsal color faded to gray brown.

Variation. Morphometric data are summarized in Table 1 . Females are larger (90.9–93.3, mean±SD=91.9± 1.1 mm in SVL) than males (60.7–69.9, 66.6± 2.8 mm in SVL). Males have relatively larger eye (REL: 14.2–15.5, median= 15.1% SVL in males vs. 12.3–15.6, median=12.8% SVL in females) but shorter first finger than females (R1FL: 11.2– 12.7, median=11.9% SVL in males vs. 13.0–13.8, median= 13.8% SVL in females). Specimens are fairly constant in coloration.

Eggs and larvae. A female collected in August had ovaries with fully developed ova of 0.80–0.90 mm in diameter, that were cream in color in both the animal and vegetal hemispheres.

Three tadpoles, stage 37 (TOTL= 68.2 mm, HBL= 23.0 mm), 41 (65.1 mm, 22.1 mm), and 41 (65.2 mm, 23.0 mm), collected from the type locality, were examined ( Fig. 6 ). Head and body slightly flattened above, spheroidal below; HBW maximum posterior to level of spiracle 52–69% (median=61%) of HBL; HBD 40–58% (median= 57%) of HBW; snout rounded; eyes dorsolateral, visible from below, eyeball 16–18% (median=18%) of HBL; interorbital wide, 185–208% (median=197%) of eyeball diameter; nostril open, dorsolateral, rim raised, much closer to tip of snout than to eye, internarial distance 51–59% (median= 55%) of interorbital, equal to eye–nostril distance. Oral disk ventral, subterminal, emarginate, width 23–25% (median= 24%) of HBW; papillae in double, staggered row along margin of lower, except for gap at center, also present at lip; denticles 5(2–5)/3; beaks strong, undivided, with black outer margins; outer surface smooth; margin of upper beak finely serrate, that of lower beak serrate; upper beak lacking pronounced medial convexity. Spiracle sinistral, non-tubular, not free of body wall; opening at 48–62% (median=57%) of HBL, closer to eye than to tail, below line between eye and insertion of hind limb, pointing upward and backward. Anal tube dextral, not reaching margin of ventral fin; loops of gut not visible in ventral view. Tail long and lanceolate, both margins convex, tapering abruptly to slightly rounded tip; tail length 184–197% (median=195%) of HBL; maximum depth at distal third of tail, 34–37% (median=34%) of tail length; dorsal fin origin at posterior end of body, as deep as ventral fin; ventral fin origin posterior to vent; caudal muscle moderate, maximum tail width 24–31% (median=27%) of HBW; muscle depth at middle of tail 31–41% (median= 39%) of tail depth, steadily narrowing posteriorly from midlength of tail, narrower than either fin in distal third of tail. Indistinct neuromasts of supranaso-orbital and oral lines discernible.

In formalin, head–body yellowish brown dorsally and laterally, densely covered with small, dark brown spots; dorsally with large, brown hourglass marking ( Fig. 6 ); ventral surface white; proximal half of caudal muscle same as headbody dorsally, with scattered larger spots ventrally; distal half of caudal muscle grayish brown dorsally, yellowish brown with scattered large, dark spots ventrally; distal half of dorsal fin and ventral fin opaque with small, dark dots. Larvae acquire adult pattern on body and hindlimb before eruption of forelimb.

Comparisons. The presence of supratympanic bony ridge differentiates P. pseudotilophus sp. nov. from all known congeneric species except for P. otilophus . However, P. pseudotilophus has a much more weakly developed bony ridge than P. otilophus , and the large dorsal hourglass marking is quite unlike P. otilophus , in which the dorsum is marked by narrow longitudinal dark stripes. The two species are significantly different morphometrically in some characters: In males, P. pseudotilophus has larger RSL, REL, RT-EL, RHW, RIND, RICD, RUEW, RIPTL, RHLL, RTL, R1TOEL, and R4FDW, but smaller SVL, RTDV, RTDH, RBRL, and RBRW than P. otilophus . In females, P. pseudotilophus has smaller RFLL and RBRL than P. otilophus .

Range . Sumatra , Indonesia: Bengkulu (Kepahiang, Merigi, Batu Ampar; Bengkulu Tengah; Bukit Barisan Selatan National Park [Bintuhan, Linau, Dirgahayu Rimba]); West Sumatra (Sipurak, Kerinci Seblat National Park); Lampung (Rata Agung, Bukit Barisan Selatan National Park ; Gunung Tanggamus, Tanggamus); Aceh (Soraya, Gunung Leuser National Park ); Palembang district ( Van Kampen 1905). Most probably also occurring in Java: Telaga Sunyi, Batur-Raden, Central Java; Salak mountain , West Java ( Riyanto et al. 2009) .

Natural History. Unknown, but supposed to be the same as that of P. otilophus , which spawns eggs in a foam nest on leaves. The larvae were collected together with the holotype in the secondary forest. They were found in a small pond with a diameter of about 1 m and depth of 50–70 cm.

Figures

Fig. 3. Dorsolateral view of male holotype of Polypedates pseudotilophus sp. nov. (MZB Amp 16304) from Kepahiang, southern Sumatra.

Fig. 4. Dorsal (A) and ventral (B) views of male holotype of Polypedates pseudotilophus sp. nov. (MZB Amp 16304) from Kepahiang, southern Sumatra. Scale bar=10mm.

Fig. 5. Ventral views of hand (A) and foot (B) of male holotype of Polypedates pseudotilophus sp. nov. (MZB Amp 16304) from Kepahiang, southern Sumatra. Scale bar=10mm.

Fig. 6. Dorsal (A), lateral (B), and ventral (C) views of larval Polypedates pseudotilophus sp. nov. from Kepahiang, southern Sumatra (MZB Amp unnumbered, Stage 41, total length=65.1mm). Scale bar=10mm.

Fig. 1. Map of Sumatra, Indonesia, showing the known distribution (open diamonds) of Polypedates pseudotilophus sp. nov. The filled circle indicates the type locality.