Litoria gasconi, Richards, Stephen J., Oliver, Paul M., Krey, Keliopas & Tjaturadi, Burhan, 2009

Richards, Stephen J., Oliver, Paul M., Krey, Keliopas & Tjaturadi, Burhan, 2009, A new species of Litoria (Amphibia: Anura: Hylidae) from the foothills of the Foja Mountains, Papua Province, Indonesia, Zootaxa 2277, pp. 1-13 : 2-8

Litoria gasconi new species

( Figs. 1 A–D, 2B, 3)

Holotype. MZB Amph. 15839 (FN SJR 6018), adult male, calling at time of collection (16 July 2004), tissue preserved in 70% ethanol, camp near Marina Valen Village (02o22.230'S, 138o12.753'E), 500 m a.s.l., southern foothills of the Foja Mountains, Papua Province, Indonesia, collected by Stephen Richards and Burhan Tjaturadi.

Paratopotype. Male, calling when collected, MZB Amph. 15840 (FN SJR 6019), with same date, locality and collectors as holotype.

Paratype. Male, calling when collected, MZB Amph. 12036 (FN SJR 9805), 17 November 2005, 'Kwerba Camp' (2o38.467' S, 138o24.916'E), 200 m a.s.l., near Kwerba Village, southern foothills of the Foja Mountains, Papua Province, Indonesia, collected by Stephen Richards and Burhan Tjaturadi.

Diagnosis. Litoria gasconi sp. nov. can be distinguished from all other Litoria by the combination of moderate size (males 39.3–41.6 mm), predominately green dorsal colouration interspersed with numerous yellow spots (light blue in preservative), white bilobed dermal ridge below the vent, and further ridges extending from heel to fifth toe and on the forearms, large eyes (EYE/SVL 0.12–0.15), thighs, groin and axillary spots orange in life without any trace of blue, absence of black vermiculations on thigh and venter, absence of a canthal stripe between the eye and nares, and advertisement call consisting of a single soft, distinctly pulsed chirp containing 4–6 pulses and lasting 0.02– 0.03 s.

Description of holotype. Adult male with vocal slits and calling when collected (with measurements given in Table 1). Body moderately slender, limbs moderately short (TL/SVL 0.56), head wider than body in dorsal profile, distinct from neck (HW/SVL 0.36). Snout rounded in dorsal profile, slightly rounded but nearly truncate in lateral profile, upper jaw protruding marginally over lower jaw. Canthus rostralis slightly curved, not sharply defined, loreal region slightly concave, nares oriented anterio-laterally, closer to tip of snout than to eyes, labial region flared. Eyes large (EYE/SVL 0.15), prominent, clearly protruding in lateral and dorsal views, pupil horizontal. Tympanum clearly visible, small (TYM/SVL 0.06), approximately half diameter of eye (TYM/EYE 0.44), annulus distinct and bordered dorsally by supratympanic fold that runs from posterior corner of eye and terminates above axilla. Choanae small and circular, close to lateral edge of palate; vomerine teeth in two moderate-sized clumps medial to choanae; tongue fleshy and ovoid. Dorsal skin finely granular; ventral skin smooth on throat, coarsely granular on abdomen; a fleshy bilobed dermal ridge below vent, and dermal ridges along outside edge of tarsus and forearm.

MZB 15839 (SJR 6018) MZB 15840 (SJR 6019) MZB 12036 (SJR 9805) Holotype Paratopotype Paratype M M M

SVL 39.3 40.7 41.6

TL 21.9 22.6 23.4

HW 14.2 13.9 15.2

HL 13.8 13.2 12.7

EYE 5.7 5.7 4.7

TYM 2.5 2.4 2.4

IN 3.9 4.1 4.2

EN 2.5 3.1 3.7

3FD 2.4 2.3 2.3

3FP 1.7 1.7 1.6

4TD 2.0 2.0 1.9

4TP 1.6 1.6 1.4

Fingers moderately long in comparison to other Papuan Litoria ( Tyler 1968) ; with relative lengths III>IV>II>I; fleshy opaque webbing between all digits: in a narrow strip between I and II, and reaching to penultimate phalanx on outer edges of II and III, to third phalanx on inner edge of III, and to disc on IV. Terminal discs on all fingers prominent (3FP/3FD 0.71), with circum-marginal grooves. Nuptial pads without pigmentation and very indistinct; single indistinct unpigmented bifid subarticular tubercles present on penultimate phalanx of all fingers, and a series of additional subarticular tubercles present on IV; single indistinct ovoid inner metacarpal tubercle present at base of I.

Toes long in comparison to other Papuan Litoria ( Tyler 1968) ; relative lengths IV>III>V>II>I; with extensive fleshy opaque webbing. Web extends to discs on outer edge of II, III and inner edge of V, to penultimate phalanx on both sides of IV and inner edge of II and III, and to penultimate tubercle on I; dermal flanges extending to disc on III and IV. Discs prominent (4TP/4TD 0.80) with circum-marginal grooves; single rounded subarticular tubercles present on all digits, small ovoid metatarsal tubercle at base of toe I, series of distinct rounded ventral tubercles of varying sizes present on proximal third of femur.

In preservative dorsal ground colour of head, body and legs slate blue with extensive randomly scattered sky-blue spots; dorsal surfaces of fingers, and lower portions of forelimbs and toes largely unpigmented, though sometimes with small patches of blue pigment, especially on toes. Lateral surfaces slate blue heavily flecked with bluish white, lateral surfaces of head distinctly lighter than dorsal surfaces of head, edge of upper jaw with a continuous white margin from rictus to rictus, orbital bordered by a thin white ring. Ventral surfaces of body and forelimbs off-white, hind limbs slightly darker with poorly defined brown stripe along posterior edge and on to toe V; prominent dermal flange below vent grades from slate blue dorsally to white ventrally, to bordered at ventral edge by a poorly defined brown stripe.

Variation. All types are very similar in overall proportions to the holotype; summary meristic data is given in Table 1 and key ratios are given in Table 2. Paratopotype MZB Amph. 15840 (SJR 6019) is missing most of the second finger on the left hand. Colouration in preservative is highly consistent, the dorsal surfaces are always slate blue with extensive sky blue spotting, ventral and hidden surfaces are off-white except for thin brown stripes below the venter and along the posterior ventral edge of the tarsus, and all specimens also possess a distinctive white dermal flange below the vent, and a further white lateral dermal flange extending from the heel to the fifth toe. All types are males that were calling when collected, but lack obvious pigmented nuptial pads and further collecting may reveal this to be an additional diagnostic character for the species.

Appearance in life. Typical colouration in life is shown in Figure 2 . The following description is based on colour photographs of all three type specimens. Colour pattern is highly consistent: dorsum mottled bright leaf green, densely flecked with small indistinct tiny yellowish dots, and much larger, scattered and indistinctly edged yellow spots of varying size; lateral surfaces grading from heavily mottled with green and yellow dorsolaterally, to mottled green and white ventrolaterally; venter white. Small amount of brown blotching present in subocular region of paratopotype MZB Amph. 15840 (SJR 6019). Exposed dorsal and lateral surfaces of arms and legs mottled green and yellow, with scattered large yellow spots as on dorsum; hidden parts of groin, thighs and axillary region bright orange. Toes and fingers predominately white with some scattered green patches on dorsal surface of outer digits. Crenulated dermal flanges on arm and tarsus white; bilobed dermal ridge and scattered tubercles below vent and thighs white. Iris white with fine brown vermiculations, pupil horizontal.

L. gasconi sp. nov. L. multiplica (male) L. multiplica (female)

n = 3 n = 22 n = 8

SVL 40.5 (39.3–41.6) 36.4 (31.1–38.9) 41.9 (37.65–47.1) TL 22.6 (21.9–23.4) 20.3 (16.4–21.9) 24.0 (20.4–27.4) HL 13.2 (12.7–13.8) 11.3 (9.5–12.8) 12.3 (10.2–14.3) HW 14.5 (13.9–15.2) 12.1 (9.8–14.0) 13.5 (11.7–15.9) EYE 5.5 (5.0–5.7) 3.9 (3.3–4.4) 3.9 (3.4–4.2) HW/SVL 0.36 (0.34–0.37) 0.33 (0.30–0.37) 0.32 (0.29–0.34) HL/SVL 0.33 (0.31–0.35) 0.31 (0.29–0.33) 0.29 (0.27–0.32) TL/SVL 0.56 (0.56–0.56) 0.56 (0.53–0.58) 0.57 (0.54–0.62) EYE/SVL 0.13 (0.12–0.15) 0.11 (0.09–0.13) 0.09 (0.08–0.10)

Advertisement call. Thirty-one calls produced by paratype MZB Amph. 15840 (SJR 6019) were recorded and analysed. The holotype and paratype MZB Amph. 12036 (SJR 9805) produced calls that were indistinguishable to the ear, but recordings were of insufficient quality for detailed analysis. L. gasconi sp. nov. produced two distinct call types, herein referred to as ‘short’ calls and ‘long’ calls. Twenty-seven of the 31 calls (87.1%) are ‘short calls’, and 4 are ‘long’ calls. ‘Short’ calls were produced on average every 9.6 s (n = 27, range = 4.3– 23.7 s, SD = 3.72) and they were all structurally similar, consisting of a single sharp chirp lasting just 0.019– 0.030 s (n = 27, mean = 0.024 s, SD = 0.003) and having a dominant frequency of 1520– 1890 Hz (n = 27, mean = 1750 Hz, SD = 67). Pulsed structure within these extremely short calls was not evident in the field, but analyses revealed that each call contains 4–6 pulses (n = 27, mean = 5.3, SD = 0.6) produced at a rate of 153.3–216.2/s (n = 27, mean = 200.5/s, SD = 12.9).

‘Long’ calls were produced less frequently than ‘short’ calls and were usually uttered in response to the call of a nearby male, suggesting a territorial rather than a mate attracting function. Length of ‘long’ calls was extremely variable (0.046– 0.146 s, SD = 0.05, n = 4) but 3 of these calls had pulse rates within the range of short calls (i.e. 187–193/s) indicating that the frogs are simply adding pulses to their calls at the same rate to produce ‘territorial’ calls. A consequence of their longer duration is that in the field these calls sounded distinctly (albeit finely) pulsed to the ear. One ‘long’ call produced by the holotype had a much slower pulse rate than all other calls (120/s) and the highest number of pulses (18). Similar calls were heard in the field, again predominantly in response to calls of nearby males, and were often produced in couplets or triplets producing a soft ‘bleating’ effect. Typical ‘short’ and ‘long’ calls are illustrated in Figure 3.

Comparisons. The combination of medium size (39.3–41.6 mm), green dorsal colouration with large yellow spots, and white dermal ridges on the forelimbs, hindlimbs and below the vent will readily distinguish Litoria gasconi sp. nov. from all Litoria except L. multiplica . Litoria gasconi differs from Litoria multiplica in lacking extensive dark markings on the groin, venter and lateral surfaces, in having bright orange groin, thigh and axillary colouration (as opposed to bright blue, or orange mixed with bright blue, see Figure 2 ), in being on average slightly larger, and in having proportionally larger eyes (see summary of meristic and FIGURE 3. Wave form (top) and spectrogram (bottom) of A) advertisement call of Litoria gasconi sp. nov. (MZB Amph. 15840), B) ‘territorial’ call of Litoria gasconi sp. nov. (MZB Amph. 15840), both recorded at an air temperature of 23 o C, and C) two components of the biphasic ' Type 1' advertisement call of Litoria multiplica (SAMA R64644) recorded at an air temperature of 20.5 o C.

mensural comparisons in Table 2). The advertisement call of L. gasconi sp. nov. is also distinctly different, consisting of a single short but distinctly pulsed note (see ‘advertisement call’ above), while that of L. multiplica consists of a very loud 2-note call with a pulse rate that is much slower than that of L. gasconi sp. nov. (30–47/s vs 153–216/s). A brief description of the call of L. multiplica is provided below.

There are a number of other predominately green, medium-sized Litoria found in New Guinea that could be superficially confused with L. gasconi sp. nov. Litoria wapogaensis and L. christianbergmanni share with L. gasconi sp. nov. distinct white dermal ridges below the vent and extending along the arms and legs. However these species are much smaller (26.9 to 32.9 mm), and the former can be further distinguished by its purplish brown thighs and the latter by its dark brown thighs and golden iris (see Günther 2008). Litoria elkeae and other members of the L. gracilenta and L. aruensis group (sensu Menzies and Tyler 2004) are of similar size, although generally slightly smaller ( Menzies and Tyler 2004) and can be spotted, but are readily distinguished by possession of a pale canthal stripe and absence of a prominent white dermal ridge around the vent and on the fore and hindlimbs. Litoria singadanae can be distinguished by it’s transparent tympanic membrane (Richards 2005), Litoria verae by its more extensively developed crenulated fold on the outer edge of the limbs, greenish brown and finely tubercular (vs smooth) dorsum ( Günther 2004), and Litoria rubrops by its red eye and lack of a dermal fold below the vent ( Kraus and Allison 2004). Frogs of the Litoria graminea group ( Litoria dux , Litoria graminea , Litoria huntorum and Litoria sauroni ) are predominately green but are easily distinguished by their much larger size (male SVL> 55 mm), and lack of both dorsal spotting and a bilobed dermal ridge below the vent (Richards et al. 2006, Richards and Oliver 2006). Litoria mystax , L. albolabris , L. umarensis and New Guinean members of the Litoria bicolor group ( L. bibonius , L. contrastens , L. chloristona , L. eurynastes , L. lodesdema , and L. viranula ), are predominantly green but are much smaller than the new species (male SVL <35 mm) and again lack a bilobed dermal ridge below the vent ( Tyler 1968, Gunther 2004, Menzies et al. 2008).

Distribution and Natural History. Known only from two sites in the vicinity of Marina Valen and Kwerba Villages , in the southern foothills of the Foja Mountain Range, Papua Province, Indonesia ( Figure 4 ). All specimens were collected in relatively undisturbed hill forest on steep ridges between 200 and 500 m a.s.l. ( Figure 5 ). Litoria gasconi sp. nov. was not found at higher elevations despite intensive searches between 1100 m and 1700 m over a 2-week period, and further searches at similar altitudes over a three week period in 2008. Males were detected by their very soft calls, uttered from large leaves on low shrubs or tree branches between 1 and 6 m above the ground. They were found only along two streams that formed a series of shallow, disconnected pools and seeps. This species was never seen or heard in the vicinity of clear, flowing streams, or around temporary or permanent forest pools. Two other species of Litoria , L. humboldtorum and L c.f. genimaculata, were detected in microsympatry along the same intermittent streams.

Etymology. The new species is named for Claude Gascon of Conservation International, in gratitude for his support of our amphibian research in New Guinea, and in recognition of his long involvement in the conservation of amphibians globally.

Figures

FIGURE 1. Dorsal (A) and ventral (B) views of holotype MZB Amph. 15839 of Litoria gasconi sp. nov. (scale = 10 mm), (C) lateral view of head of holotype MZB Amph. 15839 (scale = 5 mm), (D) paratype MZB amph 12036 (SJR 9805) in life showing bilobed dermal fold below vent and orange thigh and axillary colourations.

FIGURE 2. Paratopotype of Litoria gasconi sp. nov. MZB Amph. 15840 (SJR 6019) (top) photographed in life at night, note distinct dermal folds on posterior edge of forearm, and Litoria multiplica (bottom) Tualapa, Southern Highlands Province, Papua New Guinea, in life, note black ventral patches and blue groin and thighs. All photographs by S. J. Richards.

FIGURE 4. Primary foothill rainforest around Marina Valen Village, Papua Province Indonesia, type locality of Litoria gasconi sp. nov.

FIGURE 5. Map of New Guinea showing the known distribution of Litoria gasconi sp. nov. and Litoria multiplica.