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Research Article
Two new species of torrent-breeding treefrogs (Anura: Pelodryadidae: Litoria) from hill forests on the southern edge of New Guinea’s Central Cordillera
expand article infoStephen J. Richards‡§, Paul M. Oliver|
‡ South Australian Museum, Adelaide, Australia
§ Binatang Research Center, Madang, Papua New Guinea
| Griffith University, Brisbane, Australia
¶ Queensland Museum, Brisbane, Australia

Corresponding author: Paul M. Oliver ( p.oliver@griffith.edu.au )

Academic editor: Deepak Veerappan
© 2024 Stephen J. Richards, Paul M. Oliver.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Richards SJ, Oliver PM (2024) Two new species of torrent-breeding treefrogs (Anura: Pelodryadidae: Litoria) from hill forests on the southern edge of New Guinea’s Central Cordillera. Vertebrate Zoology 74: 417-433. https://doi.org/10.3897/vz.74.e123251
ZooBank: urn:lsid:zoobank.org:pub:49F3D3E2-77E5-400F-B498-D53B60677AD7
Open Access

Abstract

We describe two new species of torrent-breeding Litoria Tschudi, 1838 from low-elevation hill-forest habitats on the southern fringe of Papua New Guinea’s Central Cordillera. One is currently known only from the Kikori River basin, and the other is known from the Kikori and adjacent Strickland River basins. The two new species can be distinguished from all other Litoria by aspects of morphology and advertisement call structure. Both are known only from below 500 m a.s.l. and so are considered less likely to be threatened by the devastating frog pathogen Batrachochytrium dendrobatidis Longcore, Pessier & Nichols, 1999 than torrent-breeding Melanesian pelodryadid frogs occupying higher, cooler habitats, should that pathogen be introduced to the region. One hundred and ten frog species have now been documented from the Kikori River basin, a near doubling of the total recognised when the first field guide to the region was published nearly 20 years ago, emphasising the rich anuran community of this area.

Keywords

Batrachochytrium dendrobatidis, frog species richness, Kikori River basin, Melanesia, mountains, Papua New Guinea

Introduction

New Guinea is home to the most diverse assemblage of insular frog species in the world (Menzies 2006; Oliver et al. 2022). Two radiations of torrent-breeding treefrogs in the family Pelodryadidae form a distinctive component of this biota. One radiation consists of around thirty species placed in the genus Nyctimystes Stejneger, 1916 that are characterised by having a pupil that is vertical (versus horizontal) when constricted and palpebral venation (Zweifel 1958; Menzies 2006). The other torrent-breeding radiation consists of a suite of around 25 described species that are usually ascribed to the genus Litoria (Menzies 2006; Richards et al. 2021), and which current genetic evidence suggests are likely to be a monophyletic group (Richards et al. 2023). These torrent-breeding Litoria occur in almost all hill to montane forest habitats on mainland New Guinea, and on some adjacent land-bridge islands, including Salawati, Japen, Goodenough and Normanby (Menzies 2006; Richards et al. 2021).

The number of torrent-breeding Litoria described from New Guinea has grown steadily over the last two decades (Richards 2001; Günther and Richards 2005; Richards and Iskandar 2006; Richards and Oliver 2006; Richards et al. 2021; Oliver et al. 2023; Richards and Bickford 2023). Nonetheless, the species diversity in this group remains underestimated (Oliver et al. 2022). Documenting this diversity is considered a priority for Melanesian frog taxonomy for two reasons. First, these species are dependent on swift-flowing streams that occur predominantly in montane habitats, and thus studies of this group will contribute to our understanding of how and when the uplift of New Guinea’s Central Cordillera and other mountains has generated and shaped biodiversity (Oliver et al. 2017; Tallowin et al. 2018; Slavenko et al. 2021; Toussaint et al. 2021; Pujolar et al. 2022). Second, ecologically similar Litoria species from nearby upland areas of Australia have been devastated by the frog pathogen Batrachochytrium dendrobatidis (Bower et al. 2017). If, as seems likely, most torrent-breeding Litoria in New Guinea are similarly vulnerable to this pathogen, resolving the diversity of this group is critical to create a baseline for monitoring and understanding potential chytrid impacts.

The Kikori River basin is an extensively forested region covering approximately 20,000 km2 of Gulf, Southern Highlands, Enga and Hela Provinces in south-central Papua New Guinea. The frog fauna of this region has been intensively surveyed over the last 25 years (Richards 2002; Richards et al. 2023). This work has documented an exceptionally rich frog fauna comprising over 110 species, including many that have only recently been described (Günther and Richards 2016, 2017, 2018, 2019, 2020, 2021a, 2021b; Richards and Günther 2019; Richards et al. 2023). Currently seven named torrent-breeding Litoria species are recognised from the Kikori River basin. Here we describe two additional species from this group that occupy relatively low-elevation habitats in the Kikori River basin and nearby regions.

Material and methods

Following recent papers on the taxonomy of Australopapuan treefrogs (e.g., Kraus 2018; Oliver et al. 2019; Richards et al. 2023), the species described herein are assigned to Litoria sensu Tyler and Davies (1978) pending a comprehensively sampled and phylogenetically informed resolution of generic boundaries within Pelodryadidae. Our morphological and ecological data support the distinctiveness of the new species and indicate that their relationships lie with other Litoria from New Guinea that are characterised by their torrent-breeding ecology. With one exception (Richards et al. 2021) these species are known or expected to have large, unpigmented eggs.

Frogs were located using head torches and by tracking advertisement calls. Voucher specimens were fixed in 10% formalin, stored in 70% ethanol and lodged in the Papua New Guinea National Museum, Port Moresby (PNGNM), the Queensland Museum, Brisbane (QM) and the South Australian Museum, Adelaide, Australia (SAMA). Additional comparative material (Appendix 1) was examined from: American Museum of Natural History, New York (AMNH); Natural History Museum, London (BMNH); Museum of Comparative Zoology, Harvard (MCZ); South Australian Museum, Australia (SAMA); Museum für Naturkunde Berlin (ZMB); the Natural Sciences Resource Centre of the University of Papua New Guinea, Port Moresby (UPNG); Museum Zoologicum Bogoriense, Cibinong, Indonesia (MZB); Museo Civico di Storia Naturale, Genoa (MSNG); and the Queensland Museum, Brisbane (QM). Additional information for comparisons was taken from Johnston and Richards (1994), Günther and Richards (2005) and Tyler (1968). SJR and JCUNQ[SJR] refer to original field collection numbers of S.J. Richards. Call recordings and images of recorded animals have been uploaded to iNaturalist (https://www.inaturalist.org) and will have their taxonomy updated upon publication of this work.

Measurements, terminology, and abbreviations follow Tyler (1968) and Richards and Oliver (2006). Measurements made to the nearest 0.1 mm with callipers were: SVL – body length from snout to vent; TL – tibia length from heel to outer surface of flexed knee; HL – head length, from tip of snout to posterior margin of tympanum; HW – head width at level of tympana. Measurements to the nearest 0.1 mm made with a dissecting microscope fitted with an ocular micrometer were: EN – distance from anterior corner of eye to posterior margin of naris; IN – internarial distance, between medial margins of external nares; EYE – horizontal diameter of eye; TYM – horizontal diameter of tympanum including tympanic annulus; 3FD – transverse diameter of disc of finger 3; 3FP – transverse diameter of penultimate phalanx of finger 3; 4TD – transverse diameter of disc of toe 4; and 4TP – transverse diameter of penultimate phalanx of toe 4. Sex was determined by examination of vocal slits, nuptial pads, the presence of eggs and/or by observation of calling.

Calls were recorded using a Sony Professional Walkman recorder with an Electret ECM-Z200 Condenser Microphone. We analysed calls using Avisoft-SASLab Pro (v4.34, available from Avisoft Bioacoustics: http://www.avisoft.com) following procedures and terminology recommended by Köhler et al. (2017) and calculated audiospectrograms with fast-Fourier transform (FFT) of 256 points, 50% overlap, using Hamming windows.

DNA was extracted from a small number of samples of the two new species and from recently collected material of L. spartacus, using a Puregene DNA isolation kit (Gentra Systems, Minneapolis, MN, U.S.A.) following the manufacturer’s protocol for DNA purification from solid tissue. A fragment of the mitochondrial NADH dehydrogenase subunit 4 (ND4) gene was amplified and sequenced using the forward primers 5′-TGACTACCAAAAGCTCATGTAGAAGC-3′ with the reverse primer 5′-CATTACTTTTTACTTGGATTTGCACCA-3′. Each PCR was carried out in a volume of 25 μl with a final concentration of 1X GeneAmp PCR Gold buffer, 2–4 mM MgCl2, 200 M of each dNTP, 0.2 mM of each primer and 0.5 U of AmpliTaq Gold DNA polymerase (Applied Biosystems, Foster City, CA, U.S.A.). Amplifications consisted of an initial denaturation step of 94°C for 9 min, followed by 34 cycles of PCR with the following temperature profile: denaturation at 94°C for 45 s, annealing at 55°C for 45 s, and extension at 72°C for 1 min, with an additional final extension at 72°C for 6 min. The double-stranded amplification products were visualised on 1.5% agarose gels. Sequencing was outsourced to the company Macrogen.

Sequences were aligned with Muscle v 6.814b (Edgar 2004) implemented in Geneious Pro v8.1.4 (Kearse et al. 2012) and are deposited in GenBank (Appendix 2). The final alignment was 654 base pairs long and comprised entirely of coding region of ND4. We calculated p-distances between species using MEGA v11 (Tamura et al. 2021).

Systematics

Litoria kikori sp. nov.

https://zoobank.org/8B0086AB-99D6-4E83-AD3A-CF9469F7A7CB
Figures 1, 2A, B, D, E, 3, 4

Kikori torrent treefrog

Holotype

SAMA R69990 (SJR[JCUNQ]3245), adult male with vocal slits and nuptial pads, calling when collected, Libano Sok, Hegigio River, Southern Highlands Province, Papua New Guinea (6.3989°S, 142.9761°E; 250 m a.s.l.), collected by Stephen Richards on 7 August 2003.

Paratypes

SAMA R69986 (SJR[JCUNQ]3222), R69987 (SJR[JCUNQ]3240), R69988 (SJR[JCUNQ]3243), R69989 (SJR[JCUNQ]3244, R69991–R69992 (SJR[JCUNQ]3246–3247), QMJ 98371 (JCUNQ[SJR]3241), PNGNM JCUNQ[SJR]3242), all males with same locality and collector details as holotype, collected between 4–7 August 2003; SAMA R72336 (SJR14135), male, and R72337 (SJR14141), female, Bifo Creek, Southern Highlands Province, Papua New Guinea (6.4483°S, 142.9597°E; 360 m a.s.l.), collected by Stephen Richards on 2 and 4 August 2014 respectively.

Diagnosis

A species of Litoria that can be distinguished from all congeners by the following unique combination of characters: size moderate (male SVL 29.9–35.8); snout moderately long (EN/IN 0.51–0.75), slightly pointed in dorsal view, truncate in lateral view; canthus rostralis curved in dorsal view, relatively sharply defined in lateral view; limbs long (TL/SVL 0.59–0.68); finger webbing moderate, extending to distal subarticular tubercles between fingers 3 and 4; toe webbing extensive, reaching to disc or to intercalary cartilage at base of disc on all digits except toe 4; finger and toe discs moderately narrow (3FD/SVL 0.04–0.05, 4TD/SVL 0.04–0.05); dorsal skin finely rugose with numerous larger tubercles on exposed surfaces of torso; hindlimbs with low, crenulated dermal ridges on outer edges of tibiae and tarsi; heels with 2–3 low conical tubercles; vomerine teeth in two prominent raised clumps; vocal slits present in males; dorsal colouration mottled green and brown; hidden surfaces of shanks and groin purplish in life; and advertisement call a single loud, unpulsed musical note lasting 0.03–0.05 s and produced at intervals of ~12–37 seconds for long periods.

Comparisons with other species

We emphasize comparisons with torrent-breeding Litoria because based on taxa genetically sampled so far (e.g., Richards et al. 2021, 2023) they form a monophyletic group that is also ecologically distinctive. The new species can be distinguished from non torrent-breeding Litoria by the following combination of characters: dorsum mottled green and brown, skin tuberculate (Fig. 1A–C), canthus rostralis strongly curved and moderately sharply defined in dorsal view, snout-tip shallowly acuminate, webbing on fingers moderate, extending to distal subarticular tubercles on outside of fingers 2 and 3, and adult size moderate (male SVL 30–36 mm).

Figure 1. 

In-life images of Litoria kikori sp. nov.: A adult female paratype (SAMA R72337) from Bifo Creek, Papua New Guinea; B adult male paratype (SAMA R72336) from Bifo Creek, Papua New Guinea; C adult male, unvouchered specimen from Libano Sok, Papua New Guinea. All photographs by Stephen Richards.

Litoria kikori sp. nov. can be distinguished from other torrent-breeding Litoria in New Guinea as follows: it is larger than L. amnicola Richards, Tjaturadi, Krey & Donnellan, 2021, L. brongersmai (Loveridge, 1945), L. lakekamu Richards & Bickford, 2023, L. leucova (Tyler, 1968), L. megalops Richards & Iskandar, 2006, L. napaea (Tyler, 1968), L. rara Günther & Richards, 2005 and L. rivicola Günther & Richards, 2005 (male SVL > 30 mm versus < 25 mm); and further differs from L. amnicola, L. brongersmai, and L. napaea in having prominent vomerine teeth (versus indistinct, detectable only as slight bumps); from L. lakekamu and L. leucova in its green-and-brown-mottled dorsum (versus green); from L. megalops in having moderate finger webbing (versus absent), and in its smaller eye (EYE/SVL 0.12–0.14 versus 0.14–0.17); and from both L. rara and L. rivicola by its longer hindlimbs (TL/SVL > 0.59 versus < 0.56) and green or brown dorsal colouration (versus predominantly grey or greyish brown). Litoria kikori sp. nov. is substantially smaller than L. angiana (Boulenger, 1915) (max male SVL <40 mm versus >50 mm), and further differs in having the snout distinctly acuminate (versus relatively blunt) in dorsal aspect, canthus rostralis curved in dorsal view (versus straight), and dorsum and lateral edge of tarsus strongly tuberculate in life (versus relatively smooth).

Litoria kikori sp. nov. differs from the following ten similar-sized or slightly larger torrent-breeding species – L. arfakiana (Peters & Doria, 1878), L. becki (Loveridge, 1945), L. bulmeri (Tyler, 1968), L. oenicolen Menzies & Zweifel, 1974, L. fuscula Oliver & Richards, 2007, L. macki Richards, 2001, L. micromembrana (Tyler, 1963), L. modica (Tyler, 1968), L. spinifera (Tyler, 1968) and L. wollastoni (Boulenger, 1914) – in having moderately extensive finger webbing that extends to distal subarticular tubercle on fingers 2, 3, and 4 (versus at most basal webbing between fingers 3 and 4); and further differs from L. arfakiana, L. oenicolen, L. spinifera and L. wollastoni in its less sharply acuminate snout tip and lacking prominent spiniform tubercles on heel (and in L. spinifera across body); from L. becki in its extensively webbed toes (versus toes half-webbed); from L. bulmeri by lacking a dark brown to black lateral band on head and body (versus present); from L. fuscula in having prominent vomerine teeth (versus indistinct, detectable only as slight bumps), green and/or brown mottled dorsal colouration (versus dark brown with no obvious pattern), and in having small conical tubercles along heel (versus no tubercles); and from L. macki in having low, indistinct tubercles on eyelids (versus prominent and large) and dark purplish-brown colouration in groin (versus yellow).

Litoria kikori sp. nov. can be distinguished from four similar-sized species with moderate webbing between the fingers as follows: from L. dorsivena (Tyler, 1968) and L. hastula Oliver, Iskandar & Richards, 2023 by its green-and-brown mottled dorsal colouration (versus predominantly brown) and snout relatively rounded in lateral view (versus distinctly acuminate in both lateral and dorsal views); from L. pratti (Boulenger, 1911) by its curved canthus rostralis (versus straight) and slightly longer limbs (TL/SVL > 0.59 versus < 0.57); and from L. scabra Günther & Richards, 2005 by its longer limbs (TL/SVL > 0.59 versus < 0.56), hindlimbs with series of low lateral tubercles (versus a crenulated ridge), and green or green-and-brown mottled dorsal colouration (versus predominantly grey or greyish brown) (Günther and Richards 2005).

Litoria kikori sp. nov. is most similar to L. spartacus Richards & Oliver, 2006 (Fig. 2A) and is closely related to it (see below), but can be differentiated by its smaller size (male SVL 29.9–35.8 versus 35.6–37.4, female SVL 45.4 versus 51.1), narrower finger pads (3FD/SVL 0.045–0.052 versus 0.048–0.062), narrower toepads (4TD/SVL 0.037–0.050 versus 0.052–0.062) (Fig. 2B), distal subarticular tubercle of finger 4 wider than long and slightly bifid (versus roughly equal in width and length and not bifid) (Fig. 2B), groin in life unpigmented or light purplish (versus orange) (Fig. 2C–E), throat in males without brown mottling (versus typically with brown mottling) and call consisting of a single note repeated at 12–37 second intervals for at least several minutes (versus multiple notes in short series lasting 5–20 seconds; Richards and Oliver 2006).

Figure 2. 

Detailed comparisons of Litoria kikori sp. nov. and L. spartacus: A dorsal views of L. spartacus (top) and L. kikori sp. nov. (bottom) holotypes; B comparisons of underside of fingers, showing wider discs and rounded subarticular tubercle on finger 4 in holotype of L. spartacus (left) versus narrower pads and bilobed tubercle on finger 4 on holotype of L. kikori sp. nov. (right); C orange groin and lower shanks of L. spartacus from Moro, Papua New Guinea; and unpigmented or, at most, slightly purplish groin and shanks on L. kikori sp. nov.; D holotype; E paratype SAMA R72337. All photographs by Stephen Richards.

Description of holotype

Adult male with vocal slits and indistinct pale-brown nuptial pads with fine asperities. Habitus moderately slender, limbs long (TL/SVL 0.67), head wide (HW/SVL 0.36). Snout protruding distinctly beyond lower jaw, rounded in lateral view, moderately acuminate in dorsal view (Fig. 3A, B). Canthus rostralis with rounded edge, but clearly defined in both dorsal and lateral view and curved in dorsal view; loreal region steeply sloping, slightly concave. Nostrils near top of snout, oriented laterally, not visible in dorsal view. Vomeropalatines forming two prominent elevations, each with 3–4 teeth positioned midway between choanae. Tongue small, nearly round, with prominent posterior notch; vocal slits laterally in floor of mouth, extending from near angle of jaws about one half distance to front of jaw. Eyes large (EYE/SVL 0.14), prominent, protruding in dorsal and ventral views; pupil horizontal, pigmentation on nictitating membrane restricted to very thin narrow band of maculations along dorsal edge. Tympanum moderately small (TYM/SVL 0.05), one-third diameter of eye (TYM/EYE 0.32), tympanic annulus clearly defined, except dorsal edge obscured by thick, slightly curved supratympanic ridge.

Figure 3. 

Details of the holotype (SAMA R69990) of Litoria kikori sp. nov.: A dorsal view of head; B lateral view of head; C dorsal view of hindlimbs and dorsolateral view of hidden surfaces of thighs; D hand; E foot. Scale bar = 5 mm.

Skin on dorsal surfaces of torso and head rugose, with numerous large, rounded tubercles (Fig. 3A), skin on throat finely granular, on abdomen coarsely granular. Forelimbs finely tuberculate on exposed surfaces, with scattered tubercles on ventral surface, and distinct ventrolateral fold along outer edge of forearm. Hindlimbs tuberculate on exposed dorsal surfaces of tibia and tarsus, outer edge of tibia and tarsus with series of tubercles (Fig. 3C), heel with three low white tubercles. Ventral surfaces of thighs coarsely granular proximally, becoming less so distally, ventral surfaces of tarsus and tibia smooth.

Fingers long, relative lengths 3>4>2>1. All fingers webbed (Fig. 3D), in thin strip between fingers 1–2, and extending to distal subarticular tubercles on outside of fingers 2 and 3, and inside of finger 4 (Figs 2B, 3D). Tips of all digits expanded into prominent discs (3FD/3FP 1.6) with circum-marginal grooves. Subarticular tubercles rounded or bifid, distal tubercles of fingers 3 and 4 most notably bifid (Fig. 3D); outer metacarpal tubercles ovoid, indistinct; inner metacarpal tubercle prominent, visible as lunate lateral extension from base of finger 1 in both ventral and dorsal view. Nuptial rugosity on outer metacarpal tubercle finely granular, indistinct.

Toes long, relative lengths 4>3>5>2>1, all webbed (Fig. 3E); web reaching to terminal disc or to intercalary cartilage at base of disc on toes 1, 2, 3 and 5 and to distal subarticular tubercle on both sides of toe 4. Discs prominent (4TD/4TP 1.6), with supramarginal grooves. Subarticular tubercles prominent, rounded or slightly bifid (Fig. 3E); inner metatarsal tubercle indistinct and ovoid, outer metatarsal tubercle slightly smaller, indistinct and rounded.

Colour in preservative

Dorsal surfaces predominately dark blueish green with small areas of dark brown (Fig. 3A); lateral surface of snout predominately brown, with diffuse blueish green blotch extending anteriorly from lower edge of eye; prominent brown blotch below supratympanic fold; labial region with numerous small white spots; upper lips and region around rictus of jaws white (Fig. 3B). Ventral surfaces largely off white, with some tiny brown maculations along edge of jaw. Dorsal surfaces of arms and legs predominately greenish brown, towards extremities brown colouration becomes more diffuse and off-white ground colouration becomes more visible. Most ventral surfaces of limbs largely off white with scattered patches of brown, particularly on hands, lateral edge of arms and femur; tarsi and feet (including webbing) off white, heavily spotted with brown.

Variation

Measurements and proportions of males in the type series are similar (Table 1) and all paratypes have similar webbing on the hands and feet. Dorsal colour pattern is variable, ranging from bluish green heavily mottled with dark brown, through to predominantly greyish-brown with a small amount of blueish-green splotching. Ventral colouration is consistently off white to buff, with only slight variation in the extent of light-brown mottling on the legs and along the sides of the torso. The single female is substantially larger than the males in the type series (Table 1) and has more extensive greyish-brown mottling on the ventral surfaces but is otherwise similar in colouration and proportions.

Table 1.
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Measurements and proportions of the type series of Litoria kikori sp. nov.

SAMA R69990 R72336 R69989 R69986 QMJ 98371 R69987 R69991 PNGNM R69988 R69992 R72337 Mean SD Min
Sex M M M M M M M M M M F males only
SVL 31.0 33.3 32.0 34.0 35.8 35.2 35.0 33.9 29.9 31.0 45.5 33.1 2.0 29.9–35.8
TL 20.9 20.7 18.9 22.2 21.9 23.0 22.5 20.0 19.5 21.0 28.4 21.1 1.3 18.9–23.0
HW 11.2 10.6 10.3 11.4 11.1 11.5 12.4 10.9 11.0 10.8 14.6 11.1 0.6 10.3–12.4
HL 11.5 11.0 12.0 12.0 11.8 12.5 12.7 11.4 11.4 11.5 15.0 11.8 0.5 11.0–12.7
EN 2.5 2.7 2.2 2.5 2.9 2.9 2.7 2.8 2.4 2.3 3.5 2.6 0.2 2.2–2.9
IN 4.3 3.6 4.3 4.3 4.4 4.4 4.5 4.6 4.0 4.1 5.5 4.3 0.3 3.6–4.6
EYE 4.4 4.4 4.5 4.5 4.3 4.4 4.5 4.3 3.9 4.0 5.6 4.3 0.2 3.9–4.5
TYM 1.4 1.4 1.4 1.3 1.7 1.6 1.6 1.5 1.5 1.5 2.0 1.5 0.1 1.3–1.7
3FD 1.6 1.6 1.6 1.7 1.6 1.6 1.8 1.5 1.5 1.5 2.3 1.6 0.1 1.5–1.8
3FP 1.0 0.9 1.0 0.9 1.1 1.0 1.2 1.1 0.9 1.0 1.5 1.0 0.1 0.9–1.2
4TD 1.4 1.3 1.4 1.5 1.5 1.3 1.5 1.4 1.4 1.4 1.8 1.4 0.1 1.3–1.5
4TP 0.9 0.8 0.9 0.9 1.1 0.9 1.2 1.1 0.9 1.1 1.3 1.0 0.1 0.8–1.2
TL/SVL 0.67 0.62 0.59 0.65 0.61 0.65 0.64 0.59 0.65 0.68 0.62 0.64 0.03 0.59–0.68
EN/IN 0.58 0.75 0.51 0.58 0.66 0.66 0.60 0.61 0.60 0.56 0.64 0.61 0.07 0.51–0.75
TYM/SVL 0.05 0.04 0.04 0.04 0.05 0.05 0.05 0.04 0.05 0.05 0.04 0.05 0.00 0.04–0.05
TYM/EYE 0.32 0.32 0.31 0.29 0.40 0.36 0.36 0.35 0.38 0.38 0.36 0.35 0.04 0.29–0.40
EYE/SVL 0.14 0.13 0.14 0.13 0.12 0.13 0.13 0.13 0.13 0.13 0.12 0.13 0.01 0.12–0.14
HW/SVL 0.36 0.32 0.32 0.34 0.31 0.33 0.35 0.32 0.37 0.35 0.32 0.34 0.02 0.31–0.37
HL/SVL 0.37 0.33 0.38 0.35 0.33 0.36 0.36 0.34 0.38 0.37 0.33 0.36 0.02 0.33–0.38
3FD/SVL 0.05 0.05 0.05 0.05 0.04 0.05 0.05 0.04 0.05 0.05 0.05 0.05 0.00 0.04–0.05
4TD/SVL 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.05 0.05 0.04 0.04 0.00 0.04–0.05
4TD/3FD 0.88 0.81 0.88 0.88 0.94 0.81 0.83 0.93 0.93 0.93 0.78 0.88 0.05 0.81–0.94
3FD/3FP 1.6 1.8 1.6 1.9 1.5 1.6 1.5 1.4 1.7 1.5 1.5 1.6 0.16 1.4–1.9
4TD/4TP 1.56 1.63 1.56 1.67 1.36 1.44 1.25 1.27 1.56 1.27 1.38 1.46 0.16 1.25–1.67

Colour in life

The following description of colouration in life is based on photographs of three specimens (Figs 1A–C, 2D, E). Dorsal surfaces of torso, snout, forelimbs and most exposed surfaces of hindlimbs mottled with medium brown and bright green, with relative extent and dominance of green and brown areas showing considerable variation across specimens. Exposed surfaces of thigh light brown without green pattern. Tympanum always brown. Posterior edge of upper jaw usually with at least some small off-white blotches. Lateral surfaces of body sometimes with large ragged-edged silvery-yellow blotches. Where portions of venter are visible in photos (2D) they are translucent, but heavily overlaid with white spots and brown maculations. Hidden posterior edge of thighs, shanks and inguinal region purplish. Tubercles around vent white. Iris silver with thin dark-brown vermiculations.

Advertisement call

We recorded 13 calls from four individuals. Calls were similar among all individuals and were combined for analysis. The call of Litoria kikori sp. nov. is a single loud, musical note, sounding like ‘tink’, uttered from leaves and branches between 2 and >5 m above the banks of large foothill streams. Calls are 0.03–0.05 s long (mean = 0.04, SD = 0.008, n = 13); notes are not pulsed, but two notes are partially divided into two subpulses. Frequency is concentrated in two bands, one at about 3600 Hz and the other at 1800 Hz (Fig. 4). The higher band is dominant in 11 calls (3460–3660 Hz, mean = 3600, SD = 58.32) while the lower frequency was dominant in two calls produced by SAMA R69992. Calls were produced at 0.38–37.0 seconds. However, if a single rapidly repeated couplet produced by SAMA R69991 (0.38 s interval) is excluded then inter-call interval is 11.9–37.0 seconds (mean = 17.8, SD = 8.0 s, n = 8). Males produced these single-note calls in bouts lasting for at least several minutes. An exemplar call from paratype SAMA R72336 has been uploaded to iNaturalist (https://www.inaturalist.org/observations/218063325).

Figure 4. 

A waveform, B power spectrum and C spectrogram of a single call of Litoria kikori sp. nov. (SAMA R69990) recorded at an air temperature of 24.5°C.

Molecular differentiation

Genetic divergences (p-distances) between Litoria kikori sp. nov. and its closest relative L. spartacus were between 0.135–0.146 (based on comparisons of 654bp of mitochondrial ND4 gene data).

Etymology

Named in reference to the Kikori River basin to highlight the remarkable frog diversity and broader conservation significance of this region. Used as a noun in apposition.

Distribution and ecological notes

Known only from two locations, Libano Sok and Bifo Creek, located 6 km apart in the Kikori River basin along the southern slopes of the Central Cordillera of Papua New Guinea (Fig. 5).

Figure 5. 

Distributions of Litoria kikori sp. nov. (white circle), L. spartacus (blue squares) and L. grinpela sp. nov. (black circle, type locality). The black and white circle is Libano Sok where both new species occur in sympatry. Libano Sok is the type locality of Litoria kikori sp. nov.

Males in the type series were calling from leaves between 2–4 metres above swift-flowing rivers in hill forest (Fig. 6A). The female paratype (SAMA R72337) was collected from a tree adjacent to Bifo Creek. Five large, yellow eggs measured in situ were 1.7–2.0 mm diameter in diameter. At Libano Sok Litoria kikori sp. nov. occurred in sympatry with one other torrent-breeding pelodryadid frog, the new species described below. No other torrent-dwelling Litoria were detected at Bifo Creek.

Figure 6. 

A Streamside habitat of Litoria kikori sp. nov. in foothill forest at Bifo Creek, Southern Highlands Province, Papua New Guinea; B habitat of L. grinpela sp. nov at the type locality along the Liddell River, Western Province, Papua New Guinea; C a waterfall emerging out of the ground just upstream from image B. This is the lowest known locality (215 m a.s.l.) for three other stream-breeding pelodrydadid treefrog species: L. arfakiana, L. spartacus and Nyctimystes pulcher.

Suggested IUCN redlist status

Litoria kikori sp. nov. is known only from two sites approximately six kilometres apart. However, there are large areas of forest in the region, which is sparsely inhabited. Furthermore, it occurs at elevations at which ecologically similar torrent-breeding Litoria in tropical Australia have been able to persist in the presence of the frog pathogen B. dendrobatidis. Despite its small range, and uncertainty about the species’ ability to persist if intensive logging occurs, we suggest that this species should be considered Least Concern at this stage. However, we stress that further surveys are needed to better document this species’ distribution and the extent to which it overlaps with areas of forest loss.

Litoria grinpela sp. nov.

https://zoobank.org/2633D4E3-ED89-45E7-88E3-6B6C076B0EA4
Figures 7A, B, 8, 9

Green torrent treefrog

Holotype

SAMA R72339 (SJR10513), adult male with vocal slits and nuptial pads, Liddell River, upper Strickland River basin, Western Province, Papua New Guinea (5.8078°S, 142.3083°E; 215 m a.s.l.), collected by Stephen Richards on 30 March 2008.

Paratype

SAMA R72340 (SJR[JCUNQ]3249), adult male with vocal slits and nuptial pads, Libano Sok, Hegigio River, Southern Highlands Province, Papua New Guinea (6.3989°S, 142.9761°E; 250 m a.s.l.), collected by Stephen Richards on 7 August 2003.

Diagnosis

A species of torrent-breeding Litoria that can be distinguished from all congeners by the following unique combination of characters: size moderately small (male SVL 26.1–27.5 mm); snout rounded in both dorsal and lateral view; canthus rostralis strongly curved in dorsal view, rounded in lateral view; limbs long (TL/SVL 0.62–0.64); finger webbing moderate, web between fingers 3 and 4 extending to distal subarticular tubercle and, on finger 4, continuing as fringe to base of disc; toe webbing extensive, extending to base of disc on all toes except toe 4 where it reaches distal subarticular tubercle on both sides of digit; dorsal skin relatively smooth with no prominent tubercles; vocal slits present in males; dorsal colouration predominately mid-green with no or little pattern; thin brown canthal stripe or blotch present; hidden surfaces of thighs and groin orange; venter largely off-white with no pattern; and advertisement calls comprising 7–21 rapidly repeated unmusical tapping notes produced at a rate of 7.8–9.6 notes/s at a dominant frequency of 2707–3082 Hz.

Comparisons with other species

The combination of moderately small size (adult male SVL between 25–30 mm), snout rounded in dorsal view, dorsal skin relatively smooth with no prominent tubercles, moderate webbing on the fingers and predominantly green dorsal colouration (Fig. 7A, B) readily distinguishes L. grinpela sp. nov. from the majority of other torrent-breeding Litoria from New Guinea.

Figure 7. 

In-life images of: A holotype (SAMA R72339); B paratype (SAMA R72340) of Litoria grinpela sp. nov.; C, D specimens of the ecologically and morphologically similar and geographically overlapping torrent-breeding Litoria longicrus from the foothills of the Muller Range. Note the brown tympanic membrane and extensive white lateral markings in L. longicrus. All photographs by Stephen Richards.

Litoria grinpela sp. nov. differs from other small, green, torrent-breeding species as follows: from L. lakekamu Richards & Bickford, 2023 in its larger size (male SVL >25 versus <25 mm), white labial patch restricted to below eye only (versus full labial stripe), brown canthal stripe or patch present (versus absent), canthus rostralis moderately well defined (versus very indistinct), tympanum distinct (versus indistinct), and call consisting of 7–21 rapid popping notes (vs. a series of short, distinctly pulsed rasping notes followed by an explosive chattering; Richards and Bickford 2023); from L. leucova (Tyler, 1968) in its slightly larger size (adult male SVL >25 versus <25 mm), in having longer hindlimbs (TL/SVL > 0.62 versus < 0.57), a wider head (HW/SVL 0.36 versus 0.32–0.34), shorter snout (EN/SVL < 0.084 versus > 0.095) and yellow patches in groin and on hidden surfaces of thighs (versus translucent pink with yellow spots) (Johnston and Richards 1994); and from populations of the geographically overlapping L. longicrus (Boulenger, 1911) (Fig. 7C, D) by its slightly larger size (adult male SVL >25 versus <25 mm), plain green dorsum (versus mottled brown and green), green (versus brown) tympanic membrane, white lateral patch restricted to posterior edge of lower jaw (versus white patches extending from lower jaw along side of body almost to groin), and more extensive webbing on fingers (extending beyond distal subarticular tubercle on finger 4 versus not extending beyond distal subarticular tubercle on finger 4).

Litoria grinpela sp. nov. can be distinguished from three other species of moderately small, green lentic-breeding Litoria that occur in the Kikori region as follows; from L. auae Menzies & Tyler, 2004 by having a brown canthal stripe or blotch on the snout only (versus a white or yellow canthal stripe, and supratympanic stripe), in lacking white or yellow flecks on the dorsum (versus typically present), and by its slightly smaller size (male SVL < 28 mm versus typically greater than 30 mm); and from two species in the L. bicolor (Gray, 1842) group (L. chloristona Menzies, Richards & Tyler, 2008 and L. viranula Menzies, Richards & Tyler, 2008) by its broader head and more broadly rounded snout, the presence of a brown canthal stripe or blotch restricted to the head (versus brown and white lateral stripes extending along sides of torso) and its medium-green dorsal colouration (versus typically yellowish green or brown).

Description of holotype

Adult male with vocal slits and pale-brown nuptial pads made up of fine asperities. Habitus moderately robust, limbs long (TL/SVL 0.64), head wide (HW/SVL 0.48). Snout protruding beyond lower jaw, slightly rounded (nearly truncate) in lateral view, rounded in dorsal view (Fig. 8A, B). Canthus rostralis clearly defined, strongly curved in dorsal view, rounded in lateral view; loreal region steeply sloping, slightly concave. Nostrils near top of snout, oriented laterally, not visible in dorsal view. Vomeropalatines poorly developed, detectable but teeth insufficiently developed to count. Tongue rounded with prominent posterior notch; vocal slits laterally in floor of mouth, extending from near angle of jaws about one third distance to front of jaw. Eyes large (EYE/SVL 0.12), prominent, protruding in dorsal and ventral views; pupil horizontal, nictitating membrane unpigmented. Tympanum moderately small (TYM/SVL 0.047), less than half diameter of eye (TYM/EYE 0.39), tympanic annulus clearly defined except dorsal edge obscured by moderately thick, slightly curved supratympanic ridge.

Figure 8. 

Details of holotype (SAMA R72339) of Litoria grinpela sp. nov.: A dorsal view of head; B lateral view of head; C hand webbing in life; D foot webbing in preservative; E colouration of hidden surfaces of groin and thighs in life. All photographs by Stephen Richards. Scale bars = 5mm.

Skin on dorsum finely rugose, on dorsal surfaces of limbs largely smooth except for scattered indistinct tubercles on forearms; skin on throat finely granular, on abdomen coarsely granular. Ventral surfaces of forelimbs smooth with scattered tubercles; ventral surfaces of thighs coarsely rugose along posterior edge, becoming less so on adjacent surfaces, with scattered large pale off-white tubercles below vent; tarsi and tibiae smooth ventrally.

Fingers moderately long with expanded terminal discs (3FD/3FP 1.6; 3FD/SVL 0.058) with distinct circum-marginal grooves; relative lengths of fingers 3>4>2>1, subarticular tubercles unilobed or weakly bifid. Webbing moderate (Fig. 8C), reaching distal edge of distal subarticular tubercle and continuing to disc as narrow fringe on inside of finger 4; to base of distal subarticular tubercle on outside of finger 3; to base of penultimate subarticular tubercle on inside of finger 3; to base of distal subarticular tubercle on outside of finger 2; and in a narrow basal flange between fingers 1 and 2. Hands with long (1.3 mm) prominent ovoid inner metacarpal tubercles and shorter (0.5 mm), rounded and lower, but still distinct, outer metacarpal tubercle. Nuptial pads pale brown, comprising fine asperities, extending across base of finger 1, elongate, much longer that high, with distinct constriction demarcating short distal portion from much longer proximal portion.

Toes with expanded terminal discs with terminal grooves, some discs slightly shrivelled in preservative; disc on toe 4 distinctly narrower than disc on finger 3 (3FD/4TD 1.2). Relative lengths of toes 4>5>3>2>1. Webbing between toes extensive (Fig. 8D) reaching to distal subarticular tubercle on both sides of toe 4, to base of disc on inside of toe 5 and outside of toes 1–3, and to distal subarticular tubercle on inside of toes 2–3. Inner metatarsal tubercle oval, short (1.1 mm long) but prominent; outer metatarsal tubercle absent.

Colouration in preservative

Dorsum predominately blue with few indistinct small brown blotches just behind eyes. Lateral surfaces of snout densely spotted with blue and brown, brown maculations coalesce to form canthal stripe that extends from eye, across nostril and down to edge of jaw; white patch below eye; upper lip with thin margin lacking maculations giving appearance of an off-white labial stripe. Exposed dorsal surfaces of limbs blue, hidden surfaces of limbs buff with scattered dark-brown or green maculations, dorsal surfaces of digits buff, with scattered dark-brown flecking. Ventral surfaces largely off-white, with scattered regions of brown maculations along edges of lower jaw, extremities of limbs, and posterior edge of thighs.

Summary meristic data. These data were determined for the holotype (all measurement in mm)

SVL 27.5; TL 17.6; HW 13.4; HL 10.3; EYE 3.3; TYM 1.3; IN 3.5; EN 2.3; 3FD 1.6; 3FP 1.0; 4TD 1.3; 4TP 1.0.

Variation

The paratype (SAMA R72339) is an adult male with the following measurements: SVL 26.1; TL 16.2; HW 9.3; HL 9.9; EYE 4.5; TYM 1.3; IN 3.8; EN 2.0; 3FD 1.2; 3FP 0.8; 4TD 0.9; 4TP 0.8. It is broadly similar in colouration, nuptial pad form, and extent of webbing to holotype, but differs in having a mauve dorsal colouration in preservative (likely a preservation artefact), much more prominent white patch laterally on head extending from below eye, across tympanic membrane to insertion point of forelimb, and exposed dorsal surfaces of limbs largely cream with extensive very fine mauve maculations. The vomeropalatines are more prominent than those of the holotype, each supporting 3–4 sharp teeth medial to the choanae (vs. vomeropalatines small, poorly developed in the holotype).

Colouration in life

The following description is based on photographs of the holotype and paratype (Figs 7A, B, 8C–E,). Dorsum green with small number of darker-brown flecks. Lateral surface of snout with brown patch bordered sharply dorsally by canthus rostralis, this brown patch forming thin canthal stripe in holotype but covering most lateral surfaces of snout in paratype. Supratympanic fold light brown. Small white patch on upper lip and below eye present in both specimens but more prominent and extensive in paratype. Lateral surfaces of torso ranging from green, yellowish green to translucent with extensive buff flecks, also overlain with sparse brown flecks in paratype. Exposed surfaces of limbs green, sometimes edged by indistinct brown regions. Hidden surfaces of groin and posterior surface of thighs orange (Fig. 8E). Iris pale grey with extensive darker-brown vermiculation, pupil with very thin orange margin.

Vocalisation

We analysed 14 calls from the holotype (n = 4) and paratype (n = 10) at 23.6 and 24.5°C respectively. Calls of both animals were extremely similar and were combined for analysis. The call of L. grinpela sp. nov. is a series of 7–21 (mean = 15.0, SD = 5.03) unmusical tapping or popping notes uttered in quick succession (Fig. 9). Calls are produced at intervals of 4.3–132.0 seconds (mean = 24.1, SD = 39.4). Call length is 0.67–2.56 seconds (mean = 1.62, SD = 0.62), and notes within calls are produced at a rate of 7.8–9.6 notes/s (mean = 8.74, SD = 0.44). Dominant frequency is 2707–3082 Hz (mean = 2910, SD = 131.08). An exemplar call from the holotype has been uploaded to iNaturalist (https://www.inaturalist.org/observations/218063820).

Figure 9. 

A wave form; B power spectrum; C spectrogram of a single call of Litoria grinpela sp. nov. (SAMA R72340) recorded at an air temperature of 24.5°C. The lower-frequency peak evident in (B) is an artefact of the loud stream noise.

Molecular differentiation

Genetic divergences (p-distances) indicate that L. grinpela sp. nov. is most genetically similar to the clade comprising L. kikori sp. nov. and L. spartacus (p-distances from 0.144–0.161).

Etymology

The name combines the New Guinea pidgin word for green (grin) with its adjectival ending (-pela).

Distribution and ecological notes

Litoria grinpela sp. nov. is known from two locations along the southern slopes of Papua New Guinea’s Central Cordillera: the type locality in the upper Strickland River basin in Western Province, and Libano Sok, on the Hegigio River in the Kikori River basin in Southern Highlands Province, 100 km to the east of the type locality (Fig. 5).

Both animals were calling from foliage 3–4 m above the ground in low-elevation hill forest (Fig. 6B) adjacent to swiftly flowing rivers. Four other torrent-breeding pelodryadids were documented at the type locality, one of which (L. longicrus) occurred in microsympatry with the new species, while three others (L. arfakiana, L. spartacus and Nyctimystes pulcher Wandolleck, 1911) were found slightly upstream where a waterfall emerges from the side of a karst hill slope (Fig. 6C). At just 215 m a.s.l. this location appears to be the lowest known elevation for L. arfakiana, L. spartacus and N. pulcher (Menzies 2006; Richards and Oliver 2006). At Libano Sok L. grinpela sp. nov. occurred in sympatry with only one other stream-breeding pelodryadid, L. kikori (described above).

Suggested IUCN status

The two Litoria grinpela sp. nov. records span approximately 100 kilometres of extensively forested terrain with relatively low human population density. It also occurs at elevations (<500 m a.s.l.) at which populations of torrent-breeding Litoria in the Australian wet tropics have been able to persist in the face of the frog pathogen B. dendrobatidis. If this pathogen colonises New Guinea, this species may therefore be less vulnerable than most other Melanesian torrent-breeding Litoria, which are restricted to higher and cooler areas. For these reasons we suggest an IUCN status of Least Concern.

Discussion

Genetic data indicate that Litoria grinpela sp. nov. is most closely related to L. spartacus and L. kikori sp. nov., stream-dwelling species with which it does not share obvious affinities on the basis of external morphology alone. In contrast, L. kikori sp. nov. is both morphologically and ecologically similar to its closest known relative, L. spartacus. These two species show similar colour pattern, degree of finger webbing, rugosity of skin and body size. Based on available records (including a new record from the upper Strickland River, cf. Appendix 1), L. spartacus occurs within 28 km of the closest known location for L. kikori sp. nov. The new record of L. spartacus expands its known elevational range from predominantly montane areas to lowland forest, suggesting that its distribution could overlap with L. kikori. However, extensive surveys of frog communities undertaken by the senior author across the Kikori River basin have to date failed to detect them in sympatry. Elevational segregation of closely related species is common in the mountain ranges of New Guinea (Oliver et al. 2017; Slavenko et al. 2021) and plays an important role in enabling the accumulation of high regional species diversity (Dahl et al. 2023).

The two species described here also further highlight the rich frog diversity of the Kikori River basin. The frog fauna of this region has been extensively surveyed over the last 25 years and is now known to comprise at least 110 species. Nearly half of these have been documented since publication of the first field guide to frogs of the region (Richards 2002), emphasising a rapid growth of knowledge in the last quarter of a century as new areas within the catchment have been surveyed. Juxtaposed against this high regional diversity, it is striking that most survey sites in the region support frog assemblages not greatly exceeding 30 species. For example, 22 species were documented at the type locality for L. kikori sp. nov. (Libano Sok), and the highest documented frog diversity at a single “site” in the Kikori region was 31 species in hill forests on the Darai Plateau (Richards and Allison 2003). This alpha diversity is comparable with an area of hill forest on the Wondiwoi Peninsula (at least 35 species at 550 m. a.s.l.: Günther et al. 2023). Within the Kikori basin there appears to be high turnover of species across sites (beta diversity), a pattern that is particularly pronounced across different elevations (Richards et al. 2021). These broad patterns support the hypothesis that high beta diversity across islands, mountains or elevations is the key pattern underpinning the remarkably high species diversity of the Melanesian frog biota (Kraus 2021; Oliver et al. 2022; Dahl et al. 2023). If this pattern is confirmed in the lowlands of the Kikori River basin then it will demonstrate that the low beta diversity of amphibian assemblages across the lowlands of the Sepik River basin (Dahl et al 2009) may not be representative of the entire island of New Guinea.

The two new species described here increase the recognised diversity of torrent-breeding Litoria in New Guinea to 27 species. An additional 30+ species of Nyctimystes are also associated with streams, mostly in mountainous regions. However, species diversity in both groups remains underestimated (Oliver et al. 2022). We consider that documenting these taxa is one the highest priorities for taxonomic research in Melanesian frogs, mainly because ecologically similar Litoria species from Australia are highly vulnerable to the frog pathogen B. dendrobatidis. This pathogen is likely responsible for widespread declines in torrent-breeding pelodryadid species from Queensland’s Wet Tropics (Bower et al. 2017). Documenting the diversity of Melanesia’s torrent-breeding pelodryadids is therefore vital for predicting and understanding the impacts of this pathogen should it colonise the mountains of New Guinea. Fortunately, the two new species described here occur at relatively low elevations, so they may be less at risk than some other torrent-breeding species of Litoria that are restricted to cooler high elevation habitats.

Acknowledgements

The late Jim Robins, and Georgia Kaipu, of the PNG National Research Institute approved SJR’s research visas, and Barbara Roy and the late Barnabas Wilmott (PNG Department of Environment and Conservation, now Conservation and Environment Protection Authority: CEPA) approved the export permits. Field work in Southern Highlands and Gulf Provinces was supported by World Wide Fund for Nature (WWF), Chevron, and ExxonMobil PNG Ltd (EMPNG), and in Western Province was supported by EMPNG. Rose Singadan and Paulus Kei (University of PNG) provided valuable support in Port Moresby. PMO was supported by the Australian Pacific Science Foundation and the Queensland Museum. SJR thanks Max Kuduk and Tanya Leary of WWF for their support of his field studies in the Kikori basin over many years, and we thank the following curators and collection managers for access to specimens in their care: Carolyn Kovach, Mark Hutchinson, Dominic Capone and Sally South (SAMA); Barry Clarke (BMNH); Linda Ford, Jay Savage and Darrel Frost (AMNH); Rainer Günther (ZMB); José Rosado (MCZ), Marinus Hoogmoed and Pim Arntzen (Naturalis), Giuliano Doria (MSNG) and Miguel Vences and Axel Groenveld (ZMA).

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Appendix 1

Specimens examined

Litoria amnicola: MZB Amph.12116 (holotype), MZB Amph.12099–12104, MZB Amph.12106, MZB Amph.12113–12115, 12117, MZB Amph.12099 (paratypes), Weybya Camp, Salawati Island, Raja Ampat Archipelago, West Papua Province, Indonesia.

Litoria arfakiana: MSNG 29723A, Hatam, Arfak Mountains, Papua Province, Indonesia (lectotype).

Litoria brongersmai: MCZ 15203 (holotype) Snow Mountains, Papua, Indonesia; MZB Amph.11824–27, SAMA R61630–32 Wapoga River Headwaters, northern Papua province, Indonesia.

Litoria bulmeri: SAMA R5625 (holotype) Upper Aunjung Valley, Schrader Mtns, Madang Province, PNG.

Litoria dorsivena: SAMA R7902–R7911 (type series) Telefomin area, Sanduan Province, PNG; SAMAR72319–22, Upper Strickland River Region, Hela Province, Papua New Guinea.

Litoria hastula: MZB Amph.32872–4, SAMA R72334–5 (type series) unnamed mountain range, Derewo River Basin, Papua Province, Indonesia.

Litoria fuscula: MZB Amph. 11822 (holotype), SAMA R60724 (paratype) un-named mountain range, Derewo River Basin, Papua Province, Indonesia.

Litoria lakekamu: SAMA R70114–5, Sapoi River adjacent to Ivimka Research Station, Lakekamu Basin, Gulf province, Papua New Guinea.

Litoria macki: MZB Amph.3870 (holotype), MZB Amph.3871–2, QM J75810, SAMA R55363 (all paratypes) Wapoga Alpha Mineral Exploration Camp, Papua, Indonesia; SAMA R55364 Lagoria Landing site 21 9LS-21, Papua, Indonesia.

Litoria micromembrana: SAMA R4150 (holotype) Mount Podamp, PNG; SAMA R61629, SAMA R61637–40, UPNG 10031 Finimterre, Hindenberg Range, Western Province, PNG; SAMA R61599–01, UPNG 10029, UPNG 10032, SAMA R61602 Abalgamut, SAMA R61603 Kikiapa, both localities on the Huon Peninsula, PNG.

Litoria modica: SAMA R8108 (paratype) Oruge, PNG; SAMA R61616–19, UPNG 10030, Mount Akrik, Star Mountains, Western Province, PNG; SAMA R61609–12, UPNG 10035–36, Mount Binnie Summit, Western Province, PNG; SAMA R61604–07, UPNG 10033, Mount Sisa, Southern Highlands Province, PNG; SAMA R61608, UPNG 10030, Mount Stolle, Sanduan Province, PNG.

Litoria napaea: AMNH 49575(paratype) Idenburg River, Snow Mountains, Papua Province, Indonesia; SAMA R61620–28, MZB Amph. 11833–42 Wapoga LS21, Papua Province, Indonesia.

Litoria oenicolen: AMNH 87922(holotype) Baiyer River, Western Highlands Province, PNG.

Litoria pratti: BMNH 1947.2.23.54 (female), 1947.2.23.55, 1947.2.23.56 Wendessi, Papua Province, Indonesia; BMNH 1947.2.23.57, BMNH 1947.2.23.58 (both cotypes) Arfak Mountains, Papua Province, Indonesia.

Litoria rivicola: ZMB 60327, ZMB 60328 (paratypes) 30 km SE of Nabire, Papua Province, Indonesia.

Litoria scabra: MZB Amph. 11335(holotype), MZB Amph. 11336–40, SAMA R60706–60709, ZMB 67357–67359 (paratypes) headwaters of the Wapoga River, Papua Province, Indonesia.

Litoria spartacus: SAMA R60290 (holotype), UP8864–5, SAMA R60291–6 Moro Camp, at base of Iagifu Ridge, Southern Highlands Province, PNG; SAMA R61238 Benaria River, Southern Highlands Province, PNG; SAMA R72335, SJR10468 (unregistered material at SAM), Liddell River, upper Strickland River basin, Western Province, PNG.

Litoria spinifera: SAMA R6295–6301 (paratypes) Oruge, Western Highlands Province, PNG; SAMA R9167, Camp 1, Pio River, PNG; SAMA R9108A–D, Elmagale, Southern Highlands Province, PNG; SAMA R55357–62, UPNG 9963–4 Crater Mountain Wildlife Management area, 55–75 km S of Kundiawa, Eastern Highlands Province, PNG.

Litoria wollastoni: BM 1947.2.23.59 (holotype) Octakwa River, Papua Province, Indonesia.

Appendix 2

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XLSX

Details of ND4 sequences used to calculate genetic distances. ABTC refers to the Australian Biological Tisssues Collection at the South Australian Museum.

Species ABTC # Voucher # Locality Province Country Genbank
Litoria grinpela sp. nov. 101936 SAMA R72339 Liddell River Western Province PNG PP756388
Litoria kikori sp. nov. 98659 SAMA R69990 Hegigo River Southern Highlands PNG PP756389
Litoria kikori sp. nov. 136008 SAMA R72337 Bifo Creek Southern Highlands PNG PP756390
Litoria kikori sp. nov. 136002 SAMA R72336 Bifo Creek Southern Highlands PNG PP756391
Litoria spartacus 98345 SAMA R60294 Moro Southern Highlands PNG MT953612
Litoria spartacus 98336 SAMA R60293 Moro Southern Highlands PNG OQ447410
Litoria spartacus 101913 SAMA R72385 Liddell River Western Province PNG PP756392
Litoria spartacus 101899 NA Liddell River Western Province PNG PP756393
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