A new species of large green treefrog (Anura: Hylidae: Litoria) from northern New Guinea

Transcription

1 Zootaxa : (2006) Copyright 2006 Magnolia Press ISSN (print edition) ZOOTAXA ISSN (online edition) A new species of large green treefrog (Anura: Hylidae: Litoria) from northern New Guinea STEPHEN J. RICHARDS 1, PAUL OLIVER 1*, CHRIS DAHL 2 & BURHAN TJATURADI 3 1 Vertebrates Department, South Australian Museum, North Terrace, Adelaide, S.A. 5000, Australia. 2 Conservation International, C/O Wildlife Conservation Society, P.O. Box 277, Goroka, Eastern Highlands Province, Papua New Guinea. 3 Conservation International Papua Program, Jl. Bhayangkara, 1 # 5, Jayapura 99610, Papua Province, Indonesia. *Corresponding author, Paul.Oliver@student.adelaide.edu.au Abstract A new species of large green frog of the hylid genus Litoria is described from northern New Guinea. The new species is superficially similar to Litoria graminea and L. infrafrenata. It can be distinguished from L. graminea by the possession of a poorly defined white labial stripe that does not extend beyond the ear, and from L. infrafrenata by the combination of comparatively small adult size (males mm), fully webbed fingers and a call that is a long ( s) deep guttural growl. It is known from lowland forests around the village of Utai in north-western Papua New Guinea. Key words: Ampibia, Hylidae, Litoria, new species, New Guinea Introduction The frog fauna of New Guinea is among the most diverse and poorly known in the world. More than 280 taxa have been described from the region (Frost 2004) but numerous undescribed taxa are known and the total fauna may exceed 600 species (Günther 2006). Many recently discovered taxa are distinctive and easy to distinguish from described forms (Kraus & Allison 2004, Richards 2005). Large green treefrogs of the genus Litoria are a conspicuous component of the Melanesian frog fauna. Four species, Litoria caerulea (White, 1790), L. graminea (Boulenger, 1905), L. infrafrenata (Günther, 1867) and L. sanguinolenta (Van Kampen, 1909), are currently recognised. Litoria caerulea is a robust frog (Cogger 2000) with an Accepted by S. Carranza: 10 Apr. 2006; published: 22 May

2 ZOOTAXA unusual distribution. In Melanesia it is known from scattered and apparently isolated localities across northern and southern mainland New Guinea (Tyler 1968). Litoria sanguinolenta is a poorly known species that is only known from a small number of old specimens from the Lorentz River area in southern New Guinea. A recent report of this species from De la Riva et al. (2004) was unsupported by voucher material and the distribution of this species remains poorly documented. The two remaining species, L. graminea and L. infrafrenata, have been reported from numerous localities on mainland New Guinea (e.g. Tyler 1968, Richards 2002). Recent surveys by three of the authors (CD, SJR, BT) in northern New Guinea revealed an undescribed large green Litoria that is most similar to L. graminea and L. infrafrenata. It can be readily distinguished from these taxa by a combination of morphological and acoustic features, and is herein described as new. Material and methods Measurements (to the nearest 0.1mm) were taken with dial calipers and a stereomicroscope fitted with an ocular micrometer. They are: SVL (snout-vent length), TL (tibia length), HW (head width at tympanum), HL (head length from tip of snout to posterior edge of tympanum), EYE (horizontal eye diameter), TYM (horizontal tympanum diameter), IN (inter-narial distance), EN (distance between anterior edge of eye and posterior edge of naris), 3FD (transverse diameter of 3 rd finger disc) & 3FP (narrowest horizontal width of penultimate phalanx), 4TD (transverse diameter of 4 th toe disc) and 4TP (penultimate phalanx, as for 3 rd finger). Advertisement calls were recorded with a Sony TCM-5000 tape recorder and Sennheiser ME66 microphone, and 23 calls from one male were analyzed using the AVISOFT SAS-Lab Pro sound analysis program. Air temperature adjacent to the calling frog was measured with a digital thermometer. Newly reported specimens are deposited in the South Australian Museum (SAMA) and the Natural Sciences Resource Centre of the University of Papua New Guinea (UP). Systematics of Litoria infrafrenata Litoria infrafrenata is a large green frog that is superficially similar to our new species and has a complicated taxonomic history. The new species is substantially smaller than L. infrafrenata but exhibits a rather poorly defined off white labial stripe, suggesting there is some potential for confusion with juvenile L. infrafrenata. Based on published descriptions or examination of specimens, all names synonymised with L. infrafrenata represent animals clearly assignable to that taxon and easily distinguished from the new species by a number of morphological characters. The types of Litoria dolichopsis (Cope, 1867), L. dolichopsis var. tenuigranulata (Boettger, 1895) and Magnolia Press RICHARDS ET AL.

3 L. spengeli (Boulenger, 1912) are a minimum of 90 mm SV and often longer, substantially larger than the species described herein; furthermore the type of L. dolichopsis and one other synonym of Litoria infrafrenata (L. guttata (Macleay, 1878)), have partially-webbed (vs fully webbed) hands and a prominent off white labial stripe (Macleay 1878, Boettger 1895, Fry 1913, Loveridge 1948, Copland 1957). The males in the type series of Litoria dolichopsis var. pollicaris (Werner, 1898) have a very hard and protruding pollex rudiment, absent in the new species (Werner 1898). In addition this taxon is from New Britain where survey work has found no evidence of any Litoria similar to the new species (Richards pers. obs.). The name Litoria dolichopsis var. calcarifera (Vogt, 1912) was apparently applied erroneously to specimens from the type series of L. d. pollicaris, therefore it is regarded as a lapsus (Zweifel 1960, Günther pers. com. ); in addition, as mentioned above, the specimens involved clearly represent L. infrafrenata. Finally Tyler (1968) and Günther (pers. comm.) have both examined the types of Litoria trinilensis (Ahl, 1929) and found them to possess reduced webbing between the fingers, like Litoria infrafrenata and unlike L. graminea or the new species from Utai. ZOOTAXA Litoria hunti sp. nov. (Figs 1 4) Type material Holotype. SAMA R Adult male with nuptial pads and vocal slits, calling when collected, Utai, Sanduan Province (141 35'E, 03 23'S), collected by Chris Dahl on 28/05/ Paratypes. UPNG 10012, collected on 7/06/04; SAMA R60715, collected on 9/06/04; UPNG and SAMA R60714, collected on 11/06/04; all adult male specimens with vocal slits and nuptial pads, collected by Chris Dahl from the type locality. Diagnosis Litoria hunti can be distinguished from all other Litoria by a combination of (1) moderately large size (males mm) (2) predominately green dorsal colouration (3) presence of a thin off white mandibular stripe not or marginally extending beyond the tympanum (4) possession of two clusters of nuptial excrescences on each thumb (5) presence of prominent off white dermal fold extending from outer edge of toe V, along the tarsus and across the heel (6) prominent off white dermal fold along arm (7) moderately robust build (HW/SVL ) (8) moderately wide discs, especially on fingers (3FP/3FD ) (9) iris without black pigmentation and (10) advertisement call a long guttural grunt lasting s Description of holotype Measurements are presented in Table. 1. Moderately robust frog; head approximately A NEW LITORIA 2006 Magnolia Press 59

4 ZOOTAXA as wide as long (HW/HL 1.017), wider than body in dorsal view; snout truncate in both dorsal and lateral aspect; labial region sloping and flared; loreal region moderately sloping and marginally concave; canthus rostralis indistinct, curved; nares much closer to tip of snout than to eyes, oriented laterally but marginally visible in both dorsal and anterior views. Choanae large, roughly circular, separated by a distance approximately three times their width; vomerine teeth in bundles of 6 7 along the posterior ridge of two prominent elevations positioned medial to choanae. Eyes moderately small (EYE/SVL 0.110), protruding beyond head in both dorsal and lateral views, pupil horizontal. Tympanum moderately large (EAR/SVL 0.087), annulus distinct and raised, dorsal edge of tympanum obscured by supratympanic fold that extends from posterior edge of eye to axillary junction. In preservative body and legs smooth dorsally (slightly granular in life); ventrally throat, forelimbs and lower hindlimbs smooth, abdomen and upper portions of hindlimbs coarsely granular. Arms robust; prominent off white dermal fold extending from halfway along finger IV, along carpus and around elbow; fingers with relative lengths III>IV>II>I; discs prominent with supramarginal grooves, significantly wider than penultimate phalanx (3FP/3FD 0.730); subarticular tubercles rounded, two on digits I and II, three (with medial tubercle distinctly larger than distal and proximal tubercles) on digits III and IV; supernumerary tubercles low, indistinct, present on most proximal phalanx of II IV; single large low inner metacarpal tubercle. Nuptial excrescences in two clusters at the base of digit I, proximal cluster much longer than wide, distal cluster shorter and roughly as wide as long. All digits webbed, webbing reaching proximal subarticular tubercle between digits I II, to distal end of penultimate phalanx on II and IV, and just beyond tubercle at base of penultimate phalanx on both sides of III; slight dermal fringes on all digits. Legs moderately long (TL/SVL= 0.563); prominent off white dermal fold extending along tarsus from lateral edge of toe V across heel. Relative lengths of toes IV>III>V>II>I; discs expanded with circum-marginal grooves, significantly wider than penultimate phalanges (4TP/4TD 0.806); subarticular tubercles rounded, two on digits I and II, three on digits III and V, four on digit IV; numerous small indistinct round supranumerary tubercles visible on proximal phalanges of digits III V; prominent ovoid inner metatarsal tubercle at base of digit I. All digits webbed, webbing extends to distal end of penultimate phalanx on inner edge of digit V, both sides of digit IV and outer edges of digits III, II and I, and to approximately halfway up penultimate phalanx on inner edge of digits III and II. In preservative the dorsal surfaces of head, body, arms and thighs are pale greyish blue, with poorly defined patches of slightly darker blue on the head, dorsum and legs along one side of the body. Numerous tiny pigment spots are visible on dorsum under magnification; ventral surfaces largely off white, with bluish areas of varying intensity along the outer edge of the tarsus, toe V, on the arms just behind the elbow, and around the discs on both hands and feet Magnolia Press RICHARDS ET AL.

5 TABLE 1. Measurements (mm) and key ratios for type series of five male Litoria hunti. SAMA R60716 SAMA R60715 SAMA R60714 UPNG UPNG SVL EN EN/SVL HW HW/SVL EYE EYE/SVL TL TL/SVL IN IN/EN HL HW/HL EAR EAR/SVL TD TP TP/4TD TD/SVL FD FP FP/3FD FD/SVL ZOOTAXA Variation Measurements for the type series are presented in Table 1. The dorsal colour in preservative of the paratypes is the same as the holotype, with the exception of SAMA R60715 which is a significantly darker greyish blue. In two animals (SAMA R60714 and UPNG 10013) there is a line of brown pigment along the ventral edge of the lower jaw. The extent and intensity of the off white labial stripe varies, in some specimens it is very indistinct and does not extend beyond the edge of the jaw, while in others (including the holotype) it is more prominent and extends posteriorly to a distance approximately halfway across the tympanum. The dorsal surface of finger III and toe IV ranges from almost unpigmented to more than one half blue. In all animals the nuptial excrescences comprise two components, a long low posterior cluster and a rounded anterior cluster, A NEW LITORIA 2006 Magnolia Press 61

6 ZOOTAXA however they sometimes merge, and both overall size and relative darkness varies; some of this variation is probably attributable to variation in reproductive condition. FIGURE 1. Lateral view of head of holotype of Litoria hunti (SAMA R60716). Scale bar = 10mm. Appearance in life Based on photographs of a living specimen Litoria hunti has a relatively uniform pattern consisting of a leaf green dorsum and upper lateral zone, grading into orange-ish yellow lower lateral and ventral surfaces. In areas of integration between the two dominant colours, particularly on the mid-lateral surfaces there are a number of isolated green spots. The outer sides of the lower arms and all of the legs also leaf green. Dorsal surfaces of inner digits of both hands and feet are bright orange. Off-white labial, leg and arm stripes are clearly apparent. The eye has a distinctive orange-red outer rim, around an inner off white area that surrounds the pupil. The tympanum is largely green, except for a horseshoe shaped area of translucent skin. Advertisement call Twenty-three calls uttered by the holotype were analysed. The call is a single guttural grunt lasting s (mean 0.78 s, SD 0.05) and containing pulses (mean 131.5, SD 16.22). Pulse pattern is unusual in that pulses are `clumped' in groups, most commonly of 3 4 pulses, rather than being uniformly distributed within the call (Figure 4). Energy is concentrated nearly equally in two major bands, at about 1900 hz and 900 hz. In 19 of 23 calls the dominant frequency is at hz (mean 1926 hz, SD 70.8) but in four calls the lower frequency ( hz) is dominant (mean 899.5, SD 12.26) Magnolia Press RICHARDS ET AL.

7 Natural history Litoria hunti is an arboreal species that was normally heard calling from at least 5 8 m high in forest trees. The holotype was calling from just 1.5 m high in a swamp near Utai Village. This suggests that L. hunti breeds in lentic water bodies on or near the forest floor. The tok ples (local) name for this species is Wowo. ZOOTAXA FIGURE 2. Palmar (A) and Plantar (B) views of holotype of Litoria hunti (SAMA R60716). Scale bar = 10mm. FIGURE 3. Male holotype (SAMA R60716) of Litoria hunti in life. Photograph by C. Dahl. A NEW LITORIA 2006 Magnolia Press 63

8 ZOOTAXA FIGURE 4. Wave form of a single call of Litoria hunti (holotype, SAMA R60716). Ta 26 o C. FIGURE 5. Type locality of Litoria hunti in northern Papua New Guinea. Distribution Litoria hunti has been collected from the forests around Utai in Sandaun Province, Papua New Guinea. Two further specimens of a large green Litoria collected in the foothills of the Foya Mountains, Papua Province, Indonesia conform with this species in overall size, possession of a thin off white labial stripe, largely red iris and distinctive orange-yellow belly. Until these specimens are available for more detailed study we refrain from assigning them to L. hunti. Nonetheless it is likely that this new species has a broad distribution in the extensive lowland rainforests of northern New Guinea. Etymology Named in honour of the Hunt family of Adelaide in recognition of their generous support for research at the South Australian Museum Magnolia Press RICHARDS ET AL.

9 Comparison with other species The combination of large size and predominately green colouration make Litoria hunti superficially most similar to the New Guinea species Litoria infrafrenata and L. graminea. Litoria infrafrenata can be differentiated by its much larger adult size, less extensive webbing on fingers (generally not extending beyond the penultimate subarticular tubercle), much bolder labial stripe that extends beyond the posterior edge of the tympanum, and different call. The call of L. infrafrenata is a long series of double-notes (De la Riva et al. 2004). Litoria graminea as it is currently recognised is a complex of at least three morphologically and acoustically similar species (Richards & Oliver in prep). Litoria hunti can be distinguished from all members of the Litoria graminea group by having an off white white labial stripe, only moderately expanded discs (4FD/SVL vs in L. graminea group), smaller adult size (males vs mm) and a call consisting of a long guttural grunt lasting s (vs < 0.5 s in L. graminea group). There are a number of other medium to large, predominately green Litoria species in the Australopapuan region. Litoria caerulea is larger (to mm; Tyler 1968), has a much broader head, prominent parotoid glands and lacks an off white labial stripe. Litoria multiplica has prominent, raised white dermal folds around the vent, a hidden tympanum, tends to have black ventral patterning, and is smaller (males mm) (Tyler 1968, pers obs). Members of the Litoria gracilenta group (Litoria aruensis, Litoria auae, Litoria elkeae, Litoria gracilenta and Litoria kumae) have a distinct canthal stripe running across the eyelid, lack dermal folds and white labial or leg stripes and are considerably smaller (males mm SV; Tyler 1968, Menzies & Tyler 2004). Litoria sanguinolenta has halfwebbed hands, a flatter head and is also slightly smaller (males to 40 mm; Tyler 1968). The two Australian taxa Litoria chloris (Boulenger) and L. xanthomera Davies, McDonald & Adams are superficially similar but both lack an off white labial stripe and no or very indistinct off white dermal folds on the arms and legs. These two species have long, drawn-out finely pulsed calls with evenly spaced pulses, in contrast to the guttural grunt of L. hunti (Davies, McDonald & Adams 1986). ZOOTAXA Acknowledgements Chris Dahl is most grateful to the people of Utai for their generous hospitality, and to the New Guinea Binatang Research Centre for logistical support. Conservation International and The Wildlife Conservation Society provided support to CD without which this project would have been impossible. Rose Singadan and Paulus Kei (University of PNG) provided support in Port Moresby and Barbara Roy of the PNG Department of Environment and Conservation (DEC) approved the export permit. For approval of our work in Sandaun Province we are most grateful to DEC and the Sandaun Provincial Government. Jim Robins of the National Research Institute has always been most helpful with SJR s A NEW LITORIA 2006 Magnolia Press 65

10 ZOOTAXA research visas. Funding for laboratory equipment was provided in part by the Mark Mitchell Research Foundation, and additional support was provided by the Violet Scott Estate and the South Australian Museum Board. The curators of the following museums kindly provided access to specimens in their care; Barry Clarke (Natural History Museum, London), Marinus Hoogmoed and Pim Arntzen (RMNH), and Giuliano Doria (MSNG). Mark Hutchinson and Carolyn Secombe provided assistance at the South Australian Museum and Maya Penck kindly translated German taxonomic literature for this paper. This project was supported by a significant and generous donation from the Hunt family of Adelaide and a grant from Conservation International, to both of whom we owe a particular debt of gratitude. References Boettger, O. (1895) Liste der Reptilien und Batrachier der Insel Halmaheira nach den Sammlungen Prof. Dr. W. Kükenthals s. Zoologischer Anzeiger, 472, Cogger, H.G. (2000) Amphibians and Reptiles of Australia. Reed. Sydney. Copland, S.J. (1957) Australian treefrogs of the genus Hyla. Proceedings of the Linnean Society of New South Wales, 82, Davies, M., McDonald, K.R. & Adams, M. (1986) A new species of green tree frog (Anura: Hylidae) from Queensland, Australia. Proceedings of the Royal Society of Victoria, 98, De la Riva, I., Bosch, J. & Marquez, R. (2004) The advertisement calls of two New Guinean species of Litoria (Amphibia, Anura, Hylidae). Amphibia-Reptilia, 25, Frost, D. (2004) Amphibian Species of the World: an Online Reference. Version 3.0 (22 August, 2004). Available from: Fry, D.B. (1913) A re-examination of Macleay s New Guinea and Queensland frog types. Memoirs of the Queensland Museum, 2, Günther, R. (2006) Derived reproductive modes in New Guinean anuran amphibians and description of a new species with paternal care in the genus Callulops (Microhylidae). Journal of Zoology, 268, Kraus, F. & Allison, A. (2004) A new species of Litoria (Anura: Hylidae) from southeastern New Guinea. Herpetologica, 60, Loveridge, A. (1948) New Guinea Reptiles and Amphibians in the Museum of Comparitive Zoology and the United States National Museum. Bulletin of the Museum of Comparative Zoology, 101, Macleay W (1878) The Batrachians of the Chevert expedition. The Proceedings of the Linnean Society of New South Wales, 2, Menzies, J.I. & Tyler, M.J. (2004) Litoria gracilenta and related species in New Guinea. Australian Journal of Zoology, 52, Richards, S.J. (2002): Rokrok: An illustrated field guide to frogs of the Kikori Integrated Conservation and Development Project area of Papua New Guinea. WWF. Port Moresby. Richards, S.J. (2005) A new species of treefrog (Anura: Hylidae: Litoria) from the Huon Peninsula, Papua New Guinea. Zootaxa, 1052, Tyler, M.J. (1968) Papuan Hylid Frogs of the genus Hyla. Zoologische Verhandelingen, 96, Werner, F. (1898) Vorläufige Mittheilung über die von Herrn Prof. F. Dahl im Bismarck-archipel gesammelten Reptilien und Batrachier. Zoologischer Anzeiger, 21, Zweifel, R.G. (1960) Results of the Archbold Expedition 3. Notes on the frogs of New Britain. American Museum Novitates, 2023, Magnolia Press RICHARDS ET AL.

11 Specimens examined Litoria auae Menzies & Tyler, Papua New Guinea. Purari River, Gulf Province: Holotype UP2490; Daru Island, Western Province: Paratypes SAMA R Litoria caerulea (White, 1790). Papua New Guinea. Balamuk, Bensbach River, Western Province: SAMA R13140; Weam, Bensbach River, Western Province: SAMA R13255A-B; Kuru, Western Province: SAMA R13256A-B, SAMA R13258A-F; Mabaduan, Western Province: SAMA R13257; Moitaka, Port Moresby, Central Province: R Litoria chloris (Boulenger, 1893). Australia. Warrie National Park, Springbrook, Queensland: SAMA R ; Eungella National Park, Queensland: SAMA R Litoria elkeae Günther & Richards, Indonesia, Siewa, 100 km N.E. Nabire, Papua Province: Paratypes QMJ , MZB 3866, Litoria graminea (Boulenger, 1905). Papua New Guinea. Yuwong Village, Morobe Province, Huon Peninsula: SAMA R , UPNG 10014; Dark end Lumber, Gulf Province SAMA R57868, UP 10015; Lakekamu, Gulf Province: SAMA R55521; Darai Plateau, Southern Highlands Province: SAMA R60727; `Northern British New Guinea': Holotype BM Litoria infrafrenata infrafrenata (Günther,1867). Papua New Guinea. Lorengau, Manus Province: SAMA R5648A-D, R5801, R5999A-C; Aitape, Sanduan Province: SAMA R , R ; Lega, Oro Province: SAMA R4398A-C; Lake Kutubu, Southern Highlands Province: SAMA R8766; Balimo, Western Province: SAMA R10306A-B; Kiunga, Western Province: SAMA R10307A-B; Glabi, Western Province: SAMA R11404A-B; Tengkim, Western Province: SAMA R11416; Madang: SAMA R , R8774; Epo: SAMA R4713; Tanah Merah, upper Digoel, Western Province SAMA R4901, R4903; Kiunga, Western Province: SAMA R10244; E meti, Bamu River, Western Province: SAMA R13238A-B; Daru, Western Province: SAMA R10245; Maka, Lake Murray, Western Province: SAMA 10255; Mabaduan, Western Province: SAMA R13239; Balamuk, Bensbach River, Western Province: SAMA R13141; Boze, Western Province: SAMA R10246; Koaru Village, Gulf Province: SAMA R8810A-B; Uraru, Purari River, Gulf Province: SAMA 9292;Sogeri, Central Province: SAMA R9116; Moitaka Plantation, National Capital District: SAMA R9109; Waigani Swamps, National Capital Distirict: SAMA R9121A-B; Dinawa, Owen Stanley Range: BM , (Holotype of Litoria spengeli). Indonesia. Ajamaroe, Vogelkop Peninsula, Papua Province: SAMA R5487. Litoria kumae Menzies & Tyler, Papua New Guinea. Tari, Southern Highlands Province: Holotype UP3108 Paratypes SAMA R Litoria multiplica (Tyler, 1968). Papua New Guinea. Kassam Krakte Mountains, Eastern Highlands Province: SAMA R4946 Paratype; Amulua, Jimi Valley, SAMA R8923; Hindenburg Ranges: SAMA R11150; Bomai, Chimbu Province: SAMA R6303, R11833; Ialibu, Southern Highlands Province: SAMA R11834; Oferkaman: SAMA R5277, R11835; Dege, Western Highlands Province: SAMA R6169, R11832; Telefomin, Western Highlands Province: SAMA R R ; Magidobo, Southern Highlands Province: SAMA R Litoria sanguinolenta (Van Kampen, 1909). Indonesia. Lorentz River, Papua Province: SAMA R6318. ZOOTAXA A NEW LITORIA 2006 Magnolia Press 67

12 ZOOTAXA Litoria xanthomera Davies, McDonald & Adams, Australia. Nr Wallamin Falls, Lannercost State Forest, Queensland: Paratypes SAMA R Magnolia Press RICHARDS ET AL.