Thursday, May 3, 2018

[Herpetology • 2018] Theloderma auratum • A New Species of the Genus Theloderma Tschudi, 1838 (Anura: Rhacophoridae) from Tay Nguyen Plateau, central Vietnam


Theloderma auratum 
Poyarkov, Kropachev, Gogoleva & Orlov, 2018


ABSTRACT 

A new species of small tree frog from a primary montane tropical forest of central Vietnam, Tay Nguyen Plateau, is described based on morphological, molecular, and acoustic evidence. The Golden Bug-Eyed Frog, Theloderma auratum sp. nov., is distinguishable from its congeners and other small rhacophorid species based on a combination of the following morphological attributes: (1) bony ridges on head absent; (2) smooth skin completely lacking calcified warts or asperities; (3) pointed elongated tapering snout; (4) vocal opening in males absent; (5) vomerine teeth absent; (6) males of small body size (SVL 21.8–26.4 mm); (7) head longer than wide; ED/SVL ratio 13%–15%; ESL/SVL ratio 16%–20%; (8) small tympanum (TD/EL ratio 50%–60%) with few tiny tubercles; (9) supratympanic fold absent; (10) ventral surfaces completely smooth; (11) webbing between fingers absent; (12) outer and inner metacarpal tubercles present, supernumerary metacarpal tubercle single, medial, oval in shape; (13) toes half-webbed: I 2–2¼ II 1½–2¾ III 2–3¼ IV 3–1½ V; (14) inner metatarsal tubercle present, oval; outer metatarsal tubercle absent; (15) iris bicolored; (16) dorsal surfaces golden-yellow with sparse golden-orange speckling or reticulations and few small dark-brown spots; (17) lateral sides of head and body with wide dark reddish-brown to black lateral stripes, clearly separated from lighter dorsal coloration by straight contrasting edge; (18) ventral surfaces of body, throat, and chest greyish-blue with indistinct brown confluent blotches; (19) upper eyelids with few (3–5) very small flat reddish superciliary tubercles; (20) limbs dorsally reddish-brown, ventrally brown with small bluish-white speckles. The new species is also distinct from all congeners in 12S rRNA to 16S rRNA mitochondrial DNA fragment sequences (uncorrected genetic distance P>8.9%). Advertisement call and tadpole morphology of the new species are described. Our molecular data showed Theloderma auratum sp. nov. to be a sister species of Th. palliatum from Langbian Plateau in southern Vietnam. 

Keywords: Theloderma auratum sp. nov.; mtDNA phylogeny; 12S rRNA; 16S rRNA; Kon Tum; Gia Lai; Endemism; Taxonomy

 Figure 4 Dorsolateral view of male holotype of Theloderma auratum sp. nov. (ZMMU A-5828) in life (in situ
Photo by Nikolay A. Poyarkov

Theloderma auratum sp. nov.

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Etymology: The specific name “auratum” is a Latin adjective in the nominative singular (neutral gender), derived from Latin “aurum” for “gold”, referring to the golden-yellowish dorsal coloration of the new species.

Recommended vernacular name: We recommend the following common name in English: Golden Bug-Eyed Frog. Recommended vernacular name in Vietnamese: ´Êch Cây Sân Vàng.

Distribution and biogeography: The known distributions of Theloderma auratum sp. nov. and its sister species Th. palliatum are shown in Figure 1. To date, the new species is known from montane evergreen tropical forests of Tay Nguyen Plateau in the central Annamite (Truong Son) Mountains, and has been recorded in Gia Lai, Kon Tum, and Thua Thien-Hue provinces. It is anticipated that Theloderma auratum sp. nov. also occurs in the adjacent montane forests of Tay Nguyen Plateau; in particular, records from Quang Nam Province of Vietnam and Xekong Province of Laos are anticipated. 

Natural history notes: Our knowledge on the biology of Theloderma auratum sp. nov. is scarce. The new species was recorded in primary polydominant tropical montane evergreen forests of Tay Nguyen Plateau at elevations ranging from 800 to 1 400 m a.s.l.. Animals were recorded only in patches of primary undisturbed forest with complete multi-layered canopy and heavy undergrowth, suggesting the new species is a strict forest-dwelling specialist. At the type locality in Kon Chu Rang Nature Reserve (Gia Lai Province), the forest where the new species was recorded is dominated by large trees of the families Podocarpaceae (Dacrydium elatum, Dacrycarpus imbricatus), Magnoliaceae, Burseraceae (Canarium sp.), Myrtaceae (Syzygium sp.), Hamamelidaceae (Simingtonia sp.), Lauraceae (Litsia sp.), Rhodoliaceae (Rhodolia sp.), Fagaceae, Sterculiaceae (Scaphium sp.) (Figure 10). ....


Nikolay A. Poyarkov, Jr., Ivan I. Kropachev, Svetlana S. Gogoleva and Nikolai L. Orlov. 2018. A New Species of the Genus Theloderma Tschudi, 1838 (Amphibia: Anura: Rhacophoridae) from Tay Nguyen Plateau, central Vietnam. Zoological Research. 39(3); 156-180.   DOI: 10.24272/j.issn.2095-8137.2018.018