Saturday, June 3, 2023

[Herpetology • 2023] Nanohyla albopunctata • A New Species of Nanohyla (Anura: Microhylidae) from the lowland forests of southern Vietnam


Nanohyla albopunctata  Poyarkov, Gorin, & Trofimets,  

in Gorin, Trofimets, Gogoleva, Dac & Poyarkov, 2023.
Song Hinh Pygmy Narrow-mouthed Frog | Nhái bầu đốm trắng  ||  DOI: 10.24272/j.issn.2095-8137.2023.029 
 
We describe a new species of Nanohyla from the Song Hinh Protected Forest in Phu Yen Province, southern Vietnam, based on an integrative taxonomic approach. The new species represents a divergent lineage (16S rRNA gene uncorrected P-distance>5.3%), which clearly differs from any other Nanohyla species based on a series of morphological characters, most notably the presence of white spots on the top of its head. Morphologically, Nanohyla albopunctata sp. nov. is characterized by small body size (male SVL 18.2–20.2 mm); moderately slender body habitus; rounded snout; distinct tympanum; rounded canthus rostralis; loreal region slightly concave; skin on dorsum tubercular, ventral surfaces smooth; mid-vertebral skin ridge and dorsomedial stripe absent; superciliary tubercles absent; supratympanic fold indistinct; finger I reduced, less than half of finger II in length; II–IV fingers bearing discs with weak terminal grooves; two distinct palmar tubercles; two metatarsal tubercles; hindlimbs long, tibiotarsal articulation of adpressed limb reaching well beyond snout; fingers free of webbing; toe webbing formula: I 1–2 II 1–2 III 1–2 IV 1½–1 V; dorsum varying from dark gray to yellowish-gray, with darker "teddy-bear"-shaped brown marking; posterior surfaces of thighs and cloacal region with several brown stripes; chin, chest, and belly with gray mottling. We also report on the male advertisement call of the new species, characterized by a series of rattling sounds, consisting of 2–6 calls lasting 0.63 s, with 1–3 initial pulses and 5–9 successive pulses at a dominant frequency of ca. 3.02 kHz. To date, Nanohyla albopunctata sp. nov. is known only from the monsoon lowland tropical forest at the foothills of the Ca Mountain Range in Phu Yen Province of southern Vietnam at elevations of 200–400 m a.s.l., uncommon for the generally mountain-restricted Nanohyla genus. Our discovery brings the total number of Nanohyla species to 10, seven of which occur in Vietnam. We preliminary suggest the new species be considered as Data Deficient (DD) following the IUCN Red List categories.

Phylogenetic relationships, acoustics and external morphology of Nanohyla albopunctata sp. nov.
A: Type locality of Nanohyla albopunctata sp. nov. in Song Hinh Protected Forest, Phu Yen Province, Vietnam.
B: Holotype of Nanohyla albopunctata sp. nov. (ZMMU A-7585) in dorsal view. C: Holotype of Nanohyla albopunctata sp. nov. (A-7585) in ventral view.
E: Holotype of Nanohyla albopunctata sp. nov. (A-7585) in life.
F: Sonogram of a male advertisement call of Nanohyla albopunctata sp. nov. 
G: Phylogenetic relationships of Nanohyla based on concatenated 12S−16S rRNA and BDNF gene sequences. For a full version of a tree see Supplementary Figure S3. Values at the nodes correspond to BIPP/UFB support values, respectively; filled circles represent strongly supported nodes with BPP and UFB support >0.95 and 95%, respectively; nodes lacking circles are not supported. For specimen and sequence data see Supplementary Table S1. Photos by N. A. Poyarkov.


Nanohyla albopunctata Poyarkov, Gorin, & Trofimets sp. nov.
Song Hinh pygmy narrow-mouthed frog (English); 
Nhái bầu đốm trắng (Vietnamese) 

Diagnosis: Nanohyla albopunctata sp. nov. is characterized by a combination of the following characters: small body size (male SVL 18.2–20.2 mm); body moderately slender; snout rounded in lateral view; tympanum distinct; canthus rostralis rounded, distinct; loreal region slightly concave; nares round, oriented anterolaterally; distinct white spots on top of head; skin on dorsum tubercular, ventral surfaces smooth; dorsolateral row of glandular tubercles; mid-vertebral skin ridge and dorsomedial stripe absent; superciliary tubercles absent; supratympanic fold indistinct; finger I small, less than half of finger II in length; II–IV fingers bearing discs with weak terminal grooves; all toes bearing prominent discs with dorso-terminal grooves; two distinct palmar tubercles (inner palmar tubercle ovoid, outer palmar tubercle rounded); two metatarsal tubercles (inner elongated, prominent; outer rounded, protruding); hindlimbs long, tibiotarsal articulation of adpressed limb reaching well beyond snout; fingers free of webbing, dorsolaterally flattened; toe webbing well-developed, webbing formula: I 1–2 II 1–2 III 1–2 IV 1½–1 V; dorsum varying from dark gray to yellowish-gray, with darker “teddy-bear”-shaped brown marking; posterior surfaces of thighs and cloacal region with several brown stripes; chin, chest, and belly with gray mottling.

Etymology: The specific name ‘albopunctata’ is a Latin adjective in the nominative singular, meaning ‘white-spotted’. The name is given in reference to the distinctive white spots found on the top of the head of the new species.


Vladislav A. Gorin, Alexey V. Trofimets, Svetlana S. Gogoleva, Le Xuan Dac and Nikolay A. Poyarkov. 2023. A New Species of Nanohyla (Anura: Microhylidae) from the lowland forests of southern Vietnam. Zoological Research. DOI: 10.24272/j.issn.2095-8137.2023.029