Thursday, February 11, 2021

[Herpetology • 2020] Buergeria choui • A New Species of Buergeria (Amphibia: Rhacophoridae) from the Southern Ryukyus and Northwestern Taiwan

Buergeria choui 
Matsui & Tominaga, 2020

Buergeria japonica, long thought to be a single species widely occurring on the Ryukyu Archipelago and Taiwan, proved to include three genetically differentiated clades, (1) the Northern and Central Ryukyu, (2) the Southern Ryukyu and Northern Taiwan, and (3) the Southern Taiwan clades. The Southern Taiwan clade has already been split from the others as a distinct species. A distinct heterospecific relationship of the Southern Ryukyu and Northern Taiwan clade from the Northern and Central Ryukyu clade was also clear from genetic evidence. Morphological comparison between specimens from the Yaeyama (the Southern Ryukyu and Northern Taiwan clade) and Amamioshima, the type locality of B. japonica (the Northern and Central Ryukyu clade), confirmed genetic differences and corroborate their independent species status. Thus, we describe the Northern Taiwan and Southern Ryukyu clade as Buergeria choui sp. nov.

KEYWORDS: Buergeria choui sp. nov., mitochondrial DNA phylogeny, morphometry, Northern Taiwan, Southern Ryukyu

Dorsal (A) and ventral (B) views of male holotype of Buergeria choui sp. nov. (RUMF-ZH-01032). Scale bar = 5 mm.

Buergeria choui sp. nov.
[Japanese name: Yaeyama-Kajika-Gaeru]
[English name: Yaeyama Kajika Frog]
Polypedates japonicus: Van Denburgh, 1912, p. 205 (part); Okada, 1930, p. 192 (part); Okada, 1931, p. 207 (part); Okada, 1966, 178 (part).
Rhacophorus japonicus Inger, 1947, p. 346 (part); Nakamura and Uéno, 1963, p. 67 (part).
Buergeria japonica: Utsunomiya, 1979, p. 168 (part).
Buergeria japonica Northern Taiwan +Southern Ryukyu (NT/SR) clade: Tominaga et al., 2015, p. 240.
Buergeria japonica Japanese clade: Wang et al., 2017, p. 7.

Diagnosis: The new species is placed in Buergeriinae Channing, 1989, with distal end of the third metacarpal scarcely flattened, lacking a bony knob. It is assigned to a member of the genus Buergeria by having small body, becoming slender posteriorly; dorsum yellow to gray brown, never changing to green; pupil horizontally ellipsoid; tympanum evident; vomerine teeth degenerated; webs well developed among toes, but absent among fingers; digital disks with circummarginal grooves; tips of distal digits T-shaped, not forked clearly; skin scattered with irregular tubercles without dorsolateral fold, but with supratympanic fold; ventral surface covered with rough circular tubercles; and a single vocal sac in males. Buergeria choui sp. nov. is very similar to B. japonica but is differentiated by morphometric characteristics and number and arrangements of dark spots on lower lips. It also is similar to B. sp. ST but differs in morphometric characteristics and markings on the thighs. Also, B. choui sp. nov., as well as B. japonica, lacks a long call unique to B. sp. ST. See Comparisons below for further details.

Etymology: The specific name is dedicated to Dr. Wen-Hao Chou, Professor of the National Museum of Natural Science, Taichung, Taiwan, who first paid attention to the variation and taxonomy of B. japonica (sensu lato) at the beginning of 1990s.

Masafumi Matsui and Atsushi Tominaga. 2020. A New Species of Buergeria from the Southern Ryukyus and Northwestern Taiwan (Amphibia: Rhacophoridae). Current Herpetology. 39(2); 160-172. DOI: 10.5358/hsj.39.160