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| Nidirana shyhhuangi C.-F. Lin, Chang, Matsui, Shen, Tominaga & S.-M. Lin, 2025 |
Abstract
Nidirana okinavana (Boettger, 1895) is a small-sized ranid species belonging to the East Asian genus Nidirana Dubois, 1992. Previous studies have indicated that this species was exclusively distributed on Ishigaki and Iriomote islands in the southern Ryukyus, as well as two extremely small wetland habitats in central Taiwan. Such a restricted distribution makes it one of the most endangered frog species in both Taiwan and Japan. By using molecular, morphological, and acoustic analyses, our study reveals significant divergence between the Taiwanese and Japanese clades, supporting the recognition of the Taiwanese clade as a distinct species, described herein as Nidirana shyhhuangi sp. nov. Compared to Nidirana okinavana sensu stricto from the southern Ryukyus, the Nidirana shyhhuangi sp. nov. is characterized by a significantly smaller and non-overlapping body size, relatively longer forelimbs and hindlimbs, smaller internostril and interorbital distances, with a higher number of cross bands on thigh and shank. Acoustic analyses reveal that the Nidirana shyhhuangi sp. nov. produces calls with a rapid tempo and higher pulse number, with a higher dominant frequency compared to the Japanese clade. Due to the extremely limited distribution of this species to two small sites on Taiwan, and continuing decline in quality of its habitat, we propose that it should be classified as Critically Endangered (CR) under the IUCN criteria. Immediate and comprehensive in situ and ex situ conservation actions are necessary to ensure the sustainable viability of the population.
Key words: Acoustic analysis, Iriomote Island, Ishigaki Island, morphology, Nidirana okinavana
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| Nidirana shyhhuangi sp. nov. in life A an adult male with a pale yellowish-brown glandular ridge behind the base of the forelimb, which is diagnostic of the sexes B an adult female, with a more grayish coloration C a first-year juvenile, with a reddish lower iris color D a male calling in the nest showing its subgular vocal sac. Photographed by Chun-Fu Lin (A–C) and Chunwen Chang (D). |
Nidirana shyhhuangi sp. nov.
Diagnosis. Nidirana shyhhuangi sp. nov. is characterized by a combination of the following characters: (1) a small-sized ranid, body moderately slender; (2) SVL of preserved specimens in adult males 31.6–36.5 mm (mean ± SD = 33.8 ± 1.2 mm, n = 15), females 33.7–38.3 mm (35.9 ± 1.9 mm, n = 4); (3) head triangular, slightly longer than wide; (4) snout comparatively long, triangular in dorsal view with a slightly obtuse tip, moderately pointed in profile; (5) canthus rostralis distinct, contacting with the upper margin of nostril; (6) loreal region dark brown, extending posteriorly over eye and beyond tympanum; (7) upper lip pale white, white line extending posteriorly, forming a white stripe from below nostril to base of forelimb; (8) iris golden above canthus rostralis, dark brown below; (9) tympanum dark brown and conspicuous, dark zone extending posteriorly forming a trapezoid shape; (10) males with a single subgular vocal sac; (11) dorsum brown or yellowish-brown, sometimes ...
Etymology. The specific epithet of the new species shyhhuangi is a Latinized patronymic noun in genitive case. It is dedicated to Prof. Shyh-Huang Chen, a herpetologist and arachnologist who first discovered this species in the early 1980s. We propose the common name “Yuchi music frog” in English to demonstrate the only two sampling sites of the species in Yuchi (meaning the “fish pond”) Township, or “魚池琴蛙” (pronounced as Yú-Chí-Qín-Wā) in Mandarin for this species.
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| A type locality of Nidirana shyhhuangi sp. nov. in Lienhuachih (23.__°N, 120.__°E), Yuchi Township, Nantou County, Taiwan B a mud nest with an opening diameter of ~ 0.8 cm. The white arrow indicates the position of the opening. Photographed by Chun-Fu Lin. |
Chun-Fu Lin, Chunwen Chang, Masafumi Matsui, Chin-Chia Shen, Atsushi Tominaga and Si-Min Lin. 2025. Description of A New Music Frog (Anura, Ranidae, Nidirana) critically endangered in Taiwan. ZooKeys. 1229: 245-273. DOI: doi.org/10.3897/zookeys.1229.139344