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| Occidozyga obscura (Gray, 1831) in Lyu, Wang, Zeng, ... et Wang, 2022. |
Abstract
The recognition for the floating frogs’ genus Occidozyga is in controversy for decades, and the species diversity of these frogs has recently been considered to be underestimated. In southeastern China, two floating frog species are currently recorded, namely Occidozyga lima and Occidozyga martensii. However, their current taxonomic statuses are unresolved after a series of recent taxonomic revisions. In this work, we perform morphological examinations and phylogenetic analyses on these two recorded floating frogs from southeastern China, to clarify their current taxonomic placements. The population previously recorded as Occidozyga lima should be re-assigned to the nomenclature Occidozyga obscura comb. nov., and the population previously recorded as Occidozyga martensii should be an undescribed species which is erected as Occidozyga lingnanica sp. nov. in this work.
Keywords: Diversity, Generic recognition, Occidozyga lingnanica sp. nov., Occidozyga obscura comb. nov., Phrynoglossus
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| Morphological features of Occidozyga obscura comb. nov. in life A–D dorsolateral view, ventral view, left hand, and right foot of SYS a008122 E dorsolateral view of SYS a008123 F dorsolateral view of an uncaptured individual in situ from Shimentai Nature Reserve. |
Occidozyga obscura (Gray, 1831), comb. nov.
Diagnosis: (1) Body stocky, size small, SVL 24.2–27.5 mm in adult males (n=7) and 31.5–32.2 mm in adult females (n=3); (2) snout short triangular shaped; (3) nostrils located dorsally; (4) eye orientation vertically; (5) loreal region oblique, not concave or convex; (6) interorbital space narrower than internarial distance; (7) tongue narrow and slender, unnotched, pointed distally, lingual papilla absent; (8) vomerine ridge and vomerine teeth absent; (9) supratympanic fold distinct, raised, and granulated, curved on the temporal region; (10) tympanum hidden, edge invisible; (11) fingers with rudimentary webs, toes with full webs; (12) heels not meeting, tibio-tarsal articulation reaching between the posterior and anterior of the eye.
Etymology: The specific name obscura means ‘obscure’ in Latin.
Common name: “Chinese floating frog” in English / “中国浮蛙 (zhōng guó fú wā)” in Chinese.
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| Morphological features of the adult male holotype SYS a008846 of Occidozyga lingnanica sp. nov. in life. A dorsolateral view B ventral view C left hand D right foot E dorsal view of right hand showing the nuptial pad F calling in situ showing the subgular vocal sac. |
Occidozyga lingnanica Lyu & Wang, sp. nov.
Ooeidozyga laevis martensi — Pope 1931; Liu & Hu 1961
Occidozyga martensii — Fei et al. 1990; Zhao & Adler 1993; Li et al. 2011
Phrynoglossus martensii — Fei et al. 2009, 2010, 2012
Diagnosis: (1) Body stocky, size small, SVL 19.9–22.1 mm in males (n=8) and 26.8–28.8 mm in females (n=3); (2) snout short triangular shaped; (3) nostrils located laterally; (4) eye orientation laterally; (5) canthus rostralis visible, rounded; (6) loreal region vertical, not concave/convex; (7) tongue wide and swollen, unnotched, rounded distally, lingual papilla absent; (8) vomerine ridge and vomerine teeth absent; (9) supratympanic fold distinct and raised, slightly curved on the temporal region; (10) tympanum hidden, edge invisible; (11) relative finger lengths II=I<IV<III, relative toe lengths I<II<V<III<IV; (12) fingers without webs, toes with two third webs; (13) heels not meeting, tibio-tarsal articulation reaching at the posterior margin of supratympanic fold; (14) tarsal fold absent.
Etymology: The specific name lingnanica refers to the lingnan region, a geographic area covering Guangdong, Guangxi, and Hainan in southeastern China, where this new frog species occurs in. This specific name is also dedicated to the former Lingnan University (1888–1952) that was incorporated into Sun Yat-sen University after 1953.
Common name: “Lingnan floating frog” in English / “岭南浮蛙 (lǐng nán fú wā)” in Chinese.
Ecology: This frog inhabits natural or artificial ponds and paddy fields in hilly regions. Males call in the water surface or waterside grass from dusk to dawn. The breeding season is from May to August (this study; Fei et al. 2009). In southeastern China, Occidozyga lingnanica sp. nov. shares a similar environment to that of Occidozyga obscura comb. nov., but prefers to hilly regions compared with the latter in plain areas.
Distribution: Occidozyga lingnanica sp. nov. can be recognized from multiple localities in Guangdong and Hainan of southeastern China based on the phylogenetic result in this work (Figs 1, 2). The records of O. martensi from Yunnan, southwestern China require further clarifications with morphological examinations (see Discussion).
Zhi-Tong Lyu, Jian Wang, Zhao-Chi Zeng, Lin Luo, Yan-Wu Zhang, Chun-Peng Guo, Jin-Long Ren, Shuo Qi, Yun-Ming Mo and Ying-Yong Wang. 2022. Taxonomic Clarifications on the Floating Frogs (Anura: Dicroglossidae: Occidozyga sensu lato) in southeastern China. Vertebrate Zoology. 72: 495-512. DOI 10.3897/vz.72.e80019
