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| Formosania immaculata Sun, Zhou & Yang, 2023 |
Abstract
Formosania immaculata, a new species, is described from the Ou-Jiang basin in Zhejiang Province, Southeast China. It is distinguished from other species of the genus by having a combination of the following characteristics: body without obvious mottling; snout length longer than postorbital length; abdominal scaleless area extending to middle of pectoral-fin base; shorter rostral barbels, the outermost pair length 112.9%–140.0% of eye diameter; and shorter lower lip papillae, length 19.9%–24.4% of eye diameter. Its validity is also affirmed by its distinct Cytb gene sequence divergence from all congeners and its monophyly recovered in a Cytb gene-based phylogenetic analysis.
Key words: cytochrome b, freshwater fish, key, molecular phylogeny, morphology, taxonomy
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| Lateral (A) dorsal (B) and ventral (C) views of Formosania immaculata sp. nov. , holotype, adult, SHOU2021060325. |
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| Habitat and live specimen of Formosania immaculata sp. nov. |
Family Gastromyzontidae Hora,1950
Genus Formosania Oshima,1919
Formosania immaculata Sun, Zhou & Yang, sp. nov.
Diagnosis: Formosania immaculata sp. nov. resembles the Formosania davidi species group (F. davidi, F. galericula and F. fasciolata) in having 13 well-developed rostral barbels arranged in one irregular row (Fig. 2A), while other congeners arranged in 2 rows (Fig. 2B). It is distinguished from the three species in the Formosania davidi species group by having no obvious blotches or stripes (vs. having blotches or stripes) on the body and snout length longer than (vs. equal to) postorbital length (see Fig. 3 and Table 3). The new species differs from F. davidi in having shorter rostral barbels [outermost pair 112.9%–140.0% (average 122.2) vs. 128.3%–175.4% (average 159.0%) of eye diameter], shorter lower lip papillae [19.9%–24.4% (average 22.8) vs. 47.0%–61.9% (average 53.0%) of eye diameter] and narrower abdominal scaleless area (extending to middle of pectoral-fin base vs. extending slightly behind pectoral-fin axil) (see Table 3); from F. fasciolata in having shorter rostral barbels [outermost pair 112.9%–140.0% (average 122.2) vs. 119.8%–167.5% (average 145.6%)] of eye diameter, shorter lower lip papillae [19.9%–24.4% (average 22.8) vs. 40.3%–51.0% (average 47.0%) of eye diameter] and shorter depth of caudal peduncle [91.0%–101.9% (average 97.8%) vs. 107.9%–130.6% (average 118.8%) of caudal peduncle length]; and from F. galericula in having narrower abdominal scaleless area (extending to middle of pectoral-fin base vs. extending slightly behind pectoral-fin axil).
Etymology: The specific epithet is the Latin form of the word immaculate here referring to the unique body of no blotches or stripes. We propose the Chinese common name Wú Bān Yīng Kǒu Qiū (无斑缨口鳅).
Wei Sun, Jia-Jun Zhou, Jin-Quan Yang. 2023. Formosania immaculata, A New Species of Hillstream Loach (Teleostei, Cypriniformes, Gastromyzontidae) from the Ou-Jiang River, Southeast China. ZooKeys. 1182: 207-221. DOI: 10.3897/zookeys.1182.104240
