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| Opsariichthys iridescens Peng, Zhou & Yang, in Peng, Zhou, Gao et Yang, 2024. 虹彩马口鱼 || DOI: 10.3897/zookeys.1214.127532 |
Abstract
Opsariichthys iridescens sp. nov. is described from the Qiantang and Oujiang rivers in Zhejiang Province and a tributary of the Yangtze River adjacent to the Qiantang River. It is distinguished from congeners by the following combination of morphological features: no obvious anterior notch on the tip of the upper lip; 45–52 lateral-line scales; 18–21 pre-dorsal scales; two rows of pharyngeal teeth; a maxillary extending to or slightly beyond the vertical anterior margin of the orbit in adult males; a pectoral fin extending to the pelvic fin in adult males; nuptial tubercles on the cheeks and lower jaw of males, which are usually united basally to form a plate; uniform narrow pale pink cross-bars on trunk and two widening significantly on caudal peduncle. Its validity was also supported by its distinct Cyt b gene sequence divergence from all congeners and its monophyly recovered in a Cyt b gene-based phylogenetic analysis.
Key words: Cytochrome b, morphology, opsariichthine, phylogenetic analysis, principal component analysis (PCA), taxonomy
Family Xenocyprididae Günther 1868
Genus Opsariichthys Bleeker, 1863
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| Opsariichthys iridescens sp. nov. A live male B live female; Opsariichthys bidens C live male D live female; Opsariichthys evolans E live male F live female. |
Opsariichthys iridescens Peng, Zhou & Yang, sp. nov.
Diagnosis: The new species, Opsariichthys iridescens sp. nov. can be clearly distinguished from its two sympatric congeners in the Qiantang River and nearby geographic regions (Tables 3, 4). It can be distinguished from O. evolans by the following features: (1) lateral-line scales 45–52 (vs 42–45); (2) scales above lateral-line nine or ten (vs 8); (3) pre-dorsal scales 18–21 (vs 15–17); (4) two rows of pharyngeal teeth (vs 3 rows); (5) maxillary extending to or slightly beyond the vertical of anterior margin of orbit in adult male (vs never extending to the vertical of anterior margin of orbit); (6) pectoral fin extending to pelvic fin in adult male (vs extending far beyond origin of ventral fin); (7) almost uniform narrow pale cross-bars on trunk and widening significantly on caudal peduncle (vs gradually widened, Fig. 3E, F); (8) lower jaw with one row of large tubercles usually united basally to form a plate in male (vs 1 row of moderate tubercles well separated). The new species can be clearly distinguished from O. bidens by the following features: (1) absence of distinct anterior notch on upper lip (vs presence of conspicuous anterior notch on upper lip); (2) two rows of pharyngeal teeth (vs 3 rows); (3) maxillary extending to or slightly beyond the vertical of anterior margin of ...
Etymology: Iridescens is the Latin form of the word iridescent. Here, it refers to the unique body color, which is brighter than that of any known species in the genus. In this study, we propose the Chinese common name Hóng Cǎi Mǎ Kǒu Yú (虹彩马口鱼).
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| Image of the habitat of Opsariichthys iridescens sp. nov., near riverbed with stones. |
Xin Peng, Jia-Jun Zhou, Hong-Di Gao and Jin-Quan Yang. 2024. A New Species of Opsariichthys (Teleostei, Cypriniformes, Xenocyprididae) from Southeast China. ZooKeys. 1214: 15-34. DOI: doi.org/10.3897/zookeys.1214.127532
