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| Yunnanilus chuanheensis Jiang, Zhao, Du & Wang, 2021 |
Abstract
A new loach species (Cypriniformes: Nemacheilidae: Yunnanilini), Yunnanilus chuanheensis sp. nov., was caught from Chuanhe in the upper reaches of the Lixianjiang River, a tributary of the Red River in Nanjian County, Yunnan Province, China. This species is a member of the traditional Y. pleurotaenia species group based on the presence of a lateral line and cephalic lateral-line canals. It can be distinguished from other species in the Y. pleurotaenia species group by the following characters: lips without papillae, anterior and posterior nostrils separated, whole body scaled, eye diameter smaller than interorbital width, outer gill raker absent on first gill arch, eye diameter greater than 18% of head length, 10–11 inner gill rakers on first gill arch, and lateral line not extending to vertical through dorsal fin insertion. To the best of our knowledge, this is the first Yunnanilus species recorded from the Red River drainage.
Keywords: Loach, New species, Nemacheilidae, Yunnanilus, Red River, Yunnan
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| Figure 1. Yunnanilus chuanheensis sp. nov. Pictures show living (A) and preserved paratype (B, male, KIZ 2016007380); living(C) and lateral, dorsal, ventral, and X-ray views of preserved holotype (D, female, KIZ 2016007379); habitat photo of type locality at time of collection (E). |
Yunnanilus chuanheensis sp. nov. Jiang, Zhao, Du & Wang
Diagnosis: The new species belongs to the Y. pleurotaenia species group and is distinguished from the Y. nigromaculatus species group based on lateral line and cephalic lateral-line canals present (vs. sensory canals absent). For the other species within the Y. pleurotaenia species group, Yunnanilus chuanheensis sp. nov. can be distinguished from: (1) Y. cruciatus and Y. pulcherrimus by papillae on lips absent (vs. present); (2) Y. jinxiensis by anterior and posterior nostril separated (vs. closely placed); (3) Y. analis, Y. beipanjiangensis, Y. chui, Y. discoloris, Y. elakatis, Y. forkicaudalis, Y. macrositanus, Y. nanpanjiangensis, Y. paludosus, and Y. sichuanensis by whole body scaled (vs. scaleless or only caudal peduncle scaled); (4) Y. jiuchiensis and Y. longibulla by eye diameter smaller than interorbital width (vs. larger); (5) Y. ganheensis, Y. macrolepis, and Y. spanisbripes by outer gill raker on first gill arch absent (vs. present); (6) Y. macrogaster by eye diameter greater than 18% of head length (vs. smaller than 12%); (7) Y. parvus by 10–11 inner gill rakers on first gill arch (vs. 8–9); and (8) Y. pleurotaenia by lateral line not extending to vertical through dorsal fin insertion (vs. extending to).
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| Distribution map of Yunnanilus chuanheensis sp. nov. |
Distribution and habitat: Specimens were collected from Chuanhe in the upper reaches of the Lixianjiang River, a tributary of the Red River basin (Figure 1F). The type locality at the time of capture (dry season) consisted of clear and slow-flowing water, with a sand- and cobble-covered bottom and water depth mostly less than 1 m. The banks were fully covered with secondary forest, mostly shrubs (Figure 1E). Another Nemacheiline loach, Schistura fasciolata, was the only species collected syntopically with this new species.
Etymology: The name of the new species, chuanheensis, is derived from the Chinese name of the locality river, Chuanhe (川河), and therefore the Chinese name of this new species is "川河云南鳅".
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| phylogenetic position of Yunnanilus chuanheensis sp. nov. |
Wan-Sheng Jiang, Ya-Peng Zhao, Li-Na Du and Mo Wang. 2021. Yunnanilus chuanheensis, A New Loach Species (Cypriniformes: Nemacheilidae) from the upper Lixianjiang River in Yunnan, China. Zoological Research. 42(2); 241-245. DOI: 10.24272/j.issn.2095-8137.2020.287
