Htay Khin Yadanar, Song Xin-Yuan, Oo Thaung Naing, Chen Xiao-Yong
Southeast Asia Biodiversity Research Institute; Chinese Academy of Sciences; Yezin; Nay Pyi Taw 05282; Myanmar; Yunnan International Joint Laboratory of Southeast Asia Biodiversity Conservation; Menglun; Yunnan; 666303; China; State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Conservation of Gaoligong Mountain; Kunming Institute of Zoology; Chinese Academy of Sciences; Kunming; Yunnan; 650223; China; University of Chinese Academy of Sciences; Beijing 100049; China.
Southeast Asia Biodiversity Research Institute; Chinese Academy of Sciences; Yezin; Nay Pyi Taw 05282; Myanmar; Yunnan International Joint Laboratory of Southeast Asia Biodiversity Conservation; Menglun; Yunnan; 666303; China; State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Conservation of Gaoligong Mountain; Kunming Institute of Zoology; Chinese Academy of Sciences; Kunming; Yunnan; 650223; China.
Zootaxa. 2025 Apr 2;5618(2):221-248. doi: 10.11646/zootaxa.5618.2.3.
Danionid genus Laubuka Bleeker, 1859 is distributed in South Asia and Southeast Asia. Specimens of Laubuka from 20 locations in streams, rivers, and lakes from Kachin State, Sagaing and Ayeyarwady regions of Myanmar and Southern Thailand were compared on their morphology and phylogenetic relationships using COI gene. To date, five species of Laubuka are distributed across Myanmar, including L. laubuca, L. parafasciata, and L. tenella, in addition to two new species described herein. Laubuka myitthaensis Khin & Chen, sp. nov., collected from the Myittha River, Ayeyarwady drainage, is distinguished from its congeners by possessing dorsal-fin-base length less than half of anal-fin-base length; short dorsal-fin-base-length (11.8-13.4% SL) and 9-10 branched pectoral-fin rays. Laubuka indawgyiana Khin & Chen, sp. nov., from Indawgyi Lake, can be distinguished by possessing a convex dorsal profile, and more convex ventral profile, and 16-18 predorsal scales. The two new species can be distinguished from other species of Laubuka by the absence of any markings on the body other than the humeral spots. They are separated from other Laubuka species by a minimum genetic distance of 0.077 and 0.043 in the mitochondrial COI gene, which supports their validity as distinct species.
细须鲃属（Laubuka Bleeker，1859年）分布于南亚和东南亚。对采自缅甸克钦邦、实皆省和伊洛瓦底江地区以及泰国南部的溪流、河流和湖泊20个地点的细须鲃标本，利用细胞色素氧化酶亚基I（COI）基因对其形态和系统发育关系进行了比较。迄今为止，缅甸分布有5种细须鲃，包括劳氏细须鲃（L. laubuca）、似带细须鲃（L. parafasciata）和细纹细须鲃（L. tenella），此外还有本文描述的两个新物种。采自伊洛瓦底江水系密塔河的密塔细须鲃（Laubuka myitthaensis Khin & Chen，新物种）与其同属物种的区别在于，其背鳍基长小于臀鳍基长的一半；背鳍基长较短（占标准体长的11.8 - 13.4%），胸鳍分枝鳍条为9 - 10根。采自茵多基湖的茵多基细须鲃（Laubuka indawgyiana Khin & Chen，新物种）的区别在于，其背部轮廓凸起，腹部轮廓更凸，背鳍前鳞片有16 - 18枚。这两个新物种与其他细须鲃属物种的区别在于，除了肩部斑点外，身体上没有任何斑纹。它们与其他细须鲃属物种在细胞色素氧化酶亚基I（COI）线粒体基因中的最小遗传距离分别为0.077和0.043，这支持了它们作为独立物种的有效性。
