thacbaensis, Mastacembelus Nguyen [H. D.], Nguyen [V. H.] & Ngo [S. V.] in Nguyen 2005:633, Fig. 4 [Freshwater fishes of Vietnam v. 3; ref. 29809] Thac Ba reservoir, Yen Bai Province, Vietnam. Holotype: NCNTTS I Inst., Bac Ninh. Paratypes: (5). •Questionably a synonym of Mastacembelus undulatus (McClelland 1843) -- (Kottelat 2013:313 [ref. 32989]). •Valid as Mastacembelus thacbaensis Nguyen, Nguyen & Ngo 2005 -- (Vu et al. 2019:150 [ref. 37811]). Current status: Synonym of Mastacembelus undulatus (McClelland 1843). Mastacembelidae. Distribution: Thac Ba reservoir, Yen Bai Province, Vietnam [if valid]. Habitat: freshwater.