favus, Mastacembelus armatus var. Hora [S. L.] 1923:180 [Journal of the Natural History Society of Siam v. 6 (no. 2); ref. 15406] Mouth of Patelung River, near Lampaw, Thailand. Syntypes: (several specimens) ZSI F10340/1 (1). Type catalog: Menon & Yazdani 1968:161 [ref. 20743] erroneously with holotype. Also in Hora 1924:474, Fig. 2 [ref. 15450]. •Synonym of Mastacembelus armatus (Lacepède 1800), but a valid subspecies -- (Vu & Nguyen 1997:27 [ref. 26438]). •Valid as Mastacembelus favus Hora 1923 -- (Roberts 1986:105 [ref. 5802], Lim et al. 1990:51 [ref. 16753], Rainboth 1996:180 [ref. 22772], Kottelat 1998:117 [ref. 23436], Ng & Tan 1999:364 [ref. 24159], Britz 2007:257 [ref. 29343], Kottelat 2013:313 [ref. 32989], Ng et al. 2019:533 [ref. 36606], Vu et al. 2019:150 [ref. 37811], Duong et al. 2020:72 [ref. 37886], Ng & Tan 2020:176 [ref. 37671], Fu et al. 2021:9572 [ref. 39347]). Current status: Valid as Mastacembelus favus Hora 1923. Mastacembelidae. Distribution: Southeast Asia: Malaya (Malaysia) and Mekong basin (Yunnan/China, Thailand, Laos, Cambodia and southern Vietnam). Habitat: freshwater.