nieuwenhuisii, Neogastromyzon Popta [C. M. L.] 1905:181 [Notes from the Leyden Museum v. 25 (no. 4) (art. 15); ref. 3549] Howong River, Mahakam basin, Borneo, Indonesia. Holotype (unique): whereabouts unknown. •Valid as Neogastromyzon nieuwenhuisii Popta 1905 -- (Roberts 1989:93 [ref. 6439], Kottelat et al. 1993:55 [ref. 23448] as nieuwenhuisi, Kottelat & Lim 1996:236 [ref. 23210] as nieuwenhuisi, Doi 1997:19 [ref. 22832], Kottelat & Widjanarti 2005:157 [ref. 28284] as aff. nieuwenhuisi, Parenti & Lim 2005:189 [ref. 28285] as cf. nieuwenhuisii, Tan 2006:182 [ref. 28716], Ng & Hadiaty 2008:143 [ref. 29735] as nieuwenhuisi, Kottelat 2012:66 [ref. 32367], Kottelat 2013:195 [ref. 32989]). Current status: Valid as Neogastromyzon nieuwenhuisii Popta 1905. Gastromyzontidae. Distribution: Upper Mahakam and Kayan river basins, Kalimantan Timur, Borneo. Habitat: freshwater.