xinguensis, Tetragonopterus Steindachner [F.] 1882:178 [Anzeiger der Kaiserlichen Akademie der Wissenschaften in Wien, Mathematisch-Naturwissenschaftlichen Klasse v. 19 (no. 19); ref. 20487] Rio Xingu, Brazil. Holotype (unique): NMW 57826. Species later described in more detail in Steindachner 1882:32 [ref. 14353]. See Géry & Zarske 2004:40 [ref. 28287] for a redescription of the type. •Valid as Moenkhausia xinguensis (Steindachner 1882) -- (Zarske & Géry 2002:18 [ref. 26554], Benine 2002:293 [ref. 26541] as cf. xinguensis, Géry & Zarske 2004:40 [ref. 28287], Mirande 2010:505 [ref. 31006], Petrolli et al. 2016:168 [ref. 34395], Azevedo-Santos & Benine 2016:208 [ref. 34837]). Current status: Valid as Moenkhausia xinguensis (Steindachner 1882). Acestrorhamphidae: Stichonodontinae. Distribution: Xingu River basin, Brazil. Habitat: freshwater.