polyodon, Tetragonopterus Günther [A.] 1864:330 [Catalogue of the fishes in the British Museum v. 5; ref. 1974] Guayaquil, Ecuador. Holotype (unique): BMNH 1858.7.25.41. •Valid as Hemibrycon polyodon (Günther 1864) -- (Ovchynnyk 1967:29 [ref. 37559], Ortega & Vari 1986:8 [ref. 9708], Malabarba in Reis et al. 2003:130 [ref. 27061], Román-Valencia et al. 2006:212 [ref. 28983], Román-Valencia et al. 2007:184 [ref. 29496], Román-Valencia & Arcila-Mesa 2009:79 [ref. 30718], Román-Valencia et al. 2010:101 [ref. 30945], Bertaco & Malabarba 2010:756 [ref. 31076], Barriga Salazar 2014:107 [ref. 35745], Román-Valencia et al. 2014:121 [ref. 33572], Thomaz et al. 2015:Add. 5 [ref. 33893], Meza-Vargas et al. 2021:18 [ref. 39298]). Current status: Valid as Hemibrycon polyodon (Günther 1864). Characidae: Stevardiinae. Distribution: South America: Río Pastaza, río Marañon drainage, and upper Amazon River basin (Ecuador, Peru). Habitat: freshwater.