Olivaichthys Arratia [G.] 1987:66 Masc. Diplomystes viedmensis MacDonagh 1931. Type by original designation (also monotypic). •Valid as Olivaichthys Arratia 1987 -- (de Pinna 1998:291 [ref. 23847], Ferraris in Reis et al. 2003:256 [ref. 27061], Ferraris 2007:166 [ref. 29155], Arratia & Quezada-Romegialli 2017:6 [ref. 35155]). •Synonym of Diplomystes Bleeker 1858 -- (Burgess & Finley 1996:163 [ref. 22901], Lundberg et al. 2004:72 [ref. 27673], Muñoz-Ramírez et al. 2014:148 [ref. 33192], Muñoz-Ramírez et al. 2023:7 [ref. 40526]). Current status: Synonym of Diplomystes Bleeker 1858. Diplomystidae.