microlepis, Hydrocyon Jardine [W.] in Schomburgk 1841:247 [The Natural history of fishes of Guiana; ref. 18707] Rio Negro; Rio Branco; and Essiquibo River, South America. No types known. •Valid as Acestrorhynchus microlepis (Jardine 1841) -- (Menezes & Géry 1983:590 [ref. 8307], Ortega & Vari 1986:7 [ref. 9708], Taphorn 1992:104 [ref. 23654], Toledo-Piza & Menezes 1996:4 [ref. 22056], Lasso et al. 2001:95 [ref. 25928], Menezes in Reis et al. 2003:232 [ref. 27061], López-Fernández & Winemiller 2003:195 [ref. 27386], Toledo-Piza 2007:755 [ref. 29426], Barriga Salazar 2014:109 [ref. 35745], Sarmiento et al. 2014:183 [ref. 35004], DoNascimiento 2016:528 [ref. 34727] with author as Schomburgk, Melo et al. 2016:133 [ref. 34701], DoNascimiento et al. 2017:45 [ref. 35633] with author as Schomburgk, Urbano-Bonilla et al. 2018:83 [ref. 35773], Silvano et al. 2020:44 [ref. 38133], Meza-Vargas et al. 2021:15 [ref. 39298], Borstein et al. 2022:16 [ref. 39507], Cortés Hernández et al. 2023:455 [ref. 40760], Koerber et al. 2023:4 [ref. 40665]). Current status: Valid as Acestrorhynchus microlepis (Jardine 1841). Acestrorhynchidae: Acestrorhynchinae. Distribution: South America: Amazon and Orinoco River basins and rivers of northern South America (Brazil, Ecuador, Colombia, Bolivia, French Guiana, Guyana, Venezuela, Peru and Suriname). Habitat: freshwater.