jenynsii, Xiphorhamphus Günther [A.] 1864:356 [Catalogue of the fishes in the British Museum v. 5; ref. 1974] Freshwater Lake of Maldonado, Uruguay [probably Laguna del Diario, 34°54'S, 55°00'W, Maldonado, Uruguay]. Holotype: UMZC [Darwin no. 661] whereabouts unknown. Based on Hydrocyon hepsetus of Jenyns 1840:129 [ref. 2344] (not of Cuvier). •Valid as Oligosarcus jenynsii (Günther 1864) -- (Menezes & Géry 1983:589 [ref. 8307], Menezes 1987:22 [ref. 20060], Malabarba 1989:137 [ref. 14217], Haro et al. 1996:6 [ref. 25004] as jenynsi, Gómez & Chebez 1996:47 [ref. 23791], Miquelarena et al. 1997:68 [ref. 23469], Butí & Cancino 1999:71 [ref. 25277], López et al. 2002:63 [ref. 26808] as jenynsi, Menezes in Reis et al. 2003:151 [ref. 27061], López et al. 2003:29 [ref. 27366], Casciotta et al. 2003:87 [ref. 28130], Menni 2004:74 [ref. 28131] as jenynsi, Ribeiro et al. 2007:52 [ref. 29321], Menezes & Ribeiro 2010:653 [ref. 30976], Mirande 2010:497 [ref. 31006] as cf. jenynsii, Mabragaña et al. 2011:table S2 [ref. 31800], Fabiano et al. 2014:8 [ref. 33530], Litz & Koerber 2014:15 [ref. 33622], Sarmiento et al. 2014:185 [ref. 35004], Almirón et al. 2015:589 [ref. 33673], Ribeiro & Menezes 2015:77 [ref. 33768], Menezes & Ribeiro 2015:545 [ref. 33973], Mirande & Koerber 2015:25 [ref. 35117], Bertaco et al. 2016:414 [ref. 34561], Petry et al. 2016:302 [ref. 34966], Nión et al. 2016:28 [ref. 35565] as jenynsi, Wendt et al. 2019:5 [ref. 36952], Koerber & Serra 2020:1 [ref. 37449], Reis et al. 2020:459 [ref. 38364], Giora & Wingert 2023:75 [ref. 41026], Loureiro et al. 2023:70 [ref. 40506], Menezes & Camelier 2024:243 [ref. 40817]). Current status: Valid as Oligosarcus jenynsii (Günther 1864). Acestrorhamphidae: Acestrorhamphinae. Distribution: South America: coastal areas and interior plains of Rio Grande do Sul State and Paraná River basin (Argentina, Brazil, Bolivia and Uruguay). Habitat: freshwater.