sylvius, Gymnotus Albert [J. S.] & Fernandes-Matioli [M. de C.] in Albert et al. 1999:412, Figs. 1-2 [Copeia 1999 (no. 2); ref. 23798] Rio Ribeira de Iguapé, near Miracatu, 24°32'50"S, 47°26'13"W, São Paulo State, Brazil. Holotype: LGP 0925.1. Paratypes: LGP 0925.2 (2), 0931 (1); UMMZ 234347 (2). Plus non-type material. Type catalog: Ferraris et al. 2017:[20] [ref. 35236]. •Valid as Gymnotus sylvius Albert & Fernandes-Matioli 1999 -- (Fernandes-Matioli et al.2000:803 [ref. 30364], Albert 2001:124 [ref. 25614] as silvius, Albert & Crampton 2001:261 [ref. 25031], Campos-da-Paz 2002:185 [ref. 26073], Crampton et al. 2003:2 [ref. 27064], Albert & Crampton 2003:3 [ref. 27077], Campos-da-Paz in Reis et al. 2003:485 [ref. 27061], Crampton & Albert 2003:2 [ref. 27433], Maldonado-Ocampo & Albert 2004:2 [ref. 27978], Crampton et al. 2005:99 [ref. 28092], Fernandes et al. 2005:3 [ref. 28147], Cognato et al. 2008:382 [ref. 29363], Richer-de-Forges et al. 2009:543 [ref. 30384], Milhomem et al. 2012:804 [ref. 31815], Koerber 2014:11 [ref. 33621], Mirande & Koerber 2015:48 [ref. 35117], Ferraris et al. 2017:[20] [ref. 35236], Craig et al. 2018:65 [ref. 35800] with authors as Albert, de Campos Fernandes-Matioli & de Almeida-Toledo, Craig et al. 2019:58 [ref. 37060] in subgenus Gymnotus, Reis et al. 2020:463 [ref. 38364], Brandão et al. 2022:191 [ref. 40464], Quintela et al. 2023:6 [ref. 40727]). Current status: Valid as Gymnotus sylvius Albert & Fernandes-Matioli 1999. Gymnotidae: Gymnotinae. Distribution: South America: Paraíba do Sul River and Pardo River basins (Brazil and Argentina). Habitat: freshwater.