tenuis, Chorimycterus Cope [E. D.] 1894:67 [American Naturalist v. 28 (no. 325); ref. 966] Upper Rio Jacuhy [Jacuí], Rio Grande do Sul, Brazil. Holotype: ANSP 21576. Paratypes: ANSP 21577 (1). Type catalog: Böhlke 1984:55 [ref. 13621]. •Valid as Characidium tenuis (Cope 1894) -- (Malabarba 1989:132 [ref. 14217]). •Valid as Characidium tenue (Cope 1894) -- (Buckup 1993:102 [ref. 20831], Buckup & Reis 1997:543 [ref. 22903], Buckup & Hahn 2000:151 [ref. 24257], Zarske & Géry 2001:242 [ref. 25972], Buckup in Reis et al. 2003:91 [ref. 27061], López et al. 2003:16 [ref. 27366], Menni 2004:79 [ref. 28131], Leitão & Buckup 2014:21 [ref. 33323], Zanata & Camelier 2014:341 [ref. 33380], Litz & Koerber 2014:16 [ref. 33622], Casciotta et al. 2015:1 [ref. 33697], Melo & Oyakawa 2015:288 [ref. 33788], Zanata & Ohara 2015:375 [ref. 33970], Zanata & Camelier 2015:497 [ref. 33983], Mirande & Koerber 2015:27 [ref. 35117], Bertaco et al. 2016:414 [ref. 34561], Petry et al. 2016:301 [ref. 34966], Nión et al. 2016:27 [ref. 35565] with date 1878, Zanata et al. 2018:84 [ref. 36279], Loureiro et al. 2023:32 [ref. 40506], Buckup 2024:304 [ref. 40817]). Current status: Valid as Characidium tenue (Cope 1894). Crenuchidae: Characidiinae. Distribution: South America: Uruguay River basin and Laguna dos Patos basin (Argentina, Brazil and Uruguay). Habitat: freshwater.