undulatus, Corydoras Regan [C. T.] 1912:217 [Annals and Magazine of Natural History (Series 8) v. 10 (no. 56); ref. 14865] La Plata, Buenos Aires, Argentina [aquarium import of doubtful origin, most likely from the Entre Ríos area, Argentina]. Holotype: BMNH 1912.7.10.5. Paratypes: BMNH 1909.9.28.3-4 (2). Type catalog: Ferraris 2007:126 [ref. 29155]. •Valid as Corydoras undulatus Regan 1912 -- (Nijssen & Isbrücker 1980:214 [ref. 6910], Malabarba 1989:147 [ref. 14217], Burgess 1989:367 [ref. 12860], Isbrücker 2001:237 [ref. 26805], Knaack 2002:52 [ref. 27224], Reis in Reis et al. 2003:304 [ref. 27061], López et al. 2003:43 [ref. 27366], Casciotta et al. 2003:129 [ref. 28130], Casciotta et al. 2003:129 [ref. 28130], Shimabukuro-Dias et al. 2004:141 [ref. 27796], Menni 2004:82 [ref. 28131], Ferraris 2007:126 [ref. 29155], Calviño & Alonso 2010:200 [ref. 30829], Litz & Koerber 2014:23 [ref. 33622], Mirande & Koerber 2015:40 [ref. 35117], Bertaco et al. 2016:416 [ref. 34561], Ohara et al. 2016:550 [ref. 34772], Nión et al. 2016:31 [ref. 35565], Grant 2018:26 [ref. 36057], Bono et al. 2019:3 [ref. 36480], Loureiro et al. 2023:94 [ref. 40506]). Current status: Valid as Corydoras undulatus Regan 1912. Callichthyidae: Corydoradinae. Distribution: South America: Paraguay, Paraná and Uruguay River basins and Laguna dos Patos (Paraguay, Argentina, Uruguay and Brazil). Habitat: freshwater.