castexi, Potamotrygon Castello [H. P.] & Yagolkowski [D. R.] 1969:2, Pl.; Figs. 1-3, 7 [Acta Scientifica del Departamento de Zoología, Instituto Latinoamericano de Fisiología y Reproducción, Universidad del Salvador No. 6; ref. 7804] Río Paraná, Rosario, Argentina. Holotype: MACN 5777 (apparently lost). Paratypes: ILAFIR 100 (1), MFA 288 (1). •Valid as Potamotrygon castexi Castello & Yagolkowski 1969 -- (Ortega & Vari 1986:6 [ref. 9708], Nishida 1990:92 [ref. 19783], Compagno 1999:495 [ref. 25589], Carvalho et al. in Reis et al. 2003:24 [ref. 27061], López et al. 2003:6 [ref. 27366], Menni 2004:70 [ref. 28131], Carvalho & Lovejoy 2011:46 [ref. 31182]). •Synonym of Potamotrygon falkneri Castex & Maciel 1963 -- (Carvalho et al. 2011:26 [ref. 31264], Koerber 2014:1 [ref. 33621], Mirande & Koerber 2015:8 [ref. 35117], Weigmann 2016:155 [ref. 34211], Koerber et al. 2017:10 [ref. 35267], DoNascimiento et al. 2017:[1] [ref. 35679]). Current status: Synonym of Potamotrygon falkneri Castex & Maciel 1963. Potamotrygonidae: Potamotrygoninae. Distribution: Upper Amazon River and Paraná-Paraguay River basins: Argentina, Bolivia, Brazil, Paraguay and Peru [if valid]. Habitat: freshwater.