gordoni, Xiphophorus Miller [R. R.] & Minckley [W. L.] 1963:538, Figs. 1, 3-5 [Copeia 1963 (no. 3); ref. 5040] Laguna Santa Tecla, about 10 miles south-southeast of El Candido, Cuarto Ciénegas, Coahuila, Mexico. Holotype: UMMZ 179866. Paratypes: UMMZ 179867 (1, allotype), 179868 (193). •Synonym of Xiphophorus couchianus (Girard 1859), but a valid subspecies -- (Rosen & Bailey 1963:63 [ref. 7067]). •Valid as Xiphophorus gordoni Miller & Minckley 1963 -- (Rosen 1979:353 [ref. 22796], Espinosa Pérez et al. 1993:55 [ref. 22290], Rodriguez 1997:674 [ref. 23266], Meyer & Schartl 2002:59 [ref. 26066], Lucinda in Reis et al. 2003:573 [ref. 27061], Nelson et al. 2004:105 [ref. 27807], Lucinda & Reis 2005:44 [ref. 29205], Miller 2006:258 [ref. 28615], Scharpf 2007:23 [ref. 30398], Page et al. 2013:111 [ref. 32708], Meyer 2015:381 [ref. 34698], Huber 2019:146 [ref. 36941]). Current status: Valid as Xiphophorus gordoni Miller & Minckley 1963. Poeciliidae: Poeciliinae. Distribution: Cuatro Ciénegas valley, Coahuila, Atlantic slope of Mexico. Habitat: freshwater.