heckeli, Gambusia Bleeker [P.] 1860:485 [Acta Societatis Regiae Scientiarum Indo-Neêrlandicae v. 7 (art. 2); ref. 380] Orizaba, Mexico. Syntypes: (13) NMW 59600 (3), 76512 (6), 76514 (2, dry), 81118 (4). Unneeded replacement name for Xiphophorus gracilis Heckel 1848, not preoccupied by the later Gambusia gracilis Girard 1859. •Synonym of Poeciliopsis gracilis (Heckel 1848) -- (Rosen & Bailey 1963:136 [ref. 7067], Lucinda in Reis et al. 2003:570 [ref. 27061], Meyer 2015:287 [ref. 34698], Huber 2019:127 [ref. 36941]). Replacement Name. Current status: Synonym of Poeciliopsis gracilis (Heckel 1848). Poeciliidae: Poeciliinae. Habitat: freshwater.