alvarezi, Gambusia Hubbs [Clark L.] & Springer [V. G.] 1957:310, Figs. 3g, 14 [Texas Journal of Science v. 9 (no. 3); ref. 12145] El Ojo de San Gregorio, Chihuahua, Mexico. Holotype: UMMZ 168979. Paratypes: (650) ENCB P 349 (?), FMNH 61605 (34), CAS-SU 48134 (?), THNC 4207 (?), UMMZ 168980 (40), USNM 164253 (39). Type catalog: Ibarra & Stewart 1987:36 [ref. 12367], Parenti et al. 1999:5 [ref. 24072]. •Synonym of Gambusia gaigei Hubbs 1929 -- (Rosen & Bailey 1963:104 [ref. 7067]). •Valid as Gambusia alvarezi Hubbs & Springer 1957 -- (Rauchenberger 1989:3 [ref. 15687], Espinosa Pérez et al. 1993:45 [ref. 22290], Parenti et al. 1999:5 [ref. 24072], Lucinda in Reis et al. 2003:558 [ref. 27061], Nelson et al. 2004:103 [ref. 27807], Miller 2006:221 [ref. 28615], Lucinda & Reis 2005:41 [ref. 29205], Scharpf 2007:16 [ref. 30398], Meyer et al. 2010:13 [ref. 30817], Page et al. 2013:108 [ref. 32708], Meyer 2015:56 [ref. 34698], Huber 2019:59 [ref. 36941], Page et al. 2023:145 [ref. 40505]). Current status: Valid as Gambusia alvarezi Hubbs & Springer 1957. Poeciliidae: Poeciliinae. Distribution: Southern North America: Ojo de San Gregoria and adjacent creek, Chihuahua, Atlantic slope (Mexico). Habitat: freshwater.