santensis, Rivulus elegans var. Köhler [W.] 1906:408, Fig. [Blätter für Aquarien- und Terrarienkunde v. 17 (no. 41); ref. 19678] Western surroundings of Santos, near Pedro Taques, Estado de São Paulo, Brazil [Santos, Brazil]. Neotype: MNHN 1991-6856. Neotype designation by Huber 1992:396 [ref. 20639]. MNHN 1991-6857 (1) listed as a "Paraneotype" and many others. •Synonym of Rivulus elegans Steindachner 1880, but a valid subspecies as described -- (Costa 1991:582 [ref. 20033], Huber 1992:396 [ref. 20639]). •Valid as Rivulus santensis Köhler 1906 -- (Lazara 2001:283 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Costa 2004:105 [ref. 27824], Costa 2004:105 [ref. 27824], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2007:181 [ref. 29203], Costa 2007:128 [ref. 29225], Costa 2008:135 [ref. 29871], Costa 2008:197 [ref. 29962], Costa & Lanés 2009:94 [ref. 30256]). •Valid as Atlantirivulus santensis (Köhler 1906) -- (Costa 2011:244 [ref. 31655], Costa 2014:19 [ref. 33307], Volcan et al. 2024:98 [ref. 41345]). Current status: Valid as Atlantirivulus santensis (Köhler 1906). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal river basins, eastern Brazil. Habitat: freshwater.