rubromarginatus, Rivulus Costa [W. J. E. M.] 2007:58, Figs. 4-5 [aqua, International Journal of Ichthyology v. 13 (no. 2); ref. 29394] Stream tributary to Rio Espingarda, Rio de Pexie drainage, Rio Araguaia basin at road GO-164 crossing, Goiás State, Brazil, 14°28'27.5"S, 50°28'21.7"W, elevation 275 meters. Holotype: UFRJ 6474. Paratypes: (20) UFRJ 6475 (2), 6476 (14), 6477 (4). •Valid as Rivulus rubromarginatus Costa 2007 -- (Costa 2010:369 [ref. 30690], Costa 2010:197 [ref. 31043]). •Valid as Melanorivulus rubromarginatus (Costa 2007) -- (Costa 2011:241 [ref. 31655], Costa 2016:145 [ref. 34900], Nielsen 2017:67 [ref. 35340], Nielsen & Britzke 2019:42 [ref. 36525]). Current status: Valid as Melanorivulus rubromarginatus (Costa 2007). Rivulidae: Rivulinae. Distribution: Middle Araguaia River basin, central Brazil. Habitat: freshwater.