duckensis, Rivulus Hrbek [T.], de Deus [C. P.] & Farias [I. P.] 2004:571, Fig. 2 [Copeia 2004 (no. 3); ref. 27910] Rivulet emptying into Igarapé Barro Branco, Reserva Adolpho Ducke, Manaus, Amazonas, 2°53'S, 59°58'W, Brazil. Holotype: INPA 21444. Paratypes: INPA 21442 (6), 21443 (11); MZUSP 84223 (2); NMRJ 26192 (2). Plus non-type material. See Costa 2006:167 [ref. 28875] for dates of publication of duckensis (20 Aug.) and kirovskyi (30 Apr.). •Synonym of Rivulus kirovskyi Costa 2004 -- (Costa 2006:157 [ref. 28875] in subgenus Owiyeye). •Synonym of Laimosemion kirovskyi (Costa 2004) based on placement of kirovskyi -- (Costa 2011:239 [ref. 31655]). Current status: Synonym of Laimosemion kirovskyi (Costa 2004). Rivulidae: Rivulinae. Distribution: Tarumã basin, Amazonas, Brazil [if valid]. Habitat: freshwater.