filamentosus, Simpsonichthys Costa [W. J. E. M.], Barrera [S.] & Sarmiento [J.] 1997:84, Figs. 1-2 [Revue française d'Aquariologie Herpétologie v. 24 (no. 3/4); ref. 23467] Swamp near Rio San Pablo, Rio Mamoré basin, about 15°37'S, 63°35'W, about 60 kilometers north of Ascencion de Guarayos, route Santa Cruz-Trinidad, Depto. de Santa Cruz, Bolivia. Holotype: CBF 3002. Paratypes: CBF 3003 (7), MZUSP 51328 (2), UFRJ 3989 (4). •Valid as Simpsonichthys filamentosus Costa, Barrera & Sarmiento 1997. •Valid as Spectrolebias filamentosus (Costa, Barrera & Sarmiento 1997) -- (Nielsen 2013:81 [ref. 32696], Nielsen & Brousseau 2013:121 [ref. 32794], Sarmiento et al. 2014:187 [ref. 35004], Drawert 2023:15 [ref. 40730]). Current status: Valid as Spectrolebias filamentosus (Costa, Barrera & Sarmiento 1997). Rivulidae: Cynolebiinae. Distribution: South America: Mamoré River and Beni River drainages, Madeira River basin (Bolivia). Habitat: freshwater.