opalescens, Cynolebias Myers [G. S.] 1942:107 [Stanford Ichthyological Bulletin v. 2 (no. 4); ref. 3121] Base of Serra do Petrópolis, near Imbarié, Município de Duque de Caxias, about 22°36'S, 43°12'W, Rio de Janeiro State, Brazil. Holotype: CAS-SU 36521. Paratypes: CAS-SU 36522 (9). Type catalog: Böhlke 1953:53 [ref. 12291]. Conserved over the senior subjective synonym Cynopoecilus fluminensis Faria & Muller 1937 in Opinion 1762. Now treated as valid; Leptolebias fluminensis is on the Official Index. •Synonym of Leptolebias fluminensis (Faria & Muller 1937) -- (Costa 1995:91 [ref. 22097]). •Valid as Cynolebias opalescens Myers 1942 -- (Da Cruz & Peixoto 1983:89, 90, 93 [ref. 8235]). •Valid as Leptolebias opalescens (Myers 1942) -- (Lazara 2001:194 [ref. 25711], Costa 2002:383 [ref. 26544], Costa in Reis et al. 2003:531 [ref. 27061], Costa 2008:154 [ref. 29596] as probably extinc, Costa 2013:357 [ref. 32567] not extinct, Ferrer et al. 2014:847 [ref. 33589]). •Valid as Leptopanchax opalescens (Myers 1942) -- (Costa 2016:128 [ref. 34776], Costa 2019:82 [ref. 36869], Guedes et al. 2020:2 [ref. 37981]). Current status: Valid as Leptopanchax opalescens (Myers 1942). Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal river basins (Brazil). Habitat: freshwater.