tetramerus, Acara Heckel [J. J.] 1840:341, Pl. 29 (figs. 1-4) [Annalen des Wiener Museums der Naturgeschichte v. 2; ref. 2064] Rio Branco, Brazil. Syntypes: NMW 33757-58 (1, 1). Type catalog: Kullander 1986:346 [ref. 12439]. •Valid as Aequidens tetramerus (Heckel 1840) -- (Ovchynnyk 1967:42 [ref. 37559], Ortega & Vari 1986:20 [ref. 9708], Kullander 1986:339 [ref. 12439], Kullander & Nijssen 1989:134 [ref. 14136], Keith et al. 2000:212 [ref. 24547], Lasso & Machado-Allison 2000:38 [ref. 27968], Kullander in Reis et al. 2003:609 [ref. 27061], Barriga Salazar 2014:117 [ref. 35745], Ramos et al. 2014:5 [ref. 35321], Sarmiento et al. 2014:122, 188 [ref. 35004], Hernández-Acevedo et al. 2015:105 [ref. 34438], Melo et al. 2016:135 [ref. 34701] as gr. tetramerus, DoNascimiento et al. 2017:99 [ref. 35633], Urbano-Bonilla et al. 2018:91 [ref. 35773], Brosse et al. 2019:134 [ref. 38320], Meza-Vargas et al. 2021:27 [ref. 39298], Borstein et al. 2022:18 [ref. 39507], Koerber et al. 2022:72 [ref. 39235], Vieira et al. 2023:18 [ref. 40759]). Current status: Valid as Aequidens tetramerus (Heckel 1840). Cichlidae: Cichlinae. Distribution: South America: Amazon River basin and Orinoco River basin (Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname and Venezuela). Habitat: freshwater.