Original description as Retroculus acherontos:
- Landim, María Isabel & C.R. Moreira & C.A. Figueiredo. 2015. "Retroculus acherontos, a new species of cichlid fish (Teleostei) from the Rio Tocantins basin". Zootaxa. v. 3973(n. 2), pp. 369-380 (crc06779) (abstract)
Conservation: Retroculus acherontos is not evaluated by the international union for the conservation of nature in the iucn red list of threatened species. Landin et al. (Lucanus, 2011:378) establish an occurrence range as small as 36 km2 in an area of 1,281.3 km2 in the headwaters of Rio Tocantins. Taking into consideration that this is a rheophilic species and the large Serra da Mesa hydroelectric dam has been built inside the occurrence area, this would make R. acherontos classify as endangered according to the criteria of the International Union for the Conservation of Nature IUCN, which does not list it yet.