duodecimspinosus, Geophagus Boulenger [G. A.] 1895:524 [Proceedings of the Zoological Society of London 1895 (pt 3); ref. 14576] Paraguay. Holotype (unique): BMNH 1895.5.17.12. •Synonym of Gymnogeophagus balzanii (Perugia 1891) -- (Gosse 1976:126 [ref. 7029], Reis & Malabarba 1988:268 [ref. 6638], Kullander in Reis et al. 2003:634 [ref. 27061], Casciotta et al. 2003:155 [ref. 28130], Litz & Koerber 2014:34 [ref. 33622], Mirande & Koerber 2015:58 [ref. 35117], Koerber et al. 2017:80 [ref. 35267]). Current status: Synonym of Gymnogeophagus balzanii (Perugia 1891). Cichlidae: Cichlinae. Habitat: freshwater.