Colatreli, Meliciano, Toffoli, Farias and Hrbek (2012): Deep Phylogenetic Divergence and Lack of Taxonomic Concordance in Species of Astronotus (Cichlidae). International Journal of Evolutionary Biology 2012.
''What is currently considered Astronotus ocellatus harbors multiple species....''
http://www.hindawi.com/journals/ijeb/2012/915265/
