The genus currently contains 10 species. Based on mtDNAsequence analysis, there seem to be several clades, and a few species of the much larger genus Oreochromis (such as Oreochromis urolepis and the Blue tilapiaO. aureus) seem closer to Sarotherodon according to the mtDNA data (see discussion at Wami tilapia). Research is hampered by the fact that hybridization runs rampant in these fishes, which confounds mtDNA data, and that the fast speed of evolution makes choice of appropriate nuclear DNA sequences difficult.(Nagl et al. 2001)
"Sarotherodon". FishBase. Ed. Ranier Froese and Daniel Pauly. October 2006 version. N.p.: FishBase, 2006.
Nagl, Sandra; Tichy, Herbert; Mayer, Werner E.; Samonte, Irene E.; McAndrew, Brendan J. & Klein, Jan (2001): Classification and Phylogenetic Relationships of African Tilapiine Fishes Inferred from Mitochondrial DNA Sequences. Molecular Phylogenetics and Evolution20(3): 361–374. doi:10.1006/mpev.2001.0979