Recent taxonomic changes, newly described taxa and groups of taxa, and the introduction of taxonomic characters not previously employed require a revision of the informally recognised, essentially fluviatile group of southern African cichlids, the so-called serranochromines. The genera included in this assemblage are Pharyngochromis, Greenwood, Sargochromis Regan, Serranochromis Regan, and Chetia Trewavas.
Previously, Sargochromis was considered to be a subgenus of Serranochromis, but new evidence indicates that it should be reinstated as a distinct lineage (i.e. genus). The species originally described as Serranochromis (Sargochromis) gracilis should now be transferred to the genus Chetia. Formerly the latter taxon was thought to be monotypic, but it is now expanded to include five species. One of these, Chetia brevis Jubb, had been included tentatively in the genus Astatotilapia, but is now returned to the genus in which it was described originally.
The monophyletic origin of the serranochromines has still to be established. For that,
and other reasons, doubt is cast on the phylogenetic reality of the 'Pharyngochromis
— Chetia — Serranochromis' group of endemic species in Lake Malawi. The
suggested interrelationships of the serranochromine genera presented below, and based on
shared derived characters, cannot, for the same reasons, be considered a truly phylogenetic
one.