The Tilapiini (occasionally Tilapini) are a

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confli ...

within the family Cichlidae commonly known as tilapiine cichlids. Formerly this tribe contained many other genera and species, including the economically important ''

Oreochromis ''Oreochromis'' is a large genus of oreochromine cichlids, fishes endemic to Africa and the Middle East. A few species from this genus have been introduced far outside their native range and are important in aquaculture. Many others have very ...

'' and ''

Sarotherodon ''Sarotherodon'' is a genus of oreochromine cichlids that are native to the northern half of Africa (south as far as the Congo River basin), with a single species, ''S. galilaeus'', also ranging into the Levant. A couple of species from this ge ...

'', but a taxonomic review found that this grouping was paraphyletic and most were moved to Coelotilapini,

Coptodon ''Coptodon'' is a genus of cichlids native to fresh, brackish and coastal marine waters in Africa with ''C. zillii'' also found in the Middle East. It is the only genus in the tribe Coptodonini. Formerly included in ''Tilapia'', this genus and tr ...

ini, Heterotilapini,

Oreochromini Oreochromini is a tribe of cichlids in the Pseudocrenilabrinae subfamily that is native to Africa and Western Asia, but a few species have been widely introduced to other parts of the world. It was formerly considered to be part of the tribe T ...

and Pelmatolapiini. Together, most species in these tribes are called "

tilapia Tilapia ( ) is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes (formerly all were "Tilapiini"), with the economically most ...

s". In a more distant past, a number of other, more different genera like ''

Steatocranus ''Steatocranus'' is a genus of small rheophilic cichlids mostly native to the Congo River Basin in DR Congo/ Congo Brazzaville, although one species, '' S. irvinei'', is restricted to the Volta River in Ghana and Burkino Faso, and it belongs in ...

'' also were included in Tilapiini. With these as separate, Tilapiini now is a much more restricted tribe with only three genera and about half a dozen species from Central and

Southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...

Systematics

The tilapiines were recognised by the ichthyologist

Ethylwynn Trewavas Ethelwynn Trewavas (5 November 1900 – 16 August 1993) was an ichthyologist at the British Museum of Natural History. She was known for her work on the families Cichlidae and Sciaenidae. She worked with Charles Tate Regan, another ichthyo ...

mtDNA-based

phylogenies A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

of tilapiines must be evaluated with caution, however, as they are usually close to, but do not represent the true evolutionary relationships of these fishes. The reason is that hybridization within any one of these major lineages is known to usually produce fertile offspring, and might also do so between the lineages. Gene pools in these fishes have been kept (largely) separate by behavioral cues for millions of years, but reproductive incompatibility has been far slower to evolve, like in many

Pseudocrenilabrinae The Pseudocrenilabrinae are a subfamily in the cichlid family of fishes to which, according to a study from 2004, includes all the Middle Eastern and African cichlids with the exception of the unusual '' Heterochromis multidens'' and the Malag ...

(African cichlids).Nagl ''et al.'' (2001) A small sample size—one to a mere handful of specimens per taxon—as is often used in molecular studies further acerbates the problem. As discussed below for the example of mouthbrooder, mouthbreeding, nonmolecular data such as morphology (biology), morphology or behavior have also turned out to be extremely prone to homoplasies, not the least due to the small but ongoing gene flow between evolutionarily quite distant gene pools. Essentially, most traditional and mtDNA-based phylogenetic hypothesis for tilapiines must be considered with a high degree of caution. This problem could be alleviated to some extent by using nDNA sequences. Comparing these with the mtDNA data, hybridization effects could be discerned. Also, resolution of nDNA likely is still good enough to delimit the clades that apparently exist in the "tilapiines" if numerous taxa and specimens are sampled. Researchers could then reanalyze morphological data to discover actual autapomorphies. Evolution seems to run quickly in this group. Even the fast-evolving mtDNA sequences often are incapable of properly resolving interspecies relationships.Compare support values and proposed relationships in Nagl ''et al.'' (2001) to Klett & Meyer (2002) The precise evolutionary history of some tilapiines may not be properly resolved with presently available methods, for the reasons discussed above.

Diversity of breeding behaviour

Like other cichlids, tilapiines exhibit complex reproductive behaviours and guard their eggs and fry. Broadly speaking, the plesiomorphic trait is substratum-spawning behavior, meaning that the fish form pairs, lay the eggs on a rock or into a depression made in the substrate, and then both parents guard the eggs and fry.

Systematics

Diversity of breeding behaviour

References

Further reading