The haplochromines were in older times treated as subfamilyHaplochrominae, However, the great African radiation of pseudocrenilabrine cichlids is certainly not monophyletic without them, and thus they are today ranked as a tribe therein. They do include, however, the type genus of the subfamily Pseudocrenilabrus. Since taxonomic tribes are treated like genera for purposes of biological nomenclature according to the ICZN, the Haplochromis is the type genus of this tribe, and not the (later-described) Pseudocrenilabrus, even though the tribe name Pseudocrenilabrini was proposed earlier.
In the African Great Lakes, there has been an amazing adaptive radiation of Haplochromini. Many have interesting behavior (e.g. mouthbrooding in Astatotilapia burtoni or the "sleeper" ambushes of Nimbochromis), and brilliant colors are also widespread. Males and females are often strikingly sexually dichromatic. In the aquarium hobby, these fishes are popular; however due to their often aggressive behaviors and rather unusual water parameters, they are generally unsuitable for beginners or community tanks. There are some informal names used among aquarists for Haplochromini. Generally, any and all (as well as some similar-looking Pseudocrenilabrinae) may be referred to haplos, haps or happies. More specific terms are mbuna ("rock-dwelling browser") and utaka ("free-roaming hunter"), which are Bantu terms for these two ecological groups.
Haplochromines inhabit both rivers and lakes, but it is the lake species that have been most closely studied because of the species flocks known from some of the larger lakes, such as Lake Malawi. In the aquarium hobby, the "happies" are conveniently divided into four groups: [2]
Lake Victoria's trophic web was thoroughly upset in the second half of the 20th century, after Nile Perch (Lates niloticus) were introduced to the lake. Among the haplochromines found there, there have been many extinctions, and a number of other species only survive in aquaria. One monotypicgenus, Hoplotilapia, is believed to be entirely extinct at least in the wild.[3]
Two rather singular cichlids are also placed in the Haplochromini on occasion. These are the monotypic genera Etia and Myaka. But more usually, the former is considered incertae sedis among the Pseudocrenilabrinae, while the latter is placed in the Tilapiini.
Kishe-Machumu, Mary; Witte,Frans & Wanink, Jan H. (2008): Dietary shift in benthivorous cichlids after the ecological changes in Lake Victoria. Anim. Biol.58(4): 401-417. doi:10.1163/157075608X383700 (HTML abstract)
Loiselle Paul V. (1994): The Cichlid Aquarium (Expanded ed.). Voyageur Press. ISBN1-56465-146-0
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