![]() ![]() labrosus and emphasize its noteworthy distribution within Lake Malawi, on rocky shores lakewide excepting the southern arms. We review the little that is known about the biology of A. labrosus express high densities of taste buds. Contrary to published opinion, the hypertrophied lips of A. Abactochromis is unique in the mbuna in having greatly enlarged, lobate lips and several other autapomorphies. ![]() Therefore, we designate it the type species of Abactochromis, new genus. Melanochromis labrosus also does not fit within any other described genus. labrosus is not a Melanochromis, since it lacks the synapomorphic striped color pattern typical of that genus. Although its placement within the mbuna group remains somewhat equivocal, we unambiguously demonstrate that M. labrosus is best considered a species of mbuna. Two features of body coloration (a relatively small number of ocellate spots in the anal fin and a possible polychromatism in one population) suggest that M. labrosus belongs with the mbuna, we review the morphological traits often considered to define the mbuna as a natural group, concluding that none is a uniquely shared specialization. In addition, we extensively survey vertebral counts in the mbuna. labrosus using all obtainable specimens collected since its original description. Melanochromis labrosus is the only one of the 800 or so endemic cichlid species in Lake Malawi whose placement with mbuna or non-mbuna has been disputed on morphological grounds. Intralacustrine dispersion of Malawi cichlids is briefly addressed in appended material. I also describe three new species of haplochromines with three lateral spots and present a key to the three-spot assemblage. I present a detailed phylogenetic analysis of the Cyrtocara livingstonii species-group of ambush predators, and characterize a new species in the group. The remaining major parts of the study are concerned with particular assemblages of haplochromine cichlids in Lake Malawi. ![]() The two (or more) faunal components of Lake Malawi are ecologically distinct. A derived type of anal-fin markings present in a subset of the Malawian fauna is shared with many non-Malawian haplochromines, indicating that the species flock of Lake Malawi is not monophyletic. At a less inclusive phylogenetic level, I examine the controversy over the monophyletic status of the "species flock" of haplochromine cichlids in Lake Malawi. It possesses a distinctive suite of derived characters, but is uniquely primitive among African cichlids in infraorbital morphology and other features. I redescribe this monotypic genus and species and illustrate much of its osteology. With this review as a framework, I argue that the most phylogenetically primitive African cichlid is Heterochromis multidens, a little-known large cichlid from the Zaire River basin. At the most general level, I summarize current morphological evidence that supports cichlid monophyly and the most-inclusive groups of cichlids. Diverse systematic problems at three levels in cichlid phylogeny form the subject matter of this dissertation. The cichlids of Africa present many challenges to the taxonomist. ![]()
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