The Adaptive Radiation of Cichlid Fish in Lake Tanganyika: A Morphological Perspective

Figure 1

Schematic molecular phylogenies of the Lake Tanganyika cichlid assemblage based on combined evidence from several studies: [24, 25] for the phylogenetic tree on the left, that shows relationships among major African cichlid lineages, and [26–30] for the phylogenetic tree on the right, that shows a more detailed picture of the intertribal relationships of East African cichlids. Tribe names follow [17]. Tylochromis polylepis and Oreochromis tanganicae colonized the lake only recently and hence established themselves in an already mature adaptive radiation [25, 31]. In the phylogenetic tree on the right, lineages that underwent radiation are indicated by triangles, with their sizes corresponding to the number of species within the lineage (except for the non-Lake Tanganyika lineages). MVhL-clade was designated by [26], C-lineage by [24], and modern haplochromines by [29]. The Tropheini were shown to be nested within the haplochromine, the largest cichlid tribe that seeded the radiations of the other East African lakes and comprises the majority of North, East, and South African riverine cichlid species [29, 30].