Ecological conditions in tropical lacustrine systems are considered by focusing on the
evolution, maintenance, exploitation and vulnerability of fish communities in the African
Great Lakes. The exceptionally high biodiversities in the littoral/sublittoral zones of the
very ancient, deep, clear, permanently stratified rift lakes Tanganyika and Malawi, are
contrasted with the simpler systems in their pelagic zones, also with biodiversity in the
much younger, shallower Victoria, the world's largest tropical lake.