Cichlids are a family of freshwater fish found mainly in Africa and Central and South America. The cichlids of the African Great Lakes are one of the most striking examples of adaptive radiation in the world.The three largest lakes, Lake Victoria, Lake Malawi and Lake Tanganyika, each contain hundreds of cichlid species, and almost all of them are endemic to their own lake. In each lake, the species evolved from only a few ancestral species. Lake Victoria is thought to have dried out almost completely about 15,000 years ago, yet it now contains around 500 cichlid species, making this one of the fastest known bursts of speciation in vertebrates.Cichlids have filled a huge range of niches. Different species are specialised to:1. scrape algae from rocks2. crush snail shells3. eat insects, plankton or other fish4. eat the scales or eggs of other fish.Two features help explain their success. First, cichlids have a second set of jaws in the throat, the pharyngeal jaws, which process food. This frees the mouth jaws to evolve for catching food, so the shape of the jaws and teeth can adapt quickly to new food sources. Second, many cichlids are mouthbrooders: females carry their eggs and young in their mouths, which improves offspring survival.
Male cichlids are often brightly coloured, and species that are otherwise very similar may differ mainly in male colour. This is important in how new cichlid species form.
Male cichlids are often brightly coloured, and species that are otherwise very similar may differ mainly in male colour. This is important in how new cichlid species form.