Family (Taxonomy)

Fish families are typified by shared anatomical characters and a family-wide common ancestor. Cichlidae, with over 1,700 described species, is the third-largest vertebrate family and a textbook example of adaptive radiation — a single ancestor diversified to fill every conceivable ecological niche in African and American freshwater systems. Family names end in '-idae' for fish (Salmonidae) and are not italicized. Family concepts have been revised significantly by molecular phylogenetics: the traditional 'Serranidae' (sea basses) is polyphyletic; the groupers now placed in Epinephelinae are distributed across multiple molecular clades.