Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, Labroidei, along with the wrasses (Labridae), in the order Perciformes but molecular studies have contradicted this grouping. The closest living relatives of cichlids are probably the convict blennies and both families are classified in the 5th edition of Fishes of the World as the two families in the Cichliformes, part of the subseries Ovalentaria.
Cichlids have the largest number of endangered species among vertebrate families, most in the haplochromine group.[Cichlids are particularly well known for having evolved rapidly into many closely related but morphologically diverse species within large lakes, particularly Tanganyika, Victoria, Malawi, and Edward Their diversity in the African Great Lakes is important for the study of specification in evolution. Many cichlids introduced into waters outside of their natural range have become nuisances.
All cichlids have some form of parental care for their eggs and fry. That parental care may come in the form of guarding the eggs and fry or it may come in the form of mouth-brooding.
