Central America and Mexico have about 120 species, as far north as the Rio Grande in South Texas. Africa alone is host to at least an estimated 1,600 species. They are most diverse in Africa and South America. Ĭichlids are one of the largest vertebrate families in the world. Pelmatolapia mariae, caught on a hook and line, in Australia: Originally from Africa, the species established feral populations in Australia. Other problems center upon the identity of the putative common ancestor for the Lake Victoria superflock (many closely related species sharing a single habitat), and the ancestral lineages of Lake Tanganyikan cichlids. Īs an example of the classification problems, Kullander placed the African genus Heterochromis phylogenetically within Neotropical cichlids, although later papers concluded otherwise. A comprehensive system of assigning species to monophyletic genera is still lacking, and there is not complete agreement on what genera should be recognized in this family.
Cichlid taxonomy is still debated, and classification of genera cannot yet be definitively given. A ninth subfamily, the Ptychochrominae, was later recognized by Sparks and Smith. Kullander (1998) recognizes eight subfamilies of cichlids: the Astronotinae, Cichlasomatinae, Cichlinae, Etroplinae, Geophaginae, Heterochromidinae, Pseudocrenilabrinae, and Retroculinae. The small intestine's left-side exit from the stomach instead of its right side as in other Labroidei.Division of the lateral line organ into two sections, one on the upper half of the flank and a second along the midline of the flank from about halfway along the body to the base of the tail (except for genera Teleogramma and Gobiocichla).No bony shelf below the orbit of the eye.A single nostril on each side of the forehead, instead of two.The features that distinguish them from the other families in the Labroidei include: This is assumed to be one reason why they are so diverse. Cichlids are efficient and often highly specialized feeders that capture and process a very wide variety of food items. A complex set of muscles allows the upper and lower pharyngeal bones to be used as a second set of jaws for processing food, allowing a division of labor between the "true jaws" ( mandibles) and the " pharyngeal jaws". Ĭichlids share a single key trait - the fusion of the lower pharyngeal bones into a single tooth-bearing structure. Generally, however, cichlids tend to be of medium size, ovate in shape, and slightly laterally compressed, and generally similar to the North American sunfishes in morphology, behavior, and ecology. As a group, cichlids exhibit a similar diversity of body shapes, ranging from strongly laterally compressed species (such as Altolamprologus, Pterophyllum, and Symphysodon) to species that are cylindrical and highly elongated (such as Julidochromis, Teleogramma, Teleocichla, Crenicichla, and Gobiocichla). Īll cichlids practice some form of parental care for their eggs and fry, usually in the form of guarding the eggs and fry or mouthbrooding.Ĭichlids span a wide range of body sizes, from species as small as 2.5 cm (1 in) in length (e.g., female Neolamprologus multifasciatus) to much larger species approaching 1 m (3 ft) in length ( Boulengerochromis and Cichla). Many cichlids introduced into waters outside of their natural range have become nuisances. Their diversity in the African Great Lakes is important for the study of speciation in evolution. Cichlids are particularly well known for having evolved rapidly into many closely related but morphologically diverse species within large lakes, particularly Lakes Tanganyika, Victoria, Malawi, and Edward. Cichlids have the largest number of endangered species among vertebrate families, most in the haplochromine group.
The family also includes many popular freshwater aquarium fish kept by hobbyists, including the angelfish, oscars, and discus. Many cichlids, particularly tilapia, are important food fishes, while others, such as the Cichla species, are valued game fish. The actual number of species is therefore unknown, with estimates varying between 2,000 and 3,000. New species are discovered annually, and many species remain undescribed. At least 1,650 species have been scientifically described, making it one of the largest vertebrate families. The closest living relative of cichlids is probably the convict blenny, 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 were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this grouping. Cichlids / ˈ s ɪ k l ɪ d z/ are fish from the family Cichlidae in the order Cichliformes.
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