Cichlids are fishes from the family Cichlidae. The family is both large and diverse. At least 1,300 species have
been scientifically described, making it one of the largest vertebrate families. New species are discovered annually,
and many species remain undescribed. The actual number of species is therefore unknown, with estimates varying between 1,300 and 3,000.
Cichlids span a wide range of body sizes, from species as small as 2.5 centimeters (0.98 in) in length to much larger species approaching 1 meter (3.3 ft) in length. As a group, cichlids exhibit a similar diversity of body shapes, ranging
from strongly laterally compressed species that are cylindrical and highly elongate 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.
Many cichlids, particularly tilapia, are important food fishes, while others are valued game fish (e.g. Cichla species).
The family also includes many familiar aquarium fish, including the angelfish, oscars, and discus.
Cichlids have the largest number of endangered species among vertebrate families. Cichlids are particularly well
known for having evolved rapidly into a large number of 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 speciation in evolution. Many cichlids that have been introduced into waters
outside of their natural range have become nuisances, such as tilapia in the southern United States.
Cichlids have highly organized breeding activities.
All species show some form of parental care for both eggs and larvae, often nurturing free-swimming young until
they are weeks or months old.
Communal parental care, where multiple monogamous pairs care for a mixed school of young have also been
observed in multiple cichlid species. Comparably, the fry of Neolamprologus brichardi, a species that commonly
lives in large groups, are protected not only by the adults, but also by older juveniles from previous spawns.
Several cichlids, including discus (Symphysodon spp.), some Amphilophus species, Etroplus and Uaru
feed their young with a skin secretion from mucous glands.
Parental care falls into one of four categories:
substrate or open brooders
secretive cave brooders
at least two types of mouthbrooders
ovophile mouthbrooders and larvophile mouthbrooders.
Cichlids are the most species-rich non-Ostariophysan family in freshwaters worldwide. They are most diverse
in Africa and South America. It is estimated that Africa alone hosts at least 1,600 species.
Central America and Mexico have approximately 120 species, as far north as the Rio Grande in southern Texas. Madagascar has its own distinctive species , only distantly related to those on the African mainland.
Native cichlids are largely absent in Asia, except for nine species in Israel, Lebanon and Syria, one in Iran
and three in India and Sri Lanka. If disregarding Trinidad and Tobago (where the few native cichlids are
members of genera that are widespread in the South American mainland), the three species from the genus
Nandopsis are the only cichlids from the Antilles in the Caribbean, specifically Cuba and Hispaniola. Europe,
Australia, Antarctica, and North America north of the Rio Grande drainage have no native cichlids,
although in Florida, Mexico, Japan and northern Australia feral populations of cichlids have become
established as exotics.
The most ubiquitous aquarium hybrid is perhaps the blood parrot cichlid which is a cross of several species,
especially from genus Amphilophus. With a beak-shaped mouth, an abnormal spine, and an occasionally missing
caudal fin (known as the "love heart" parrot cichlid), the fish is controversial among aquarists.
Some have called blood parrot cichlids "the Frankenstein monster of the fish world."
Another notable hybrid, the flowerhorn cichlid, was very popular in some parts of Asia from 2001 unti
late 2003, and is believed to bring good luck to its owner.The popularity of the flowerhorn cichlid declined in 2004.
Owners released many specimens into the rivers and canals of Malaysia and Singapore where they threaten
Numerous cichlid species have been selectively bred to develop ornamental aquarium strains. The most
intensive programs have involved angelfish and discus, and many mutations that affect both coloration
and finnage are known. Other cichlids have been bred for albino, leucistic, and xanthistic pigment mutations,
including oscars, convicts and Pelvicachromis pulcher. Both dominant and recessive pigment mutation
s have been observed. In convict cichlids, for example, a leucistic coloration is recessively inherited,
while in Oreochromis niloticus niloticus red coloration is caused by a dominant inherited mutation.
This selective breeding may have unintended consequences. For example, hybrid strains of Mikrogeophagus ramirezi
have health and fertility problems.Similarly, intentional inbreeding can cause physical abnormalities, such
as the notched phenotype in angelfish.
NOTE: this article is intensely edited from the complete article that you can find at http://en.wikipedia.org/wiki/Cichlid