Cichlids are fish from the family Cichlidae in the order Cichliformes. Traditionally Cichlids were classed in a suborder, the Labroidei, along with the wrasses (Labridae), in the order Perciformes, but molecular studies have contradicted this grouping. On the basis of fossil evidence, it first appeared in Tanzania during the Eocene epoch, about 46–45 million years ago. 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. This family is large, diverse, and widely dispersed. At least 1,650 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 2,000 and 3,000.
Symphysodon is a genus of cichlids native to the Amazon river basin in Brazil. Due to their distinctive shape, calm behavior, many bright colors and patterns, and dedicated parenting techniques, discus are popular as freshwater aquarium fish, and their aquaculture in several countries in Asia is a major industry. They are sometimes referred to as pompadour fish. The discus fish has attracted a cult following of collectors and has created a multimillion dollar international industry complete with shows, competitions, and reputable online breeders.
Symphysodon discus, the red discus or Heckel discus, is a species of cichlid endemic to the Amazon Basin of Brazil, where found in the lower Rio Negro, upper Uatumã, Nhamundá, Trombetas and Abacaxis.
Cichlasoma is a genus of freshwater fish in the cichlid family. The genus was previously very large, including cichlids from North America, including Central America, and South America.
Crenicichla is a genus of cichlids native to South America commonly known as the pike cichlids. They are found in most tropical and subtropical freshwater habitats between the Andes and the Atlantic.
Apistogramma is a large genus of freshwater fish in the family Cichlidae native to South America, but also commonly kept in aquariums. They are dwarf cichlids that mostly feed on tiny animals and have breeding behaviors that vary depending on the exact species.
Aequidens is a genus of fish in the family Cichlidae found in South America. Formerly a wastebasket genus, as presently defined Aequidens is largely restricted to the Amazon Basin, Orinoco Basin and river basins in The Guianas. The only exceptions are A. plagiozonatus which also occurs in the Paraná Basin, and A. tetramerus which also occurs in the Parnaíba River.
Geophagus is a genus of cichlids that mainly live in South America as far south as Argentina and Uruguay, but a single species, G. crassilabris is from Panama. They are found in a wide range of freshwater habitats. They are part of a group popularly known as eartheaters and mostly feed by picking up mouthfuls of sediment to sift out food items such as invertebrates, plant material and detritus. The largest species reach up to 28 cm (11 in) in standard length. They are mostly kept in aquariums.
Laetacara is a small genus of cichlids native to freshwater habitats in tropical and subtropical South America, ranging from the upper Orinoco River basin in Venezuela to the Paraná River basin Argentina. The genus is also collectively known as the smiling acaras. Like all cichlids, Laetacara species have well-developed brood care.
Mesonauta, the flag cichlids, is a small genus of cichlids native to the Amazon, Orinoco, Essequibo, Paraná and Paraguay basins in South America. Mesonauta is included in the subfamily Cichlasomatinae. They occur in various freshwater habitats such as streams and lakes, especially in areas with little water movement and aquatic vegetation. They are generally found in small groups that stay near the water surface. To avoid predators, adults may jump out of the water and juveniles mimic leaves.
Paretroplus is a genus of fishes in the cichlid family, all of which are endemic to lakes and rivers of Madagascar. The vast majority are threatened and restricted to the northwestern part of the island. Only P. polyactis is found in the southern half of Madagascar and only P. polyactis and P. gymnopreopercularis are found in eastern drainages. Most are restricted to freshwater, but at least P. polyactis and P. maromandia can also be seen in brackish habitats.
The Cichlasomatinae are a subfamily of cichlid fishes, including all cichlids native to the Greater Antilles, United States, Mexico and Central America, and many of the cichlids from South America. The subfamily Cichlasomatinae is often divided into two tribes: Cichlasomatini and Heroini, however some authorities classify these two tribes as part of the wider Neotropical and marginally Nearctic subfamily Cichlinae.
Heroini is a fish tribe from the Cichlasomatinae subfamily in the cichlid family. All cichlids native to the Greater Antilles, United States, Mexico and northern Central America are members of this tribe. It also includes most cichlid species in southern Central America and several species from South America. A large percentage of its species were formerly placed in the genus Cichlasoma but have since been moved to other genera.
Apistogramma agassizii, commonly known as Agassiz's dwarf cichlid, is a species of cichlid found in the Marañón and Ucayali River in Peru, some tributaries of the Amazon River, as well as downstream to the estuary in the Atlantic. It is named after the Swiss-American zoologist and geologist Louis Agassiz (1807–1873).
Krobia is a genus of cichlid fish native to freshwater habitats in South America, with three species found in the Guianas and a single in the Xingu River basin. They are typically found in small streams or creeks with little current and they feed on small invertebrates. They reach up to 12.8 cm (5.0 in) in standard length. They were formerly included in Aequidens.
Symphysodon tarzoo, the green discus, is a species of cichlid endemic to Brazil; specifically, to rivers of the western Amazon Basin upriver from the Purus arch, although it occasionally occurs downstream. An introduced population in the Nanay River is based on stock from the Tefé region. The green discus is found in blackwater habitats with a high temperature of 27–30 °C (81–86 °F) and low pH of 4.8–5.9. Although also known from whitewater, its preference for lentic habitats such as floodplains means that the water contain little suspended material.
Mesonauta acora is a species of cichlid fish endemic to the Amazon Basin of Brazil; specifically, to blackwater in the Xingu and Tocantins River basins in South America. The species was named by François Louis de la Porte, comte de Castelnau in 1855.
The Purus várzea (NT0156) is an ecoregion of seasonally flooded várzea forest in the central Amazon basin. It is part of the Amazon biome. The ecoregion is home to a vegetation adapted to floods of up to 12 metres (39 ft) that may last for eight months. There is a great variety of fish and birds, but relatively fewer mammals. Ground-dwelling mammals must migrate to higher ground during the flood season. Threats include logging, cattle farming, over-fishing and mercury pollution from gold mining.
The Iquitos várzea (NT0128) is an ecoregion of flooded forest along rivers in Brazil, Peru and Bolivia in the west of the Amazon biome. The forest is seasonally flooded up to 7 metres (23 ft) by whitewater rivers carrying nutrient-rich sediment from the Andes. The meandering rivers often shift course, creating a complex landscape of oxbow lakes, marshes, levees and bars, with grasslands, shrubs and forests in different stages of succession. During the extended flood periods fish enter the forest in search of fruit. The várzea is accessible by the navigable rivers that run through it, and has suffered from extensive deforestation to extract timber and create pasture for livestock.
The Purus Arch is a basement high in Brazil that makes up the modern western boundary of the Amazon sedimentary basin. The Purus Arch is thought to be a former graben of Middle Proterozoic age that was inversed in the Late Proterozoic.
