In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic interactions or opens new environmental niches. Starting with a single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different morphological and physiological traits. The prototypical example of adaptive radiation is finch speciation on the Galapagos, but examples are known from around the world.
Cichlids are fish from the family Cichlidae in the order Cichliformes. 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. 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. This family is both large and diverse. 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.
Lake Tanganyika is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all cases after Lake Baikal in Siberia. It is the world's longest freshwater lake. The lake is shared between four countries – Tanzania, the Democratic Republic of the Congo (DRC), Burundi, and Zambia, with Tanzania (46%) and DRC (40%) possessing the majority of the lake. It drains into the Congo River system and ultimately into the Atlantic Ocean.
Lates is a genus of lates perches belonging to the family Latidae. The generic name is also used as a common name, lates, for many of the species.
Variabilichromis moorii has no common name and is a species of freshwater cichlid endemic to Lake Tanganyika in eastern Africa. It is a small ovate bodied fish named for an early collector of fish from the lake, John Edmund Sharrock Moore (1870-1947) who was a cytologist, zoologist and led an expedition to Lake Tanganyika and who discovered this species. Juveniles are usually yellow, and adults are dark brown to black in color. It reaches a total length (TL) of 10.3 centimetres (4.1 in). Currently it is the only member of its genus. V. moorii feeds on algae, zooplankton, and benthic invertebrates. It is also found in the aquarium trade.
Lamprologus is a genus of fishes from the cichlid family. They are native to Lake Tanganyika and the Congo River Basin in Africa. The type species for this genus is Lamprologus congoensis, a species from the Congo River. The genus is under some revision and may eventually be restricted to these riverine types.
Gnathochromis is a small genus of cichlid fish endemic to the Lake Tanganyika basin in East Africa.
Lepidiolamprologus is a small genus of cichlids endemic to Lake Tanganyika in eastern Africa. It is closely related to Altolamprologus. and there is the possibility that a revision of the genus could see more species added.
Petrochromis is a genus of cichlids endemic to Lake Tanganyika in east Africa.
Mastacembelus is a genus of many species of spiny eel fish from the family Mastacembelidae. They are native to Africa and Asia. Most are found in rivers and associated systems, but there are also species in other freshwater habitats and a particularly rich radiation is found in the Lake Tanganyika basin with 15 species. A few species can even occur in brackish water.
Synodontis is the largest genus of mochokid catfishes. It is the biggest genus within the 10 genera and 190 different species in the family Mochokidae. Synodontis has over 131 different species within the genus. Synodontis are also known as squeakers, due to their ability to make stridulatory sounds through their pectoral fin spines when handled or disturbed. Synodontis make a sound that sounds like squeaking by rubbing their spines together. They do this when they have been frightened or when they become angry. Synodontis may also squeak when they are taken out of the water. These catfish are small- to medium-sized fish with many species exhibiting attractive spotted markings. Some species are also known for naturally swimming belly-up, earning the name upside-down catfish. Some of these species are Synodontis contractus and Synodontis nigriventris. While some of these species are known to swim upside down, another species, Synodontis multipunctatus, is a brood parasitic cuckoo catfish.
Lepidophagy is a specialised feeding behaviour in fish that involves eating of scales of other fish. Lepidophagy is widespread, having been independently evolved in at least five freshwater families and seven marine families. A related feeding behavior is pterygophagy, which are fish that feed on the fins of other fish.
Rhamphochromis is a genus of East African haplochromine cichlids endemic to the Lake Malawi basin, also including Lake Malombe, Lake Chilingali, Chia Lagoon and upper Shire River. They mainly occur in offshore open waters, but a few species also near the coast. They are piscivores that typically feed on lake sardines and small utaka cichlids.
Hemibates is a genus of cichlid from the tribe Bathybatini of the subfamily Pseudocrenilabrinae. They are endemic to Lake Tanganyika. They are piscivorous. The genus was considered to be monospecific until the description of Hemibates koningsi in 2017.
The giant cichlid, also known as the emperor cichlid, is a species of fish in the family Cichlidae, endemic to Lake Tanganyika in Africa. It is the only member of its genus Boulengerochromis and tribe Boulengerochromini.
Bathybagrus is a genus of claroteid catfishes native to Africa where they are only found in Lake Tanganyika.
Perissodus is a genus of cichlids endemic to Lake Tanganyika in Africa. They feed on scales.
Plecodus is a genus of cichlids endemic to Lake Tanganyika in Africa. They feed on scales.
Trematocara is a genus of cichlids endemic to Lake Tanganyika in Africa. They are relatively small, up to 15 cm (5.9 in) long, and slender in shape. These schooling, light-shy fish are typically found in relatively deep waters, but move closer to the surface at night to feed on plankton. They are mouthbrooders.
Bathybatini is a tribe of cichlids endemic to Lake Tanganyika in Africa. They are mostly found in relatively deep waters and mainly feed on fish or plankton (Trematocara). They are mouthbrooders.
