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, 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.
Parachromis managuensis is a large species of cichlid native to freshwater habitats in Central America, where found from Honduras to Costa Rica. The scientific name refers to Lake Managua in Nicaragua from where the holotype was obtained. It is a food fish and is also found in the aquarium trade where it is variously known as the jaguar cichlid, managuense cichlid, managua cichlid, guapote tigre, Aztec cichlid, spotted guapote and jaguar guapote. In Costa Rica it is known as the guapote tigre. Males grow to a total length of 35 centimetres (14 in) and females to 30 centimetres (12 in).
The terms shell dwellers or shelldwellers, shell-breeding, or ostracophil are descriptive terms for cichlid fish that use the empty shells of aquatic snails as sites for breeding and shelter. The terms have no taxonomic basis, although most shell-dwelling cichlids are from Lake Tanganyikas lamprologine lineage. Many shell dwelling cichlids are popular with fishkeepings and are frequently kept in aquaria.
Julidochromis is a genus of cichlids in the subfamily Pseudocrenilabrinae. They are commonly called julies and are endemic to Lake Tanganyika in eastern Africa. This genus includes six formally described species, some with a number local variants of uncertain taxonomic status. Further taxonomic work is required to determine how many species exist; the closely related Chalinochromis with two more species is sometimes included here and this may be correct. Hybridization makes attempts to determine relationships with molecular phylogenetic methods difficult.
Neolamprologus similis is a shell-dwelling cichlid endemic to Lake Tanganyika where it is only known along the shores of the Democratic Republic of the Congo. N. similis is copper coloured with vertical white stripes running from the head to near the base of the tail. It can reach up to 5 centimetres (2.0 in) in total length. It is a popular freshwater aquarium fish.
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.
Neolamprologus is a genus of cichlids endemic to eastern Africa with all but one species, Neolamprologus devosi from the Malagarasi River, occurring in Lake Tanganyika. It is the largest genus of cichlids in Lake Tanganyika and also the largest genus in the tribe Lamprologini, which includes Altolamprologus, Chalinochromis, Julidochromis, Lamprologus, Lepidiolamprologus, Telmatochromis and Variabilichromis. The latter is a monotypic genus doubtfully distinct from Neolamprologus.
Lamprologus ocellatus is a species of shell dwelling cichlid endemic to Lake Tanganyika. It is a popular aquarium fish due to its small size, appearance, and intelligence.
Synodontis multipunctatus, also known as the cuckoo catfish, cuckoo squeaker, or multipunk, is a small catfish from Lake Tanganyika, one of the lakes in the Great Rift Valley system in Africa. It is a brood parasite upon mouthbrooding cichlids. This species grows to a length of 27.5 centimetres (10.8 in) TL. This species is a minor component of local commercial fisheries.
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.
Haplochromis is a ray-finned fish genus in the family Cichlidae. It has been used as the default "wastebin taxon" for Pseudocrenilabrinae cichlids of the East African Rift, and as such became the "largest" fish "genus". Many of these cichlids are popular aquarium fishes; like similar Haplochromini they are known as "haplos", "happies" or "haps" among aquarium enthusiasts.
Bathybates ferox is a species of fish in the family Cichlidae. It is found in Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia. Its natural habitat is Lake Tanganyika where it lives in shallow water and is exclusively piscivorous. The IUCN has assessed it as being a "least-concern species".
Cyprichromis leptosoma is a mouthbrooding species of fish in the family Cichlidae. It is endemic to Lake Tanganyika in Zambia and Tanzania. It seems quite common within its range and faces no particular threats, so the International Union for Conservation of Nature has assessed its conservation status as being of least concern.
Malawi eyebiter is a species of fish in the family Cichlidae. This predatory cichlid is endemic to Lake Malawi in East Africa.
The convict julie is a cichlid species in the subfamily Pseudocrenilabrinae family endemic to Lake Tanganyika. Hence it is found in Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia. The fish is named after Charles Tate Regan.
Plecodus straeleni is a species of cichlid fish that is endemic to Lake Tanganyika in East Africa. This species can reach a total length of 16 centimetres (6.3 in).
Synodontis petricola, known as the cuckoo catfish, or the pygmy leopard catfish, is a species of upside-down catfish endemic to Burundi, Zambia, the Democratic Republic of the Congo, and Tanzania where it is only known from Lake Tanganyika. It was first described by Belgian ichthyologist Hubert Matthes in 1959. The species name "petricola" is derived from a combination of the Latin petra, meaning stone or rock, and the Latin cola, meaning inhabitant. This refers to the rocky environment where this species is found.
Lamprologini is a tribe of African cichlid fishes. It contains seven genera and nearly 100 species. Over half of the species in this tribe are in the large genus Neolamprologus. Most genera in the tribe are endemic to Lake Tanganyika, but one species of Neolamprologus is from the Malagarasi River in Tanzania, and several species of Lamprologus are from the Congo River Basin.
