The Wami tilapia is a tilapiine

cichlid 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 ...

that grows to over 20 cm in length and is considered a useful food

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

and the island of

Zanzibar Zanzibar (; ; ) is an insular semi-autonomous province which united with Tanganyika in 1964 to form the United Republic of Tanzania. It is an archipelago in the Indian Ocean, off the coast of the mainland, and consists of many small islands ...

, where it may have been introduced by man. It is tolerant of

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

water and grows well in saline pools, making it particularly suitable for aquaculture by communities living close to the sea. Like other

tilapia Tilapia ( ) is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes (formerly all were "Tilapiini"), with the economically most ...

it is an

omnivore An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutr ...

and will feed on algae, plants, small invertebrates, and detritus. The common name refers to the

Wami River The Wami River is a river located in Pwani Region, Tanzania. The headwaters of the Wami and its tributaries originate in the Eastern Arc Mountains of Morogoro Region. The river then flows northeastward through of Pwani Region to empty into the ...

. Formerly considered a separate

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, it is at present merged with the Rufigi tilapia and thus the

scientific name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

is ''Oreochromis urolepis hornorum''. The obsolete scientific name ''Tilapia hornorum'' is also still seen not infrequently. However,

mtDNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA ...

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is calle ...

analysis has found that the

mitochondrial genome Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...

is possibly very similar to that of ''

Sarotherodon galilaeus ''Sarotherodon'' is a genus of oreochromine cichlids that are native to the northern half of Africa (south as far as the Congo River basin), with a single species, ''S. galilaeus'', also ranging into the Levant. A couple of species from this g ...

'' (Nagl ''et al.'' 2001); it might be moved to ''Sarotherodon'' based on these results. On the other hand,

hybridization Hybridization (or hybridisation) may refer to: *Hybridization (biology), the process of combining different varieties of organisms to create a hybrid *Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals *Nu ...

is quite common in tilapiines and hybrids even between not too closely related species may be fertile. In captivity, Wami tilapia have been hybridised with the

Mozambique tilapia The Mozambique tilapia (''Oreochromis mossambicus'') is an oreochromine cichlid fish native to southeastern Africa. Dull colored, the Mozambique tilapia often lives up to a decade in its native habitats. It is a popular fish for aquaculture. Due ...

(''Oreochromis mossambicus''). The resulting fish produce broods almost entirely consisting of males. Male tilapia grow faster and to a more uniform size than females, making them particularly useful for

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

.Frank A. Chapman
Culture of Hybrid Tilapia: A Reference Profile
/ref> Note that based on the mtDNA study by Nagl ''et al.'' (2001), the Mozambique and Wami tilapias do not appear to be closely related. 3 possibilities may explain this discrepancy: Either, the Wami tilapia and its closest relatives (such as the Rufigi and

Blue Tilapia The blue tilapia (''Oreochromis aureus'') is a species of tilapia, a fish in the family Cichlidae. Native to Northern Africa, Northern and Western Africa, and the Middle East, through Introduced species, introductions it is now also established e ...

s) belong into ''Sarotherodon''. Alternatively, they are correctly placed in ''Oreochromis'' but their ancestors hybridized with some ancestral ''Sarotherodon''. Given that only a single specimen was analyzed, it is theoretically also possible that the Wami tilapia is a

cryptic species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

. This is less likely because cryptic speciation requires barriers to

gene flow In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent a ...

which in the tilapiines are not well-developed. The mtDNA data of Klett & Meyer (2002) places the Rufigi tilapia into ''Oreochromis'' (though not close to the Mozambique Tilapia, but rather to ''

Oreochromis amphimelas ''Oreochromis amphimelas'' is a species of tilapia cichlid endemic to north–central Tanzania, where it is found in Lake Manyara and a number of other saline lakes with closed basins. Maximum recorded size is in standard length. Description ...

''). This would seem to support the second hypothesis - maternal gene flow from ''Sarotherodon'' to ''Oreochromis''; whether this is correct or not, it amply illustrates that mtDNA sequences are not a reliable indicator of phylogenetic relationships in these fish.

References

* (2002): What, if Anything, is a Tilapia? Mitochondrial ND2 Phylogeny of Tilapiines and the Evolution of Parental Care Systems in the African Cichlid Fishes. ''Molecular Biology and Evolution'' 19(6): 865-883. * (2001): Classification and Phylogenetic Relationships of African Tilapiine Fishes Inferred from Mitochondrial DNA Sequences. ''Molecular Phylogenetics and Evolution'' 20(3): 361–374. {{Taxonbar, from=Q2257958 uroelpis hornorum