The sawfin (''Pseudobarbus serra''), also known as Clanwilliam sawfin, is a ray-finned fish species in the family

Cyprinidae Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest verte ...

. It is placed with the South African redfins in ''

Pseudobarbus ''Pseudobarbus'' is a ray-finned fish genus in the family Cyprinidae. The type species is Burchell's redfin (''P. burchelli''). The scientific name is derived from the Ancient Greek ''pseudes'' ("false") and the Latin word ''barbus'' ("beard", ...

''. It is tetraploid. Its closest living relative is probably the

Cape whitefish The Cape whitefish or Berg-breede River whitefish (''Pseudobarbus capensis'') is a ray-finned fish species in the family Cyprinidae. It is placed with the South African redfins in ''Pseudobarbus''. It is tetraploid. Its closest living relative w ...

(''P. capensis'').de Graaf ''et al.'' (2007) This sizeable cyprinid can grow to over long and weigh more than .

Distribution and ecology

It is endemic to the Western Cape Province of South Africa, where it was formerly widespread in the Olifants River and its tributaries. Its range has decreased throughout most of the 20th century, and by now it is apparently only found in the upper Olifants River as well as the Biedou,

Doring Doring is a town in Haa District in southwestern Bhutan Bhutan (; dz, འབྲུག་ཡུལ་, Druk Yul ), officially the Kingdom of Bhutan,), is a landlocked country in South Asia. It is situated in the Eastern Himalayas, between ...

, Driehoeks, Jan Dissels, Oorlogskloof, Ratels and

Tra Tra River Tra or TRA may refer to: Biology * TRA (gene), in humans encodes the protein T-cell receptor alpha locus * Tra (gene), in ''Drosophila melanogaster'' encodes the protein female-specific protein transformer * Tra gene, a transfer gene * Triple rele ...

s. It is rather euryoecious, inhabiting a wide variety of small and large rivers. While young fish are common in pools in the

foothill Foothills or piedmont are geographically defined as gradual increases in elevation at the base of a mountain range, higher hill range or an upland area. They are a transition zone between plains and low relief hills and the adjacent topograp ...

s, adults will move further down to where the rivers enter the coastal plain and the water is deeper. The sawfin is omnivorous, but mainly eats aquatic insects and their larvae. Its breeding season runs from late spring to summer (October to December), when schools of adults form to migrate upriver to shallow riffles with

cobble Cobble may refer to: * Cobble (geology), a designation of particle size for sediment or clastic rock * Cobblestone, partially rounded rocks used for road paving * Hammerstone, a prehistoric stone tool * Tyringham Cobble, a nature reserve in Tyr ...

ground, where they spawn. This species is long-lived and slow-growing, with yearlings being about long. It is only half-grown at about 4 years of age, and can get more than 10 years old.

Status and conservation

This species is considered Near Threatened by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

, as it has declined much between the 1930s and 1970s. This seems to have been mainly due to the introduced smallmouth bass (''Micropterus dolomieu''), which can kill off antire subpopulations by eating the juveniles. Clanwilliam yellowfish (''Labeobarbus capensis'') might be regarded as a competitor for food, but this is apparently not significant. Other threats are water pollution and overuse, mainly due to agriculture. Overall however, its stocks are healthy wherever the smallmouth bass is absent, but this still restricts its range quite a lot. It is also listed as Endangered by the

Nature Conservation Ordinance Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are p ...

of Western Cape Province. For the time being, it may not be killed or caught. Considerable populations are found in the

Cederberg Wilderness Area The Cederberg mountains are located near Clanwilliam, approximately 300 km north of Cape Town, South Africa at about . The mountain range is named after the endangered Clanwilliam cedar (''Widdringtonia wallichii''), which is a tree end ...

, Matjies River Nature Reserve and

Oorlogskloof Nature Reserve The Oorlogskloof Nature Reserve (Afrikaans for war-gorge), covers and is located 10 km south of Nieuwoudtville in the Northern Cape, South Africa. Geography The Oorlogskloof River gorge runs along the eastern border of the reserve; the we ...

. In 2004, the

Greater Cederberg Biodiversity Corridor Greater may refer to: *Greatness, the state of being great *Greater than, in inequality * ''Greater'' (film), a 2016 American film *Greater (flamingo), the oldest flamingo on record * "Greater" (song), by MercyMe, 2014 *Greater Bank, an Australian ...

was established by CapeNature and private landowners to better preserve and develop high-quality habitat. This project aims at restoring the river ecosystems for

sustainable development Sustainable development is an organizing principle for meeting human development goals while also sustaining the ability of natural systems to provide the natural resources and ecosystem services on which the economy and society depend. The des ...

. The sawfin has been bred in captivity at the Clanwilliam Yellowfish Conservation Station, but captive breeding success is not sufficient and improved techniques are needed.

References

* (2007): Evolutionary origin of Lake Tana's (Ethiopia) small ''Barbus'' species: indications of rapid ecological divergence and speciation. '' Anim. Biol.'' 57(1): 39–48. (HTML abstract) * {{Taxonbar, from=Q2218155 Pseudobarbus Freshwater fish of South Africa Fish described in 1864 Taxa named by Wilhelm Peters Taxonomy articles created by Polbot