The Cape whitefish or Berg-breede River whitefish (''Pseudobarbus capensis'') 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 was at one time considered the

sawfin The sawfin (''Pseudobarbus serra''), also known as Clanwilliam sawfin, 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 is proba ...

(''P. serra'').

Distribution and ecology

It is endemic to the Western Cape Province of South Africa, where it occurs in the Breede River's

Brandvlei Dam Brandvlei Dam is an earth-fill type dam on the Lower Brandvlei River in Western Cape, South Africa. It was completed in 1983 and the inlet is the Holsloot River. See also *List of reservoirs and dams in South Africa *List of rivers of South Afric ...

and Sanddrift Dam, as well as the Hex River. Formerly, it was also found in and around the

Berg River The Berg River (also called Great Berg River or in Afrikaans: Bergrivier) is a river located just north of Cape Town in the Western Cape Province of South Africa. It is approximately 294 km (183 mi) long with a catchment area of 7,715& ...

, but it seems to have disappeared from there. Populations have also been transplanted to farm water catchments, but it is not well known if these have thrived or failed.Impson & Swartz (2007) It inhabits the deeper stretches of rivers with rocky shores or riparian trees. While young fish are common in riffles, adults are not rheophilic and will thrive in slow-moving water. Young fish are carnivores, eating zooplankton and small aquatic invertebrates. Adults have more omnivorous diets that consist of

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

invertebrates and algae. The breeding season is in late spring (about October) when the water has warmed to above . Schools of adults form to migrate to riffles with over one meter/yard deep water and spawn in the late hours of morning. A good-sized adult female produces about 100,000 eggs. In dams, it will use rocky and

gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

ly substrate in the shallows as a spawning place. The species is long-lived.

Status and conservation

This species is considered Endangered 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 in recent decades. The main threat is the introduced smallmouth bass (''Micropterus dolomieu''), which has killed off the stocks of the fish in the

watershed Watershed is a hydrological term, which has been adopted in other fields in a more or less figurative sense. It may refer to: Hydrology * Drainage divide, the line that separates neighbouring drainage basins * Drainage basin, called a "watershe ...

by eating juveniles. In

, where the barb's population is most healthy, the

African catfish ''Clarias gariepinus'' or African sharptooth catfish is a species of catfish of the family Clariidae, the airbreathing catfishes. Distribution They are found throughout Africa and the Middle East, and live in freshwater lakes, rivers, and swa ...

(''Clarias gariepinus'') is spreading; its impact will need to be assessed. The

common carp The Eurasian carp or European carp (''Cyprinus carpio''), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Arkive The ...

(''Cyprinus carpio'') and Mozambique tilapia (''Oreochromis mossambicus''), introduced 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 ...

, are competing with the Cape whitefish for food. Water pollution is also a problem. 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 and only caught for supervised transfer trials to other habitats. An initiative is aimed at restoring the stocks, so this large fish can be used in fishing and maybe

as an alternative to the harmful introduced species. There are many reasons as to why the population of the cape whitefish have recently been declining, with human-related activity being one of them. A severe flood in 2008 as well as invasions of other predatory fish species are a likely cause of the decline as well. In order to prevent further decline, there are conservation actions in place such as managing non-native fish invasions as well as lessening the agricultural impact on aquatic habitat.

Footnotes

References

* * {{Taxonbar, from=Q302487 Pseudobarbus Freshwater fish of South Africa Fish described in 1841 Taxa named by Andrew Smith (zoologist) Taxonomy articles created by Polbot