The Cape whitefish or Berg-breede River whitefish (''Pseudobarbus capensis'') is a

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

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 ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

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 Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

n 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 Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains ...

. 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 Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Western Cape Province The Western Cape is a province of South Africa, situated on the south-western coast of the country. It is the fourth largest of the nine provinces with an area of , and the third most populous, with an estimated 7 million inhabitants in 2020 ...

, where it occurs in the

Breede River The Breede River ( af, Breederivier), also known as Breë River, is a river in the Western Cape Province of South Africa. Travelling inland north from the city of Cape Town, the river runs in a west to east direction. The surrounding western mou ...

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 Afri ...

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 A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used fo ...

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 A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...

trees. While young fish are common in

riffle A riffle is a shallow landform in a flowing channel. Colloquially, it is a shallow place in a river where water flows quickly past rocks. However, in geology a riffle has specific characteristics. Topographic, sedimentary and hydraulic indica ...

s, adults are not

rheophilic A rheophile is an animal that prefers to live in fast-moving water. Examples of rheophilic animals Insects *Many aquatic insects living in riffles require current to survive. *''Epeorus sylvicola'', a rheophilic mayfly species ( Ephemeroptera) ...

and will thrive in slow-moving water. Young fish are

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

s, eating

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

and small aquatic

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s. Adults have more

omnivorous 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 nutri ...

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

alga Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mi ...

e. The breeding season is in late spring (about October) when the water has warmed to above .

School A school is an educational institution designed to provide learning spaces and learning environments for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is sometimes compuls ...

s of adults form to migrate to riffles with over one meter/yard deep water and

spawn Spawn or spawning may refer to: * Spawn (biology), the eggs and sperm of aquatic animals Arts, entertainment, and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** '' Spawn: Ar ...

in the late hours of morning. A good-sized adult female produces about 100,000 eggs. In

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...

s, 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 An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

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'') 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 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''), 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 Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water ...

is also a problem. It is also listed as endangered by the Nature Conservation Ordinance of

. For the time being, it may not be killed and only caught for supervised transfer trials to other

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s. An initiative is aimed at restoring the stocks, so this large fish can be used in

fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment, but may also be caught from stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques inclu ...

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