The smallscale redfin ('Pseudobarbus asper'') is a freshwater fish in the

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

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 v ...

which is endemic to South Africa. It is

threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensa ...

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

and the impact of

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...

Description

Its meristic data are that there are three-four

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

spines and 7 rays while the nail fin has three spines and five rays and the lateral line has 37-40 small scales. It has a single pair of barbels and the males develop dark red fins and tubercules on the head when breeding. It grows to around 12 cm total length.

Distribution

''Pseudobarbus asper'' occurs in the arid

Karoo The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe !Orakobab or Khoemana word ''ǃ’Aukarob'' "Hardveld") is a semi- desert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its ...

region of South Africa in the Gamtoos and

Gourits River Gourits River ( af, Gouritsrivier), sometimes spelled 'Gouritz River', is situated in the Western Cape, South Africa. The Gourits River flows from the confluence of the Gamka River and Olifants River and is joined by the Groot River, before flow ...

systems of the Eastern Cape in South Africa.

Biology

The smallscale redfin is found in turbid, eutrophic waters which have soft silty beds or over boulders to boulder in the Karoo region of South Africa. Its small size is understood to be an adaptation to the highly variable environment this fish inhabits, making it able to exploit food resources occurring in small spaces such as under boulders. It has a relatively long gut and this allows it to exploit a wider range of food than related species. The juvenile fish are found in sheltered areas of the rivers such as erosion gullies and areas with high levels of vegetation cover. It has a "boom and bust" population level, breeding rapidly and expanding its population when conditions are suitable allowing it to colonise temporary habitats, the fish mature early breeding in their first year, can breed more than once a year, are fast growing and short-lived, their lifespan is three years compared to up to six years of the closely related ''

Pseudobarbus afer The Eastern Cape redfin (''Pseudobarbus afer'') is an African freshwater fish species in the family Cyprinidae, this appears to be a species complex rather than a single species. It is endemic to the Sundays, Swartkops and Baakens river system ...

''. The adults are generally found in small groups. They breed during summer when they move into faster water to deposit their eggs. The eggs are deposited in mid channel crevices and have envelopes which may be slightly adhesive or not adhesive at all. After hatching the larvae are carried by the river's current to quieter stretches such as pools or backwaters where there are rich resources of food.

Conservation

The species is threatened by the invasion of its rivers by invasive fish, in particular the North African catfish ''

Clarias gariepinus ''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 sw ...

'' which has become established in the Gamtoos River and is known to have been introduced to farm dams in the catchment of the Gourits River. The fish can be encouraged to breed by the release of water from dams and impoundments to simulate a spate.

References

External links

* {{Taxonbar, from=Q509705 smallscale redfin Freshwater fish of South Africa Endemic fish of South Africa smallscale redfin Taxa named by George Albert Boulenger Taxonomy articles created by Polbot