Cape Whitefish
Encyclopedia
The Cape Whitefish or Berg-breede River Whitefish (Barbus andrewi) is a ray-finned fish species
in the family
Cyprinidae. It is placed in the "wastebin genus" Barbus
– the typical barbels and relatives – by default. But actually it is far less closely related to the typical barbels than to the South Africa
n redfins in Pseudobarbus
, and may well belong in the latter genus. Like Pseudobarbus but unlike most other Africa
n "barbs", it is tetraploid. Its closest living relative is probably the Sawfin
(B. serra).
, where it occurs in the Breede River
's Brandvlei Dam
and Sanddrift Dam, as well as the Heks River. Formerly, it was also found in and around the Berg River
, 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.
It inhabits the deeper stretches of rivers with rocky shores or riparian trees. While young fish are common in riffle
s, adults are not rheophilic and will thrive in slow-moving water. Young fish are carnivore
s, eating zooplankton
and small aquatic
invertebrate
s. Adults have a more omnivorous diet that consist of benthic invertebrates and algae. The breeding season is in late spring (about October) when the water has warmed to above 20 °C (68 °F). Schools of adults form to migrate to riffles with over 1 meter/yard deep water and spawn
in the late hours of morning. A good-sized adult female produces about 100,000 eggs. In dam
s, it will use rocky and gravel
ly substrate in the shallows as a spawning place. The species is long-lived.
(Micropterus dolomieu), which has killed off the stocks of B. andrewi in the Berg River
watershed
by eating juveniles. In Brandvlei Dam
, where the barb's population is most healthy, the African Catfish (Clarias gariepinus) is spreading; its impact on B. andrewi will need to be assessed. The Common Carp
(Cyprinus carpio) and Mozambique Tilapia (Oreochromis mossambicus), introduced for aquaculture
, 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 of Western Cape Province. For the time being, it may not be killed and only caught for supervised transfer trials to other habitat
. There is an initiative aimed at restoring the stocks, so that this large fish can be used in fishing
and maybe aquaculture
as an alternative to the harmful introduced species.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Cyprinidae. It is placed in the "wastebin genus" Barbus
Barbus
Barbus is a ray-finned fish genus in the family Cyprinidae. The type species of Barbus is the Common Barbel, first described as Cyprinus barbus and now named Barbus barbus...
– the typical barbels and relatives – by default. But actually it is far less closely related to the typical barbels than to the South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
n redfins in Pseudobarbus
Pseudobarbus
Pseudobarbus is a ray-finned fish genus in the family Cyprinidae. The type species is Burchell's Redfin . The scientific name is derived from the Ancient Greek pseudes and the Latin word barbus . This genus contains some of the South African redfins...
, and may well belong in the latter genus. Like Pseudobarbus but unlike most other Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
n "barbs", it is tetraploid. Its closest living relative is probably the Sawfin
Sawfin
The Sawfin , also known as Clanwilliam Sawfin, is a ray-finned fish species in the family Cyprinidae. It is placed in the "wastebin genus" Barbus – the typical barbels and relatives – by default...
(B. serra).
Distribution and ecology
It is endemic to the Western Cape Province of South AfricaSouth Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, where it occurs in the Breede River
Breede River
The Breede River , is a river in the Western Cape Province of South Africa. Travelling inland north from Cape Town, the river runs in a west to east direction, the surrounding western mountains thus forming the first continental divide experienced by European settlers in the 18th century...
's Brandvlei Dam
Brandvlei Dam
Brandvlei Dam is dam on the Lower Brandvlei River in Western Cape, South Africa.- References :* from the Department of Water Affairs and Forestry...
and Sanddrift Dam, as well as the Heks River. Formerly, it was also found in and around the Berg River
Berg River
The Berg River is a river located just north of Cape Town in the Western Cape Province of South Africa. It is approximately 294 km long with a catchment area of 7,715 km² and outlets into the Atlantic Ocean. About 65% of the Berg River area is under agriculture...
, but it seems to have disappeared from there. Populations have also been transplanted to farm
Farm
A farm is an area of land, or, for aquaculture, lake, river or sea, including various structures, devoted primarily to the practice of producing and managing food , fibres and, increasingly, fuel. It is the basic production facility in food production. Farms may be owned and operated by a single...
water catchments, but it is not well known if these have thrived or failed.
It inhabits the deeper stretches of rivers with rocky shores or riparian trees. While young fish are common in riffle
Riffle
A Riffle is a short, relatively shallow and coarse-bedded length of stream over which the stream flows at higher velocity and higher turbulence than it normally does in comparison to a pool....
s, adults are not rheophilic and will thrive in slow-moving water. Young fish are carnivore
Carnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
s, eating zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
and small aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s. Adults have a more omnivorous diet that consist of benthic invertebrates and algae. The breeding season is in late spring (about October) when the water has warmed to above 20 °C (68 °F). Schools of adults form to migrate to riffles with over 1 meter/yard deep water and spawn
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
in the late hours of morning. A good-sized adult female produces about 100,000 eggs. In dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
s, it will use rocky and gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...
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 as it has declined much in recent decades. The main threat is the introduced Smallmouth BassSmallmouth bass
The smallmouth bass is a species of freshwater fish in the sunfish family of the order Perciformes. It is the type species of its genus...
(Micropterus dolomieu), which has killed off the stocks of B. andrewi in the Berg River
Berg River
The Berg River is a river located just north of Cape Town in the Western Cape Province of South Africa. It is approximately 294 km long with a catchment area of 7,715 km² and outlets into the Atlantic Ocean. About 65% of the Berg River area is under agriculture...
watershed
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
by eating juveniles. In Brandvlei Dam
Brandvlei Dam
Brandvlei Dam is dam on the Lower Brandvlei River in Western Cape, South Africa.- References :* from the Department of Water Affairs and Forestry...
, where the barb's population is most healthy, the African Catfish (Clarias gariepinus) is spreading; its impact on B. andrewi will need to be assessed. The Common Carp
Common carp
The Common carp is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia. The wild populations are considered vulnerable to extinction, but the species has also been domesticated and introduced into environments worldwide, and is often considered an invasive...
(Cyprinus carpio) and Mozambique Tilapia (Oreochromis mossambicus), introduced for aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
, are competing with the Cape Whitefish for food. Water pollution
Water pollution
Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....
is also a problem.
It is also listed as Endangered by the Nature Conservation Ordinance of Western Cape Province. For the time being, it may not be killed and only caught for supervised transfer trials to other habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
. There is an initiative aimed at restoring the stocks, so that this large fish can be used in fishing
Fishing
Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....
and maybe aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
as an alternative to the harmful introduced species.