''Clarias gariepinus'' or African sharptooth catfish is a species of
catfish
Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive ...
of the family
Clariidae, the airbreathing catfishes.
Distribution
They are found throughout
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
and the
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...
, and live in freshwater
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
s,
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of w ...
s, and
swamps, as well as human-made habitats, such as
oxidation ponds
Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding envir ...
or even urban sewage systems.
The African sharptooth catfish was introduced all over the world in the early 1980s for
aquaculture purposes, so is found in countries far outside its natural habitat, such as
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
,
Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
,
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
, and
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
.
Description
The African sharptooth catfish is a large, eel-like fish, usually of dark gray or black coloration on the back, fading to a white belly. In Africa, this catfish has been reported as being second in size only to the
vundu
The vundu (''Heterobranchus longifilis'') is a species of large airbreathing catfish found widely in rivers and other freshwater habitats of sub-Saharan Africa, as well as the Nile. It is also called the sampa, cur, lenda, or certa.
Description ...
of the
Zambesian waters,
[Ecotravel South Africa]
although
FishBase suggests the African sharptooth catfish surpasses that species in both maximum length and weight.
[
''C. gariepinus'' has an average adult length of . It reaches a maximum length of TL and can weigh up to .] These fish have slender bodies, flat bony heads, notably flatter than in the genus ''Silurus
''Silurus'' is a genus of catfishes
Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior ...
'', and broad, terminal mouths with four pairs of barbels
In fish anatomy and turtle anatomy, a barbel is a slender, whiskerlike sensory organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and some s ...
. They also have large accessory breathing organs composed of modified gill
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...
arches. Also, only the pectoral fins have spines.[
]
Habits
It is a nocturnal fish like many catfish. It feeds on living, as well as dead, animal matter. Because of its wide mouth, it is able to swallow relatively large prey whole. It has been known to take large waterbirds such as the common moorhen
The common moorhen (''Gallinula chloropus''), also known as the waterhen or swamp chicken, is a bird species in the rail (bird), rail family (Rallidae). It is distributed across many parts of the Old World.
The common moorhen lives around well-v ...
. It is also able to crawl on dry ground to escape drying pools. Further, it is able to survive in shallow mud for long periods of time, between rainy seasons.
African catfish sometimes produce loud croaking sounds, not unlike the voice of the crow
A crow is a bird of the genus '' Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifica ...
.
Natural spawning
Spawning mostly takes place at night in the shallow, inundated areas of the rivers lakes and streams. Courtship is preceded by highly aggressive encounters between males. Courtship and mating takes place in shallow waters between isolated pairs of males and females. The male lies in a U-shape curved around the head of the female, held for several seconds. A batch of milt
Milt is the seminal fluid of fish, mollusks, and certain other water-dwelling animals which reproduce by spraying this fluid, which contains the sperm, onto roe (fish eggs). It can also refer to the sperm sacs or testes that contain the seme ...
and eggs is released followed by a vigorous swish of the female's tail to distribute the eggs over a wide area. The pair usually rests after mating (from seconds up to several minutes) and then resumes mating.
Parental care for ensuring the survival of the catfish offspring is absent except by the careful choice of a suitable site. Development of eggs and larvae is rapid, and the larvae are capable of swimming within 48–72 hours after fertilization.
Rearing
The rearing of the African sharptooth catfish in Africa started in the early 1970s in Central and Western Africa, as it was realized to be a very suitable species for aquaculture, as:
* It grows fast and feeds on a large variety of agriculture byproducts
* It tolerates adverse water quality conditions
* It can be raised in high densities, resulting in high net yields (6–16 t/ha/year).
* In most countries, it fetches a higher price than tilapia
Tilapia ( ) is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes (formerly all were "Tilapiini"), with the economically most ...
, as it can be sold live at the market
* It matures and relatively easily reproduces in captivity.
* It tolerates difficult conditions in aquaculture
Hybridisation
''Clarias gariepinus'' could be easily crossed with '' Heterobranchus longifillis'' to get the so-called hybrid ''Hetero-clarias''. This cross has advantages over ''C. gariepinus'':
* Cannot reproduce (so does not spend energy on reproduction)
* Has white meat (usually preferred by customers)
A major disadvantage of the'' Hetero-clarias'' hybrid, though, is its susceptibility to stress.
Parasites and diseases
''C. gariepinus'' may host several species of digeneans, in addition to other endo- and ectoparasites.[Jansen van Rensburg, C., van As, J.G. & King, P.H. 2013. New records of digenean parasites of ''Clarias gariepinus'' (Pisces: Clariidae) from the Okavango Delta, Botswana, with description of ''Thaparotrema botswanensis'' sp. n. (Plathelminthes: Trematoda). '']African Invertebrates
''African Invertebrates'' is a peer-reviewed open access scientific journal that covers the taxonomy, systematics, biogeography, ecology, conservation, and palaeontology of Afrotropical invertebrates, whether terrestrial, freshwater, or ma ...
'' 54 (2): 431–44
/ref>
References
External links
Reproduction of African catfish
African catfish - RAS Fish farming system
All Catfish Species Inventory
* Handbook on the rearing and artificial reproduction of the African catfis
* The African catfis
* Chari in the Bari, Homestead rearing of African catfis
{{Taxonbar, from=Q387344
Clarias
Freshwater fish of Africa
Taxa named by William John Burchell
Fish described in 1822