Clarias gariepinus
Encyclopedia
Clarias gariepinus or African sharptooth catfish is a species of catfish
of the family Clariidae, the airbreathing catfishes.
and the Middle East
and live in freshwater lake
s, river
s, swamp
s, as well as human-made habitats, such as oxidation ponds
or even urban sewage systems.
The African sharptooth catfish has been moved all over the world in the early 80s for rearing purposes and is therefore found in countries far outside its natural habitat like Brazil
, Vietnam
and India
.
, this catfish is second in size only to the Vundu of the Zambesian waters. Clarias gariepinus has an average adult length of 1-1.5 meters. These fish have slender bodies, a flat bony head, notably flatter than in the genus Siluris
, and a broad, terminal mouth with four pairs of barbels. They also have a large, accessory breathing organ composed of modified gill
arches. Also, only the pectoral fins have spines. They can weigh up to 29 kg.
. It is also able to crawl on dry ground to escape drying pools. Furthermore, 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
.
There is no parental care for ensuring the survival of the catfish offspring 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.
It grows fast and feeds on a large variety of agriculture by-products.
It is hardy and can tolerate 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 fetch a higher price as tilapia's as it can be sold live at the market.
It matures and is relatively easy to reproduce in captivity.
Catfish
Catfishes 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 heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
of the family Clariidae, the airbreathing catfishes.
Natural Distribution
They are found throughout AfricaAfrica
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...
and the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
and live in freshwater lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s, river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s, as well as human-made habitats, such as oxidation ponds
Sewage treatment
Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants...
or even urban sewage systems.
The African sharptooth catfish has been moved all over the world in the early 80s for rearing purposes and is therefore found in countries far outside its natural habitat like Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
and India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
.
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 AfricaAfrica
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...
, this catfish is second in size only to the Vundu of the Zambesian waters. Clarias gariepinus has an average adult length of 1-1.5 meters. These fish have slender bodies, a flat bony head, notably flatter than in the genus Siluris
Wels catfish
The wels catfish , also called sheatfish, is a large catfish found in wide areas of central, southern, and eastern Europe, and near the Baltic and Caspian Seas. It is a scaleless fresh and brackish water fish recognizable by its broad, flat head and wide mouth...
, and a broad, terminal mouth with four pairs of barbels. They also have a large, accessory breathing organ composed of modified gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
arches. Also, only the pectoral fins have spines. They can weigh up to 29 kg.
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 MoorhenCommon Moorhen
The Common Moorhen is a bird in the Rallidae family with an almost worldwide distribution. The North and South American Committees of the AOU and the IOC have voted on or before July 2011 to split the American forms into a new species Common Gallinule, however, no other committee has voted to...
. It is also able to crawl on dry ground to escape drying pools. Furthermore, 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
Crow
Crows form the genus Corvus in the family Corvidae. Ranging in size from the relatively small pigeon-size jackdaws to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents and several...
.
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 is held for several seconds. A batch of milt 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 rest after mating (from seconds up to several minutes) and then resume mating.There is no parental care for ensuring the survival of the catfish offspring 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 of African catfish
The rearing of the African sharptooth catfish in Africa started in the early seventies in Central and Western Africa as it was realized that it was a very suitable species for aquaculture as:It grows fast and feeds on a large variety of agriculture by-products.
It is hardy and can tolerate 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 fetch a higher price as tilapia's as it can be sold live at the market.
It matures and is relatively easy to reproduce in captivity.
External links
- All Catfish Species Inventory
- Handbook on the rearing and artificial reproduction of the African catfish http://aquanic.org/species/catfish/documents/Clarias.pdf
- The African catfish http://cdserver2.ru.ac.za/cd/catfish/catfish/
- Chari in the Bari, Homestead rearing of African catfish http://www.nefisco.org/Chari%20in%20the%20Bari.htm