''Hydrocynus vittatus'', the African tigerfish, tiervis or ngwesh is a predatory freshwater fish distributed throughout much of Africa. This fish is generally a

piscivore A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

but it has been observed leaping out of the water and catching barn swallows in flight. Includes a video. Includes a video.

Appearance

The African tigerfish is overall silvery in colour, with thin black stripes running horizontally. It has an elongated body and a red, forked

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

with a black edge. Its head is large, as well as its teeth, of which there are eight per jaw. The teeth are sharp and conical which are used to grasp and chop prey. They are able to replace their teeth simultaneously on the upper and lower jaws. Males are larger and more full-bodied than females. It grows to a length of SL.

Distribution

This species' distribution covers the

Niger ) , official_languages = , languages_type = National languagesBénoué, Ouémé River, Senegal River,

Nile The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest ...

Omo River The Omo River (also called Omo-Bottego) in southern Ethiopia is the largest Ethiopian river outside the Nile, Nile Basin. Its course is entirely contained within the boundaries of Ethiopia, and it empties into Lake Turkana on the border with Keny ...

Congo River The Congo River ( kg, Nzâdi Kôngo, french: Fleuve Congo, pt, Rio Congo), formerly also known as the Zaire River, is the second longest river in Africa, shorter only than the Nile, as well as the second largest river in the world by discharge ...

, Lufira,

Lualaba River The Lualaba River flows entirely within the eastern Democratic Republic of the Congo. It provides the greatest streamflow to the Congo River, while the source of the Congo is recognized as the Chambeshi. The Lualaba is long. Its headwaters are i ...

Luapula The Luapula River is a section of Africa's second-longest river, the Congo. It is a transnational river forming for nearly all its length part of the border between Zambia and the DR Congo. It joins Lake Bangweulu (wholly in Zambia) to Lake Mwe ...

Zambezi The Zambezi River (also spelled Zambeze and Zambesi) is the fourth-longest river in Africa, the longest east-flowing river in Africa and the largest flowing into the Indian Ocean from Africa. Its drainage basin covers , slightly less than hal ...

Limpopo River The Limpopo River rises in South Africa and flows generally eastward through Mozambique to the Indian Ocean. The term Limpopo is derived from Rivombo (Livombo/Lebombo), a group of Tsonga settlers led by Hosi Rivombo who settled in the mountain ...

Rovuma Ruvuma River, formerly also known as the Rovuma River, is a river in the African Great Lakes region. During the greater part of its course, it forms the border between Tanzania and Mozambique (in Mozambique known as ''Rio Rovuma''). The river is ...

Shire River The Shire is the largest river in Malawi. It is the only outlet of Lake Malawi and flows into the Zambezi River in Mozambique. Its length is . The upper Shire River issues from Lake Malawi and runs approximately before it enters shallow Lake Malo ...

and Wami River; as well as Lakes -

Lake Bangweulu Bangweulu — 'where the water sky meets the sky' — is one of the world's great wetland systems, comprising Lake Bangweulu, the Bangweulu Swamps and the Bangweulu Flats or floodplain.Camerapix: ''Spectrum Guide to Zambia.'' Camerapix Internation ...

, Mweru,

Tanganyika Tanganyika may refer to: Places * Tanganyika Territory (1916–1961), a former British territory which preceded the sovereign state * Tanganyika (1961–1964), a sovereign state, comprising the mainland part of present-day Tanzania * Tanzania Main ...

, Upemba,

Rukwa Rukwa Region (''Mkoa wa Rukwa'' in Swahili) is one of Tanzania's 31 administrative regions with a postcode number 55000. The regional capital is the municipality of Sumbawanga. According to the 2012 national census, the region had a population ...

and Malagarazi. It is also found in the

Okavango Basin The Kalahari Basin, also known as the Kalahari Depression, Okavango Basin or the Makgadikgadi basin, is an endorheic basin and large lowland area covering approximately 725,293 km2 covering most of Botswana and Namibia, as well as parts of Angol ...

and lower reaches of coastal systems south to the

Pongola River The Phongolo River is a river in South Africa. It is a tributary of the Maputo River. It rises near Utrecht in northern KwaZulu-Natal, flows east through Pongolo, is dammed at Pongolapoort, and crosses the Ubombo Mountains; then it flows north ...

and in man-made

Lake Kariba Lake Kariba is the world's largest artificial lake and reservoir by volume. It lies upstream from the Indian Ocean, along the border between Zambia and Zimbabwe. Lake Kariba was filled between 1958 and 1963 following the completion of the Karib ...

, Lake Jozini and Schroda Dam.

Ecological significance

Tigerfish are an important food and income source for locals. Not only do they provide a natural source of protein, the presence of the fish also promotes tourism through recreational and

sport fishing Recreational fishing, also called sport fishing or game fishing, is fishing for leisure, exercise or competition. It can be contrasted with commercial fishing, which is professional fishing for profit (economics), profit; or subsistence fishing ...

. As a result of their ecological and economic importance, African tigerfish have been extensively studied by conservation groups and university researchers.

Habitat and ecology

African tigerfish mainly live near the bottom of the large freshwater rivers and lakes they inhabit. During the day they tend to be found closer to the surface and then move towards the bottom at night. They thrive in highly oxygenated water in warm climates.

Population and conservation status

This species is common and widespread over most of its range. In the most studied population, that of

on the Middle

River, the population fluctuated markedly, apparently in direct relation to the abundance of the introduced

clupeid Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeoids include many of the most important food fishes in the world, and are also commonly caught for production of ...

'' Limnothrissa miodon'' which forms a major part of its diet. There is a commercial fishery in

Lake Rukwa Lake Rukwa is an endorheic lake located the Rukwa Valley of Rukwa Region, Songwe Region and Katavi Region in southwestern Tanzania. The lake is the third largest inland body of water in the country. Geography The alkaline Lake Rukwa lies midw ...

, where it forms about 3.9% of the yield. ''Hydrocynus vittatus'' have declined in some river systems in southern Africa as a result of pollution,

water abstraction Water extraction (or water withdrawal) is the process of taking water from any source, either temporarily or permanently, for flood control or to obtain water for, for example, irrigation. The extracted water could also be used as drinking wate ...

and obstructions by dams and

weirs A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...

that prevent migration. It is locally threatened by unregulated gillnet fisheries and has been placed on the South African protected species list. In east Africa, threats to populations include overfishing, reductions in water quality due to agricultural activities and deforestation, and pesticide pollution. According to the IUCN Red List of Threatened Species, tigerfish are of least concern with a wide distribution but are protected in some reserves.

Behaviour

Smaller African tigerfish can be found roaming the waters in

schools 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 compulsor ...

containing similar sized fish. Larger African tigerfish tend to live and hunt alone. The breeding habits of this fish are somewhat elusive but it is thought that breeding may take place over a couple of days during December or January. The timing depends on when the rivers and streams begin to swell due to the start of the

rainy season The rainy season is the time of year when most of a region's average annual rainfall occurs. Rainy Season may also refer to: * ''Rainy Season'' (short story), a 1989 short horror story by Stephen King * "Rainy Season", a 2018 song by Monni * '' ...

. Females will lay their eggs in submerged vegetation in shallow water close to the shore. Hatchling African tigerfish will remain in the safety of the vegetation until the water levels become low enough to force them further into the water. These fish may migrate up to 100 km within the stream or river they inhabit.

Feeding behaviour

These fish are fierce hunters and are mostly

piscivorous A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

and tend to eat whatever fish is most available. Smaller fish will hunt in large schools while larger African tigerfish hunt alone. Favoured prey fish include

cichlids Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted th ...

gobies Gobiidae or gobies is a family of bony fish in the order Gobiiformes, one of the largest fish families comprising more than 2,000 species in more than 200 genera. Most of gobiid fish are relatively small, typically less than in length, and the ...

, carp, and clariid catfish.

Insects Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...

and

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 ...

may also be part of the African tigerfish's diet, especially during juvenile stages of life. A highly unusual feeding behavior has been confirmed in the Schroda Dam population of ''Hydrocynus vittatus''. The fish jump out of the water and catch

barn swallow The barn swallow (''Hirundo rustica'') is the most widespread species of swallow in the world. In fact, it appears to have the largest natural distribution of any of the world's passerines, ranging over 251 million square kilometres globally. ...

s ''Hirundo rustica'' on the wing as they fly near the surface of the lake feeding on insects. This behaviour was speculated previously but this was the first time it had been observed during a specific research project. The researchers observed an average success rate of 25% for predation attempts, with as many as twenty birds caught per day over a relatively small lake (4.1 x 106 m³). African tigerfish were observed to pursue the birds from the surface further below the water. The depth of pursuit will affect the fish's perception of the bird due to

light refraction In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenomeno ...

in the water. It is thought that these tigerfish will pursue the bird at a depth that allows the individual to perceive the birds the easiest. This is the only documented instance of a freshwater fish exhibiting this particular behavior. Other freshwater fish have been observed catching birds that are swimming or floating on the water, but not catching them mid-flight.

Pet trade

Due to its ferocious appearance, people may be tempted to keep the African tigerfish as a pet. However, this is generally not recommended and should only be attempted by those with advanced skills in keeping

freshwater aquarium A freshwater aquarium is a receptacle that holds one or more freshwater aquatic organisms for decorative, pet-keeping, or research purposes. Modern aquariums are most often made from transparent glass or acrylic glass. Typical inhabitants inclu ...

s.African Tiger Fish, Animal-World Pet and Animal Information
/ref> These fish can get extremely large and require at least a tank. They do not get along well with any fish smaller than them (even of their own species) since smaller fish make up a majority of their diet. As they grow larger, these fish can become very difficult to handle. This is especially true because of their aggressive nature and sharp teeth. Anyone set on having one needs to check the local wildlife laws to determine if import of this fish is legal. It is illegal to import this species into

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, and

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

.African Tiger Fish ''Hydrocynus vittatus'', Live Aquaria
/ref>

References

External links

* {{Taxonbar, from=Q596263 Alestidae Freshwater fish of Africa Taxa named by François-Louis Laporte, comte de Castelnau Fish described in 1861