Nile perch | |
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Lates niloticus | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Perciformes |
Family: | Latidae |
Genus: | Lates |
Species: | L. niloticus |
Binomial name | |
Lates niloticus | |
Synonyms | |
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The Nile perch (Lates niloticus), also known as the African snook, Goliath perch, African barramundi, Goliath barramundi, Giant lates or the Victoria perch, is a species of freshwater fish in family Latidae of order Perciformes. It is widespread throughout much of the Afrotropical realm, being native to the Congo, Nile, Senegal, Niger and Lake Chad, Volta, Lake Turkana, and other river basins. It also occurs in the brackish waters of Lake Maryut in Egypt. The Nile perch is a fish of substantial economic and food-security importance in East Africa. [2] Originally described as Labrus niloticus, among the marine wrasses, the species has also been referred to as Centropomus niloticus. Common names include African snook, Victoria perch (a misleading trade name, as the species is not native to Lake Victoria, though they have been introduced there), and many local names in various African languages, such as the Luo name mbuta or mputa. In Tanzania, it is called sangara, sankara, or chenku. In Francophone African countries, it is known as capitaine. Its name in the Hausa language is giwan ruwa, meaning "water elephant".
L. niloticus is silver in color with a blue tinge. It has distinctive dark-black eyes, with a bright-yellow outer ring. One of the largest freshwater fishes, it reaches a maximum length of nearly 2 m (6 ft 7 in), weighing up to 200 kg (440 lb). [3] Mature fish typically range from 1.21–1.37 m (4 ft 0 in – 4 ft 6 in), although many fish are caught before they can grow this large. [4]
Adult Nile perch occupy all habitats of a lake with sufficient oxygen concentrations, while juveniles are restricted to shallow or nearshore environments. A fierce predator that dominates its surroundings, the Nile perch feeds on fish (including its own species), crustaceans, molluscs, and insects; the juveniles also feed on zooplankton. [5] Nile perch use schooling as a mechanism to protect themselves from other predators. [6] [7]
Nile perch have been introduced to many other lakes in Africa, including Lake Victoria and the artificial Lake Nasser. The World Conservation Union's Invasive Species Specialist Group considers L. niloticus one of the world's 100 worst invasive species. [8]
The state of Queensland in Australia levies heavy fines on anyone found in possession of a living Nile perch, since it competes directly with the native barramundi, which is similar and grows to 1.5 m (4 ft 11 in) long, while the Nile perch grows to 2.0 m (6 ft 7 in) long. [9]
The species is of great commercial importance as a food fish. The Nile perch is also popular with sport anglers, as it attacks artificial fishing lures, and it is also raised in aquaculture. [10]
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The introduction of this species to Lake Victoria is one of the most cited examples of the negative effects alien species can have on ecosystems. [12]
The Nile perch was introduced to Lake Victoria in East Africa in the 1950s, [13] [14] and has since been fished commercially. In 2003, Nile perch sales to the EU reached 169 million euros. Sport-fishing in the region of Uganda and Tanzania provided additional income from tourism.
Its introduction was ecologically disruptive and is attributed with causing the extinction or near-extinction of several hundred native species, with some populations fluctuating with commercial fishing and the actual Nile perch stocks. The Nile perch initially fed on native cichlids, but with decreasing availability of this prey, it now consumes mainly small shrimp and minnows.
The alteration of the native ecosystem had disruptive socioeconomic effects on local communities bordering the lake. Many local people have been displaced from their traditional occupations in the fishing trade and brought them into the cash economy, or before the establishment of export-oriented fisheries, turned them into economic refugees. At least initially, nets strong enough to hold adult Nile perch could not be manufactured locally and had to be imported for a high price. [15]
The introduction of Nile perch has also had additional ecological effects on shore. Native cichlids were traditionally sun-dried, but because Nile perch have a high fat content (higher than cichlids), they need to be smoked to avoid spoiling. This has led to an increased demand for firewood in a region already hard-hit by deforestation, soil erosion, and desertification.
The Academy Award-nominated documentary Darwin's Nightmare by Hubert Sauper (a French-Austrian-Belgian production, 2004) deals with the damage that has been caused by Nile perch introduction, including the import of weapons and ammunition in cargo planes from Europe, which are then used to export Nile perch, further exacerbating conflict and misery in the surrounding regions. [16]
Regardless of whether it is considered positive or negative, [17] the trophic web of Lake Victoria appears to have been drastically impoverished by the introduction of this novel near-top-level predator. While the ecosystem seems to be moving towards a new equilibrium, neither its former state nor the state of fisheries on Lake Victoria can ever easily be brought back. [18] [19] [20]
Despite being a successful invasive species, the fish faces threats. Being a species of megafauna, the most obvious threats to the species are overfishing and the use of illegal fishing gear, as well as invasive water hyacinths. Prey depletion is also a factor, as it decreases the size of the fish and makes it vulnerable to larger predators, such as crocodiles.[ citation needed ]
In 2021, The Uganda Fish Processors and Exporters Association called on the parliament to ban the local consumption of the species so as to protect its export. [21]
Nile perch were involved with the worship of Neith. [22] As a result nile perch were sometimes mummified. [22] A deposit of several thousand mummified perch was excavated in an area to the west of Esna where there was a temple to Neith. [23] Mummified perch have also been found at Gurob near a temple to Neith while perch statuettes have been found at Sais again in the context of a temple to Neith. [23]
Perch is a common name for freshwater fish from the genus Perca, which belongs to the family Percidae of the large order Perciformes. The name comes from Greek: πέρκη, romanized: perke, meaning the type species of this genus, the European perch.
Cichlids are fish from the family Cichlidae in the order Cichliformes. Traditionally Cichlids were classed in a suborder, the Labroidei, along with the wrasses (Labridae), in the order Perciformes, but molecular studies have contradicted this grouping. On the basis of fossil evidence, it first appeared in Tanzania during the Eocene epoch, about 46–45 million years ago. The closest living relative of cichlids is probably the convict blenny, and both families are classified in the 5th edition of Fishes of the World as the two families in the Cichliformes, part of the subseries Ovalentaria. This family is large, diverse, and widely dispersed. At least 1,650 species have been scientifically described, making it one of the largest vertebrate families. New species are discovered annually, and many species remain undescribed. The actual number of species is therefore unknown, with estimates varying between 2,000 and 3,000.
Lake Victoria is one of the African Great Lakes. With a surface area of approximately 59,947 km2 (23,146 sq mi), Lake Victoria is Africa's largest lake by area, the world's largest tropical lake, and the world's second-largest fresh water lake by surface area after Lake Superior in North America. In terms of volume, Lake Victoria is the world's ninth-largest continental lake, containing about 2,424 km3 (1.965×109 acre⋅ft) of water. Lake Victoria occupies a shallow depression in Africa. The lake has an average depth of 40 m (130 ft) and a maximum depth of 80–81 m (262–266 ft). Its catchment area covers 169,858 km2 (65,583 sq mi). The lake has a shoreline of 7,142 km (4,438 mi) when digitized at the 1:25,000 level, with islands constituting 3.7% of this length.
Tilapia is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes, with the economically most important species placed in the Coptodonini and Oreochromini. Tilapia are mainly freshwater fish inhabiting shallow streams, ponds, rivers, and lakes, and less commonly found living in brackish water. Historically, they have been of major importance in artisanal fishing in Africa, and they are of increasing importance in aquaculture and aquaponics. Tilapia can become a problematic invasive species in new warm-water habitats such as Australia, whether deliberately or accidentally introduced, but generally not in temperate climates due to their inability to survive in cold water.
Lake Kyoga or Lake Kioga is a large shallow lake in Uganda, about 1,720 km2 (660 sq mi) in area and at an elevation of 1,033 metres. The Victoria Nile flows through the lake on its way from Lake Victoria to Lake Albert. The main inflow from Lake Victoria is regulated by the Nalubaale Power Station in Jinja. Another source of water is the Mount Elgon region on the border between Uganda and Kenya. While Lake Kyoga is part of the African Great Lakes system, it is not itself considered a great lake.
The barramundi, Asian sea bass, or giant sea perch is a species of catadromous fish in the family Latidae of the order Perciformes. The species is widely distributed in the Indo-West Pacific, spanning the waters of the Middle East, South Asia, Southeast Asia, East Asia, and Oceania.
Lates is a genus of freshwater and euryhaline lates perches belonging to the family Latidae. The generic name is also used as a common name, lates, for many of the species.
The Latidae, known as the lates perches, are a family of perch-like fish found in Africa, Asia, and the Indian and western Pacific Oceans. Including about 13 species, the family, previously classified subfamily Latinae in family Centropomidae, was raised to family status in 2004 after a cladistic analysis showed the original Centropomidae were paraphyletic.
Bruce Kinloch MC was a British army officer, wildlife conservation leader and author.
Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations.
Lake Kwania is in the districts of Lira, Apac and Amolatar in the Northern Region of Uganda. It is part of a large wetland along the White Nile between Lake Victoria and Lake Albert. The wetland, which includes Lake Kwania, the even larger Lake Kyoga, and other water bodies and swamps, consists of about 3,420 square kilometres (1,320 sq mi) of open water and about 2,180 square kilometres (840 sq mi) of permanent swamps. Of this total, Lake Kwania accounts for 540 square kilometres (210 sq mi), about 16 percent, of the open water.
The silver cyprinid also known as the Lake Victoria sardine, mukene, and omena, dagaa (Swahili) is a species of pelagic, freshwater ray-finned fish in the carp family, Cyprinidae from East Africa. It is the only member of the genus Rastrineobola.
Oreochromis esculentus, the Singida tilapia or Graham's tilapia, is a species of cichlid endemic to the Lake Victoria basin, including some of its satellite lakes such as Kyoga, in Tanzania, Uganda, and Kenya. Its common name refers to Lake Singida, but this population is the result of an introduction that happened in the 1950s. This fish is highly valued by local fishermen, who know it as ngege.
There are two major sources of fish in Uganda; one is from aquaculture, the other from fishing in rivers and lakes. The latter has made up the largest and most significant share of all fishing. Open water covers 15.3 percent of Uganda's surface and comprises five major lakes which are the main sources of fish in the country. Lake Victoria continues to be the most important water body in Uganda both in size and contribution to the total fish catch, followed by Lake Albert and Lake Kyoga.
Lake Victoria supports Africa's largest inland fishery, with the majority of the catch being the invasive Nile perch, introduced in the Lake in the 1950s.
This is a list of notable events relating to the environment in 1954. They relate to environmental law, conservation, environmentalism and environmental issues.
Haplochromis vonlinnei is a species of cichlid endemic to Lake Victoria. It is greyish in color with a distinct mid-lateral band, and a rather slender shape. It feeds mainly on smaller fish. This species can reach a length of 15.9 centimetres (6.3 in) SL. The population of the species has declined due to the introduction of the Nile perch in the 1950s. It has not been recorded since 1980 and the IUCN lists it as "Critically Endangered" and considers it may already be extinct. This fish is named in honour of the Swedish naturalist, Carl Linnaeus.
There are two major sources of fish in Uganda; one is from aquaculture, the other from fishing in rivers and lakes. Different types of fish flourish in different water sources. The waters of Uganda contain an impressive array of fish species—over 90 in all. This count does not include the Haplochromis complex, which itself is made up of more than 200 species.
Fishing gear and methods used in Uganda are both modern and traditional. Fish in Uganda are caught mostly with plank canoes and to a lesser extent, fiberglass boats. Some dugout canoes are also still being used. The plank canoes are generally 4–12 m (13.12–39.37 ft) in length and dugout canoes average 3.5 m (11.48 ft). The total number of vessels is about 17,000 and about 20% of these are motorized. Artisanal fishermen use various gear including gillnets, seines and hook and line. In a number of localities, traditional methods including baskets, traps and mosquito nets continue to be used. The gear commonly used includes gillnets, lift nets, scoop-nets used in light fishing; hook and line gear and fish traps.
Lake Victoria supports Africa's largest inland fishery, with the majority of present catch being the invasive Nile perch, introduced to the Lake in the 1950s. Prior to the introduction of Nile perch as well as Nile tilapia, the fish community was very different and consisted mainly of 'Ngege' and Victoria tilapia as well as vast numbers of Haplochromis species. Fish communities in the first half of the 20th century are known primarily from a unique fisheries survey conducted in 1927-1928 by the Colonial Office.