Nile Perch

The scientific name Nile Perch is Lates niloticus, it is also known as the Goliath perch, African snook, Giant lates, or the Victoria perch. It is a species of freshwater fish that belongs to the family Latidae of order Perciformes. It is spread throughout the regions of the Afrotropical realm, these are considered to be native to the Nile, Congo, Niger, Senegal, Volta, Lake Turkana, Lake Chad, and other river basins. It is also found in the regions of Egypt in the brackish waters of Lake Maryut. The Nile Perch is considered as one of the cartilaginous fishes that have the importance of substantial economic and food security in the regions of East Africa. Originally these are described as Labrus niloticus, the species are also been referred to as Centropomus niloticus among the marine wrasses. Common names include Victoria perch, African snook, and many local names are given in various African languages.

The Nile Perch also carries enough amounts of parasites and diseases in its gills and some other areas of its body. These are considered detrimental to the health of several other species that are native to the area that cannot fight off these viruses. This is letting the overall present biodiversity and the richness of the respective ecosystem at risk and it is promptly declining. Their fast rate of reproduction and the domination of this fish in waters make it one of the most dangerous and invasive species. Over three hundred native species of the fishes have already gone to the stage of extinction due to the effects that have occurred to the Nile Perch. Lake Victoria, which is a freshwater lake, was another example of a water source or an ecosystem service, which has been getting affected negatively by the Nile Perch due to the process of eutrophication and pollution.

[Image will be Uploaded Soon]

Nile Perch-Lake Victoria

One of the most cited examples which can have negative effects on alien species present in the ecosystem happens due to the introduction of this species to Lake Victoria. The Nile perch was introduced to Lake Victoria in the 1950s in the regions of East Africa and since then it is fished commercially. In the year 2003, the Nile perch was exported to the EU where it reached sales of about 169 million euros. In the region of Uganda and Tanzania, sport-fishing provided an additional income from tourism. Its introduction of these species was ecologically attributed with causing the extinction or near-extinction of the several hundreds of native species. Some populations were found fluctuating with commercial fishing and the stocks of actual Nile perch. The Nile perch initially fed on available cichlids that are native, due to the decreasing availability of this prey, it now depends mainly on the small shrimp and minnows for the purpose of consumption.

The introduction of the Nile perch has also had severe additional ecological effects on the shore. Native cichlids found in Lake victoria were traditionally sun-dried, but because Nile perch have a high-fat content and it is higher than cichlids, they are to be smoked in order to avoid spoiling. This in turn led to an increased demand for firewood in a region that already facing deforestation, desertification, and soil erosion.

On Lake Victoria, the only trawlers that were present belong to the research institutes. Small-scale fishing boats present are mostly propelled by sails, whereas paddles are being used on the smallest boats. However, the number of boats that are propelled by outboard engines was raised, this denotes a greater capital intensity for the fishery in local Nile perch areas. If there are one to three fishermen then they make use of a boat. The fishes are caught mainly with the help of gill nets and hand lines and sometimes by using long lines. The fishes which are caught by gill nets are usually found dead when the nets are lifted. The fish that are placed in the boat without any kind of protection or ice is taken mostly to the beaches. They were weighed and purchased by the company buyers using certain insulated boats or vans which consist of ice, or the fish that are bought by local women.

The fishery also indirectly generates employment for additional fish transporters, processors, factory employees, and others. All along the shores of the lake, “boomtowns” have been developed in response to the demand created for fishing crews.

Nile Perch Fish Description

We have gained information about the improvements, advantages, and losses that occurred about Nile perch - Introduction to Lake Victoria, now let us learn about the Nile perch.

1. Geographic Range: Lates niloticus or Nile perch is widely spread throughout the Ethiopian Region of Africa, and found occurring commonly in all the major river basins including Niger, Nile, Senegal, Chad, and Volta. The nilotic population penetrates towards the north into the geographical limits of the region of the Mediterranean sea and it is present in the waters of Lake Mariout that is situated in the Nile Delta. Towards the South, the distribution includes the parts of the Congo Basin region. The most common place to find the species of Nile perch is in Lake Victoria where the species was introduced in the year 1962.

2. Habitat: Nile perch are found majorly in freshwater. They prefer warm and tropical waters where they can grow to large sizes and these occur in higher densities. Adult Nile perch is capable of occupying all the habitats in lakes and rivers where there is enough amount of oxygen content. This excludes the swamps, rocks, and the pelagic zone.

3. Physical Description: Nile perch fishes are silver in color which has a blue tinge on it. These consist of a distinctive dark black eye which has a bright yellow outer ring. Nile perch are usually found are about two-four kgs but which have been caught and seen are at sizes up to 200 kg. The average length is around 85-100 cm but these can grow to 193 cm. The female fishes are generally larger compared to male fishes. The preopercle and pre-orbital bones of these fishes are armed with the spines; it consists of a large spine on their free edges of the operculum.

4. Reproduction: Nile perch fishes are sexually dimorphic in nature. The male fishes have only anal and urogenital openings which are present just anterior to the anal fin, whereas the female fishes have a genital orifice that can be separated from the urinary opening. These become sexually mature at the age of three years. The ovulation process takes place in the spring season with the rising temperature of the water. The spawning process usually occurs in sheltered areas but it can also occur in open waters.

5. Lifespan or Longevity: Nile perch fish can live up to the age of sixteen years. There is a higher rate of mortality for males than compared to females.

6. Food Habits: The diet of Nile perch includes insects, fishes, crustacea, and some mollusks. This type of prey is ingested by the predators on the size of predators, availability of prey, and abundance within a given habitat. Juvenile Nile perch feed on copepods, prawns in the genus Caridina, fish fry, small gastropods, and bivalves. As the fish matures and moves to greater depths haplochromine cichlids constitute over 95% of their food consumption. Occasional items found in the Nile perch's diet include smaller fish in the genera Barbus, Clarias, Haplochromis, Lates, Oreochromis, and Xenoclarias. 

7. Ecosystem Roles: The Nile perch acts as a major predator in its native and introduced habitats. Nile perch have been observed with several different kinds of parasites, Lernea, arguilids, and various nematodes.