The Kapenta fish is widely known by two names, the Lake Tanganyika Sardine, and Matemba. Matemba is a commonly used term used in Zimbabwe, Zambia, and Malawi.
This sardine is divided into two species:
The scientific name is the Limnothrissa modern and it is the most common.
It is a species of freshwater fish in the family of Clupeidae. The kapenta originated from Lake Tanganyika hence the name Lake Tanganyika Sardine.
The sardine species was later introduced to several lakes in Africa. The expansive Lake Kariba is among the few lakes where this species was artificially introduced.
The species is found in Lake Tanganyika extending into the Malagarasi River. Lake Tanganyika is where the species originated.
It is also found in:
They are a small silver fish with a brighter stripe down the lateral line. It also has a broad snout with tapering sides.
It has a very large swim bladder which allows it to travel long vertical distances in the water.
The species reaches a maximum length of 17 centimeters in adulthood.
Kapenta are known for vertical migration. This is thought to be inspired by following food sources, which include zooplankton.
However, in Lake Kariba, these movements are created by the fish responding to light intensity.
This means they spend the day in tight shoals in deep water and they rise to the surface at dawn and dusk.
They spend the remainder of the night widely spread throughout the shallows of the Lake.
However, this behavior is different from the species found in Lake Kivu. There they rise to the surface during the early morning and late afternoon.
The young prefer clear water of around 1.5 meters deep with a rocky or sandy bottom. They like to dwell in areas with steep shores too.
The adults move into deeper water as they grow bigger.
For this reason, they are generally found in depths of no more than 20 meters.
The adults move into the shallow water to reproduce, which is during the rainy season.
The months where reproduction is high are in the periods between May and June. Also favorable is the period between December and January.
However, reproduction has been recorded throughout the year.
The ability to produce more eggs depends on the length of the fish. The longer the length the higher the number of eggs produced.
Studies in lake Kariba and Lake Tanganyika have proved this.
Kapenta with a length of 11,4 cm produced 14,044 in Lake Kariba. Fish with a length of 14cm in lake Tanganyika produced 55,000 eggs.
These fish are omnivorous, which means they mainly feed on zooplankton and phytoplankton. They will feed on the most abundant prey in the area, including insects.
Insects are usually eaten at dusk when the fish comes to the surface.
The kapenta in Lake Kariba are smaller than they are in Lakes Tanganyika and Kivu. This because of their diet.
The absence of shrimps in Lake Tanganyika as a source of food has led to small-sized fish. While the small size in Kariba is a result of their unstable environment.
This instability is caused by various factors. A low level of water retention and a high level of predation by the voracious Tiger fish.
They are easily caught at night due to their feeding behavior.
The fish are caught commercially by kapenta rigs. These rigs use LED lights or kerosene lamps to attract the fish to the rig.
In this way, large quantities are caught very quickly.
The conservation status shows that it is not yet in danger. However, they has been a decline in the population.
This is largely due to overfishing and unorthodox fishing methods.
The authorities have placed laws to manage fishing habits. It is now illegal to fish in shallow water of fewer than 20 meters.
It is in these shallow waters where most of the breeding occurs.
Authorities have also introduced licenses to control and monitor fishing.
Kapenta is a source of food for many people in Zambia, Malawi, and Zimbabwe.
They are usually sold fresh and dried. Fresh kapenta is generally more expensive as compared to dried.
To dry the fish for selling it is mixed with salt at a ratio of 2.5 kg of salt as to 30kgs. It is then dried in the sun on a clean surface or drying racks which give favorable results.
Drying can take from 1 to several days depending on the Kariba weather. The rainy season presents losses for fishermen.
The rain disturbs the drying process hence lowering quality and price.
Kapenta is also used as chicken feed. It is cheap as well as being nutritious for poultry.
Kapenta remains one of the most eaten fish in the African community. It is one of the cheapest proteins one can find.
However, due to overfishing, availability is at risk. There is now a need to start preserving this wonderful species.