Lake Tanganyika, Lake Victoria, and Lake Malawi are the three largest freshwater lakes in Africa. They are also among the largest in the world. These names are no stranger to the aquarium enthusiast because of the typical cichlid species that occur in them.
Situation
The three lakes are located in and around the great rift valley (sometimes also called the great rift). This valley is best known for being widely regarded as the birthplace of humans. Here the first hominids are said to have developed and spread further across the world. The great valley stretches from Syria to southwest Africa. It is approximately 6400km long and has a width that varies between 30 and 100km. The rift valley was created because two tectonic plates move apart at this location. The formation of the rift valley started about 25 million years ago.
In the eastern part of the valley is Lake Malawi, in the western branch is Lake Tanganyika, and Lake Victoria is formed between these two branches.
Lake Victoria
The lake is located on the border of Uganda, Kenya and Tanzania. It is the largest lake in Africa and the second largest in the world. It covers an area of almost 69,500 km² and is the source of the Victoria Nile.
Geologically, Lake Victoria is very young, it is only 500,000 years old. About 15,000 years ago, the lake is said to have dried up completely and has since been populated with fish from the streams that flow into the lake. The cichlid species of Lake Victoria have undergone a very rapid evolution, resulting in more than 500 species at any one time. Each species with its own specific niche and food. About 95% of the more endemic cichlid species can be traced back to a common ancestor of the genus Haplochromis.
Since the Nile perch was released in the 1950s, the diversity of the fish stock has declined drastically. What seemed like an economic opportunity has turned into an ecological nightmare.
Lake Malawi
The lake was discovered by the famous explorer David Livingstone. It is approximately 560km long and up to 75km wide at its widest point. Lake Malawi is the 9th largest freshwater lake in the world. It borders Mozambique, Tanzania and Malawi (hence its name). It is best known for the many endemic species that are found nowhere else.
Lake Malawi used to be part of a colony of the British Empire called Nyassaland. That is why the name Lake Nyssa is sometimes still used. The cichlids of Lake Malawi are the most colorful of the three and can be roughly divided into two categories.
Mbuna, which houses in the rocky areas, and non-Mbuna species that prefer a more sandy surface. The water composition of Lake Malawi is similar to that of Lake Victoria. That is why fish from both lakes can sometimes be found in the same aquarium, although this is not recommended. The lake consists of approximately 2/3 rocky areas and has very clear water.
Lake Tanganyika
Lake Tanganyika is widely believed to be the second oldest and deepest lake in the world. It has an area of almost 33,000 km² and is up to 1.5 km deep at its deepest point. The lake is fed by temporary streams during the rainy season and some permanent rivers from the surrounding areas. The lake is bordered by Burundi, Congo-Kinshasa, Zambia and Tanzania. Lake Tanganyika is an important food source for the local population. In the 1980s, fishing had a huge impact on fish stocks. Fortunately, this has stabilized in recent years, but irreparable damage has nevertheless been done to the ecosystem.
Because the lake has only one outlet, the Lukuga River, the water is very mineral rich. Many minerals are supplied via the rivers that flow into the lake, but they are hardly discharged.
This lake also has very clear water. The upper water layers are very oxygenated, so it is very important to keep the temperature constant for keeping Lake Victoria cichlids in an aquarium. This is because of the delicate balance between the metabolism of the fish and the saturation of the water.
There are about 200 unique cichlid species in Lake Tanganyika, many of which are caught by the locals to sell to fishmongers.
