Lake Tanganyika.
Continued…
The stable stratification of the lake’s waters strongly affects the living conditions of hydrobionts. From a hydrobiological point of view, the most important consequence of this stratification is the fact that only the upper layers of the lake, where mixing processes take place, are enriched with dissolved oxygen and therefore suitable for life. The entire rich and diverse fauna of Tanganyika is concentrated only in the upper, oxygen-rich part of the water mass of the lake. It is believed that the lower boundary of the water layer suitable for fish habitation runs at a depth from 100 meters in the north of the lake to 230 meters in the south.
The zooplankton of the lake (dominated by copepods, with the freshwater Tanganyika jellyfish also being characteristic) is photophobic and during the day, escaping from sunlight, goes to a depth of more than 50 meters; planktivorous fish go there in search of food, and predatory fish follow them. On the contrary, with the onset of darkness, zooplankton rises to the surface, followed by fish, and the lake waters “come to life”.
Cichlids dominate in the large lakes of East Africa, accounting for 74–93% in Lake Victoria, 87% in Lake Malawi (Nyasa), and 71% in Lake Tanganyika of the entire ichthyofauna. The ichthyofauna of Tanganyika is exceptionally rich in species composition – more than 200 species of cichlids, of which more than 90% are endemic. Here, along with an abundance of endemic species, there are many variations differing in body coloration. Lake cichlids have rather strict requirements for water composition and purity. Inhabitants of Lakes Malawi and Victoria are not so demanding regarding water composition and have a higher adaptability to adverse conditions.
The fish of Lake Tanganyika are more delicate, presenting rather strict requirements for the composition and purity of water and feed. Lake Tanganyika has harder (15-20 dH) and alkaline (pH 8-8.5) water. Excessive amounts of decaying organic matter lead to the formation of toxic compounds that cause disease and death of fish. Therefore, they are kept by experienced aquarists who can afford the technical equipment and the fish themselves. The fish tolerate sharp fluctuations in pH poorly (not lower than 7.5°), require very careful water changes (no more than 1/10 per week), a temperature of 25-27°C, and for Tanganyika cichlids, the water temperature should never exceed 29°C (fatal!). Continuous filtration, aeration, and heating are mandatory.
Many cichlids from Lake Tanganyika do not have clearly expressed sexual dimorphism; only the dominant male in the school can be reliably distinguished, while other specimens may look completely identical. They are inferior in brightness and variegation to the fish of Lake Malawi. Many species of cichlids in Lake Tanganyika lead a schooling lifestyle, so an aquarium with such species can only be stocked once (and for all). While the fish of these species are juveniles, corrections can still be made to the number, species, and sex composition of the aquarium population, but once they reach the stage where sexual characteristics become distinct, fish of the same species group into a school, into which it is practically impossible to squeeze any other fish of the same species, regardless of the aquarium volume.
Within the school of Tanganyika cichlids, either pairing takes place (Lamprologus), or a dominant male is singled out, having the honorable right to be the main inseminator of the females of the school. Any new inhabitant of the aquarium (regardless of its species) is automatically recorded by the school as an enemy, and within an hour (sometimes up to several days) the newcomer is destroyed.
Keeping several species of Tanganyika cichlids sometimes also becomes problematic within a single tank, since with the arrival of the spawning season, the stronger school tends to control the entire territory allocated to it. In aquariums with schooling Tanganyika cichlids, even the sailfin pleco (Pterygoplichthys) gets harassed, and most often in such an aquarium, it will look tattered.
Males of many species acquire a characteristic fatty hump on the head with age, which noticeably distinguishes them from females. The dominant male, destined by fate to be the continuer of the line, is the first to acquire these differences, which he usually manages brilliantly. Subdominant males in most cases have an intermediate coloration between females and the dominant male.
It should also be noted that cichlids from different regions of Africa have different inclinations and temperaments, meaning they cannot be recommended for joint maintenance. Cichlids of Lakes Malawi and Victoria get along well with each other, but severely suppress their family relatives from Lake Tanganyika. Appropriate-sized shelters are necessary. Most cichlids need aquariums with sufficient swimming space, with shelters made of rocks stacked in the form of caves, turned-over flower pots, ceramic pipes, driftwood, etc.
For Tanganyika cichlids, coarse sand with a 1 cm layer and a fraction of up to 2 mm is most suitable – the natural bottom material of Lake Tanganyika. The substrate particle size directly depends on the lifestyle and size of the cichlids. For example, small shell-dwelling cichlids need a fine fraction of 0.7 – 1.5 mm; they like to arrange the space around their house and often dig in the sand, and can move or bury their house almost completely, leaving a narrow entrance.
For spawning of some rare Tanganyika cichlid species, a thicker layer of sand is required, as in their natural habitat they build crater-like nests up to 40 cm in diameter and up to 10 cm deep. However, such cichlids are usually kept in pairs in large tanks without other neighbors. Very often, many Tanganyika cichlids fade on excessively bright substrate or acquire uncharacteristic shades on unnaturally dark substrate.
Cichlids of Lake Tanganyika differ in the types of food they consume: most of them feed mainly on plant foods, and many also eat plankton. There are fish that feed only on snails or larvae of certain insects. Some species eat the scales of conspecifics. In an aquarium with inhabitants from Tanganyika, a certain lighting regime must be strictly observed. For the normal development and well-being of the fish, it is absolutely necessary that the side walls and rock structures are partially overgrown with green algae. Therefore, it is necessary to provide sufficient illumination of the body of water with artificial light sources.
The criterion for proper lighting is the rapid overgrowth of the upper half of the rock structures. The appearance of blue-green algae in the aquarium indicates an unfavorable lighting regime or salt composition of the water. Tropheini from Lake Tanganyika need a special diet composed of plant components and crustaceans. This factor must be taken into account when choosing feed for such “algae-eating” cichlids as Tanganyika Tropheus, Petrochromis, and Simochromis. Many representatives of Tanganyika cichlids feed on small species of crustaceans and snails. Many species readily eat dry foods, especially balanced combination foods.
Lake Tanganyika – main landmarks of fish habitats.
• Bangwe; Bemba; Bujumbura; Bulu Point; Bwassa;
• Cape Banza; Cape Caramba; Cape Chaitika; Cape Kabogo; Cape Kachese; Cape Kipimbi; Cape Korongwe; Cape Mpimbwe; Cape Muzimu; Cape Nangu; Cape Tembwe; Chikalakate; Chilanga; Chimba; Chisanse; Chisanza; Chituta;
• Fulwe;
• Gombi;
• Halembe; Hinde;
• Ikola; Isanga; Isonga;
• Kabemba; Kabimba; Kabwe; Kafungi; Kala; Kala Island; Kalemie; Kalila; Kalo; Kamakonde; Kambwebwe; Kambwimba; Kamvira; Kanoni; Kantalamba; Kapamba; Kapemba; Karema; Karenge; Karilani; Kasaba; Kasakalawe; Kasanga; Kaseke; Kasenga; Kasoje; Katato; Katete; Katibili; Katili; Kavala; Kekese; Kerenge; Kibige; Kigoma; Kikonde; Kiku; Kilemba; Kilewa; Kipili; Kiriza; Kisambala; Kisoshi; Kitumba; Kizike;
• Livua; Luagala Point; Lubungwe Bay; Lueba; Luhanga; Lumbye; Lunangwa; Lupota; Lusingu; Lyamembe;
• M’toa; M’toto; M’Vua; Mabilibili; Magambo; Magara; Makobola; Mamalesa; Maswa; Mbete; Mboko; Milima; Miyako; Mkinga; Moba; Moliro; Molwe; Mpala; Mpulungu; Msalaba; Mtosi; Muzi; Mvuna;
• Namansi; Ndole Bay; Nkamba Bay; Nkondwe; Nyaza-Lac;
• Resha; Rumonge; Rutuku; Rutunga; Ruziba;
• Sibwesa; Siyeswe Bay; Sumbu;
• Tembwe (Deux);
• Ujiji; Ulwile; Utinta; Uvira;
• Wampembe;
• Zongwe.
Lake Tanganyika Cichlids. Biotopes, Habitats. 
