Rocky habitat at Mtoto bay, Lake Tanganyika, DRC

_th place in Biotope Aquarium Design Contest 2020

Volume: 1100lt
Dimensions: 235 x 55 x 70 cm
List of fishes: Cyphotilapia gibberosa , Cyathopharynx furcifer , Cyprichromis leptosoma
List of plants: no plants at the aquarium
Description of decorations: At this biotope there is only rocks, so we use Greek limestone and fine quartz gray sand.
Description of equipment: Sump filter 140x45x45cm run with a eheim 1262 pump, shego heater 300w, Leadzeal malibu s300 x2.
Water parameters: Tempeaure 24-27C, pH 8.2, Gh 12, Kh 9
Additional info: Cyatopharynx foae(foai) is a distinct sympatric species of cyatopharynx furcifer occur at deeper part of the lake and have darker coloration.


Description of the area surrounding the biotope: Lake Tanganyika is an African Great Lake estimated to be the second or third largest freshwater lake in the world by volume. This large rocky lake is also known to be the second deepest lake (1,470 m) next to L. Baikal in Siberia and the longest in the world (670 km). Almost 1/6 of the world’s freshwater is contained in this 9-12 million years old lake.
Located along the East African Rift, Lake Tanganyika is home to a great deal of fish. According to Widipedia, at least 250 species of cichlid and 150 non-cichlid species inhabit the lake. Almost all (98%) of the Tanganyikan cichlid species exist nowhere else in the world outside the Lake Tanganyika watershed. The lake also contains one of the only freshwater jellyfish, numerous mollusks, sponges, and aquatic snakes that are endemic as well.

Description of the underwater landscape of the biotope: Lake Tanganyika is a large lake with many different habitats. The rocky shore, the open water and the sandy bottom are some of them. The rocky habitat is the “rocky sediment free habitat” where the rocks are much larger in size and is covered with algae which attract many herbivores cichlids. This habitat is the one we present in this aquarium, at a depth of about 20m of Mtoto bay (-6.967500, 29.730556) , big rocks coming from shallow water until the bottom of the lake. Only rocks exist at this part of the lake.

Description of the parameters of the habitat: The water in Lake Tanganyika is alkaline with a pH ranging from 7.8 to 8.8 and is medium hard with a dH from 7-11. The water of the lake is generally warm with a surface temperature that ranges from 23 to 31 °C. However, most fish species inhabit areas with a temperature from 24-29 °C.

List of fishes and invertebrates occurring in the nature biotope: Lamprologus ornatipinnis , Lamprologus leloupi , Lamprologus sexfasciatus , Limnochromis dhanisi , Cyphotilapia gibberosa , Cyathopharynx furcifer , Cyprichromis leptosoma , synodontis polli, chalinochromis popelini, lamprologus callipterus, lamprologus lemairii, lepidiolamprologus elongatus, lepidiolamprologus profundicola, neolamprologus petricola, neolamprologus tretocephalus, telmatochromis brachygnathus, telmatochromis temporalis, variabilichromis moorii.

List of plants found in the nature biotope: no plants at the biotope

Threats to the ecology: Lake Tanganyika Fisheries Declining From Global Warming. The decrease in fishery productivity in Lake Tanganyika since the 1950s is a consequence of global warming rather than just overfishing, according to a new report from an international team led by a University of Arizona geoscientist.
The lake was becoming warmer at the same time in the 1800s the abundance of fish began declining, the team found. The lake’s algae–fish food–also started decreasing at that time. However, large-scale commercial fishing did not begin on Lake Tanganyika until the 1950s.
Some people say the problem for the Lake Tanganyika fishery is ‘too many fishing boats,’ but the study shows the decline in fish has been going on since the 19th century. The sientist said “We can see this decline in the numbers of fossil fish going down in parallel with the rise in water temperature.”
Lake Tanganyika yields up to 200,000 tons of fish annually and provides about 60 percent of the animal protein for the region’s population, according to other investigators.
The team acknowledge that overfishing is one cause of the reduction in catch. However, they suggest sustainable management of the Lake Tanganyika fishery requires taking into account the overarching problem that as the climate warms, the algae–the basis for the lake’s food web–will decrease.

Sources of information:


Comments of the members of the jury of Biotope Aquarium Design Contest 2020