Intermediate Rocky Habitat, Lake Tanganyika, Tanzania

_th place in Biotope Aquarium Design Contest 2020

Volume: 216 L
Dimensions: 60x60x60 cm
List of fishes: Neolamprologus pulcher
List of
plants: None
Description of decorations: I used 45 kg rock in total I collected from nature in my design. I placed the rocks in accordance with the sample visions of rock structure of the region. As N. pulcher  use rock caverns as breeding nests by their very nature, this is what I paid attetention to most in my design.The rocks were large in the upper parts, smaller and flat in the middle and medium in size in the lower parts.My aim is to make the fish lay eggs between the rocks that look like caves in the middle parts of the aquarium and make the offspring feel safer in this area.When positioning the rocks in this area, I planned to make the light coming from the surface cut off in the middle area and make the fish feel safe in the dim light.The rocks I used on the ground were used to give the appearance of small fragments that were detached from the large rocks in the lake.Since there is a small amount of sand in the habitat, I obtained silica sand from a mine that has the closest appearance to the sand I saw in the visuals.
Description of equipment: Filter: Tetra EX 700 (700 L/H), Heater : Eheim 150w, Lightning : Sylvania Aquastar T5 24w

Water parameters: TEMP:27° C, EC:600 µS, GH:11, KH:19, PH:8,7, Do:% 0,7

Additional info: I used natural silice sand on the bottom and crushed coral in filter to rise Ph to 8,5. I keep %25 water changes weekly and do vacuum cleaning between rocks. Weekly I clean algae on glasses and on equipments. I clean filter in every 3 mounts. I feed my fish with high quality foods according to a schedule. I don’t over lighten tank not to promote algae growth. Decoration of tank helps couple to behave natural and shelter from each other if needed. I closely watch water parameters. I feed my fish in same times every day so I don’t disturb them much.


Description of the area surrounding the biotope: Tanganyika Lake in East Africa, one of the Great African Lakes, located in the East African rift zone. The lake is divided among four countries, Tanzania, Democratic Republic of the Congo (DRC), Burundi, and Zambia. It covers an area of 34400 km², is the longest freshwater lake in the world and the deepest African lake. The lake is located at an altitude of 773m above sea level. The average depth is 570 m, while the maximum reaches 1435m. The lake is located in the tropical climate zone. The average annual rainfall is 200mm. Average annual temperature around 20 C. Kantalamba is located in Tanzania on the eastern shore of the lake. The described biotope is located in the zone of Litoral.
of the underwater landscape of the biotope:  Biotope is an intermediate rocky bottom habitat of Lake Tanganyika which is about 5 meters depth. Rocks lie on each other or sand in habitat. Rocks sizes are variable and not bigger than 1-2 meters. Rocks are gray or white color and curved edged. Sand is beige thin mixed type. Rocks are partly covered with algae as a very weak thin layer. Sediment is not found much and can be seen on rocks in bottom like a dust on biocover. Connection places of sand and rocks in bottom are potential shelters for species which digs sand and build shelters for whole family. Gradual inclination can be seen from rocks towards sandy bottom. Biotope harbors lots of species as start depth of heavily populated area in intermediate habitats. Rocks provide shelters, feeding areas and breeding places for lots of species in habitat.
Description of the parameters of the habitat:  Ph:8,5-9, Ec: 620 μS/cm, Gh:12, Kh:20, Water temp: 27,5, Do: %0,7
List of fishes and invertebrates occurring in the nature biotope:  Altolamprologus compressiceps, Benthochromis horii, Cyphotilapia gibberosa, Cyprichromis pavo, Cyprichromis sp. 'leptosoma jumbo, Enantiopus melanogenys, Eretmodus cyanostictus, Julidochromis cf. marlieri, Lepidiolamprologus elongatus, Neolamprologus bifasciatus, Neolamprologus buescheri, Neolamprologus fasciatus, Neolamprologus pulcher, Ophthalmotilapia ventralis, Paracyprichromis nigripinnis, Petrochromis ephippium, Petrochromis famula, Petrochromis macrognathus, Petrochromis polyodon, Petrochromis sp. Red Mpimbwe, Tropheus moorii, Tropheus moorii, Xenotilapia flavipinnis, Xenotilapia sp. papilio sunflower

List of plants found in the nature biotope:  N/A
Threats to the ecology:  Climate Change, Pollution, Deforestation and Over Fishing Threatens the Ecology, Ecological Stability and Ecosystem of Lake Tanganyika. Over the last century, warming water temperatures have caused changes to the lake's ecosystems that threaten the fish species both endemic beautiful fish and the fish people depend on for food. In last 100 years, surface waters of Lake Tanganyika have warmed by 1.6 to 2.3° F (0.9 to 1.3° C). From these records, scientists are finding that Lake Tanganyika’s surface waters are warming more rapidly than its depths. This has the effect of creating an even sharper gradient between the upper and lower layers of the lake, and thus creating an even greater barrier to wind-induced mixing. On the other hand, number of people live in the lake’s drainage basin, and the overall populations are growing rapidly. The population growth in nearshore areas around Lake Tanganyika is nearly double the national’s average. For the most part, the lake has relatively high quality water, except in a few areas where urban and industrial runoff has affected the lake. This is in part due to the lake’s enormous volume but this has a limit. The buffering capacity of the lake cannot handle more than a certain pollution load. Deforestation, Over-exploitation of the fishery and siltation caused by erosion from deforested areas are considered one of the main threats to the health of the lake. With increased population pressure, the ongoing problem of siltation, and now climate change added to the mix, fish stocks, biodiversity, and water quality are expected to decline. The particles in the lake and those washing into it, through rivers, streams, shoreline erosion, and even pollution discharges, eventually settle out to the bottom along with the decomposed remains of aquatic organisms. In a lake as deep as Tanganyika, these particles are essentially locked away in layers of mud. The bottom sediments are like a secure vault, storing the ecological history of the lake and its surrounding watershed. In the case of Lake Tanganyika, this process has been occurring for millions of years, making it a treasure trove of information for scientists to study trends, such as the effects of climate change. Surface Water Warming More Rapidly Than Its Depths. Because of the temperature differences, the bottom water is effectively isolated from the surface water. Temperature boundary formed in the lake, typically at a depth of 60 or 70 meters, as acting like a drain for nutrients and energy from the surface. When these materials reach the oxygen-starved bottom of the lake, the difference in temperature between the upper and lower layers acts as a barrier – like oil on water – that inhibits the mixing that could replenish nutrients in brightly-lit surface waters. I am worried about humanity will facing a serious pollution problem from various sources, such as discharge of domestic sewage, population growth, rise of industrialization, use of pesticides and chemical fertilizers in agriculture, sedimentation and erosion resulting from deforestation. Today Lake Tanganyika are highly polluted by different harmful contaminants from human activities in large cities established on its catchment areas but this areas are growing. Moreover, rift lake sediments of the type found in Lake Tanganyika are well known among geologists as reservoirs of hydrocarbons, as over millions of years vast quantities of plankton have died and settled on the lake floor. International scientists at the site are warning that if the activities are not pursued carefully, they could cause massive and long-term environmental disaster. Countries are signing new agreements for oil and gas exploration.

Sources of information:  

  12. Konings, A. 2019. Tanganyika Cichlid in Their Natural Habitat. 4th Edition, Cichlidpress, El Paso Tx.

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