Lake Tanganyika, deep rocky sedimented habitat at Kitumba, D.R. Congo

_th place in Biotope Aquarium Design Contest 2020

Volume: 750 liters
Dimensions: 250x 60x 50 cm
List of fishes: Cyphotilapia frontosa (kitumba) 2m/6f
List of plants: no plants except for algea on rocks
Description of decorations: “freckle stone”, about 125kg ( with few algea) similar to rocks in shape and colour to the rocks at the sedimented deep rocky habitat.
Sand, about 125kg, similar to the sand in Lake Tanganyika in size and colour.
Description of equipment: filter: JBL Cristal profi e 1902 (up to 1900l/h) ,2x heater: JBL proTemp s300 , 2x light: 15W led lights on top (partly covered), 2m coloured led strip on the back (window covered with frosted glass film)
Water parameters: temperature is about 25°C in winter and 27°C in summer
Ph is about 9,0
GH is about 15.
conductivity is about 650 uS/cm
Additional info: weekly change of water about 1/3 of volume, addition of JBL aquadur and JBL biotopol


Description of the area surrounding the biotope: Lake Tanganyika is about 650km long and 50km wide in average and in a roughly north to south position. (1) It’s the second deepest lake in the world (1470m) after Lake Baikal in Russia.(2) The lake is very deep, but oxygen is only in the upper water level present. In the south the oxygen-bearing layer has a depth of 240m, in the northern part of the lake only 100m.(3)
Lake Tanganyika is 9-12 millions of years old. The Democratic Republic of the Congo, Tanzania, Burundi and Zambia are positioned around Lake Tanganyika. It consists of three or four major basins: Zongwe, Kalamie, Kigoma and eventually Bujumbura. Tectonic activities and rising water levels led them fusing into a single deep clearwater lake 5-6 millions of years ago. Several times drier climate and drops of water levels led to changes in the lake and seperation of the basins with effect on fish and other life in the lake. The shores of the lake are variable in topography and the types of terrain alternate around the lake at the 2000km long coast. There are long stretches of rocky shores, sandy beaches, as well as areas with small stones and pebbles. The mouths of rivers -most of them are temporary- are usually marked by lots of vegetation.(4)
Another description of the lake comes from a well known expert of Lake Tanganyika, Ad Konings, he describes the lake by dividing it into nine different habitats: The waved-washed upper rocky habitat, that’s not deeper than three meters with wave-washed and algea-covered rocks, (5) the shallow rocky habitat, (6) the deep rocky habitat, (7) the shallow intermediate habitat, (8) the intermediate habitat with sandy bottom and numerous rocks, (9) the sand, (10) large amounts of empty shells in sandy or muddy bottoms, (11) muddy bottoms, that are quite common in the lake and mostly deeper than 60m (12) and the unknwon depths, we don’t know much about.(13)
Description of the underwater landscape of the biotope: The deep rocky habitat is characterized by rocky subtrate, deeper than 20m and sediment-covered rocks. The rocks can be smaller than 0,5m, but also few meters big (up to about 3 meters). In this depths and the subdued light only few algea and no other plants exist. Especially brown and reddish-brown algea grow in this habitat. (14) + (15) As mentioned above, the lake changed water levels several times in its millions of years old history. The enormous long time and the fact, that some of the deeper rocks might where wave-washed when the water level was lower, took the edges of those rocks.
Furthermore the area is quite dark and calm. That’s the environement Cyphotilapia frontosa needs in an aquarium as well. This kind of environement the fish is used and adapted to, explains why the species gets scared so fast. Only younger C.frontosa and maybe some special location variants of C.frontosa are used to the upper water area.
Kitumba is located about 30km in North-western direction from Moba. (16)
Description of the parameters of the habitat: temperature on surface 25.5°C (August) to 27,7°C (February)
Ph 8,8 to 9,2
conductivity 590 to 700 uS/cm (17)
GH 11 to 17 (18)
List of fishes and invertebrates occurring in the nature biotope: Petrochromis(19), Neolamprologus (bifasciatus(20), buescheri, ventralis (21)), (Cyphotilapia frontosa)(22), Paracyprichromis (nigripinnis, brieni)(23), Cyprichromis sp. leptosoma Jumbo(24), Xenotilapia papipio(25), Greenwoodochromis christyi(26), Gnathochromis permaxillaris(27)
List of plants found in the nature biotope: in this depth there are no plants, except for algea. Mainly brown and reddish-brown, only few green algea can exist there.(28) + (29)
Threats to the ecology:
Sources of information: Tanganyika Cichlids in their natural Habitat, 4th Edition, Ad Konings: (1)p.6, (3)p.8, (4)p.6-7, (5)p.24, (6)p.52, (7)p.186, (8)p.230, (9)p.251, (10)p.320, (11)p.348, (12)p.380, (13)p.395, (14)p.186, (16)p.14, (17)p.8, (19)p.186, (20)p.190, (21)p.191, (22)p.199, (23)p.203/204, (24)p.215, (25)p.222, (26)p.225, (27),p.226, (28)p.186 (2) (18) (1:05) (15)+ (29)

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