Shallow Rocky Habitat, Kigoma, Tanganyika,Tanzania

_th place in Biotope Aquarium Design Contest 2020

Volume of your aquarium:
216 liters
Dimensions of your aquarium:
60x60x60 cm
List of fishes and invertebrates in your aquarium:
Eretmodus marksmithi
List of plants in your aquarium:
Description of decorations and substrate:
I collected round edged rocks (55 Kg) from a nearby seaside. I placed rocks to create hiding places for my female Eretmodus marksmithi and I covered back of the tank with rocks to give effect of rocky bottom. I used light coloured rocks similar to ones in biotope. I used very fine, natural light-colored sea sand (40 kg). I poured the sand over the rocks after I positioned them, then the sand flew under and it is not seen as in biotope, but it exists on the bottom to promote beneficial bacteria and maintain water parameters. Every visual details in my design are inspired from photos and videos of biotope. After hardscape set up was completed, I started to lighten aquarium to promote algae growth, because I wanted my E. marksmithi couple to feed naturally on the rocks covered with algae. Therefore, my aquarium has little more algae than biotope but this is to create opportunity of natural feeding for specie. I tried to create different cave and shadow areas in aquarium to help the female not to get stressed or to hide from male when she broods.
Description of equipment:
Filter: Tetra EX 700 (700 L/H)
Heater : Eheim 150w
Lightning : Sylvania Aquastar T5 24w
2 x Sylvania 75w par30 halogen
Water parameters:
TEMP:27° C,
EC:600 µS,
Do:% 0,7

Additional info:
I used natural sea sand on the bottom and crushed coral in filter to rise Ph to 8,5. I keep %20 water changes weekly and do vacuum cleaning between rocks. In every 1-2 days I clean algae on glasses and on equipments. I clean filter in every 3 mounts. There is only one couple of Eretmodus marksmithi in my aquarium . Decoration of aquarium helps to keep stress on low level which can happen because of territorial conflicts. I feed my couple with 3 different high quality food and they also feed on naturally growth algae on rocks all day along. I am very careful about water parameters and I keep them stable by
water changes and constant temperature. All listed above helps me to keep fish active and healthy.


Description of the area surrounding the biotope: Biotope is located in a small bay in the shoreline of Kigoma. A narrow steep, rocky and bushy
shoreline is covered with bushy and forestry hills. After shoreline a rising inclination starts. Shoreline is not longer than 50 meters. Surrounding area has a terrestrial beauty and a popular region. There are residents living nearby and formed region according to their needs. Wet and dry season are two major seasons observed in area.

Description of the underwater landscape of the biotope:

Biotope is typical shallow rocky bottom habitat of Lake Tanganyika which is 1-3 meters depth and close to shoreline. It shows clearly it is extension of steep and rocky shoreline. Rocks are positioned on each other and create an amazing scene. Substrate (sand) of the bottom is not seen and the bottom is almost completely covered with rocks. Because of waves, sediment is not deposited on rocks and high amount of sunshine due to depth promotes algae growth. Rocks are curved edged and in light colors. Rock sizes differ from huge plates to hand-sized stones. The habitat is a feeding area for lots of species, because algae existence invites algae eater species. Omnivores and carnivores go around them. Visibility is high and water color is light blue. Thanks to turbulence, water is highly saturated, low nitrated and faunal waste (CO2) sent to atmosphere fast. Low depth keeps temperature very steady.

Location : -4.813371, 29.609666

Description of the parameters of the habitat:  

Temp:27,5° C,
EC: 620 µS,
GH: 12,
PH: 8,5-9,0
Do: %0,7
List of fishes and invertebrates occurring in the nature biotope:  Altolamprologus compressiceps, Aulonocranus dewindti, Bathybates ferox, Benthochromis horii, Boulengerochromis microlepis, Callochromis macrops, Callochromis pleurospilus, Cyathopharynx foae, Cyathopharynx furcifer, Cyphotilapia frontosa, Cyprichromis microlepidotus, Cyprichromis sp. leptosoma, Enantiopus melanogenys, Ectodus sp. north Kigoma, Eretmodus cf. cyanostictus, Eretmodus marksmithi, exGnathochromis pfefferi, Grammatotria lemairii, Haplotaxodon trifasciatus, Julidochromis cf. regani, Lamprologus callipterus, Lamprologus kungweensis, Lamprologus lemairii, Lamprologus ocellatus, Lamprologus ornatipinnis, Neolamprologus bifasciatus, Neolamprologus boulengeri, Neolamprologus brevis, Neolamprologus brichardi, Neolamprologus cunningtoni, Neolamprologus furcifer, Neolamprologus mondabu, Neolamprologus niger,
Neolamprologus tetracanthus, Neolamprologus toae, Neolamprologus tretocephalus, Neolamprologus ventralis, Neolamprologus walteri, Ophthalmotilapia sp. ‘Paranasuta’, Ophthalmotilapia sp. Whitecap, Petrochromis ephippium, Petrochromis famula, Petrochromis sp. kasumbe Pseudosimochromis marginatus, Spathodus marlieri, Spathodus sp. Erythrodon Tanganicodus irsacae, Telmatochromis cf. temporalis, Trematocara cf. stigmaticum, Trematocara zebra, Tropheus brichardi, Tropheus duboisi, Xenotilapia bathyphilus, Xenotilapia boulengeri, Xenotilapia flavipinnis, Xenotilapia nasus, Xenotilapia ochrogenys,
Xenotilapia sp. spilopterus north.
List of plants found in the nature biotope:  none
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:







7- (0:54-2:23)





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