Lake Tanganyika, Rocky Shores of Ikola, Tanzania and Pelagic Waters of Kitumba, Congo

37th place in Biotope Aquarium Design Contest 2017

turkey Turkey. Fatih Ozdemir

Volume: 487 L
Dimensions: 150x65x50 cm
List of fishes: 1-Tropheus Sp.Ikola (2 M/5 F), 2-Cyprichromis Leptosoma Kitumba (2 M/3 F), 3-Neolamprologus Brichardi (1 M/1 F), 4-Tropheus Sp.Ikola Fries, (I counted 9 but not sure about exact number mostly hiding under pile of peeples), Naturally released by mother in tank. As for adding species to tank, my not to do’s are adding any predator species and outnumber the livestock population
List of plants: N/A
Description of decorations: 1- 120 kg Natural Dolamite Stones, Dolamite stones are the hardest stones i could find around lest it doesnt resolve to the water or even it dissolves it will be calcium or salt also their round edges helped me to represent Shallow Rocky Shores as well as not harming Tropheus Sp. Ikolas.
2- 60 kg Caribsea Ac00778 Eco-Complete African Cichlid Substrate (Natural Argonite Sand From Sea Floor) reason to use this sand explained in water parameters part.
3- Turquaz coloured background, I choosed that coloured background in that it s the nearest color to my biotopes background color in lake at daytime.
Description of equipment: Ligthening System:
1- 4 x Led Fluorescent (13 W,6500 K) For Ligthening Tank. 2- 1 x High Output T8 Fluorescent (30 W,2000 Lm) For Ligthening Tank, 3-1 x Pink T8 Fluorescent (30 W,850 Lm) For Ligthening Tank, 4-3 meters led ligth for background ligthening, 5-2 x Warmwhite LED Lamps (4,5 W,2800 K, 400 Lm, ) for giving effects of shimmering sunshine at ikola shores part.
6- Cooling system for all the lamps (8×12 V coolers). My ligthinig system is automatically turns on and turns off gradually to give affect of dawn and dusk to fish. It takes six hours all ligths gets on and takes 4 hours all the ligths gets off.
Filtering System: 1- Tetra 1200 ( 1300 lt/h), 2-Lifetech 838 (1200lt/h), 3- Hopar (1800 lt/h), 4- Aquanic Aq 1200 (950 lt/h). These 4 external filters are connected to eachother in parallel with a system i did by myself. Thanks to this system water is drained through one hose and after filtering it is send back to tank through one hose. This system gives me advantages such as more surface for bacterias, high flow rate( over 3500 lt/h approximately) and less equipment visions in tank.
Heaters: 1-Eheim Jagger 300 W, 2- Hopar H-338 (300 W)
Water parameters: Though both Rocky Shores Of Ikola and Pelagic Waters of Kitumba consist of dark colored fine sand which mixed with very, very small piece of pepples mostly. Healthy water according to species’ needs comes first for me. So in my tank to catch and maintain high ph water, i choosed argonite sand and used dolomite stones in addition to unionised salt, also created water flow hitting to surface of tank’s water. My tank’s water parameters are Ph: 8,4-8,6, Temp: 26,7°C, 502 µS, GH 9, KH 28,5 in addition Nitrate: 5-15 ppm and Nitrite: 0 ppm.

Description of the area surrounding the biotope: Lake Tanganyika is the second largest of the lakes of eastern Africa. Moreover it s also the longest (660 km) freshwater lake and the second deepest (1,436 metres) lake in the world. Comparatively narrow, it’s width varies from 16 to 72 km, it covers about 32,900 square. GPS coordinates for lake Tanganyika is -6°29’59.99″ S 29°29’59.99″ E. The lake is divided between 4 countries, Tanzania, Democratic Republic of the Congo (DRC), Burundi, and Zambia, with Tanzania (46%) and DRC (40%) possessing the majority of the lake. It occupies the southern end of the Western Rift Valley, nearly all the land along it’s shores rises steeply and consists of stony and sandy beaches or steep slopes. The lake is not the centre of an extensive drainage area, however fed by a number of rivers. The largest rivers discharging into the lake are the Malagarasi, the Ruzizi, and the Kalambo, which has one of the highest waterfalls in the World (215 metres). Its outlet is the Lukuga River, which flows into the Lualaba River. Lake Tanganyika is so deep that it contains over one-third of all the fresh water on the planet. The lake has no outlets via rivers that might link it to other lakes. The Basin is renowned for its terrestrial biodiversity and scenic beauty as is Lake Tanganyika. The surrounding are inhabited by lots of animals, dominantly hippopotamus and crocodiles. It is also home for lots of bird species. The surrounding area of Lake Tanganyika contains several forest reserves and national parks. The lake and its surrounding areas provide a diverse range of ecosystem services that sustain the livelihoods of millions of people. Surrounding area of Ikola is in same pattern of general Tanganyika coast. Besides it consists two kind of beaches such as sandy and stoney beaches. About Kitumba coasts we can tell it is the same with type of Ikola coasts, but less foresty when going inside to lands from coasts. Extensions of this type of stoney and sandy beaches and steep huge stone walls creates various biotopes in underwater at both region Ikola and Kitumba which include magnificient views. Espacially when we go further from Kitumba coasts we can see some huge stone walls come from bottom of lake till surface (not seen at surface in wet seasons) these also creates various types of biotopes for many various species. Effects of dry and wet seasons are prominent factors for life in lake Tanganyika. (Ref. 1-3,30).

Description of the underwater landscape of the biotope: Lake Tanganyika, like all of the other African Rift lakes except for Lake Victoria, lies in a graben (a down-dropped block of land bounded by extensional, or normal, faults) along the axis of the great rift. As a result of this, it is a lake which has occured due to tectonic movements in a very long time (7-12 m years). Thanks to frequent teuctonic movements several types of biotopes are created which are very different from each others. Lake Tanganyika includes six main biotopes and they are respectively the rocky shores, the surge, the sandy bottom, the muddy bottom, the pelagic waters, and the benthic waters. The materials of all types of biotopes are sand ,cemented sand, rubble, semented rubble ,rocks and shells (some plants rarely). Though it s a tectonic lake. For me the amazing thing in Tanganyika is that transtition between biotopes are always in a harmony and creates very spectecular scenes, regardless of transtition distance. My tank respresents two biotopes of Lake Tanganyika first it starts with Shallow Rocky Shores of Ikola and then heads to west Pelagic Waters of Kitumba. In Shallow Rocky Shores of Ikola you can see types of natural hardscapes such as stones on stones and stones on sandy bottoms and it also includes every size of stones from peeples to huge ones in addition to stone walls. That rocky structures are mostly consist of stones without sharp edges due to erosion caused by strong waves and also covered with sand partly. Thanks to strong sunshine and low depth, stones are covered with rich of nutritious algea and create lots of shelter for offsprings. When we go deeper pepples hardly found and stones turns out more huge but still covered with algea without sediment. But 3-5 meters deeper algae leaves it s place to sediment. Sunshine, being reflected on stones by the waves serves in so many ways for Ikola Shore’s inhabitants and makes a good view. Strong waves lets nothing shrink down to floor surface or float freely in water such as dead fish, organic dirth and zooplankton in addition to turning the water into a blurry coloured, very clean, oxygen rich compound. After we move from Ikola shores and pass it’s continious biotopes towards west, we reach Pelagic Zones of Kitumba, mostly some very huge underwater stone walls stiuated around which in bottom contains scattered rocks. The strong sunlight in Kitumba’s pelagic waters provides energy for a thriving population of phytoplankton which serves as food for zooplankton. So Pelagic waters of Kitumba gives a magnificient view of thousands of schooling fish, enjoying sunshine and zooplanktons. The smooth, calm waves and low flow doesnt causes a much blurry water and also strong sunshine enligths extra for inhabitants in Kitumba’s Pelagic Waters. So, in contrast to Shallow Waters of Ikola, water has more clear color. In spide of africa’s strong sun, the bottoms of pelagic waters cant be enligthed enough for rich nutrious algae growth due to depth instead covered with sand dust or sediment, therefore lots of rocky structures exist which are dimmed and perfect for ambushing places to hunt the ones who need to dive down from pelagic zones for several purposes like realasing fries or dying. Pelagic zones of Kitumba may just look like a simple body of water around huge underwater rocky structures with lots of schooling fish around, rather it s source of cycle for whole types of biotopes nearby. (Ref. 4-10,30).

Description of the parameters of the habitat: In lake Tanganyika most of the volume of the lake is anoxic as below 100-200 m depth there is no free oxygen in the water. Due to fossil-water and lack oxygen, the lake is uninhabitable for the fish below 200 m. Unlike other deep lakes, the water of Lake Tanganyika does circulate and a thermocline is not created. This stituation gives opprotunity to the theory about Lake Tanganyika could be heated by the earth’s core at its depths. Lake Tanganyika also has a retention time of 440 years and Its waters tend to be brackish. Chemical analsies and parameters of Tanganyika’s water changes sligthly according to being in wet or dry season or depth of the samples taken. But generally water chemistry and parameters in Ikola Shores and Pelagic Waters Of Kitumba aren’t very different from other regions but still waves, flows, depth and sunligth causes some differences between two biotpoes in terms of water parameters and water chemistry espacially in PH and temparute. Waves, hitting water to rocks also makes water so low nitrate in Ikola Shores. Water consists of Na: 57mg/L, K: 18 mg/L, Ca: 9,2 mg/L, Cl: 20,9 mg/L, Na2CO3: 125 mg/L, KCl: 59 mg/L, KNO3: 0.5mg/L, Li2CO3: 4mg/L, CaCO3: 30mg/L, MgCO3: 144 mg/L, Al2(SO4)3*18 H2O: 5mg/L, K2SO4: 4mg/L, Na2SO4: 1mg/L, FeCl3 * 6 H2O: 0.5 mg/L, Na3PO4 * 12 H2O: 0.4 mg/L, Na2SiO3: 13.5 mg/L and water parameters are Temp: 24-28°C, 502 µS, GH: 9, KH: 28,5, pH: 8,5-9,2. When we go deeper from shores temprature and PH goes down but density of chemical compounds arises. (Ref. 11-17,27).

List of fishes: Pelagic Waters Of Kitumba doesnt consist of many species other then Cyprichromis Leptosoma Kitumba, but in depths it consist some predators Cyphotilapia Frontosa is a prominent one. In Shallow Rocky Shores of Ikola when accepted as Mpimbwe there are so many species and they are Altolamprologus compressicep, Altolamprologus fasciatus, Aulonocranus dewindti, Callochromis macrops, Chalinochromis sp. bifrenatus, Ctenochromis horei, Cyathopharynx foae, Cyprichromis leptosoma utinta, Eretmodus marksmithi, Gnathochromis pfefferi, Julidochromis marksmithi, Lepidiolamprologus attenuatus, Limnotilapia dardennii, Neolamprologus callipterus, Neolamprologus calliurus, Neolamprologus caudopunctatus, Neolamprologus cylindricus, Neolamprologus timidus, Neolamprologus lemairii, Neolamprologus modestus, Neolamprologus pulcher, Neolamprologus savoryi, Neolamprologus sexfasciatus, Neolamprologus tetracanthus, Ophthalmotilapia ventralis, Petrochromis ephippium, Simochromis babaulti, Telmatochromis brachygnathus, Variabilichromis moorii, Xenotilapia boulengeri, Asprotilapia leptura, Xenotilapia spilopterus, Tropheus sp ikola. But with my great apologies, I think more then listing species living in biotope, to employ all the lake in a different approach then examine how, why and what lives in biotopes is more helpfull. In this manner Lake Tanganyika is the hotspot of biodiverstiy for the world. For it is one of the oldest lake in the world. But most fish species only inhabit the first 170 m from the water’s surface in various types of biotopes. As for species in Lake Tanganyika, It harbours about 1500 species out of which approximately about 500 are currently considered endemic to the lake. 450-500 of these species are fish species and 8 species of crab, 15 species of shrimp, some 60 species of snail, various bivalves, leeches, sponges, a water-living snake, a jellyfish etc. Among 450-500 fish species 200-250 species are cichlids. Fish species in Lake Tanganyika mainly comes from 23 families of non-cichlids and 12-16 (12-17 in some sources) tribes of cichlids. The exiciting story starts at this point according to scientific researhces it is thougth that Lake Tanganyika cichlids evolved from a common ancestor after the formation of the lake with exception of Tylochromis polylepis and Oreochromis tanganicae. The answer to the question how that can be possible is ADAPTIVE RADIATION. This scientificly proved theory means that drastic habitat changes, which is believed to be happened mainly due to tectonic movements in lake Tanganyika througth out its histroy, caused species to become extinct or find new rotue to new habitat or enriched habitat for thriving. I want to explain this issue by taking you to a journey in my tank and also you can see my aim at why my tank represents two different biotopes. When we set out our journey at Rocky Shores of Ikola we meet with Tropheus Sp.Ikola from Tropheini tribe. Their story is quite interesting. Somehow long time ago some cichlids needed to live in Shallow Rocky Shores of Ikola. So They needed to adapt themselves for swiming in strong waves at shore, being able to live without much food of carve for strong waves lets nothing dead or alive to shrink down to bottom or swim freely in surface including zooplanktons, protecting themselves from dangers coming from out of water due to low depth and going on to reproduce in this biotope. So these cichlids adapted their bodies, organs and natural behaviours in accordinance with Shallow Rocky Shores of Ikola. They decided to live near bottom and middle level of water in addition to being territorial. But that wasn’t enough to survive in a wavey shallow rocky coast so they transformed their fins into long, firm dorsal and anal fins to maintain their balance, also strong, big cadual and pectoral fins to swim and steer in strong waves. Then they needed to solve the problem of getting fed so they transformed their mounths to the form covered with flexible muscles type insead of bones and teeth consisting type so that they could bite stones and feed with algae on stones which is abundant at Ikola Shores. Even they decided to live at bottom and middle level when they were getting fed on stones they were prone to hunter birds atacks then they added a yellow coloured large band on middle of their bodies so that they could camouflage themselves by showing their bodies as a shimmering sunshine on algae covered stones underwater. Finally to solve reproducing issue, male cichlids decided to let female ones getting fed on their territories to seduce them for reproducing and female ones decided to carry their eggs on her mounth till her offsprings can swim well enough in strong waves and able to hide between stones at bottom. So These cichlids done their adaptaion towards to be able to survive in Shallow Rocky Shores of Ikola. We go on our journey by going down from ikola shores and we meet with Neolamprologus Brichardis from Lamprologini tribe between 3-25 m depth, the bitope they live is not far away from Tropheus Sp. Ikola’s but they totally adapted in a different way. The reason to different adaptation is because they needed to live at a biotope like that is deeper and different then ikola’s one with scatered rocks where there s not much algae instead biofilm on stones, crustaceans and invertebrates exist as food moreover lower current and some larger predators swimming around to hunt. So they adapted in the way like, a small and strong mounth with teeth and bones to feed with invertables, dead fish and other substrate spawner’s friesor eggs, a small, slide body with small but long fins to swim between rocks and go into slits, shells to look for food or hide also being an agressive, protective, nursing, stepped breeding and territorial substrate spawners in response to enviroment and predators swiming around. We go on towards west and reach Pelagic Waters of Kitumba where Cyprichromis leptosoma Kitumba lives from Cyprichromini tribe. I believe when we compare Cyprichromis Leptosoma Kitumba with Tropheus Sp. Ikola in terms of biotopes’ type they live in and their features, it makes me feel Radiative Adaptation theory is %100 true. Cyprichromis Leptosoma Kitumba lives in Pelagic Waters of Kituma where it s just a body of water and bottom is with scattered rocks on sand which is home for predators also some huge stone walls situated nearby sometimes. Also there s not much waves and current. So accordinance with the biotope which they needed to live, they choosed being mobilized and schooling in large numbers in order to go after zooplanktons instead of being territorial, they adapted their mouths to a protrusable type froming a suction tube which is used for sucking in pelagic zooplanktons for feeding, as there is nothing else much to eat found in pelagic zones, they found a reproducing strategy in middle water level like kind of a dancing in the air for they couldn’t dive down to bottom which is home for predators. Suprisingly both Tropheus Sp. Ikola and Cyprichromis leptosoma Kitumba has same movements and figures when reproducing. In contrast to Ikola they didnt need to swim in strong waves or current so they had a slender bodies which don’t have big fins. From the information about species and their biotopes you can come to some conclusion about their adaptions and reasons. But the point is that all these adaptations didn’t happen out of blue, instead it took very long time but when comparing with other species adaptaion to enviroment we can say they had a rapid adaptations and very succesfull evolutionary strategies. We can see 3 different types of cichlids, which shows their natural behaviors of adaptive radiation by using their adapted body and organs in my tank that includes two types of biotope so that we can enjoy, compare and make conclusions by ourselves about species similiraties and differences, not to metion watching a beatiful scene. (Ref. 18-25, 28, 29).

List of plants: N/A

Threats to the ecology: Lake Tanganyika has been recently declared the “Threatened Lake of 2017”, adversely affected by human activity in the form of climate change, deforestation, overfishing and hydrocarbon exploitation. These are the threats nearly for all the enviroment in our days and nothing is significiant has done yet. In here i want to talk about something we also cause but we can change easily by ourselves. Actually my decision about setting up a biotope started with this story. I bougth WC Tropheus Sp. Ikola colony four years ago, they were my first and last WC fish. After a while i have reliased that they were not peaceful and non stressted in my tank. So i decided to change tank to a larger volume one but nothing much changed then i decided to set up a tank same like their place where they came from in addition to changing the tank to a larger volume again. This made some changes in their behaviours but with an agony and pain, i reliased that they could never feel like same as they felt in lake. Because they were trapped in a tank and it was me who kind of caused them to be trapped. But i also realiased something else as a solution, we buy WC fish as they have vivid colours and behaves more natural. So we cause fish exporters catch and sell them. WC fish after first generation (F1) loose their vivid colour and natural behaviours due to being kept in unlike lake conditions. So what if we keep fish which are from after F1 generation in perfect biotope for them in terms of decoration, water parameters and feeding. I think this will end up with fish with quality near to WC ones . In my biotope That s what I try now there are 8-10 Tropheus Sp. Ikola fries which is released by mother naturally and they live under peeples go out to feed and swim sometimes i excitedly wait how their colours will be. As for other species in my tank Cyprichromis leptosoma Kitumba’s have really changed their colours to more vivid after 1 week adding them to biotope even they are not WC. Neolamprologus brichardis are not different they cant be seen much in tank other then feeding times and in last days female one not seen any but have seen her in a cave under stones from back window so i believe they have eggs in there. As you can see also in my video when fish are kept in a perfect biotope it ends up with natural reproducing and better offsprings. Maybe we all need to think about again instead of buying WC fish and contribute to devastating effects to lake’s fauna and flora, we can choose to keep aquarium bored ones in perfectly conditioned biotopes so that they can thrive as well as they do in nature. Also my another recommandation is there have to be more strict rules against exproting WC fish. (Ref. 26).

Sources of information: 1-
7- Cichlids from East Africa: A Handbook for Their Identification, Care and Breeding pg. 44
8- Reproductive Biology of Teleost Fishes pg.180
9- Lake Tanganyika Cichlids (main guide book)
10- Tanganyika cichlids in their natural habitat (main guide book)
29- Feeding

Comments of the members of the jury of Biotope Aquarium Design Contest 2017

It always surprises how many combinations can be made from monotonous stones alone. The aquarium looks atmospheric. There are pleasant proportions and biotopeness too. Good composition. The frames in the corners are noticeable, and this somewhat spoils the general impression of the aquarium.

Yuriy Yancher (Ukraine)