Did You Know?
- The northen coastline is made up of the Ruzzizi River Delta, a low, level plain of swamps and sandy beaches that extends for about 35 kilometres.
- The southern coast is lined by a massive escarpment of around 500 metres in height. It separates Lake Tanganyika from the swampy Bangweolo, Moero and Moero Wantipa Lakes in the Congo River Basin.
- The eastern and western coastlines have a succession of mountain ranges that rise from 2,500-3,000 metres in the north to 1,500-2,000 metres in the south. The western wall is the highest. It is from the west that the only outlet, the Lukuga River, runs.
Lake Tanganyika is the largest museum of natural history in the world. It is probably also the oldest isolated body of water cichlids could settle.
Geological studies have revealed that Lake Tanganyika is at least 20 million years old, during which time its water level rose and dropped repeatedly. In fact until about 40,000 years ago, the water level was 600 metres below its present level.
Lake Tanganyika was formed by earthquakes and volcanic action. It was isolated for six million years and as recently as 100,000 years ago developed its outlet to the Congo River System.
Lake Tanganyika is divided into a northern part and a southern part.
It is the deepest of the Rift Lakes and the second deepest in the lake in the world after Lake Baikal, in the Russia. Lake Tanganyika holds the greatest volume of fresh water.
Lake Tanganyika is the second largest lake in Africa and is:
- 34,000 square kilometres in area (Ed Note: about half the size of Tasmania) and has more than 2,500 kilometres of coast line (Ed Note: about the same as the length of Victoria’s state borders).
- the longest lake in the world being around 750 kilometres (Ed Note: this is about the distance from Brisbane to Rockhampton),
- the second deepest in the world reaching 1,570 metres
- up to 80 kilometres wide in places in the central and southern areas, with an average width of 40 kilomteres and
- located 840 metres above sea level.
Lake Tanganyika’s only outlet is the Lukuga River, which flows into the Congo River. This gives it a particularly high mineral content as most of the salts that flow into it are left behind when the water evaporates. The main rivers flowing into the Lake are the Rusizi and the Malagarasi.
The lake has a remarkable variety of fish fauna, much of it unique. It has at least 300 species of cichlid and six non-cichlid species. Almost all the cichlid species are only found in the lake.
Lake Tanganyika has been a natural source of food for local peoples throughout their existence. There are currently t around 45,000 people directly involved in fisheries on the lake, operating from almost 800 sites and there are around 1 million people who are dependent on the fishers.
Evaporation accounts for 95% of the total water loss from the lake, as the annual outflow is very small – accounting for its high alkalinity.
Unlike other large lakes, a thermocline is not created as the water circulates throughout the depths of the lake. This phenomenon suggests to some scientists that Lake Tanganyika could be, at its maximum depths, heated by the earth’s core.
The lake has a relatively uniform temperature. The water in the lake is very clear. In the upper 40 metres, the water is especially oxygen-rich.
Crocodiles and hippopotamuses are often found on the shores of the lake, making collecting a sometimes hazardous occupation. Because of wars in the area, the borders of Burundi have been closed to fish exports until very recently.
The lake has a predominantly sandy biotope, with a few rocky habitat areas.
The Fish
Over 300 species of endemic cichlids have been described. They belonging to over 50 genera and it is likely that many more undescribed species exist.
The predominant fish type in the lake is the cichlid. Other fish present in the lake and riverine environemnts that drain to the lake include Catfish, Polypterus, Eels and Characins. Although not as rich in species as Lake Malawi, the species of Lake Tanganyika are more specialised and diverse.
Most fish species only inhabit the first 137 metres of the water column, because the water is stagnant below this depth, and there is no oxygen.
Physical description…
Lake Tanganyika cichlids have adapted to the ecological niches of the lake in order to survive. This means that they vary enormously in body shape, size and habit. A number of species have specialised adaptions – for example, using empty shells as shelter in the absence of suitable rocks; a reduced swim-bladder to live in the turbulent surge-zones or a compressed or elongated body shape to fit into the cracks and crevices of the rocks.
Most Lake Tanganyika cichlids range in size from around 6 centimetres to 15 centimetres. The largest and smallest cichlid species in the world also live in the lake – Boulengerochromis microlepsis which can reach 90 cm in length, and Neolamprologus multifasciatus, a dwarf shell-dweller that reaches about 4 centimetres in size.
Habitat and tank care…
In most cases, an 80 centimetre tank is sufficient for a community of small Lake Tanganyika cichlids. In larger tanks, a greater variety of fish, including those from different biotopes, can be combined. The tank should be set-up to duplicate the natural biotope.
In most cases, a Tanganyikan cichlid will fall into one of three groups:
- Open water (pelagic) – these fish are not reliant on rocks for food or shelter and swim and live far from the shore.
- Deep bottom (benthic) – live down to the deepest habitable depths, often under open water and far from the shore – but always in contact with the bottom and slopes leading to the shore.
- Littoral – these fish live near the water’s edge and on the slopes leading to the shore on one side and the open water on the other. The shore-dwelling species can be subdivided into:
- Rock-dwellers: fish from this habitat should be kept in a tank with a rocky set-up. Rocks can be used to construct caves, overhangs, tunnels, and crevices. These structures serve as fine spawning sites and, more importantly, are essential for harassed fish, as hiding places. Dominant fish will quickly establish territories among the caves, so it is important to provide a shelter for each fish. Examples of rocky habitat fish include Altolamprolologus and Julidochromis.
- Sand-dwellers: fish from this habitat need a sand substrate as they feed or build spawning nests in the sand. Many sand-dwelling cichlids will seek shelter in snail shells scattered on the sand and also use them as spawning sites. Examples of sand-dwellers include Enantiopus, Callochromis and Neolamprologus (shell-dwellers).
- Rock-dwellers: fish from this habitat should be kept in a tank with a rocky set-up. Rocks can be used to construct caves, overhangs, tunnels, and crevices. These structures serve as fine spawning sites and, more importantly, are essential for harassed fish, as hiding places. Dominant fish will quickly establish territories among the caves, so it is important to provide a shelter for each fish. Examples of rocky habitat fish include Altolamprolologus and Julidochromis.
Plants are not abundant in the lake, but they do thrive in shallow, protected coves and in the river estuaries and lagoons. Specialised plant eaters select the planted areas as their habitat. Plants include Myriophyllum, Potamogeton, Ceratophyllum, Azolla and Vallisneria.
General water parameters:
- pH: 7.5-9.0
- Hardness: 7-18 dH
- Temperature: 24-28oC.
Using marble chips, coral rubble or shell-grit as the substrate or as part of the substrate will help keep the pH alkaline. The most important factor in keeping Tanganyikans is stability – they do not tolerate fluctuations in pH or water quality. High temperatures can also be a killer for many of these fish, particularly the fish from the oxygen-rich lake habitats.
Compatibility…
As with many other cichlids, Lake Tanganyika cichlids can exhibit aggressive behavior. The aggression can be dispersed by keeping a good number of fish in a tank with plenty of rocky retreats. If only a small number of cichlids are kept, quarrels may be more common.
For a community tank, Lake Tanganyika of a similar size can be easily combined with other Lake Tanganyika species. In a large tank, cichlids of different biotopes (rocky, sand, and/or open water) can be combined.
Some Lake Tanganyika cichlids can also be kept with other cichlids, catfish and other fish with similar water requirements. Some species of Lake Malawi cichlids are suitable companions.
Feeding…
Most Lake Tanganyika cichlids will happily take live foods especially brine shrimp or frozen brine shrimp or Mysis Shrimp. Most species will take commercially prepared dry foods including flakes, tablets, and pellets and some will graze algae. Tropheus species should be fed an almost exclusively vegetarian diet, as their digestive tract is designed to extract protein from algae, not meat. All Lake Tanganyika cichlids should be given a varied diet to keep them in top condition.
In the lake, their distribution along the coast depends almost exclusively on their feeding habits, which correspond to their adaptations in terms of teeth, shape and size. For instance, fish that chase their prey have stream-lined bodies, while fish that graze on algae from the rocks have a short maneouverable body to achieve the right angle on the uneven rock surface.
Some of the feeding groups available in Queensland include:
- Herbivorous rock-grazers – example: Tropheus, Petrochromis. They mainly live on the plant material growing on the rocks, with some invertebrates that live among the algal biocover being eaten.
- Carnivorous biocover grazers – example: Eretmodus, Spathodus, Tanganicodus (Goby Cichlids). They are the opposite of the herbivorous rock-grazers, living mainly on the invertebrates living in the algal cover on the rocks. The ratio of animal to plant proteins varies with the species.
- Carnivorous zoobiocover grazers – example: Julidochromis. They specialise in picking crustaceans and insect larvae from the rocks.
- Carnivorous zooplankton eaters – example: Neolamprologus brichardi complex, Neolamprologus leleupi which live close to the rocks and Cyprichromis which feed mid-water.
- Phytoplankton eaters – example: Ophthalmotilapia, Cyathopharynx, Aulonocranus. They feed mainly on drifting plant plankton in midwater. These fish are known as Featherfins.
- Bivalve shell crushers – example: Neolamprologus sexfasciatus and tretocephalus. These fish feed on small bivalve molluscs.
- Sand-sifters – example: Xenotilapia, Callochromis, Enantiopus. These fish scoop up mouthfuls of sand with their forward slanting teeth and sift it through their gills. They eat the crustaceans that are hidden in the sand.
- Macro-predator – example: Cyphotilapia, Lepidiolamprologus, Altolamprologus. These fish eat other fish or fry and eggs of other fish.
Breeding…
The cichlids of Lake Tanganyika are shelter brooders. Most fall into one of two groups
Substrate spawners – include Altolamprologus, Lepidiolamprologus, Julidochromis and Neolamprologus.
- They are secretive substrate spawners, with a pair either digging a pit in the substrate between or in rock structures or using the surface of the rock.
- They will establish a territory around the chosen site. Depending on the species, from ten to several hundred eggs will be laid at a time.
- The pair will defend the territory against outside invaders. Often «helpers,» immature fish from prior spawnings, will help the pair guard the eggs and the territory (Neolamprologus brichardi is a good example of this practice).
- Another type of secretive substrate brooder found in Lake Tanganyika is the snail shell spawner, typically Neolamprologus species and dwarf Altolamprologus species. Each female establishes a territory in an empty snail shell – usually of the genus Neothauma.
- The female lays the eggs in her shell. Depending on the species, the male is monogamous or polygamous. Monogamous males will visit the female’s snail shell and fertilise her eggs.
- Polygamous males will visit the shells of several females, fertilising the eggs of each one as he visits.
- In both cases the females are left to care for the young and the fry.
Mouth-brooders – include Cyphotilapia, Cyprichromis, Eretmodus, Tropheus, and Xenotilapia.
- Usually the eggs are scattered or laid on the substrate. Males of sme species build elaborate pits or «bowers» to entice the female to spawn.
- The eggs are fertilised by the male, either in the female’s mouth or on the substrate. The number of eggs varies greatly depending on the species.
- The eggs are incubated for about 30 days at a warm temperature of 28-30oC.
- When they emerge from the female’s mouth, the fry are fairly large, from around 1 – 2 centimetres in length depending on the species.
- The young are free-swimming and capable of surviving on their own. Although the young are independent they still take refuge in the mother’s mouth at times of danger and sometimes at night.
- The mother eats while she is holding the eggs, so it is possible that the fry also eat in their time in the throat cavity.
- After about a week, the fry are abandoned by the parents to fend for themselves.
Despite the fairly good availability of Tanganyikan cichlids in general, many remain fairly unknown to many fish keepers. One reason could be that, as juveniles, many Tanganyikans look like boring silver fish.
Those that show colour and pattern as juveniles are more likely to be included in a tank. Some Tanganyikans are almost iconic, such as the Frontosa. It is probably the most popular and well-recognised of the Tanganyikan cichlids.
Many Tanganyikans have a relatively high price. This price reflects to some degree the difficulty in keeping some species and the difficulty in breeding and obtaining others.
Many Tanganyikans are being successfully bred, but they don’t tend to produce as many eggs as many other cichlids and the fry are quite slow-growing. It might even have something to do with the fact that very few Tanganyikans have common names – making it a bit harder to ask for what you want.
These are, however, very interesting fish and deserving of more attention. We hope that our Fact Sheets will help to give a bit better understanding of Tanganyikan Cichlids – and maybe even tempt some people to give them a go.
The following list of cichlids that are, or have been, available at WetPetz is not exhaustive. We will be adding to it as more fish become available through our suppliers.
About the Fact Sheet Information
Lake Tanganyika cichlid species
| Goby Cichlids Eretmodus cyanostictus Kapampa & Mabilibili Orange Tanganicodus irsacae KapampaFeatherfins Aulonocranus dewindti Cyathopharynx foai Cyathopharynx furcifer Karilani CopperOphthalmotilapia nasuta Chimba Ophthalmotilapia ventralis Ikola Ophthalmotilapia ventralis Kapemba Open water Cyphotilapia frontosa (Frontosa) Cyprichromis leptosoma Cyprichromis microlepidotus Lepidiolamprologus elongatus Lepidiolamprologus kendalli Variabilochromis moorii Sand-sifters Callochromis macrops Callochromis melanostigma Callochromis pleurospilus Callochromis stappersi Ectodus descampsi Enantiopus melanogenys Enantiopus sp Kilesa Gnathochromis permaxillaris Xenotilapia flavipinnis Xenotilapia ochrogenys Ndole Bay Xenotilapia spilopterus | Rock-dwellers Altolamprologus calvus Altolamprologus compressiceps Altlamprologus sp Shell (Mbita Pearl) Altolamprologus spSumbuAstatotilapia (Haplochromis) burtoni Chalinochromis ndobnoi Julidochromis dickfeldi Julidochromis marlieri Julidochromis ornatus Julidochromis regani Julidochromis transcriptus Gombe Neolamprologus brichardi Neolamprologus buescheri Neolamprologus cylindricus Neolamprologus leleupi Neolamprologus mustax Neolamprologus pulcher Neolamprologus sexfasciatus Gold Neolamprologus tetracanthus Neolamprologus tretocephalus Paracyprichromis nigripinnis Petrochromis trewavassae Tropheus duboisi Tropheus moori Shell-dwellers Neolamprologus brevis Neolamprologus caudopunctatus Neolamprologus meeli Neolamprologus multifasciatus Neolamprologus ocellatus Neolamprologus speciosus |
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