The shell dwelling cichlids of Lake Tanganyika are dwarf cichlids that inhabit sandy environments at the bottom of Lake Tanganyika. Lately, these fish, lovingly called ‘shellies’, have become ever more popular, mostly because they are easier to house than many other cichlids as they are so small, but also because they still have the very traits we love cichlids for: their charming personalities, their sheer spunk and their strong will.
Shell dwellers derive their name from the fact that they utilize abandoned shells to protect themselves from predators. When you keep Tanganyikan shell dwellers, you will soon notice how rapidly they can escape into a shell as soon as they are frightened by something. In fact, these tiny cichlids should never be kept in an aquarium without shells, as this makes them feel insecure and stressed. Even in an aquarium completely free from predators, the shellies, who can pick up even the slightest vibrations, can still be scared by noises around them, or by people approaching the tank.
In their natural habitat these tiny shell dwellers use and prefer the shells of a common aquatic snail, Neothauma tanganicensis , after it died. In nature these fish form vast colonies of thousands of individuals in the beds of empty Neothauma shells on the lake floor, and spend their day darting in and out of their shells, raising families, and avoiding predation. Due to their diminutive size, and consequentially smaller territorial needs and aggression levels, many of these Cichlids are ideal for small aquaria.
In the aquarium, any shell will do, as long as they are at least 5cm deep. The entrance to the shell must naturally be large enough for the cichlid to enter, typically one 2.5 cm across. However if the cichlids grow, they must be provided with larger and larger shells. If a shell dweller cannot find a fitting shell, they stress and typically refrain from eating. If this carries on for too long a time, the cichlids will become severely stressed, lose colour and even die.
Neolamprologus multifasciatus is the appropriate choice if your aquarium is small, since it is one of the smallest cichlid species in the world and is also very docile and non-aggressive. The male reaches barely five centimeters in length, and the female only 2.5 centimeters. This species is commonly sold as ‘The Many Banded Shell Dweller’ or simply ‘The Multi’. Each cichlid will typically claim about 25 square cm. as their own territory, so a 40 litre tank will be suitable for about 5 cichlids.
If you want to keep several shell dwelling species in the same aquarium, the tank must be larger; 80 litres or more, even for peaceful species. Two spawning shell dwellers can, however, be kept in a 35—40 litre aquarium during the breeding period.
Neolamprologus brevis is also a highly suitable species. It is easy to keep even for beginners, but will grow bigger than the Neolamprologus multifasciatus and requires more space.
TANK CONDITIONS AND TANK-MATES
For those who wish to combine Tanganyika shell dwellers with other types of fish in the aquarium, other Tanganyikan species is the best suggestion, since they will like the same water chemistry and temperature as the shell dwellers. Free swimming cichlids like the Aulonocranus species will usually do well with shell dwellers, as the spaces they use are irrelevant to the shellies. If you choose bottom dwelling species it is important that they are not too timid, since they will share the bottom with the shell dwellers and might have to compete for space. Any bottom dwelling fish must tolerate the abuse of the cichlids when they intrude upon the Shell-Dweller’s territories. The best fish to try include are Plecos of the genus Peckoltia and Ancistrus. These plecos tend to reach lengths of 4 inches, which is suitable for small aquariums. They are heavily armoured and can usually handle some abuse. Avoid Corydoras and Otocinclus. These fish are usually murdered upon introduction.
Although it is advisable to stick with Tanganyikan species as tank mates, you could also keep other common aquarium fish with your shell dwellers. The best companions in that case are fast moving surface fish, such as Melanotaenia praecox (Dwarf Neon Rainbowfish) and various Danios (Zebra, Gold, Leopard,Pearl). Again, these fish tend to occupy space which is irrelevant to the Cichlids, although they may receive some “attention” if the Shell-Dwellers are breeding.
You should, however, add all your shell dwellers at one time. This prevents any Cichlids from developing a “Home Court Advantage” with regards to newcomers. Purists will tell you that it is better to house only ONE species/variety in the tank to prevent any possible hybridizing. If the tank is larger, and you have enough females, hybridisation is less likely to occur.
Depending on the sexes of the juvenile fish, two future outcomes can be expected as the fish mature. If there is an excess of females, many shell dwellers will live in a harem, where one male presides over several females, each of which establishes their own territory within the male’s territory. If there is an even sex ratio, or an over-abundance of males, it is more likely that the female will choose a male partner and live in a monogamous pair arrangement. In this case, it is more likely that subordinate fish will not be tolerated. These poor, harassed individuals can be noted by ragged fins, darkened coloration, or even being “pinned” into the upper corners of the tank. If this should occur, it is best to remove these poor victimised individuals and allow the pair or pairs to live in peace. Alternately, you could try adding more females.
Since sand is the Shell Dwelling Cichlid’s natural environment, you need a sand substrate of at least 5 cm. deep, as they like to move around their shells and dig them into the sand. In fact, shell dwellers have a talent of moving their shells and sand to their liking, completely re-arranging your idea of a suitable aquascape. They can open their bottom jaws to an amazing 90 degree angle. They position themselves on the shell, and with a great deal of wiggling movement, they move the shell into the desired position. Then they plant themselves into the sand and with even more frantic movement, they send a cloud of sand onto the shell, covering it completely. Any sand in the shell is then removed. So note, please, that gravel is not a suitable substrate for this species! Crushed coral sand, on the other hand, will help maintain the hardness and alkalinity of your water, reducing the risk of a drastic drop in pH which can harm your fish.
You must provide plenty of shells, since several shells are needed for each cichlid, as most of these fish will inhabit more than one shell. A good rule is 2 or 3 shells for every shellie. This allows more hiding places and more territories, which will minimize disputes. Be sure to get shells large enough for your shellies to fit comfortably into. Marine shells may work, but they always look somewhat disconnected in a freshwater environment. Avoid shells that have too many spirals, in which a shellie can get injured. Shells are usually sold in pet shops and fish stores, but also craft, or hobby shops. Deli-shops of course sell the shells of edible snails, and those look very authentic. Create an attractive environment by arranging some rocks around the aquarium floor, around which the shellies can establish their territories. These not only help delineate territories, but the shellies always seem to feel more secure in the leeway of rocks. And please do not be mean! These little guys depend on their shells for security!
A recent scientific study of the species found that Lamprologus ocellatus and L. ornatipinnis responded to new shells in a variety of ways; shells were moved, buried (and used) or hidden (buried and not used). How shells are utilised seems to be dependant on a complex of factors such as the size and quality of the new shells and the number already in the territory. Shell use may also be affected by neighbour species, sex, size and predation levels. There are inter-specific differences in the size of shells used, and in the methods of shell use. The latter results in species-characteristic shell orientations: vertical burial in L. ocellatus and horizontal burial in L. ornatipinnis. Shell orientation does affect other species’ use of shells too. Shell movement and vertical orientation appear to be apomorphic (meaning a derived or specialised characteristic) while shell hiding and burial are pleisiomorphic (meaning an evolutionary trait) within the genus Lamprologus. Numerous cues are involved in stimulating shell burial. Most of these cues are actively sought by the fish via external and internal inspections. Shell burial therefore appears to be a method of reducing the information gathering ability of potential shell-dwelling competitors. Shell burial can therefore be regarded as an investment process which enhances the resident’s ability to defend its territory. Males can also control the distribution of open shells within territories, and thus control mate access to shells. This behaviour could be a significant factor in the evolution of marked sexual dichromatism exhibited within the genus.
In short, folks, the shells are important!
Plants are usually a futile exercise, because the shelleys are such notorious diggers, giving many of the new world cichlids and even mbuna a run for their money in the digging department. Shellies will dig for days to make their territory just the way they like it. They shoot the sand out of their mouth and dig vigorously brushing their bodies against the sand. If you must add plants, try sturdy species that can tolerate some digging, such Anubias, Microsorium (Java Fern), Java Moss, Apondgenton, Cryptocaryne, Sagittaria, and Vallisneria. To me the logical solution would be to rather opt for floating plants!
Tanganyikan Cichlids prefer clean water with stable conditions. Rapid changes in the composition of the water can cause harm. So, replicate the water of Lake Tanganyika: Keep the pH between 8.0 and 8.3 and the hardiness between 10.0 and 20.0 dH. and keep the tank well filtrated.
Water changes should be done about once or twice a month. Yes, this sounds unusual, and also as if it is not enough to keep any fish healthy, but shell dwellers are very sensitive to changes in their water quality. That is why your filtration must be extra good! Many people have their shell dwellers spawning healthy broods of fry with only a 40% water change once a month.
All fish do best when given a wide variety of foods. This practice helps to ensure a balanced diet. Furthermore, if one food should lack a needed nutrient, another may provide it. Shell dwelling cichlids are micro-predators by nature, so a protein based diet including such items as Cichlid Flake Foods, freeze-dried or frozen brine shrimp, daphnia, lobster eggs, plankton, and similar foods are ideal. They love live daphnia and live brine shrimp, which they would very much appreciate as an occasional treat. They should also be fed Spirulina based pellets or flakes, or frozen spirulina. They also appreciate the occasional peeled pea, or piece of spinach. Also give small quantities of crushed high protein cichlid pellets on a regular basis. When cichlid fry are present in the aquarium, newly-hatched brine shrimp, micro-worms, and powdered or crushed flake food should be added to the aquarium to provide ample fodder for these baby fish. Feeding them twice a day is enough.
It is comparatively easy to breed Tanganyika shell dwellers in aquariums. Once the fish reach sexual maturity, the fun begins. They pair off on their own and are either loyal to each other, or breed in harems (one male fish and several females). When pairs are kept together in a separate tank, they stay as a pair and spawn.
To trigger spawning, some people do a water change, some feed extra amounts of live foods, some slightly fluctuate the water chemistry and some just leave the fish alone. My opinion? Do not disturb your shell dwellers very often; this can upset them and stop any spawning activity. Just allow nature to take its course.
Tanganyikashell dwellers will typically display aggressive behaviour during the breeding period. You may notice a pair of fish, or a female which becomes more aggressive and defensive of a territory. If everything is to their liking, the pair will soon start to produce eggs. You can tell that the fish are pairing off if the female stays very close to her shell, and the male is frequently going into the female’s shell. Spawning is usually very secretive. The female seduces the male to her shell by quivering on her side. If she is successful, the male will follow her into her shell where the eggs are laid and fertilized. A sign that a pair has spawned is when the male and female begin to share the same shell. The eggs of all Shell-Dwellers are laid and fertilized in the shell, and the brood is usually guarded by both parents — violently if necessary. An average batch will contain 20-40 eggs, but the number can vary a lot between different shell dwelling species. The number of eggs, as well as the size of the eggs, is also affected by the size of the female.
The series of beautiful images below, taken by award-winning photographer Andreas Werth, captures some of the courtship and breeding behaviour of Neolamprologus brevis.
After the fry have hatched, they are kept in the shell for a while, under close supervision of the female. Many times if you look down into the water or into the shell, you can see the tiny fry peeking out into their new world. The female may keep her offspring in the safety of the shell for up to 5 days. After she lets the fry out, they are ignored. Not eaten, nor guarded — just ignored. At this time you should be begin to add small foods such as baby brine shrimp and powdered flake food to provided bite-size morsels for the new fish. As the fry grow, they become more adventuresome and move into empty shells within their parent’s territories.
Before you know it, your tank may be heavily populated with the offspring of your original fish. It is wise to “thin the herd” every so often. These fish can be removed to start new colonies in other tanks.
I personally advocate removing the fry into another tank so they can get full nutrition and growth. Typically, one spawning consists of about 25-30 fry. A maximum of about 60 is considered a large accomplishment on the fish’s behalf! If the parents are kept healthy, they will breed like clock-work. This means that every three to four weeks, you could be greeted with tiny little eyes gazing out of the female’s shell.
A word of warning, though! Be careful not to disturb the tank when your shell dwellers are breeding. Shell dwellers need calm and quiet if they are to breed. You should try to cut back on water changes to every 2 to 3 weeks, as to not stress the parents or the fry which can die at the snap of a finger when stressed. This is also why you must make sure to keep the water chemistry very stable for fry.
A further word of warning: I you have chosen Brevis as your species, you cannot keep the fry with Brevis forever, like you can with most other shell dwellers. They will eventually decide to spawn again and unlike their other shell dwelling cousins, they will fiercely attack and kill (or eat depending on the size but not usually) their previous brood in order to make room for their new brood. N. brevis also guards their breeding territory more fiercely than any other shell dwellers, attacking anything that comes into the small area around their shell. The actually act like miniature Oscars!
Make sure to use cichlid specific supplements. These include Cichlid Buffers, Salts, and Trace Elements. Cichlid buffers help to maintain the pH and alkalinity of your water. The Cichlid salts help recreate the natural water chemistry which they evolved in. These salts help maintain proper coloration and help to prevent growth defects. Cichlid Trace Elements are essential for the well-being of your Shell-Dwellers. Most Tanganyikan fish are susceptible to deficiencies of iodine or magnesium; without the addition of trace elements the likelihood of gill tumours and other ailments significantly increases. All of these products drastically improve the chance of successful spawning in your aquarium.
For those of you who doubt that fish can learn from one another, even across species, this little copy-cat is proof that you are wrong:
The interesting behaviour and coloration of African Cichlids is largely responsible for their popularity as aquarium residents. Sometimes a hobbyist doesn’t have the space, time, or money to set up and maintain a large aquarium full of boisterous Cichlids. If this is your situation, the Shell Dwelling Cichlids of Lake Tanganyika is the group of Cichlids which will fill all your needs, providing hours of endless fascination and enjoyment.