7/21/11
Tanganyika Cichlids: Cavity Brooders
Cichlids are usually shelter brooders, and the cichlids in Lake Tanganyika are no exception. In Lake Tanganyika you can find both mouth brooding and cavity brooding cichlids. The mouth brooders protect their offspring inside the mouth of a parent, while the cavity brooders place their offspring in some sort of cavity, such as a crevice between rocks, and guard this cavity until the fry is large enough to be free swimming. In Lake Tanganyika several genera is made up by cavity brooding cichlids, such as the genera Altolamprologus, Julidochromis, Lamprologus and Neolamprologus.
Most cavity brooders in Lake Tanganyika form pairs and choose a spawning site together. Some chose an existing cave or crevice among the rocks, while others dig a pit in the substrate. The female cichlid deposits her eggs at the spawning site where they are fertilized by the male. The number of eggs in a batch varies significantly, from less then ten to several hundreds. The parents guard the spawning site and the surrounding area violently if necessary. The eggs are carefully cleaned by the parents to prevent attacks from bacteria or fungus. Sometimes juvenile fish from an earlier spawning will help out with the cleaning and guarding. After a few days fry will emerge, and the fry will also receive care and attention from both parents. The fry are kept inside the pit where they can be guarded until they are large enough to survive on their own.
One type of Lake Tanganyika cavity spawners are the snail shell spawners, e.g. the Lamprologus species. A female Lamprologus species will establish a territory and choose a snail shell on her own. She will usually pick a shell from a Neothauma snail if she can find one. She will then deposit her eggs inside the snail shell and wait for a male Lamprologus cichlid to pay her a visit. Some male Lamprologus species are monogamous and will only fertilize the eggs in one single shell, while others will visit as many shells as they can find. In all Lamprologus species the male will leave the shell as soon as the eggs are fertilized, and he will not guard and clean the offspring like the other male cavity brooders do. Lamprologus fry are instead guarded and cleaned by the female alone.
Most cavity brooders in Lake Tanganyika form pairs and choose a spawning site together. Some chose an existing cave or crevice among the rocks, while others dig a pit in the substrate. The female cichlid deposits her eggs at the spawning site where they are fertilized by the male. The number of eggs in a batch varies significantly, from less then ten to several hundreds. The parents guard the spawning site and the surrounding area violently if necessary. The eggs are carefully cleaned by the parents to prevent attacks from bacteria or fungus. Sometimes juvenile fish from an earlier spawning will help out with the cleaning and guarding. After a few days fry will emerge, and the fry will also receive care and attention from both parents. The fry are kept inside the pit where they can be guarded until they are large enough to survive on their own.
One type of Lake Tanganyika cavity spawners are the snail shell spawners, e.g. the Lamprologus species. A female Lamprologus species will establish a territory and choose a snail shell on her own. She will usually pick a shell from a Neothauma snail if she can find one. She will then deposit her eggs inside the snail shell and wait for a male Lamprologus cichlid to pay her a visit. Some male Lamprologus species are monogamous and will only fertilize the eggs in one single shell, while others will visit as many shells as they can find. In all Lamprologus species the male will leave the shell as soon as the eggs are fertilized, and he will not guard and clean the offspring like the other male cavity brooders do. Lamprologus fry are instead guarded and cleaned by the female alone.
Julidochromis marlieri – a cavity brooder from Lake Tanganyika.
If you want to breed cavity brooders from Lake Tanganyika, the first step is to obtain a compatible pair. A recommended method is to buy six or more immature cichlids and place them in the same aquarium. If it is a polygamous cichlid species, you should instead buy one male and at least four females. By letting immature Tanganyika cichlids grow up together, you make it possible for them to form their own pairs. Avoid placing new fish of the same species in the aquarium later, since the male might favour the females that he is accustomed to and kill the newcomers. The aquarium where you place your cichlids should be decorated with rocks and the substrate must be appropriate for pit digging. Try to resemble the natural environment of your specific species. Many cavity spawners will require caves and crevices as spawning sites and you will have to decorate the aquarium accordingly. When the Tanganyika cichlids have reached maturity it can take several months before any spawning occurs.
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