Fish, Tanks and Ponds


Fish, Tanks and Ponds
A comprehensive guide to fish

Melanochromis auratus

Gold mbuna

Gold mbuna, Melanochromis auratusGold mbuna, Melanochromis auratus
Photos by Andy Rapson

A little about Lake Malawi

Lake Malawi is often quoted as containing hard alkaline water. This isn't so, the water in Lake Malawi is relatively soft when compared with other large lakes in the African Rift Valley.

  • The average dGH is 7 - 9
  • The average pH is 7.8 - 8.5
  • The average temperature varies throughout the year from 23 - 28°C

The difference in pH is accounted for by differing levels of CO2 found in the water. Deeper water and sheltered bays may have higher levels of CO2 and so the pH will be lower. Wind swept shallow water will have a better gas transfer at the surface and so will contain less CO2 making the pH higher.

Lake Malawi contains approx only one third of of the dissolved mineral level of nearby Lake Tanganyika and so chemically the two lakes are very different and this is one reason why it is a bad idea to keep fish from the two different lakes in one aquarium.

Etymology:

Melanochromis: Greek, melas, melanos = black + Greek, chromis = a fish, perhaps a perch

General Notes:

Melanochromis auratus is one of the cichlids which as a group are called Mbuna which is an African word meaning rock dweller. All the Mbuna come from just one lake in the East African Rift Valley, Lake Malawi. The Mbuna are mostly blue or yellow with just a few other colours but they make a very striking display when housed in a biotope aquarium. All Mbuna are aggressive with most of the Melanochromis genus being among the most aggressive.
Early attempts to keep these fish failed because fish keepers tried to house them as pairs which resulted in the female being injured or killed. All Mbuna need to be very carefully stocked in an aquarium. If there are too few fish, one of the larger males will become hyper-dominant. With an over crowded tank the fish will all be stressed and the water quality will be difficult to maintain. Somewhere in-between the two is the magic number where the fish will live peacefully together without being stressed. It is also worth keeping in mind that this is likely to be a dynamic situation rather than a permanent one and intervention may be needed at some point in order to keep things peaceful. This is especially true where Melanochromis are concerned. Try an initial stocking level of 1 inch of fish per 8²in of water surface (around four average Mbuna per sq foot of floor space). This seems a lot by normal stocking standards but it is important to do this. Obviously tank maintenance and filtration have to be stepped up to cope with this too. Even with this stocking level only one male per species should be housed in the same aquarium with three or four females per male, doing this will reduce the risk of hybrids being produced. All Mbuna need alkaline water, it is often said that Lake Malawi's water is hard and alkaline, this isn't really the case, the water is alkaline but it isn't particularly hard especially when compared to neighbouring Lake Tanganyika.

Feeding

Wild Melanochromis auratus feed on 'aufwuchs' which is algae along with all the organisms which live on and among the algae. In captivity Melanochromis auratus is a very bold feeder which will accept all the food it is offered. Spirulina based flake or pelleted food is ideal along with algae, cucumber, occasional bloodworm, daphnia and cyclops (live or frozen) will together form the basis of a good diet. No Mbuna should be mixed with other fish, they are generally far to aggressive and they have very particular needs which other fish don't have.

Sexing

Sexing Melanochromis auratus couldn't be easier. Adult males loose their golden colour and replace it with black. Females and juveniles of both sexes all look the same.

Breeding

Healthy Mbuna don't need any encouragement to breed, they will all spawn quite freely in a Mbuna community tank. All Mbuna are mouth brooders which means that one of the adults (mostly the female) will collect the fertile eggs in her mouth and keep them there for protection until the fry are at the free swimming stage. It is because of the mouth brooding that so many cichlids can be housed together, most cichlids need a large territory to raise a brood but this doesn't apply to Mbuna. It is also the reason why over stocking other non-Mbuna cichlids in order to try to curb aggression doesn't work.

The fry are 'born' at a very advanced stage and are quite large and easy to care for. Once released by their mother the fry are fully independant and able to care for themselves, they will instinctively head for some nooks and crannies in the rock work and even in a busy Mbuna community it isn't unusual for some fry to reach adulthood without any help. But if you want to raise a brood you will need a separate aquarium. After spawning has taken place leave the fish as they are for a few days in order to allow the female to bond with the eggs or she may spit them out if caught to soon, but don't leave it to long because there is a chance that the fry may be harmed in the transfer if they have hatched, two to three days is about right to make the transfer.

Some breeders insist on trying to extract the eggs from the female and raise them artificially, this risks injuring the female and there really is no advantage to raising the eggs this way, female Mbuna have been making a great job of it for thousands of years so it is best just to let them get on with it.
The fry will emerge about 28 days after spawning at which time the female can be removed.

Brooding female Mbuna don't eat while brooding, so don't offer any food to fish in the brooding tank. A month without food is a long time and it is normal for a brooding female to lose some condition during brooding. But it is surprising how quickly this is regained once back in the community tank. Try not to disturb brooding females to much as this will force them to use up important reserves of energy, just leave them quietly to themselves.

Wild status

Melanochromis auratus is widespread throughout the southern end of Lake Malawi and under no immediate threat.

Information at a glance

H: 7.6 - 8.4
dGH: 7.8 - 8.5
Temperature: 23 - 28°C (74 - 82°F)
Lighting:
Diet: Omnivore
Size: 10cm (4in)
Min tank size: 225 litres
Difficulty level: Difficult
Aquarium type: Mbuna Community
Swimming level: Middle

Distribution and habitat

distribution map for Gold mbuna, Melanochromis auratus

Origin: East Africa, Endemic to Lake Malawi.

Habitat: Rocky reefs in shallow water from the surface to 10m.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Cichlidae
Genus: Melanochromis
Species: M. auratus, (Boulenger, 1897)

Common name:
Gold mbuna

Synonyms: Tilapia aurata, Pseudotropheus auratus, Chromis auratus