Fish, Tanks and Ponds


Fish, Tanks and Ponds
A comprehensive guide to fish

Cyrtocara moorii

Malawi blue dolphin

Malawi blue dolphin, Cyrtocara mooriiMalawi blue dolphin, Cyrtocara moorii
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:

Cyrtocara: Greek, kyrtos, -e, -on = bent + Greek, kara = face

General Notes:

All though the Malawi blue dolphin is endemic to Lake Malawi it is not one of the mbuna and it doesn't live in a rocky environment and neither should it be kept with mbuna as its needs are entirely different. The Malawi blue dolphin can be a nervous, flighty fish even when adult and well established in its aquarium, keep large area of swimming space open as this is natural to this species and it will help to prevent the fish from injury by banging in to things when startled. Keep one male and several females in a species aquarium or keep in a community with similar fish such as Aulonocara, Fossorochromis, Copadichromis and Nimbochromis.

Feeding

Cyrtocara moorii is a micro predator their diet should include lots of live or frozen blood worms, glass worms, brine shrimp and even lancefish. Use a good quality granular or suitably sized pelleted food alongside these to ensure a balanced diet.

Sexing

Adult males tend to be larger than adult females and although both sexes have a nuchal hump that of the male tends to be larger.

Breeding

Breeding Cyrtocara moorii is relatively simple as they will breed without any special care. Males will claim a small spawning territory and begin to display to passing females. When a female is ready to spawn she will respond to the males display and follow him to the spawning site. The fish begin circling each other and the eggs are laid and fertilised a few at a time as they do this. The eggs are immediately picked up by the female and stored in her brood pouch. After spawning the male plays no further part in brood care.

The eggs are carried for three to four weeks and then the fry are released at which point they are fully independent free swimming mini replicas of their parents, the fry are relatively large and easy to raise and will normally number from 20 to 70 depending on the size and condition of the mother.

There is one tricky decision to make when breeding this species. If the female is left in the community tank very few fry will make it to adulthood, if the mother is moved she may spit out the eggs and show no interest in them also C. moorii live in a group with a pecking order and removing a fish means it will lose its place in the pecking order and re-introduction will be difficult especially for a fish which is in poor condition through not eating for several weeks.

One possible solution is to time how long it is before the first brood is released and then remove the female at the last possible moment for consecutive broods and replace her as soon as possible after the fry are released. Or if they are kept in a species tank remove the other fish and leave the female in the original aquarium until the fry are released and then transfer the fry to a raising tank before reintroducing the other fish.

Wild status

The ICUN Red List of Threatened Species lists Cyrtocara moorii as 'Least concern' the fish is widespread throughout Lake Malawi and is particularly common at the South end of the lake. Potential threats include over collection for the aquarium trade, sedimentation and local over fishing. Specimens offered for sale may be wild caught, commercially bred  or even home bred.

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: 20cm (8in)
Min tank size: 450 litres
Difficulty level: Intermediate
Aquarium type: Community
Swimming level: All levels

Distribution and habitat

distribution map for Malawi blue dolphin, Cyrtocara moorii

Origin: E Africa, Lake Malawi (endemic)

Habitat: Shallow open water with a sandy substrate.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Cichlidae
Genus: Cyrtocara
Species: C. moorii, Boulenger, 1902

Common name:
Malawi blue dolphin

Synonyms: Haplochromis moorii