- Scientific name: Haplochromis nubilus
- Synonyms: Astatotilapia nubila, Haplochromis annectidens, Haplochromis desfontainesii, Haplochromis nuchisquamulatus, Paratilapia victoriana, Tilapia nubila
- Common name: Blue Victoria Mouthbrooder
- Group: Cichlids
- Habitat: West Africa; Lake Victoria basin
- Size: Male: 13 cm, female: 10 cm.
- Biotope: Found throughout the Lake Victoria basin in lakes, rivers, and swamps. Inhabits shallow, papyrus areas near the shore.
- Social behavior: Territorial when spawning; dominant males are extremely aggressive and intolerant of conspecific males and other male haplochromines.
- Diet: Omnivorous; all kinds of libe foods, particularly small crustacea and insect larvae. Juveniles and females are also feed on algae and detritus.
- Breeding: Quite easy
- Tank: Minimum 250 litres
- Population: 1 male and 4-5 female for 250 litres
- Decoration: The tank can be densely planted around the edges. The animals should be offered many hiding places among rocks, rock edifications, and roots; at the same time, preserve sufficient open swimming space. The substrate should be sand or fine-grained gravel. Cover the tank well, since the fishes are accomplished jumpers.
- Temperature: 23-26°C
- pH: 7.5-8.5
- Hardness: 10-15 NK°
- Lifespan: 10 years
Description: Males are black during the spawning season with red-fringed anal and dorsal fins and pronounced egg spots on the anal fin. No other fish from this region feature this colour pattern. Males are capable of drastic color changes depending on mood. The female have a drabber colouration consisting of various shades of green and gray. The fish is very sensitive for nitrate. It is necessary to change the water for 50 % every week.
A maternal mouthbrooder. Males establish territories among the rocks or over the sand near vegetation, and spawning occurs within the male's territory.To minimize the risk that the dominant male injures or even kills a female, at least 4-5 females should be kept. The more females, the more the male's aggressions are distributed. The anmals spawn like mouthbrooders, whereby the eggs are inseminated by the egg spot method. One female can lay up to 60 eggs, but 20-40 eggs are more common. A brooding female will seek refuge among the rocks or vegetation. At 25°C, the young are released from the female's mouth after about 2 weeks. They are 8-10 mm long at that time. Feed them with Artemia nauplii.