• Scientific name: Paratilapia polleni
• Common name: Black diamond cichlid
• Group: Cichlids
• Habitat: Africa; Madagascar
• Size: 25-30 cm.
• Biotope: Lakes, swamps.
• Social behavior: Polleni Cichlids are aggressive to conspecifics, especially if a pair bond develops
• Diet: They eat any and all commercial foods, flakes, pellets, frozen
• Breeding: Very hard
• Tank: Minimum 250 litres (for 1 couple)
• Population: 6-8 fish for 800 litres
• Decoration: Rocks
• Temperature: 20-28°C
• pH: 6,5-8,0
• Hardness: 8-25
• Lifespan: 5-8 years

Description: Adult Polleni Cichlids, and sub-adult dominant individuals are jet black in color, covered with brilliant iridescent spots which shift from golden to blue depending on the movement of the fish and the angle of the light, the eye is a bright yellow. This coloration makes them among the most beautiful and desirable of cichlids. The male Polleni Cichlid can reach 30cm in length, females usually half that length. Sexing individuals becomes easier as they mature. As noted above, males are larger than females. In addition, males tend to have longer and sharper pelvic fins, and the edge of the dorsal and anal fins are often straighter in males, and more 'rounded' in females. Among aquarists it is often said that the females, though smaller are more beautiful in their coloration patterning.

The pair bond between males and females is sporadic and easily broken. If this happens the female can become imperiled by the male's aggression if not removed. Despite these qualities, the Polleni Cichlid is not well known in the aquarium trade, though this is beginning to change. Polleni of both sexes display their best coloration during courtship and spawning. Successful aquarium spawnings are common.