Can Black Ocellatus and Rio Negro Dwarf Cichlid Live Together?

Both Black Ocellatus and Rio Negro Dwarf Cichlid are semi-aggressive species with an aggression score of 7/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Both Black Ocellatus and Rio Negro Dwarf Cichlid are highly aggressive, increasing the risk of violent confrontations.

Black Ocellatus and Rio Negro Dwarf Cichlid both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Two territorial species may clash over territory, especially in smaller tanks. Shrimp eaters may also prey on very small nano fish.

The safe temperature window for both species falls between 23°C and 28°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Black Ocellatus (7.5–9) and Rio Negro Dwarf Cichlid (4–6.5) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Black Ocellatus needs 8–25 dGH while Rio Negro Dwarf Cichlid requires 0–5 dGH.

To house Black Ocellatus and Rio Negro Dwarf Cichlid together, plan for an aquarium of at least 110 litres with a minimum length of 80 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Shells (Breeding/Hiding), Leaf Litter/Blackwater, Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Black Ocellatus and Rio Negro Dwarf Cichlid are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Feeding time deserves special attention with this pairing. Rio Negro Dwarf Cichlid is a known shrimp eater and may prey on small invertebrates or nano fish like Black Ocellatus.