Can Aequidens sp. Atabapo and Figure 8 Puffer (Brackish) Live Together?

Aequidens sp. Atabapo is a moderately assertive species (6/10), while Figure 8 Puffer (Brackish) is semi-aggressive (8/10). This modest difference means Figure 8 Puffer (Brackish) may occasionally assert dominance over Aequidens sp. Atabapo.

Aequidens sp. Atabapo and Figure 8 Puffer (Brackish) both frequent the Middle (Open Water) and 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.

The safe temperature window for both species falls between 25°C and 28°C. Aim for the midpoint of this range (around 26.5°C) for optimal comfort.

The pH requirements of Aequidens sp. Atabapo (4.5–7) and Figure 8 Puffer (Brackish) (7.5–8.5) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Aequidens sp. Atabapo needs 1–8 dGH while Figure 8 Puffer (Brackish) requires 10–25 dGH.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

To house Aequidens sp. Atabapo and Figure 8 Puffer (Brackish) together, plan for an aquarium of at least 110 litres with a minimum length of 90 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), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Shells (Breeding/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.

Aequidens sp. Atabapo and Figure 8 Puffer (Brackish) 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.