Can Banded Archerfish (Brackish) and Freshwater Harlequin Shrimp (Sulawesi) Live Together?

Banded Archerfish (Brackish) is a moderately assertive species (6/10), while Freshwater Harlequin Shrimp (Sulawesi) is peaceful (0/10). This notable difference means Banded Archerfish (Brackish) may occasionally assert dominance over Freshwater Harlequin Shrimp (Sulawesi).

Large aggression gap (6 points) between Banded Archerfish (Brackish) and Freshwater Harlequin Shrimp (Sulawesi) increases stress risk for the more peaceful fish.

In terms of spatial distribution, Banded Archerfish (Brackish) prefers the Top (Surface) zone, whereas Freshwater Harlequin Shrimp (Sulawesi) occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Freshwater Harlequin Shrimp (Sulawesi) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Banded Archerfish (Brackish) is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 26°C and 30°C. Aim for the midpoint of this range (around 28.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 and 8.5. Maintaining a stable value within this band is more important than hitting an exact number.

Hardness requirements are incompatible: Banded Archerfish (Brackish) needs 15–30 dGH while Freshwater Harlequin Shrimp (Sulawesi) requires 4–8 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 Banded Archerfish (Brackish) and Freshwater Harlequin Shrimp (Sulawesi) together, plan for an aquarium of at least 300 litres with a minimum length of 120 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), Established Algae (Otocinclus), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

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

Banded Archerfish (Brackish) and Freshwater Harlequin Shrimp (Sulawesi) 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.