Can Celestial Pearl Danio (Galaxy Rasbora) and Smallmouth Bass Live Together?

Celestial Pearl Danio (Galaxy Rasbora) is a peaceful species (2/10), while Smallmouth Bass is semi-aggressive (7/10). This notable difference means Smallmouth Bass may occasionally assert dominance over Celestial Pearl Danio (Galaxy Rasbora).

Celestial Pearl Danio (Galaxy Rasbora) and Smallmouth Bass 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.

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

Additional behavioural considerations to keep in mind: Aggressive fish may bully and stress shy, slow-moving species. Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Smallmouth Bass is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 20°C and 25°C. Aim for the midpoint of this range (around 22.5°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range.

To house Celestial Pearl Danio (Galaxy Rasbora) and Smallmouth Bass together, plan for an aquarium of at least 680 litres with a minimum length of 180 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: Plants - Densely covered, Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Celestial Pearl Danio (Galaxy Rasbora) prefers Low (Still Water) flow while Smallmouth Bass needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Celestial Pearl Danio (Galaxy Rasbora) and Smallmouth Bass 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. Smallmouth Bass is an aggressive eater that may prevent Celestial Pearl Danio (Galaxy Rasbora) from getting enough food.

Because Smallmouth Bass is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Celestial Pearl Danio (Galaxy Rasbora) receives an adequate share.