Can Peacock Bass Orinocensis and Thai Micro Crab Live Together?

Peacock Bass Orinocensis is a semi-aggressive species (8/10), while Thai Micro Crab is peaceful (0/10). This notable difference means Peacock Bass Orinocensis may occasionally assert dominance over Thai Micro Crab.

Large aggression gap (8 points) between Peacock Bass Orinocensis and Thai Micro Crab increases stress risk for the more peaceful fish.

In terms of spatial distribution, Peacock Bass Orinocensis prefers the Middle (Open Water) and Top (Surface) zones, whereas Thai Micro Crab 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: Aggressive fish may bully and stress shy, slow-moving species. Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Thai Micro Crab is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Peacock Bass Orinocensis is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 26°C and 28°C. Aim for the midpoint of this range (around 27.0°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 6–15 dGH. Regular testing will ensure conditions stay within this range.

To house Peacock Bass Orinocensis and Thai Micro Crab together, plan for an aquarium of at least 750 litres with a minimum length of 200 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), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. 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.

Peacock Bass Orinocensis and Thai Micro Crab 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.