Can Giant Danio and Mexican Dwarf Crayfish (CPO) Live Together?

Giant Danio is a generally mild-mannered species (3/10), while Mexican Dwarf Crayfish (CPO) is generally mild-mannered (4/10). This modest difference means Mexican Dwarf Crayfish (CPO) may occasionally assert dominance over Giant Danio.

In terms of spatial distribution, Giant Danio prefers the Top (Surface) and Middle (Open Water) zones, whereas Mexican Dwarf Crayfish (CPO) 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.

Worth noting: Giant Danio is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 22°C and 25°C. Aim for the midpoint of this range (around 23.5°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 8. 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. An aquarium test kit is recommended for monitoring.

To house Giant Danio and Mexican Dwarf Crayfish (CPO) together, plan for an aquarium of at least 132 litres with a minimum length of 90 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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. Meeting these requirements will help both species thrive.

Giant Danio prefers High (River/Stream) flow while Mexican Dwarf Crayfish (CPO) needs Low (Still Water) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.