Can Mexican Dwarf Crayfish (CPO) and Royal Pleco (L190) Live Together?

Mexican Dwarf Crayfish (CPO) is a generally mild-mannered species (4/10), while Royal Pleco (L190) is moderately assertive (5/10). This modest difference means Royal Pleco (L190) may occasionally assert dominance over Mexican Dwarf Crayfish (CPO).

Mexican Dwarf Crayfish (CPO) and Royal Pleco (L190) both frequent the 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.

Worth noting: Royal Pleco (L190) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Mexican Dwarf Crayfish (CPO) and Royal Pleco (L190) to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

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 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. An aquarium test kit is recommended for monitoring.

To house Mexican Dwarf Crayfish (CPO) and Royal Pleco (L190) together, plan for an aquarium of at least 540 litres with a minimum length of 150 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Sand (Sifters), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater. Meeting these requirements will help both species thrive.

Mexican Dwarf Crayfish (CPO) prefers Low (Still Water) flow while Royal Pleco (L190) needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.