Orange CPO Dwarf Crayfish

The Orange CPO Dwarf Crayfish, Cambarellus patzcuarensis, is a dwarf crayfish species native to Lake Pátzcuaro in Michoacán, Mexico. The species name CPO stands for Cambarellus Patzcuarensis Orange, referring to the vivid orange colouration of the selectively bred aquarium strain. Unlike their larger crayfish relatives, CPOs are remarkably small — reaching only around 4 cm — and display a notably more peaceful temperament that makes them compatible with many community fish and invertebrate species. The Orange CPO is an omnivore that forages actively through substrate and plant surfaces, consuming organic detritus, small food particles, algae, and occasional protein-rich morsels. Its small size makes it suitable for tanks from 30 litres and compatible with small peaceful fish including nano tetras, ember tetras, and other species too fast to be threatened by the crayfish. While peaceful by crayfish standards, CPOs may still interact aggressively with shrimp on occasion, particularly dwarf shrimp species, and close observation is recommended in mixed setups. Males display brighter orange colouration than females. CPOs are sexually dimorphic and relatively easy to breed in aquariums, with females carrying eggs under their tail until they hatch into miniature fully-formed juveniles. The species is considered threatened in its natural habitat and is primarily maintained through captive breeding.

Tank Setup House in a minimum 30-litre aquarium. Planted tanks with fine substrate are ideal. Provide small caves, coconut shells, and hiding places for refuge and breeding. CPOs are less destructive toward plants than larger crayfish species. Include driftwood and leaf litter for a naturalistic setup. A secure lid is advisable.

Water Parameters Maintain pH 7.0–8.0, temperature 18–24°C. CPOs tolerate a reasonable range of water conditions. Moderate water hardness is preferable. Regular partial water changes maintain water quality and health. Avoid extremes of temperature or pH.

Feeding Feed sinking dwarf crayfish pellets, micro pellets, blanched vegetables, frozen bloodworm, and brine shrimp. CPOs are active foragers and will eat most sinking foods readily. Feed every 1–2 days in small amounts. Variety in diet supports good colouration and reproductive health.

Compatibility Peaceful enough for community tanks with small, fast-moving fish. Compatible with nano tetras, small rasboras, and most fish that remain off the bottom. Use caution with dwarf shrimp as CPOs may predate on them opportunistically. Not suitable with snail species they can easily overpower.

Health and Maintenance Moulting is the most critical period — ensure hiding places are available and never remove shed exoskeletons. Provide calcium-rich foods to support healthy moulting. Bright orange colouration is an indicator of health. Perform regular water changes and monitor parameters monthly.