A highly entertaining, fully aquatic dwarf crayfish. In the aquarium trade, the bright orange 'CPO' morph is the most popular. Unlike larger crayfish, they are generally safe with plants and fast-moving mid-to-top dwelling fish. However, they are opportunistic omnivores with claws; they will hunt dwarf shrimp and may nip the fins of slow, long-finned bottom dwellers.
At a Glance
Tank Requirements
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Water Parameters
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Temperament & Compatibility
Available Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard / Orange (CPO)
The widely available standard in the hobby, selectively bred for a striking, bright orange coloration that stands out against dark substrates.
Differs in 1 trait from base species
Also known as: CPO, Orange Dwarf, Tangerine Crayfish
Wild Type (Brown/Grey)
The natural wild coloration of the species, featuring mottled brown, grey, and tan patterns that provide excellent camouflage in leaf litter.
Differs in 1 trait from base species
Also known as: Wild Type, Brown Dwarf Crayfish, Natural
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🟢Ideal Tank MatesMexican Dwarf Crayfish (CPO) Care Guide Summary
The Mexican Dwarf Crayfish (CPO), scientifically known as Cambarellus patzcuarensis, belongs to the Invertebrates family group. Adults reach a maximum size of approximately 5 cm and have a depressed body shape with a moderate growth rate. Classified as mostly peaceful, this species primarily occupies the bottom zone of the aquarium and produces a low level of biological waste.
To thrive, the Mexican Dwarf Crayfish (CPO) requires a freshwater only aquarium with a minimum volume of 19 litres and a tank length of at least 30 cm. Water temperature should be maintained between 15°C and 25°C, with a pH range of 6.5–8 and a general hardness of 6–15 dGH. A low water flow is preferred. An aquarium test kit can help you monitor these values.
Due to its specialist needs, the Mexican Dwarf Crayfish (CPO) is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Standard / Orange (CPO) and Wild Type (Brown/Grey). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Mexican Dwarf Crayfish (CPO) Habitat Setup
When setting up an aquarium for the Mexican Dwarf Crayfish (CPO), a low water flow best suits their natural preferences. Because this species occupies the bottom zone, the aquarium layout should prioritise sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour, driftwood, which can serve as both a hiding place and a dietary supplement, and leaf litter or blackwater tannins to replicate their natural soft-water habitat. Browse aquarium sand substrate options to find the best fit.
Mexican Dwarf Crayfish (CPO) Compatibility Notes
Classified as mostly peaceful, the Mexican Dwarf Crayfish (CPO) is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, avoid housing with slow-moving or long-finned species that may become targets for fin nipping, ornamental shrimp are not safe companions, territorial behaviour may cause issues if hiding spots or floor space are limited, and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the bottom zone can help reduce competition and territorial overlap.
Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Mexican Dwarf Crayfish (CPO).
5 Gallon
10 Gallon Standard
15 Gallon Standard
20 Gallon High
20 Gallon Long
29 Gallon Standard
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Frequently Asked Questions About Mexican Dwarf Crayfish (CPO)
How big does Mexican Dwarf Crayfish (CPO) get?
Mexican Dwarf Crayfish (CPO) (Cambarellus patzcuarensis) typically reaches a maximum adult size of approximately 5 cm. They have a depressed body shape and a moderate growth rate.
What tank size does Mexican Dwarf Crayfish (CPO) need?
A minimum aquarium volume of 19 litres and a tank length of at least 30 cm are recommended for Mexican Dwarf Crayfish (CPO). This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Mexican Dwarf Crayfish (CPO) need?
Mexican Dwarf Crayfish (CPO) thrives in freshwater only conditions with a temperature range of 15–25°C, a pH between 6.5 and 8, and a general hardness of 6–15 dGH. A low water flow is preferred.
Is Mexican Dwarf Crayfish (CPO) peaceful or aggressive?
Mexican Dwarf Crayfish (CPO) is classified as mostly peaceful with an aggression score of 4 out of 10. They are generally well-suited to peaceful community tanks.
Can Mexican Dwarf Crayfish (CPO) live alone?
Yes, Mexican Dwarf Crayfish (CPO) can be kept singly or in a group. They are flexible and adapt well to both setups.
Is Mexican Dwarf Crayfish (CPO) safe with shrimp?
No. Mexican Dwarf Crayfish (CPO) is known to eat ornamental shrimp and is not recommended for shrimp tanks. Even larger shrimp species like Amano Shrimp may be at risk.
Does Mexican Dwarf Crayfish (CPO) have any special tank requirements?
Yes. Mexican Dwarf Crayfish (CPO) benefits from sand (sifters), driftwood (digestion/hiding), and leaf litter/blackwater in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
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