Dwarf orange crayfish care guide
Also called: CPO, CPO crayfish, Mexican dwarf crayfish, Dwarf Mexican crayfish, Orange dwarf crayfish, Mexican dwarf orange crayfish, Cambarellus patzcuarensis orange
The dwarf orange crayfish (CPO) is a bright orange crayfish only about 1.5 inches (4 cm) long. It suits small tanks and most small, peaceful fish, but it eats small shrimp and snails, males fight each other, and it needs lots of hiding places and a tight lid.
Dwarf orange crayfish need a tank of at least 10 gallons (38 L), and water at 18–24°C (64–75°F) with a pH of 7–8. They grow to about 4 cm (1.6 in) and are semi-aggressive.
Plan a tank with dwarf orange crayfishSee all tank mates
Dwarf orange crayfish quick facts
| Scientific name | Cambarellus patzcuarensis (orange form) |
|---|---|
| Family | Cambaridae |
| Origin | Lake Pátzcuaro area, Michoacán, Mexico (the orange form is captive-bred; the wild species is Endangered) |
| Adult size | 4 cm (1.6 in) |
| Minimum tank | 10 gallons (38 L) |
| Temperature | 18–24°C (64–75°F) |
| pH | 7–8 |
| Hardness (GH) | 6–15 dGH |
| Group size | Alone, or 1 male with several females |
| Temperament | Semi-aggressive; males fight each other |
| Swims at | Bottom |
| Diet | Omnivore |
| Care level | Easy |
| Lifespan | 1.5–3 years |
| Safe with plants? | Mostly (nibbles soft plants) |
- Cold-water species: no heater needed in most homes.
- Known jumper: keep a tight-fitting lid.
Tank setup
A 10-gallon (38 L) tank suits a pair, ideally one male and one female, and 20 gallons (76 L) holds about four. Floor space matters more than height. Add plenty of rocks, wood, tubes and plants so each crayfish has its own hiding spot. Cover every gap in the lid and around tubing, because they climb out.
How many dwarf orange crayfish in a tank?
The smallest common tank that suits dwarf orange crayfish is a 10 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.
| Tank | Dwarf orange crayfish (alone) |
|---|---|
| 3 gallon | Too small |
| 5 gallon | Too small |
| 10 gallon | Up to 27 |
| 15 gallon | Up to 40 |
| 20 gallon | Up to 54 |
| 20 gallon long | Up to 54 |
| 29 gallon | Up to 79 |
| 40 gallon | Up to 109 |
| 55 gallon | Up to 149 |
| 75 gallon | Up to 204 |
| 125 gallon | Up to 340 |
Numbers are bioload limits only. Males fight, so keep one male, alone or with several females.
What you need for dwarf orange crayfish
Sized for a 10 gallon tank, the smallest common size that suits dwarf orange crayfish. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.
Tank and equipment
- 10 gallon aquarium (tank or kit) (opens Amazon in a new tab)Bigger tanks are more stable and easier for beginners. How to choose
- Sponge filter for 20 gallons (opens Amazon in a new tab)Gentle flow, about 30–50 GPH, suits shrimp and snails, which prefer slow water. Needs a small air pump. How to choose
- About 25 lb of aquarium gravel (opens Amazon in a new tab)Enough for a layer about 2 in (5 cm) deep. Smooth gravel suits most community fish. How to choose
- Water conditioner (dechlorinator) (opens Amazon in a new tab)Removes chlorine and chloramine from tap water. Seachem Prime is a popular, concentrated choice. How to choose
- Liquid test kit (ammonia, nitrite, nitrate, pH) (opens Amazon in a new tab)Liquid kits are more accurate than strips. The API Freshwater Master Test Kit is the common choice. How to choose
- Gravel vacuum (siphon) (opens Amazon in a new tab)Cleans the gravel and does the water change in one go. How to choose
- LED aquarium light, about 20 in long (opens Amazon in a new tab)Match the light to the tank length. Basic LEDs grow easy plants. How to choose
Food and extras for dwarf orange crayfish
- Sinking pellets or wafers (opens Amazon in a new tab)Bottom feeders need food that reaches the floor.
- Caves and hides (opens Amazon in a new tab)Gives shy and territorial fish their own space.
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Water parameters
Keep them at 18–24 °C (64–75 °F), pH 7.0–8.0 and 6–15 dGH. They come from a cool highland lake, so most homes need no heater, and they tend to live shorter lives in warm tropical tanks. Soft water causes failed molts, so add minerals if your GH is low. Only add them to a cycled tank, keep nitrate low and never use copper.
Best tank mates for dwarf orange crayfish
These popular species share dwarf orange crayfish' water needs and temperament. See the full list of 17 good matches.
Neon tetra
3.5 cm (1.4 in) · 21–25°C (70–77°F)
Panda corydoras
4.5 cm (1.8 in) · 21–25°C (70–77°F)
Bronze corydoras
7 cm (2.8 in) · 21–26°C (70–79°F)
Zebra danio
5 cm (2 in) · 18–25°C (64–77°F)
Celestial pearl danio
2.5 cm (1 in) · 20–25°C (68–77°F)
Platy
6 cm (2.4 in) · 20–26°C (68–79°F)
White cloud mountain minnow
4 cm (1.6 in) · 16–22°C (61–72°F)
Hillstream loach
6.5 cm (2.6 in) · 20–24°C (68–75°F)
Avoid keeping dwarf orange crayfish with
- Cherry shrimp: Dwarf orange crayfish eats small shrimp like cherry shrimp.
- Nerite snail: Dwarf orange crayfish eats snails, including nerite snails.
- Assassin snail: Dwarf orange crayfish eats snails, including assassin snails.
- Boesemani rainbowfish: They need different temperatures: Dwarf orange crayfish 18–24°C (64–75°F), boesemani rainbowfish 26–29°C (79–84°F).
- Clown loach: They need different temperatures: Dwarf orange crayfish 18–24°C (64–75°F), clown loach 25–30°C (77–86°F).
- Discus: They need different temperatures: Dwarf orange crayfish 18–24°C (64–75°F), discus 28–30°C (82–86°F).
Feeding
They are scavengers that eat almost anything. Feed sinking pellets, algae wafers and blanched vegetables, plus protein such as bloodworms, brine shrimp or blackworms a few times a week. Calcium-rich foods help with molting. Leave shed shells in the tank, because they eat them.
Behavior
Busy and bold for their size, but territorial. Males chase and fight each other, so keep one male per group or give a large tank with many caves. They rarely harm fish that swim above them, but they may pinch slow fish, long fins or fish resting on the bottom. Shrimp, shrimplets, small snails and molting tank mates are at risk, and they may nip at bigger snails. Cichlids, loaches and large fish will hunt them.
Breeding
They breed easily. A female carries 20–40 eggs, sometimes more, under her tail for about three to four weeks. Tiny young cling to her at first, then scatter. Adults and bigger siblings eat small young, so add moss and cover or raise them apart. They mature in about three months.
Tips from experienced keepers
- Seal the lid and gaps around cords and tubing. Crayfish are escape artists.
- Keep one male per tank unless you have lots of floor space and hiding places.
- Don't add them to a dwarf shrimp breeding tank. They catch shrimplets and molting shrimp.
- A crayfish hiding for a day or two after a molt is normal. Leave it and its old shell alone.
- Never release them into the wild. The wild species is endangered and released crayfish harm native wildlife.
Frequently asked questions
Can dwarf orange crayfish live with shrimp?
It's risky. They can catch small or molting shrimp and readily eat shrimplets. Larger shrimp like amanos usually survive, but a cherry shrimp colony will shrink.
Will CPO crayfish eat my fish?
Healthy fish that swim in the middle and top of the tank are usually safe. Weak fish, fry and fish that rest on the bottom may get pinched.
How many CPO crayfish can I keep in a 10 gallon tank?
About two, ideally one male and one female. A 20-gallon (76 L) tank can hold around four if there are plenty of caves.
Sources
We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.