Red swamp crayfish
One of the most damaging freshwater invasive species in the world, farmed for food, sold as an aquarium animal, and named individually on the EU list of invasive alien species of Union concern. It burrows through banks, eats everything, and carries the crayfish plague that has removed native European crayfish from whole river systems.
Quick profile
- Scientific name
- Procambarus clarkii
- Adult size
- 12–15 cm (4.7–5.9 in)
- Lifespan
- 2–5 years
- Temperature
- 15–28 °C (59–82 °F)
- pH
- 7–8.5
- Hardness
- 6–25 °dGH
- Minimum tank
- 100 L (26 US gal)
- Minimum length
- 80 cm
- Swimming zone
- Bottom
- Social
- Solitary and territorial
- Diet
- Omnivore
- Overall confidence
- moderate confidence
What keeping this species involves
Physically among the easiest animals in this catalogue to keep alive, and among the hardest to keep responsibly. Every requirement it has is about containment.
Almost any still or slow fresh water, including seasonal and degraded sites it can burrow through.
Identity and names
- Common name
- Red swamp crayfish
- Scientific name
- Procambarus clarkii
- Family
- Cambaridae
- Order
- Decapoda
- Class
- Malacostraca
- Also sold as
- Louisiana crawfish, Procambarus clarkii, red swamp crawfish
Adult size and growth
12–15 cm (4.7–5.9 in)
Typical lifespan in an aquarium: 2–5 years. Almost every animal sold in a shop is a juvenile, so the tank has to suit the size in the first line rather than the size in the bag.
Water and tank requirements
A large, territorial, burrowing decapod needs floor area and its own shelter; a moulting animal must be able to get away from every other one.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 15–28 °C (59–82 °F) | Stability matters more than hitting an exact figure. |
| pH | 7–8.5 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 6–25 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 100 L (26 US gal) | A floor, not a recommendation. |
| Minimum footprint | 80 cm long | A large, territorial, burrowing decapod needs floor area and its own shelter; a moulting animal must be able to get away from every other one. |
| Water flow | low | Match the outflow to this rather than to the filter's rating. |
| Lid required | Yes | Reduces evaporation and prevents accidents. |
| Structure | Deep substrate it can dig, several separate caves, and a fully secure cover. It climbs equipment and leaves open tanks. |
Behaviour
- Burrows extensively and rearranges or undermines everything in the tank.
- Climbs filter pipes and cables and leaves an uncovered tank.
Telling males from females
Mature males carry disproportionately long claws and a pair of hardened appendages behind the walking legs; females are broader through the tail.
Feeding
Eats plants, invertebrates, fish eggs and any animal slow enough to catch.
- Diet type
- Omnivore
- Staples
- Sinking pellets, Blanched vegetables, Frozen foods, Leaf litter
Breeding
- Strategy
- Female carries eggs and juveniles beneath the tail
- Difficulty
- incidental
- Parental care
- carries eggs
Extremely fecund and matures fast, which is a large part of why it establishes wherever it is released.
Tankmates and compatibility
Assessments are derived from stored traits by the compatibility engine, with the reasoning shown. A verdict is a statement about probability, not a guarantee — individual temperament can override it.
| Towards | Risk | What it means |
|---|---|---|
| Small fish | high | Anything that fits in the mouth is at risk once this species reaches adult size. |
| Adult dwarf shrimp | near-certain | Cover reduces losses but rarely prevents them where the risk is high. |
| Shrimplets | near-certain | Determines whether a shrimp colony can grow rather than merely persist. |
| Snails | near-certain | Applies to snails you wanted as well as snails you did not. |
| Long or trailing fins | none | Fin damage is an entry point for secondary infection. |
| Plants | consumes | Tough species such as Anubias and Java fern survive most grazers. |
Assessed pairings
Any pair in the catalogue can be assessed with the compatibility checker.
Welfare considerations
Points where the way this species is commonly sold or kept differs from what it actually needs.
- Not a community animal. It takes fish that sleep on the bottom, strips planting and eats other invertebrates.
- A carrier of Aphanomyces astaci, the crayfish plague, which is lethal to European native crayfish and is spread by water as well as by animals. Never release it and never dispose of tank water, substrate or plants into drains or natural water.
- Turns on its own kind while the shell is soft, so shelters have to outnumber the animals rather than merely exist.
Problems to watch for
Most problems in a tank containing this species are general rather than species-specific. Start with the troubleshooting index and work from the observation rather than from a guess at the cause.
What AquariumHQ does not yet hold
Species-level disease susceptibility is modelled in the graph and is not yet populated. Health pages will not be published until each condition has veterinary sourcing, because health content written without evidence is the most harmful thing this product could publish. The gap is recorded in the coverage report.
Where it comes from
- Native range
- Native to the south-central United States and north-eastern Mexico; introduced and invasive across Europe, Africa and Asia
- Habitat
- Almost any still or slow fresh water, including seasonal and degraded sites it can burrow through.
What the checklists say
58 distribution statements retrieved from GBIF checklists. Establishment means is reproduced from the source where it states one, and left unstated where it does not — a record of presence is not a record of origin.
| Status | Places | What this means |
|---|---|---|
| Introduced | 50 | A checklist states the species arrived here with human help. That is not a statement that it is established, harmful or illegal. |
| Recorded as present, establishment means not stated | 8 | The source records the species as present and does not say whether it is native or introduced. AquariumHQ does not fill that in. |
No checklist AquariumHQ holds positively calls this species native anywhere, so the native range above rests on AquariumHQ’s own reading of the literature rather than on a cited checklist.
Legal status and responsible practice
Restriction note
This species appears by name on the EU Union list of invasive alien species of Union concern under Regulation (EU) No 1143/2014, an annex AquariumHQ read directly; it names crayfish individually and Procambarus clarkii is among them. A Union listing carries bans on keeping, breeding, transporting, selling and releasing. England and Wales adds an older and separate restriction, the Crayfish (Prohibition of Keeping) Order 1996, which licenses the keeping of any Astacidae, Cambaridae or Parastacidae — this is a cambarid. It is regulated as a pest in a number of jurisdictions outside Europe as well. None of this is legal advice; check with the national authority for your own country first.
Never release aquarium life into the wild
Aquarium animals, plants, and aquarium water must never be released into ponds, rivers, canals, drains or the sea — not even in a country where the species is sold freely. Released fish and invertebrates establish populations that displace native species, and released plants and water carry pathogens, parasites and fragments capable of spreading without any animal at all. If you can no longer keep an animal, rehome it through an aquarium society, a retailer that accepts returns, or another keeper.
- Rehome through a local aquarium society, a specialist retailer or another keeper.
- Unwanted plants go in household waste or a hot compost heap, never in a watercourse or a garden pond.
- Never empty a bucket of tank water into a drain that discharges to open water.
- If an animal is beyond rehoming, ask an aquatic veterinarian about humane euthanasia rather than releasing it.
Legal status is recorded from the sources named and was correct on the verification date shown. Rules change, and sub-national rules often differ from national ones. Check the current position with the relevant authority before acquiring, selling or moving any animal or plant.
Evidence
Every stored value with the kind of support behind it and where to check it. Evidence type and confidence are separate axes: an editorial position held confidently and a measurement held tentatively are different things.
| Claim | Value | Evidence type | Confidence | Source |
|---|---|---|---|---|
| scientific name | Procambarus clarkii | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Native to the south-central United States and north-eastern Mexico; introduced and invasive across Europe, Africa and Asia | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 12–15 cm | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| lifespan | 2–5 years | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| temperature | 15–28 °C | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| ph | 7–8.5 pH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| general hardness | 6–25 °dGH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 100 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 80 cm | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
Last reviewed 2026-08-10. Values labelled as an aquarium-literature consensus are AquariumHQ editorial positions rather than measurements — see how evidence is handled.
Why we say this
What each figure on this page rests on, and how far that is from being independently established.
Every figure on this page has a provenance. Open any claim to see what AquariumHQ holds for it, which sources say what, and what a claim of that kind actually needs. Different claims need different evidence: an accepted scientific name is settled by one authority, while a legal restriction needs a current primary instrument. A single source is often the right answer rather than a thin one.
scientific nameAquariumHQ's own position, externally checkableBased on a verified authoritative source.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: accepted scientific name and classification — 1 authoritative source in an appropriate context. Checked against gbif on 2026-08-12. One authoritative backbone is what this class requires.
What would improve this: Go and read a source. This is reachable and has not been reached.
native rangeAquariumHQ's own position, externally checkableBased on a verified authoritative source.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: where the species occurs — 1 authoritative source in an appropriate context. 58 distribution statements held from GBIF checklists — introduced in 19 country. Establishment means is reproduced from the source, never inferred from occurrence.
What would improve this: Go and read a source. This is reachable and has not been reached.
adult sizeAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: size a well-kept specimen reaches — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
lifespanAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
temperatureAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
phAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
general hardnessAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
minimum tank volumeAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: minimum tank size — no external source is required, provided AquariumHQ shows its reasoning. No authority publishes this. AquariumHQ derives it, and the derivation is recorded with its inputs and assumptions.
What would improve this: Keep the rationale current. There is no source to find.
minimum tank lengthAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: minimum tank size — no external source is required, provided AquariumHQ shows its reasoning. No authority publishes this. AquariumHQ derives it, and the derivation is recorded with its inputs and assumptions.
What would improve this: Keep the rationale current. There is no source to find.
Group size and social behaviour
Holds ground and eats rivals caught mid-moult. One animal per tank unless the floor can be divided into territories that do not overlap.