Slough crayfish
The sexually reproducing species from which the all-female marbled crayfish arose in the aquarium trade. It is unremarkable in itself and is in this catalogue because of what it explains: a lineage that became a listed invasive species is not the same taxon as its ancestor.
Quick profile
- Scientific name
- Procambarus fallax
- Adult size
- 7–11 cm (2.8–4.3 in)
- Lifespan
- 2–3 years
- Temperature
- 18–27 °C (64–81 °F)
- pH
- 7–8.5
- Hardness
- 6–20 °dGH
- Minimum tank
- 60 L (16 US gal)
- Minimum length
- 60 cm
- Swimming zone
- Bottom
- Social
- Solitary and territorial
- Diet
- Omnivore
- Overall confidence
- low confidence
What keeping this species involves
An ordinary cambarid: hardy, territorial, and needing calcium and cover. The care is unremarkable and the context is not.
Seasonally flooded marsh, slough and wet prairie.
Identity and names
- Common name
- Slough crayfish
- Scientific name
- Procambarus fallax
- Family
- Cambaridae
- Order
- Decapoda
- Class
- Malacostraca
- Also sold as
- Procambarus fallax, Everglades crayfish
Adult size and growth
7–11 cm (2.8–4.3 in)
Typical lifespan in an aquarium: 2–3 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 mid-sized territorial crayfish with a shelter per animal and floor it can dig.
Why these ranges: Warm-temperate Florida wetland water, moderately hard. The band follows the habitat; nothing species-specific is published, and the moulting requirement for calcium is what actually constrains it.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 18–27 °C (64–81 °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 | 6–20 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 60 L (16 US gal) | A floor, not a recommendation. |
| Minimum footprint | 60 cm long | A mid-sized territorial crayfish with a shelter per animal and floor it can dig. |
| Water flow | low | Match the outflow to this rather than to the filter's rating. |
| Lid required | Yes | Reduces evaporation and prevents accidents. |
| Structure | Caves, leaf litter and deep enough substrate to burrow, under a secure cover. |
Behaviour
- Burrows into soft substrate and forages at dusk.
- Reproduces sexually, unlike the marbled crayfish derived from it.
Telling males from females
Males have paired hardened appendages behind the walking legs and larger claws.
Feeding
- Diet type
- Omnivore
- Staples
- Sinking pellets, Blanched vegetables, Leaf litter, Frozen foods
Breeding
- Strategy
- Sexual reproduction; the female carries eggs and juveniles beneath the tail
- Difficulty
- straightforward
- Parental care
- carries eggs
Requires a male, which is the entire difference between this species and the parthenogenetic lineage derived from it.
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 | moderate | 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 | high | 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. |
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. Bottom-resting fish and all invertebrates are at risk overnight.
- Frequently confused with the marbled crayfish it gave rise to. They are not the same taxon and are not in the same legal position.
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
- Florida and southern Georgia, United States
- Habitat
- Seasonally flooded marsh, slough and wet prairie.
What the checklists say
15 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 | 11 | A checklist states the species arrived here with human help. That is not a statement that it is established, harmful or illegal. |
| Recorded as invasive | 1 | A checklist states the species is invasive here. AquariumHQ reproduces that assessment; it does not make one. |
| Recorded as present, establishment means not stated | 3 | 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
NOT named on the EU Union list of invasive alien species of Union concern. The marbled crayfish derived from this species IS named there, as Procambarus virginalis. A listing is read at the name the instrument gives and not at the lineage it implies, so the ancestor's position and the derived lineage's position are different questions with different answers. Separately, the Crayfish (Prohibition of Keeping) Order 1996 in England and Wales catches this species at family level. Confirm the position with your own national authority before acquiring one.
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 fallax | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Florida and southern Georgia, United States | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 7–11 cm | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| lifespan | 2–3 years | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| temperature | 18–27 °C | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| ph | 7–8.5 pH | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| general hardness | 6–20 °dGH | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 60 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 60 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 2026-08-13. 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. 15 distribution statements held from GBIF checklists — introduced in 11, recorded invasive in 1 countries. 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
Territorial and cannibalistic around moults; separate shelters or separate tanks.