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CrayfishfreshwaterModerate

Zebra crayfish

A boldly striped New Guinea crayfish with long slender claws, reaching around twelve centimetres and among the more manageable Cherax in the trade. Like every crayfish it will catch a sleeping fish and will strip soft plants.

Quick profile

Scientific name
Cherax peknyi
Adult size
10–13 cm (3.9–5.1 in)
Lifespan
3–5 years
Temperature
22–28 °C (72–82 °F)
pH
6.5–7.8
Hardness
6–20 °dGH
Minimum tank
80 L (21 US gal)
Minimum length
70 cm
Swimming zone
Bottom
Social
Loose group — at least 1
Diet
Omnivore
Overall confidence
moderate confidence

What keeping this species involves

Hardy and easy to feed, needing hard enough water to moult in, enough caves, and tankmates that do not sleep on the substrate.

Slow lowland streams and swamps with soft bottoms and submerged wood, in warm soft water.

Identity and names

Common name
Zebra crayfish
Scientific name
Cherax peknyi
Family
Parastacidae
Order
Decapoda
Class
Malacostraca
Also sold as
Cherax peknyi, Cherax papuanus, tiger crayfish, peknyi

Adult size and growth

10–13 cm (3.9–5.1 in)

Typical lifespan in an aquarium: 3–5 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.

Shape, which is what the compatibility engine reads instead of length alone: depressed — flattened top to bottom with a moderate. Assigned from what is typical of Parastacidae, not examined for this species.

Water and tank requirements

A crayfish claims floor and defends it. The area is what allows a second individual to be somewhere the first is not, and it is measured in floor rather than volume.

Temperature (°C)

Zebra crayfish
22–28

Scale: 0 to 36 °C.

pH (pH)

Zebra crayfish
6.5–7.8

Scale: 4 to 9.5 pH.

Hardness (°dGH)

Zebra crayfish
6–20

Scale: 0 to 30 °dGH.

The bands AquariumHQ publishes for the zebra crayfish, each drawn against the full range this catalogue uses for that parameter. A narrow band on a wide scale is a specialist; a wide one is a genuinely tolerant animal. Source: AquariumHQ husbandry position for this record — an editorial range, not a measurement

Why these ranges: Lowland New Guinea water, warm and moderately soft. The hardness floor is set for shell formation rather than from the habitat: a moulting crayfish in very soft water has nothing to build with, and this is a general requirement across the group.

Where these figures come from

Habitat class

Lowland floodplain

Seasonally inundated flat country — várzea, chaco, swamp margin — where the water body changes size, depth and chemistry through the year.

The habitat's defining feature is change, so a single band describes it badly. Species from here are generally tolerant of a wide range and intolerant of nothing much — which makes them easy to keep and easy to keep wrongly.

Conductivity
40–300 µS/cm
Flow
still
Dissolved oxygen
low
Seasonality
strong

These are figures for the KIND of water body, not measurements of this species. They are AquariumHQ’s summary of the general limnology and are given wide because the water is.

TemperatureReasoned on this record
This record states its own reason for this band. See the water section.
pHReasoned on this record
This record states its own reason for this band. See the water section.
General hardnessSet by a requirement of the animal
Hardness here is set by moulting rather than by habitat. A crayfish rebuilds its entire exoskeleton several times a year and draws the calcium for it from the water and from its own gastroliths; in soft water the moult is where the animal dies. The band is a provision for that, and it is deliberately firmer than some of these species' recorded habitat.
RequirementValueNotes
Temperature22–28 °C (72–82 °F)Stability matters more than hitting an exact figure.
pH6.5–7.8A stable pH outside the ideal band is usually better than an unstable one inside it.
General hardness6–20 °dGHCheck your supplier's published figure before choosing species.
Minimum volume80 L (21 US gal)A floor, not a recommendation.
Minimum footprint70 cm long × 40 cm deepA crayfish claims floor and defends it. The area is what allows a second individual to be somewhere the first is not, and it is measured in floor rather than volume.
Water flowmoderateMatch the outflow to this rather than to the filter's rating.
Lid requiredRecommendedReduces evaporation and prevents accidents.
StructureCaves and pipes — at least one per animal and preferably more — with sand and wood. A moulting crayfish is defenceless and needs somewhere nobody can reach it.

Group size and social behaviour

Tolerant of its own kind where there are enough separate shelters and enough food. A freshly moulted individual is at risk from every other crayfish in the tank, which is what the spare caves are for.

Structure
Loose group
Minimum group
1

Behaviour

  • Excavates under any object resting on the substrate, which regularly undermines rockwork and decor.
  • Withdraws into a shelter for several days around each moult and does not feed until the new shell has hardened.

Telling males from females

Males have larger claws and, in mature animals, a red or white patch at the claw tip. Sexing is reliable from the position of the genital openings on the underside.

Feeding

An opportunistic omnivore taking plant material, detritus and anything it can catch. Calcium in the diet matters for moulting and is supplied by shell-based foods or by hard water.

Diet type
Omnivore
Staples
Sinking pellets, Blanched courgette, Indian almond leaves, Frozen bloodworm

Breeding

Strategy
Eggs carried under the female's tail until the young are fully formed
Difficulty
straightforward
Parental care
carries eggs

Young emerge as miniature crayfish and are immediately independent, and immediately at risk from the adults.

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.

Risk this species poses to common tankmates
TowardsRiskWhat it means
Small fishmoderateAnything that fits in the mouth is at risk once this species reaches adult size.
Adult dwarf shrimpnear-certainCover reduces losses but rarely prevents them where the risk is high.
Shrimpletsnear-certainDetermines whether a shrimp colony can grow rather than merely persist.
SnailshighApplies to snails you wanted as well as snails you did not.
Long or trailing finsnoneFin damage is an entry point for secondary infection.
PlantsconsumesTough 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.

  • Climbs out of open tanks using filter pipes and cables. Crayfish escapes are frequent and almost always fatal for the animal.
  • Never release a non-native crayfish or its water into open drains or waterways. Crayfish are among the most damaging freshwater invaders and several carry disease fatal to native species.

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
Southern New Guinea — the Fly River system of Papua New Guinea and Papua
Habitat
Slow lowland streams and swamps with soft bottoms and submerged wood, in warm soft water.

What the checklists say

4 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.

StatusPlacesWhat this means
Introduced1A 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 stated3The 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.

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.

ClaimValueEvidence typeConfidenceSource
scientific nameCherax peknyiObserved / measuredhigh confidenceCatalogue of Life; GBIF — Global Biodiversity Information Facility
native rangeSouthern New Guinea — the Fly River system of Papua New Guinea and PapuaObserved / measuredmoderate confidenceGBIF — Global Biodiversity Information Facility
adult size10–13 cmAquarium-literature consensusmoderate confidenceAquariumHQ husbandry synthesis
lifespan3–5 yearsAquarium-literature consensusmoderate confidenceAquariumHQ husbandry synthesis
temperature22–28 °CAquarium-literature consensusmoderate confidenceAquariumHQ husbandry synthesis
ph6.5–7.8 pHAquarium-literature consensusmoderate confidenceAquariumHQ husbandry synthesis
general hardness6–20 °dGHAquarium-literature consensusmoderate confidenceAquariumHQ husbandry synthesis
minimum tank volume≥ 80 LAquariumHQ editorial positionmoderate confidenceAquariumHQ husbandry synthesis
minimum tank length≥ 70 cmAquariumHQ editorial positionmoderate confidenceAquariumHQ husbandry synthesis
minimum group size≥ 1AquariumHQ editorial positionmoderate confidenceAquariumHQ 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 2026-08-29. 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. 4 distribution statements held from GBIF checklists — introduced in 1 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.

minimum group sizeAquariumHQ'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: group size — 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: Keep the rationale current. There is no source to find.

Guides relevant to this species

Chosen from this record's own traits rather than listed on every page.