Redclaw Crayfish

About

The redclaw is the Australian crayfish sold as a blue lobster, and its legal position in Europe is not the one people assume from its red swamp cousin. Cherax quadricarinatus is not on the EU list of invasive alien species of Union concern: it is absent from the original Annex to Commission Implementing Regulation (EU) 2016/1141, and it is still absent from the consolidated list after the 2025 update — even though that update added a different member of its own genus, the common yabby Cherax destructor, with effect from 7 August 2025. Symmetry inside a genus is not how these lists work, and the check has to be done species by species. The animal itself is the largest crayfish most people will ever put in a tank. USGS gives 250 mm total length and 600 g, Wikipedia 30 cm and 600 g, and two aquarium care sources go as far as 35 cm; whichever number is right, this is not a nano-tank invertebrate. It is a non-burrowing tropical species from northern Australia and New Guinea, farmed commercially in Queensland, and unusual among crayfish in that adults are, as Shrimp and Snail Breeder puts it, 'generally gregarious and non-aggressive, amenable to stocking at relatively high densities in the ponds'. Juveniles are the opposite: aggressive, competitive and cannibalistic. What the calm adult temperament does not mean is that it is safe company — Aquadiction states plainly that 'passing fish, regardless of size, may fall prey to these Crayfish' and that it is best kept in a single-species tank.

Care

Take the legal check first, and do it for your own country. In the European Union the instrument is Regulation (EU) No 1143/2014, and this species is not on the Union list adopted under it, so the Article 7 restrictions on keeping, breeding, transport and sale do not attach to it — while they do attach to Cherax destructor from 7 August 2025 and to Procambarus clarkii since 2016. Two caveats belong with that. Article 12 of the same Regulation lets a member state establish its own national list of invasive alien species of Member State concern and apply Article 7-style measures on its own territory, so a national ban is possible without any change to the Union list; in Lithuania no Cherax appears in the Ministry of the Environment's combined table of the EU and Lithuanian lists, but that table's own coverage stops at the 2022 update. Outside the EU it varies again: in England and Wales the government guidance names the red-clawed crayfish as the one non-native crayfish you do not need a licence to keep 'in indoor aquaria for ornamental use', while in the United States the federal injurious-wildlife listing at 50 CFR 16.13 prohibits Cherax destructor and says nothing about this species. None of that is legal advice — check the rule where you live, and check it under this binomial rather than under 'crayfish'. On husbandry: one adult per 120 litres, which is what both Shrimp and Snail Breeder and Aquadiction ask for, and a metre of floor rather than height. This entry stops at that one adult: the volume gate is a floor the tank has to clear, not a per-animal allowance, so nothing else would stop a second and a third going into the same 120 litres. 23–28 °C, pH 7.0–8.5, hard water with plenty of calcium, and caves — the species is a non-burrower that shelters in rock instead of digging its own hole, and a moulting crayfish without a hide is a crayfish that gets eaten. Cover the tank: 'they are very good escape artists' and 'pretty strong and can move light lids'. Do not plant it. Aquadiction records a 'propensity for uprooting and consuming plants, as well as consuming sunken wood', Shrimp and Snail Breeder answers the question with 'The short answer is no! Cherax quadricarinatus are not plant safe and cannot be kept in planted tanks', and the wild diet work in Lake Kariba found macrophytes to be the dominant food item at 57%. Plastic plants, floating plants or plants you are willing to lose. Snails, shrimp and aquatic frogs are food, and so is any fish slow enough to be caught, so plan on a species-only tank. And whatever the law says where you are, never release one: this is the second most cosmopolitan crayfish on the planet after the red swamp crayfish, and every one of those feral populations started with someone letting it go.

Diet

Omnivorous detritivore with a strongly plant-based adult diet. Sinking pellets, algae wafers, blanched vegetables and leaf litter as the staple, meaty food twice a week, calcium for moulting. Juveniles need far more protein or they eat each other.

Telling males from females

There is no reliable way to sex this species by eye. That is the honest answer, not a gap in our data.

Also in these lists

Similar species

Same category and the closest water parameters — if this species isn't quite it, start here.

Sold in Lithuania

These Lithuanian shops listed this species in their public catalogue (checked August 8, 2026). Stock moves — ask before you travel.

These links are unpaid: we get nothing for them and ask for nothing.

Frequently asked questions

What tank size does a Redclaw Crayfish need?

A Redclaw Crayfish needs an aquarium of at least 120 litres (31.7 US gallons) with a footprint at least 100 cm (39.4 in) long — for this species, swimming length matters as much as raw volume.

What water parameters does a Redclaw Crayfish need?

Redclaw Crayfish does best at 15–32 °C (59–89.6 °F), pH 6.5–9 and a general hardness of 5–25 °dGH.

Is the Redclaw Crayfish suitable for beginners?

Redclaw Crayfish sits in the middle of the difficulty scale — manageable for a careful beginner who has done the reading, but it has specific needs worth researching first.

Sources

• Commission Implementing Regulation (EU) 2016/1141 — Annex, list of invasive alien species of Union concern (legislation.gov.uk reproduction of the adopted text)
• Wikipedia — List of invasive alien species of Union concern
• Invasive Species Northern Ireland — Consolidated List of IAS of Union Concern (July 2025, PDF)
• Regulation (EU) No 1143/2014, Article 12 — Invasive alien species of Member State concern (text as adopted, legislation.gov.uk)
• LR aplinkos ministerija — Sąjungai susirūpinimą keliančių invazinių svetimų rūšių, Lietuvos invazinių rūšių sąrašas (bendra lentelė, PDF)
• USGS Nonindigenous Aquatic Species — Cherax quadricarinatus (Australian redclaw crayfish)
• Wikipedia — Cherax quadricarinatus
• Marufu, Dalu, Crispen, Barson, Simango, Utete & Nhiwatiwa (2018) — The diet of an invasive crayfish, Cherax quadricarinatus, in Lake Kariba, BioInvasions Records 7(2): 121–132
• Shrimp and Snail Breeder — Red Claw Crayfish: Detailed Guide, Care, Diet, and Breeding
• Aquadiction — Red Claw Crayfish, Cherax quadricarinatus Profile & Care Guide
• GOV.UK — Introduce or keep non-native fish and shellfish (applies to England and Wales)
• eCFR — 50 CFR 16.13, importation of live or dead fish, mollusks, and crustaceans (current text)