4 kinds · tap one for a closer look
Aggressive and will eat fish, shrimp and plants.
134 species in our list are a good match.
Aggressive and will eat fish, shrimp and plants. Digs and escapes.
Check your local laws. EU: on the Union list of invasive alien species since 2016, so it may not be imported, kept, bred, transported, sold or released in the EU. England and Wales: a permit/licence from Natural England or Natural Resources Wales is needed to introduce, hold, keep or sell it. US: native in the south, but introduced populations exist in many states; state rules were not checked here. Check the rules where you live before you buy one, and never release it into the wild.
Good to know: Invasive; restricted in many places including the EU.
Sinking pellets, vegetables and meaty foods.
Tap a food to see what it is.
Males have bigger claws than females. Sperm is released at the base of the male's 5th walking legs; the female's opening is at the base of the 3rd walking legs.
Common problems. Tap one to see the signs. This is a guide, not a diagnosis.
Egg-bearing mating pairs · Easy
Mates in open water; the female attaches 100-500 fertilised eggs to her swimmerets, often inside a burrow. Eggs hatch after about 3 weeks; the young stay attached through two moults and remain with the mother up to eight weeks. Matures in as little as 3 months and can spawn year-round in warm climates.
One male and 2 females in a large tank with hides.
Large tank with caves and sand; separate female when berried.
Seasonal temperature changes and good feeding.
Usually 200-500 eggs (about 100 in small females, up to 500 in a 10 cm female); incubation about 21 days.
Juveniles are tiny crayfish; feed meaty foods and keep separate to prevent cannibalism.
A hardy crayfish from the southern USA and north-eastern Mexico, farmed in huge numbers for food (Louisiana, and now mostly China) and sold in pet colour forms (white, blue, orange). It is one of the most invasive crayfish in the world, spreading crayfish plague, burrowing into banks and rice fields, and is banned in the EU.
Charles Girard described this crayfish in 1852. It is the famous crawfish of Louisiana cooking and has been farmed and moved around the world, becoming invasive in many countries.
First described by Charles F. Girard in 1852. Named for Named after collector John H. Clark.
15 facts checked with sources
Invertebrate (freshwater crayfish). Valid name.
WoRMS / DecaNet (2026): Procambarus clarkii (AphiaID 465540, REST record)New value.
WoRMS / DecaNet (2026): Procambarus clarkii (AphiaID 465540, REST record)Total length; adults 5.5-12 cm. Legacy 12 cm is the upper end.
USFWS Ecological Risk Screening Summary: Red Swamp Crayfish (Procambarus clarkii), rev. 2015 · Wikipedia: Procambarus clarkii (cites IUCN, EU Union list)Optimum 21-27 °C. Legacy 15-28 °C is survivable (it is eurythermal, growth stops below 12 °C), so the change is to the optimum range; the legacy range is not wrong as a tolerance.
USFWS Ecological Risk Screening Summary: Red Swamp Crayfish (Procambarus clarkii), rev. 2015 · FAO Cultured Aquatic Species Information Programme: Procambarus clarkiiLegacy 6.5-8.5 lies inside the tolerated 5.8-10 (Huner & Barr 1991). No source gives an optimum.
USFWS Ecological Risk Screening Summary: Red Swamp Crayfish (Procambarus clarkii), rev. 2015FAO says it prefers hard water but gives no number.
FAO Cultured Aquatic Species Information Programme: Procambarus clarkiiWild lifespan 2-5 years; legacy 3-5 years.
USFWS Ecological Risk Screening Summary: Red Swamp Crayfish (Procambarus clarkii), rev. 2015Sources describe it as carnivorous/omnivorous and cannibalistic in burrows, but none uses a temperament term for tank keeping.
Animal Diversity Web (Univ. Michigan): Procambarus clarkiiBottom-living burrower.
Animal Diversity Web (Univ. Michigan): Procambarus clarkiiNew value.
Wikipedia: Procambarus clarkii (cites IUCN, EU Union list) · USFWS Ecological Risk Screening Summary: Red Swamp Crayfish (Procambarus clarkii), rev. 2015Legacy's 'hooks on legs' (ischial hooks of male cambarids) is plausible but not quoted; the claw-size difference is verified.
Wikipedia: Procambarus clarkii (cites IUCN, EU Union list) · Animal Diversity Web (Univ. Michigan): Procambarus clarkiiLegacy '100-500 eggs; juveniles hatch in a few weeks' agrees. ADW gives ~6 weeks on the swimmerets and 'over 600 viable young' for large females; FAO's 21-day incubation is used. Wikipedia also notes research suggesting occasional parthenogenesis.
FAO Cultured Aquatic Species Information Programme: Procambarus clarkii · Animal Diversity Web (Univ. Michigan): Procambarus clarkiiLegacy breeding.eggs only says 'Females carry eggs under the tail'; count and timing added.
FAO Cultured Aquatic Species Information Programme: Procambarus clarkii · USFWS Ecological Risk Screening Summary: Red Swamp Crayfish (Procambarus clarkii), rev. 2015Legacy story correct. Colour morphs in pet stores are mentioned by Wikipedia without a citation.
Wikipedia: Procambarus clarkii (cites IUCN, EU Union list)Legacy 'Banned in the EU, several US states and many countries' - EU part confirmed; the US state and other-country bans were not checked (Japan's 2020 ban on most North American crayfish, per Wikipedia's marbled crayfish page, may cover it, but the quoted source names only marbled crayfish).
EUR-Lex: Commission Implementing Regulation (EU) 2016/1141 (Union list), consolidated text 7 Aug 2025 · Wikipedia: Procambarus clarkii (cites IUCN, EU Union list) · GOV.UK (Defra): Introduce or keep non-native fish, lobsters and crayfish (England and Wales; last updated 15 Oct 2026)