Marron

Quick facts

Adult size

30 cm, 400 g typical harvest weight

Days to harvest

540 to 1095 days from fingerling

Lifespan (max)

up to 12 years

Diet

omnivore

Temperature class

cool-water

Difficulty

advanced

Water parameters

Temperature range

12–26°C (optimum 22°C)

pH

6.5 to 8.5

Hardness

8 to 25 dGH

Minimum tank

300 L per individual at harvest size

Feed and growth

Feed protein

32% target

Daily feed (warm water)

1.50% of body weight per day

Daily feed (cool water)

0.60% of body weight per day

Max stocking density

25 g per litre of system water

A 400g adult eats about 6.0 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 60 g of feed daily.

Legality

Aquaculture and possession rules vary by jurisdiction and change over time. This table reflects regulations as of the verified date on each row. Verify with your local fisheries or wildlife authority before stocking.

Jurisdictions not listed here default to "check local regulations". A non-listing is not a green light; rules in your specific county or municipality may apply.

Habitat and origin

Native to freshwater rivers and streams in southwestern Western Australia. The species (Cherax cainii) is the largest freshwater crayfish in Western Australia and the third-largest in the world, reaching 2 kg and 38 cm in exceptional specimens, though culture size is typically 60–150 g at harvest. Marron inhabit clear, well-oxygenated streams with woody debris and undercut banks. They're a prized food item in Western Australia, with firm, sweet flesh comparable to marine lobster. Marron aquaculture began in the 1970s and has grown into a significant industry in Western Australia, with production from purpose-built ponds and integrated aquaculture systems. The species has been introduced to other parts of Australia and to a few countries internationally.

Climate and outdoor ponds

Climate classification

temperate (handles seasonal swings)

Outdoor pond zones (USDA)

7 to 10 (winter low around -18°C or warmer)

Heating in a temperate climate

Not required (handles seasonal cool periods)

Cooling in a temperate climate

Required if your summer water temperatures exceed the upper tolerance

Zone bounds reflect year-round outdoor pond viability with no active heating. Anywhere outside the bounded zone, the species can still be kept in an indoor heated tank or a seasonally-managed system. Verify your specific microclimate, as a sheltered yard zone can run a half-zone warmer than the regional rating.

Care notes

A premium freshwater crayfish for aquaponics in temperate climates with cool to warm water (15–25°C optimal). Marron grow slowly compared to tropical crustaceans: 60–150 g in 18-24 months on commercial crayfish pellet (28-35% protein). FCR is approximately 2.0-3.0, typical for crayfish. The payoff is flavor and market value: marron command $30-80/kg in Australian markets, which makes even small harvests worthwhile. Temperature tolerance is moderate (8–28°C), but growth is very slow below 15°C and the species stresses above 28°C. Dissolved oxygen above 5 mg/L is important because marron are less tolerant of low oxygen than warm-water crayfish like red claw. Stocking is calculated by bottom area: 5-10 marron per square meter. They need shelter (PVC pipe sections, stacked tiles, or mesh bundles) to reduce aggression and cannibalism during molting. Marron are more sensitive to water quality than yabbies or red claw; maintain ammonia below 0.5 mg/L. Fingerlings (called juveniles) are available from Western Australian hatcheries. Legal to culture in Western Australia and some other Australian states; check regulations for interstate or international movement. For non-Australian aquaponics operators, marron are rarely available; red claw crayfish or freshwater prawn are more accessible alternatives.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else