Redclaw is native to the upper reaches of rivers in northeastern Australia, and in Papua New Guinea. Its
preferred habitat is in high turbidity, slow moving streams or static water holes (billabongs) that characterise the
rivers in that region. These are flushed seasonally with monsoonal wet season rains, which may wash the
redclaw downstream. Redclaw display a strong tendency to move upstream to the preferred habitat, and to
avoid being stranded in the lower river reaches that often dry up in the dry season. Its adaptation to the natural
habitat has generated a host of biological attributes that are well suited to aquaculture, as summarised below:
Breeds easily, with no larval stage development.
Potential for selective breeding; many wild population strains.
Tolerates high stocking densities.
Requires low protein diet, not reliant on fishmeal.
Market position as a high value crustacean.
Flesh texture and flavour compares favourably with other crustaceans.
Meat recovery rate acceptable.
Reaches commercial size in nine months grow-out.
Survives well out of water for transport to market.
Straightforward production technology.
Tolerant of variations in water quality - low dissolved oxygen, wide daily pH changes, low alkalinity,
temperature variations, high nutrient loads.
FAO Fisheries and Aquaculture Department
Tolerates saline water up to 5 ‰ indefinitely and up to 15 ‰ for several days. This provides broad
geographic potential and a means of enhancing flavour, purging and cleaning before sending to market.
No destructive burrowing.
Non aggressive – cannibalism not regarded as an issue.
Redclaw is a tropical species endemic to northeastern Australia. The harsh physical extremes of this
distribution have given this species a robust nature with broad climatic tolerances. Its preferred temperature
range is 23 ºC to 31 ºC and it will perish at 36 ºC. Reproduction will only occur while water
temperature remains above 23 ºC.
Female redclaw brood their eggs for six-ten weeks, depending on temperature. Most produce between 300 and
800 eggs per brood. There may be between three to five broods during the breeding season. Hatchlings
resemble the adult form and remain attached to the underside of the female for several weeks before
progressively becoming independent.
Production
Production cycle
Production cycle of Cherax quadricarinatus
Production systems
Seed supply
Selected berried females or mature broodstock from the harvests of grow-out ponds are stocked into juvenile
rearing ponds. Breeding and production of seed occurs naturally during the summer months, when
temperatures are >25 ºC.
Hatchery production
FAO Fisheries and Aquaculture Department
There is no hatchery production. Redclaws are reared directly in the juvenile ponds.
Juvenile production
Juvenile production and grow-out to market size are managed separately, although both are performed in
earthen ponds. A managed juvenile production programme is essential to provide the advanced juveniles
required for grow-out, and to make effective use of the superior broodstock selected. Depending on
temperature and whether berried females or mature broodstock are used, a culture period of 3 to 4 months is
necessary to achieve a mean size of juveniles of 5 to 15 g. The two most critical factors in juvenile production
are the provision of shelter and food. The general management of juvenile rearing ponds is the same as that
described in this fact sheet under ongrowing techniques.
Typically juvenile ponds are stocked with mature females and males at a ratio of 4:1 and a density of 1 500/ha,
carefully selected as the best of the stock available from grow-out harvest. Under well managed conditions, 50-
100 advanced juveniles will be produced per broodstock female, providing a yield of 60 000 to 120 000
juveniles/ha.
At water temperatures above 25 ºC, a juvenile production pond stocked with male and female broodstock is
ready for harvest in four months. Alternatively, when berried females are stocked, the juvenile production pond
is ready to harvest in three months. To maximise survival and growth of the juvenile redclaw, an abundance of
shelter in the ponds is essential. This is usually provided in the form of bundles of synthetic mesh, tied onto a
line with a weight at one end and a float at the other. Arranged in this manner, these bundles extend from the
pond floor up into the water column providing many spaces and surfaces for the juveniles to utilise. These
mesh bundles are stocked at one every 5 m2.
Juvenile production ponds are carefully managed to provide an abundance of planktonic organisms which the
juvenile crayfish utilise as food. The planktonic organisms include both phytoplankton and zooplankton; it is
primarily the latter that are consumed by the juvenile crayfish. As they grow, they progressively consume less
plankton and more of the detrital food that occurs on the surface of the shelter material and, more especially, on
the mud surface.
Maintaining high levels of plankton involves regular checking of water quality and periodic fertilisation of the
water with nitrogen and phosphorus (typically diammonium phosphate at 50 kg/ha).
Harvesting of the juveniles is achieved by a number of methods. Sometimes individual mesh shelters are
removed and the juveniles shaken out. However, the most effective method is to employ a flow trap. With this
method, the pond is completely drained and all the crayfish are attracted into a trap. From there they can be
removed to tanks and sorted, counted and then stocked into the grow-out ponds.
Ongrowing techniques
Although all commercial redclaw grow-out occurs in earthen ponds, there is some interest in tank culture.
Ponds
Redclaw aquaculture, both in juvenile and grow-out ponds, is performed in earthen ponds, typically 0.05 to 0.5
ha, with a depth of 1.0-2.5 m and a V-shape that allows rapid and complete drainage. Water is sourced from
surface supplies or underground and should have a pH of 6.5-8.0, hardness of >40 ppm, and low levels of
salinity (