Broodstock selection ensures that individuals displaying desirable characteristics, such as fast growth rate, are able to contribute their genes to the successive generations. After harvesting the best crayfish are selected as broodstock, with the majority of the production being sold.
In order to effectively manage the pond environment and the stock of redclaw within the pond, it is essential to drain and dry every pond at least once each year. This solicits a response from the crayfish and they move into the current, up the ramp and into a harvest box. A current of water is directed into the pond through a ramp. Flow trapping is the most successful technique and utilises the animal's natural behaviour. These include bait trapping, drain harvesting and flow trapping. Redclaw farmers use several harvesting techniques, either independently or together. This natural production can be enhanced by organic and inorganic fertilisation, as long as ammonia (5.0mg/L) remain within the acceptable range. Some form of aeration is normally installed (usually airlift pumps) to increase the carrying capacity of the ponds.įeeding of formulated pellets is often supplemented by a mixture of grains to provide a basic food base for the animal, although much of the nutritional requirements can be obtained from natural pond production (e.g. Feedingįeeding is normally undertaken 3 times a week just before dusk to coincide with the animal's peak foraging behaviour. The best forms of shelter are mesh materials, such as onion bags or shadecloth, and short lengths of pipe. Providing shelter increases the survival and growth potential of farmed redclaw. Immediately after moulting, redclaw have soft shells and are vulnerable to predation by other crayfish in their pond. Like all crustaceans, redclaw moult or shed their shell as they grow. Several market size grades exist from 35g to over 100g. Stock is often harvested progressively due to differential growth rates. The total growout time is about 6-9 months (plus the 3–4 months spent in the juvenile production pond). The stock and pond water is carefully managed to maximise growth and animal health.
Similar sized juveniles are stocked in prepared ponds at 5–15 animals per square metre. Commercial growout is normally undertaken in earthen ponds, which usually range from 1000m² to 1200m² with sloping bottoms (1.3–1.8m deep) to facilitate drain harvesting.
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