Several potentially disease causing organisms, including protozoans, bacteria and viruses, have been identified in redclaw. All have been implicated at one time or another in some mortality or poor production from specific farms, although there has never been any documented widespread outbreak of disease. Farmers are well aware that careful quarantining and good health monitoring and management will minimise the risk of disease. By maintaining good culture conditions that maximise survival and growth, crayfish stress is managed and the threat of disease minimised.
Common Name: Red Claw Crayfish Latin Name : Cherax quadricarinatus
Harvesting may involve a number of methods, although the most effective is the use of a flow-trap; this exploits the strong response of redclaws to flowing water. A slow but steady flow of water into the pond via a box and ramp illicit movement of crayfish against the flow and into the box. Flow-trapping should involve 95 percent drainage of the pond over 24 hours from dawn to dawn. There should be several thousand litres of water remaining in the deepest part of the pond at dawn, when the redclaw are removed. This slow drainage enables the crayfish to move out of shelters and with the main body of water, so that they concentrate and respond most effectively to the flow trap. Both the flow trap and the last remaining water must be well aerated or the entire harvest may easily be lost. The stock should be quickly removed and transported to clean water in a tank system. Care should be taken to minimise crushing by not exceeding 15 kg of stock per transport container (typically a 60 x 40 x 40 cm fish basket).
Other harvesting methods include bait trapping and drain harvesting with manual collection of stock.
Feeding Red Claw Crayfish - YouTube
Easy to raise, red claw lobsters pose a unique opportunity for anyone with the desire to nurture something unusual. Red claw lobsters, also known as crayfish, are a fresh water crustacean that are inexpensive to care for and fun and can be raised for food, reselling, or pure family enjoyment.
It's feeding time for our 30 juvenile red claw crayfish.
Please keep all comments constructive to Austrailian Red Claw Crayfish husbandry methods and care. Any degrading, sarcastic, or disrespectful comments will be removed. There is no hatchery production. Redclaws are reared directly in the juvenile ponds.
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.