Key Data for Keeping Red Clawｓ

Temperature
Red claw lives in higher temperature of 24-32℃. Best growth is at 29-30℃. Water temperatures below 21℃ significantly reduce growth rates. Water temperatures below 10℃ are fatal. Red claw starts to perish at 34℃ and has an upper lethal temperature of 36℃.


Dissolved Oxygen
Red claw can tolerate very low dissolved oxygen and can survive even at 1ppm. However, the water should preferably contain over 5ppm. The dissolved oxygen level above 6ppm is ideal.


Water Quality
Red claw, like yabby or red swamp crayfish, seems to tolerate a wide range of water quality conditions.

pH
pH 6.5-9.0

Salinity
Red claw tolerates salinity to a level half that of seawater. However, salinity level should not regularly exceed 2ppt.

Hardness
The water must be hard enough (as dissolved calcium level of 20-300ppm) to maintain strength in the shell. 80-200ppm is the best range.

Others
Red claw tolerates unionized ammonia concentrations up to 1.0ppm and nitrite as high as 0.5ppm for short periods, but ammonia and nitrite level should be kept below 0.5ppm and 0.3ppm respectively.


Reproduction
Red claw generally reaches sexual maturity by the age of 6-12 months, when its weight ranges 30-85g. Mature male red claw develops a distinctive red or orange patch on the outside of the claws.
Red claw requires a period of cooler water temperature to stimulate spawning. Warmer water temperature of 27℃ and a longer photoperiod of 12-14 hours of light will increase spawning rates.
Each female will produce 100-1000 eggs, depending on her size. An average of 6.2 eggs per gram of female can be expected. Red claw may breed several times in any one season.
The length of time taken for the eggs to hatch entirely depends on the temperature. Hatching will normally occur in 4-6 weeks, and within 30 days at 29℃ but as many as 45 days at 24℃. The juvenile becomes independent of the mother over a period of 1-3 weeks.


Growth
After hatching, red claw can reach a weight of 30-85g in 6-12 months. A weight of 50-100g can be gained in a 6-month growing season. Red claw shows rapid growth in the wild , reaching 150-300g in 2 years and can grow to over 600g and 35cm in length at last.
Red claw grows more in relatively warm water of 24-30℃ and grows best at 29-30℃. Below 21℃ significantly reduces growth rates.


Disease

Porcelain disease (White tail disease)
This disease is caused by a single-celled animal, microspordian, Thelohania. The red claw, being an opaque or whitish blotched abdomen in the advanced phase, will die. The disease is transmitted through cannibalism of infected individuals. There is no known treatment for Thelohania. The disease may be managed by screening out and destroying animals, though the disease can not be easily detected in the early stage.

Crayfish plague
Crayfish plague caused by fungus Aphanomyces astaci and originated in the United States spread to Europe and destroyed their crayfish stocks. The fungus is not present in Australia, but it is not known whether the fungus is present in Japan or not.
The fungus grows best at temperature below 18℃ and does not appear to be infective above 21℃.

Parasites
A temnocephalan or an epistylis are found on the gill or shell. They are not actively harmful to the red claw but they may cause the harm if there are too many. Temnocephalan or epistylis may be removed with salt baths. Dose: either 30 grams of salt (not table salt but sea salt or artificial sea salt) per liter of bath, for 2-3 minutes; or 10 grams per liter of bath, for 30 minutes.


Diets
Red claw is omnivorous detritivores and prefers to eat decaying plant or animal matter. In its native habitat its diets consist mostly of decaying plant material but under culture condition red claw accepts a wide variety of foods including formulated diets.