Although crayfish are highly adaptable, a suitable growing environment is essential for raising high-quality crayfish. So what are the requirements for the crayfish's growing environment? Details are as follows:
1. Suitable water temperature
Crayfish are not particularly demanding in terms of water temperature; they can survive in water temperatures ranging from 1 to 40°C. However, the suitable water temperature is 16 to 33°C, with the optimal temperature being 20 to 32°C. If the water temperature is lower or higher than this optimal range, the growth rate of crayfish will decrease. Furthermore, crayfish will still emerge from their burrows to forage during the winter when temperatures drop, but they will retreat back into their burrows to hibernate when the water temperature falls below 10°C.
2. Suitable water quality
(1) Dissolved oxygen: It is best to maintain the dissolved oxygen level in the pond in the range of 4-8 mg/L, and it should not be lower than 3 mg/L. In particular, the dissolved oxygen requirement is higher during the molting period, and the dissolved oxygen in the water must be above 5 mg/L.
(2) pH value: The suitable pH value range is 7.0-8.5. During the production process, quicklime can be used to clean the pond or quicklime water can be sprinkled to improve the acidity and alkalinity of the water.
(3) Salinity and transparency: Crayfish usually live in freshwater, and the salinity of the water should not be too high. The suitable salinity range is 2.0%-2.5% in the early stage, 1.5%-2.0% in the middle stage, and 0.5%-1.0% in the later stage. In addition, the transparency of the aquaculture water should also be controlled at 30-40 cm.
(4) Heavy metal ions: Crayfish cannot come into contact with heavy metal ions, as they can cause serious toxicity to crayfish. The main sources of heavy metal ions include industrial wastewater, domestic sewage, and wastewater from farming and breeding.
3. Suitable foods
Crayfish are omnivorous animals. Their diet includes various tender aquatic plants, benthic animals, mollusks , large zooplankton, and the carcasses of various fish and shrimp, as well as the carcasses of their own kind. Therefore, it is best to have these natural food sources in the environment where crayfish are farmed .
4. Suitable habitat
Crayfish are burrowing creatures, preferring to inhabit relatively concealed places such as aquatic plants, branches, and rocks . Therefore, the living environment of crayfish requires sufficient shelter and hiding places.
