The living habits of crayfish
Crayfish have no strict requirements for water environment. They can survive in water with PH value of 5.8~8.2, temperature of-15℃~40℃ and dissolved oxygen no less than 1.5 mg/L. They can survive naturally in most areas of China. The optimum pH value for crayfish growth is 7.5~8.2, dissolved oxygen is 3 mg/L, and water temperature is 20~30℃.
Crayfish are thermophilic and afraid of light. They have obvious vertical movement phenomenon day and night. When the light is strong, they sink into water or hide in caves. When the light is weak or dark, they begin to move. They usually hug the weeds or suspended substances in the water and lie on their sides on the water surface. They have the habit of digging holes. The depth of digging holes is 50~80 cm.
Crayfish is omnivorous animals, all kinds of fresh aquatic plants, water benthos, molluscs, large zooplankton, fish and shrimp carcasses and similar carcasses are their favorite food, artificial feed is also very fond of eating.
After molting for the first time, larvae began to feed on phytoplankton, small cladocera larvae and rotifers. Crayfish are more gluttonous, food shortage will be cannibalistic, to eat small, molting shell or just molting shell of the soft-shelled shrimp is most likely to be residual food.
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