The living habits of Hymenopsis clarkii

Crayfish is commonly known as crayfish. For the beginners of crayfish, understanding the living habits of crayfish and taking targeted culture technical measures are the key factors for the success of crayfish culture. The main living habits related to culture of crayfish are introduced as follows.

Activity habits of crayfish are nocturnal animals, camp benthic crawling life. During the day, they often lurk in dim corners, rocks, grass or caves at the bottom of the water body, and come out to feed at night. Therefore, feed feeding should be given priority to once in the afternoon.

Crayfish has strong climbing ability and migration ability. Under the condition of lack of oxygen, pollution, lack of feed and drastic changes in other biological and physical and chemical factors, crayfish often climb out of the water surface and enter another water body. Therefore, it is necessary to set up anti-escape facilities for breeding crayfish.

Crayfish has a strong ability to dig holes. Crayfish often dig holes in embankments where there are no stones, weeds and caves to hide. In the water body with large fluctuation of water level and the breeding period of shrimp, the cave dug is deeper: in the water body with stable water level and the overwintering period of shrimp, the cave dug is shallow; in the growing period, crayfish basically does not dig holes. Proper addition of artificial nests in the culture pond can greatly reduce the damage of crayfish to the pond ridge and embankment.

Ecology requires crayfish to have strong adaptability to eutrophication and hypoxia, and can survive more than one week without water in dark, humid and low temperature environment. If the dissolved oxygen in general water is kept above 3 mg / L, it can meet the needs of its growth.

The suitable temperature range of crayfish is 0: 37 ℃, the suitable growth temperature is 20: 33 ℃, and the optimum temperature is 20: 30 ℃. When the water temperature is below 20 ℃, it enters the hole state of non-feeding or semi-feeding, and when the water temperature is below 15 ℃, it enters the overwintering state of non-feeding. The suitable water temperature for hatching and larval development of fertilized eggs is 24-28 ℃.

Crayfish are often sensitive to heavy metals and some pesticides such as organophosphorus pesticides and pyrethroids. Organophosphorus pesticides in water will be poisoned if the concentration of organophosphorus pesticides exceeds-0.7 g / m3. Very low levels of pyrethroids pesticides will cause poisoning and death. Therefore, aquaculture water bodies should meet the national fishery water quality standards and pollution-free food fresh water quality standards.

The feeding habits of crayfish are omnivorous and animal, which can eat all kinds of grains, cakes, vegetables, terrestrial forages, aquatic plants, algae, zooplankton, aquatic insects, small benthos, fish and shrimp, animal scraps, etc., and also like to eat artificial compound feed. To carry out artificial large-scale breeding, it is better to feed special compound feed.

Like other crustaceans, crayfish have the habit of molting. Crayfish at molting stage are vulnerable to enemy damage and similar attacks. Artificial culture must set up some shelter in the shrimp pond or plant some aquatic plants in the pond for them to hide when they molt. The growth rate of crayfish is faster, and in the pond with good conditions, the young shrimp that leave the mother can grow for 2-3 months to meet the market specifications.

The breeding habit of crayfish is spawning in autumn and winter, spawning once a year, and the mating season is from July to December. After mating, the parent shrimp begins to dig holes, and the process of female spawning and hatching of fertilized eggs is mostly completed in the cave.

The hatching time of fertilized eggs of crayfish is closely related to the temperature. If the water temperature is too low, the hatching of fertilized eggs may take several months. This is why the shrimp can still be seen in March-May of the second year. Some people observe spawning shrimp in May and assume that crayfish spawn in spring or twice a year, which is wrong.