Under the condition of artificial culture, the life span of crayfish will be slightly higher than that in natural growth environment. Therefore, in crayfish culture, we can't blindly seek to cultivate large-sized crayfish, but we can sell them as long as they can meet the sales specifications, so as to avoid losses to farmers due to natural death of crayfish.
About crayfish breeding:
In the natural environment, it takes a year for crayfish to develop from seedlings to sexual maturity, that is, crayfish are sexually mature organisms every other year. Even under the condition of artificial culture, it takes 6 months for crayfish to mature sexually.
In the natural environment, the seedlings that leave the mother in September will not mature until July-August of the following year.
Crayfish will mate from early May to September every year, and the peak of group mating is concentrated in July-August every year. Another factor to judge mating is the water temperature, but when the water temperature reaches 15℃, sexually mature male and female shrimps can mate.
After male and female mating of crayfish is completed, the female shrimp will not lay eggs immediately, but will start laying eggs about 7-40 days after laying eggs. The eggs produced by the female shrimp are discharged from the reproductive cavity and combined with the sperm stored in the sperm pod to form a fertilized egg. The fertilized egg will attach to the swimming feet in the abdomen of the female shrimp, and provide rich oxygen to the fertilized egg through the swinging water body of the swimming feet.
Therefore, it takes August-September every year for males and females to mate to form fertilized eggs.
Unencubated fertilized egg
The incubation time from fertilized eggs to seedlings is directly related to the temperature of the water in which crayfish live, and is affected by dissolved oxygen, bait and water source. The higher the corresponding water temperature, the shorter the incubation time of crayfish.
However, the formation of fertilized eggs of crayfish is mostly concentrated in autumn, when the ambient temperature gradually decreases, which will affect the hatching time of crayfish. Especially in crayfish culture, some farmers do not pay attention to the management of crayfish reproduction, which leads to crayfish hiding in caves for a long time, and only some shrimps can wait until the next spring to hatch. This is why some farmers can see the eggs-holding shrimp in the spring of the following year. This part of the eggs-holding shrimp was not formed by mating that year.
Therefore, according to the whole sexual development process, mating, reproduction and hatching time of crayfish, sexually mature female shrimp can only hatch and produce once a year, so crayfish can only produce 1-2 times in the whole life cycle.