How to control excessive autumn reproduction of shrimp

Prawns mature early, have strong fecundity and lay eggs in autumn. When holding eggs in autumn, most of the nutrition absorbed by parent shrimp is used for embryonic development, and the growth rate slows down; in addition, a large number of autumn seedlings compete with parent shrimp for food and space, which restrict each other. When catching at the end of the year, the proportion of offspring green shrimp is large, the specification is difficult to improve, and uneven. Therefore, controlling the excessive autumn propagation of green shrimp can improve the commodity rate and benefit of green shrimp.

Green shrimp

Purchase high-quality seedlings: buy seedlings, please go to the original improved seed farm of green shrimp, avoid self-breeding for many years, because many times of inbreeding will lead to continuous homozygous harmful genes, so that the quality of green shrimp becomes worse and the size becomes smaller.

Neutron irradiation: 0.8-1cm seedlings were irradiated with low dose neutron radiation, and the gonadal development was retarded by activating polymerase activity in shrimp seedlings.

Control the water temperature of the pond: in summer and autumn, the water level of the shrimp pond can be properly deepened to more than 1m, and the area of aquatic plants in the pond can be increased. The principle of this method is to postpone the gonadal development of shrimp by controlling the effective accumulated temperature in a certain period of time.

Control the frequency of changing water: change the water once every 10 days, and each time accounts for about 1 per cent of the total amount of water. Changing water too frequently will accelerate the gonadal development of shrimp due to frequent water stimulation.

Delay the release time: the green shrimp seedlings released from May to June can produce a large number of offspring in September. On the other hand, when the stocking time of green shrimp is going to be autumn propagation, that is, releasing seedlings in early July, autumn reproduction can be controlled by suddenly changing the living environment of green shrimp.

Sprinkle lime water: sprinkle the whole pond with 20ml 25kg raw lime slurry per mu. Through the lime water, the pH value of the pond water can be quickly increased, and the larvae and flea larvae that have not yet metamorphosed will die because of the high PH value.

Control pond water quality: in the autumn and summer season in September, the pond water quality should be properly adjusted to "thin", with transparency above 40cm, which will reduce the survival rate of clear shrimp seedlings due to lack of sufficient plankton bait.

Culture of silver carp and bighead carp fingerling: 30 silver carp and bighead carp species of about 10 kg each are raised in the shrimp pond. Silver carp and bighead carp filter out most of the plankton in the pond, and the flea larvae before metamorphosis are the "delicacies" of bighead carp. This method can also control the number of young prawns.