Industrial breeding techniques of Penaeus vannamei

Penaeus vannamei includes parent shrimp cultivation, gonadal maturation, induction of mating and spawning, and fry techniques such as fertilized egg collection and hatching, larval cultivation conditions, and fry management need to be familiar with. In order to make shrimp grow fast, there are strict requirements on water quality, throwing density, depth of pond water and feeding of bait.

First, parent shrimp cultivation

The parent shrimp should be cultivated with a body weight of more than 40g and a body length of about 13cm. The parent shrimp should be put into the soil pond to promote ripening and temporary culture. The density of parent shrimp should be controlled at 20 tails / square meter, the ratio of male to female is 1:15, the water temperature should be about 28 ℃, the salinity should be about 35 ‰, and the feeding amount should be about 20% of the body weight of parent shrimp every morning and evening.

2. Gonadal maturation of parent shrimp induced by cutting.

The right eyeball excision method was used to promote the ripening of parent shrimp, and the female and male shrimps were removed evenly. After the right eyeball was removed, the right eyeball was cultured in the soil pond for a period of time, and then the left eyeball was removed to induce gonadal maturation of male and female shrimp. After ripening, the shrimp was checked every 3 days, and the ripeness reached more than Ⅳ stage. The parent shrimp was fished out with a net and put into the induction pond for temporary culture.

3. Mating and spawning

When the ratio of female to male parent shrimp is 1:3 and the temporary culture density is 15 ind / m3, the method of artificial induction and natural mating is used to achieve mating and spawning. Female prawns usually lay eggs between night and early morning.

Collect fertilized eggs for hatching

After the female shrimp lays eggs, check the development of the eggs, collect, wash and count the eggs, and then put the eggs into a special bucket for hatching. The hatching temperature should be controlled at about 30 degrees, and the hatched larvae should adopt the light-induced method.

5. Conditions for larval cultivation

The basic conditions for the development of Penaeus vannamei are as follows: the density is controlled at 120000 ind / m3, the water depth is about 1.5m, the water temperature is about 29 ℃, the salinity of water is 32 ‰, the pH is about 8.1, and the dissolved oxygen is not lower than 6mg/L. You also need to pay attention to the following aspects.

1. Water quality treatment

The cultivation of juvenile shrimp requires high water quality, and the seawater pumped from the sea area needs strict filtration, dark sedimentation and two-stage sand filtration, and needs to be filtered again with a filter bag before entering the breeding pond. In order to prevent the harm of heavy metals, chelating agents can be added to the water for water quality treatment.

2. Feeding bait

The feeding amount of (Z) Z1 and Z2 in flea stage is 30-50 000 cells / mL. If artificial bait is used, it should be evenly sprinkled into the pond after silk washing. The daily feeding amount of 3-5 g Z3 per 10 000 larvae is 4-5 g per 10 000 larvae.

M) M1 and M2 were mainly fed with rotifers, the density of rotifers in water should be kept at 510 / mL, the larvae of Artemia were mainly fed at M3, and the density should be kept at 1 / mL.

The larval shrimp was mainly fed with artificial diet, and the feeding amount was 15 ~ 18g per ten thousand larvae, and the larval shrimp could also be fed with appropriate egg yolk in the later stage.

VI. Seedling management

1. Regular microscopic examination of plankton. The species and quantity of plankton need regular microscopic examination, observe the vitality and development of larvae in the pond, and calculate the number of larvae, so as to grasp the number and survival rate of larvae in time.

2. Determine the indexes in water regularly. Regularly detect the PH value, water temperature and dissolved oxygen in the breeding pond, adjust the water temperature needed by the larvae according to the requirements, ensure the relative stability of good specific gravity, and ensure sufficient dissolved oxygen at any time.

3. Timely discharge and change of water. Observe the development of seedlings in the seedling pond, remove sewage in time and add fresh sea water. To ensure the fresh sea water needed by flea larvae and nauplius, the amount of sea water exchange should be appropriately increased during the larval stage, and it is most appropriate to reach 50% in the later stage.

7. How to manage the breeding period

1. Aquaculture pond setting

The culture pond is rectangular, the pond is built with concrete, the depth is about 3.5 meters, the center of the pond is set up with a drain, and there needs to be an adequate supply of fresh water around the pond.

2. Release of seedlings

The pond should be cleared thoroughly before seedling release, and the silt and weeds on the bottom of the pond should be thoroughly removed. Rest around the pond, install a gate net at the inlet and outlet, and disinfect it with quicklime, which is used to kill fish and other enemy pests.

After detoxification, 1.5 m deep water was injected into the pond, brine and industrial salt were added to make the specific gravity of the pond water reach 1.016 and the PH value was about 8.6. Urea and calcium superphosphate were added to cultivate natural bait. For the release of shrimp seedlings, 700000 high-quality shrimp seedlings with a body length of about 1cm should be selected, and the density should be controlled at 30, 000 / mu. After putting them in fresh water for 10 days, the artificial bait should be fed and the aerator should be turned on to ensure enough itching.

3. Daily management

Seven days after release, the artificial compound feed was fed three times a day, in the morning, evening and night, and the feeding amount was determined according to the feeding condition of shrimp. Cast more bait in the morning and evening, less at night, more when the water quality is good, and less when the water quality is poor. We should also invest less in rainy and cold weather. In the process of shrimp growth, the feeding amount should also be changed according to the body length of shrimp.

The requirements of water depth in each growing period of Penaeus vannamei are as follows: the water depth is about 1.5m in the early stage, 2m in the middle stage and 2.8m in the later stage. The pond water is mainly fresh water in the early stage of culture, and the water exchange volume should be determined according to the quality of pond water and the growth of shrimp seedlings in the middle and later stage of culture, and it should be gradually changed into seawater in the later stage of culture until the harvest is listed on the market. The water body should be kept clean at any time, sundries should be removed in time, and the bottom of the pond should be kept clean, which is more conducive to the growth of shrimp.

The bottom of the culture pond should be arranged with inflatable pipes, equipped with generators and inflated by blowers to achieve the oxygen required by prawns. Persist in patrolling the pond in the morning, in the evening, check the improvement of the facilities, record the water temperature, salinity and dissolving itching of shrimp growth, sample the shrimp in the pond every half a month, know the growth rate of shrimp in time, and adjust the daily feeding amount at any time.

4. Disease control

During the period of shrimp culture, we should strictly adhere to the principle of "prevention first, early treatment of disease", regularly use biological agents, and add VC and immune polysaccharides to the diet to enhance the immunity of shrimp. Chinese herbs such as mulberry leaves, Phellodendron Phellodendri and rhubarb are mixed into the bait every half a month, and when conditions permit, 10 ‰ imported fish oil and 1 ‰ high stable western Vc can be used for morning and evening meals, which can enhance the physique of shrimp, improve immunity and promote the rapid growth of Penaeus vannamei.