1. Site selection, construction and environmental sanitation

Farming sites should be in line with the aquatic mudflat aquaculture plan formulated by the local fishery administrative department. For the construction of aquaculture ponds, the size, form and scale of the ponds should be determined scientifically and rationally according to different breeding species, patterns and conditions.

In terms of water intake and drainage channels, it is required that the water intake and drainage should be as far away from each other as possible, and the water intake and drainage channels should be set up independently and separately, and the newly built farms should not be located near the water intake or drainage of the existing farms.?

2, dredging

Before farming, use seawater to remove dirt and debris from the breeding pool, and repair the pool and water inlet and outlet channels. When a cement pond is selected as a breeding pond, it must be repeatedly scrubbed. If you choose to use a pond as a breeding pool, the place where the sediment is thicker must be dredged and exposed to the sun to promote the decomposition of organic matter. Found dead individuals should be moved to land as soon as possible, centralized destruction.

3, substrate regulation

After all the dredging, eliminate the disease-carrying intermediate hosts and breeding enemy organisms that are unfavorable to the cultivation of sea cucumbers, and regularly use quicklime and bleaching powder to eliminate the breeding ponds and the channels in and out of the water. Firstly, inject 10-20cm of fresh water, put in the drug to dissolve, and then splash the drug into the culture pool. Cement pools should be rinsed several times with pool water dissolved with disinfectant drugs, followed by 2 rinses with sand filtered water or clean water.

Ponds can be soaked in disinfectant water for a period of time and then replaced with sand filtered water or clean water a few days before releasing the seedlings. The water used for aquaculture must be imported from a non-polluted area and properly treated before and after use, and the water quality should be tested regularly. Meanwhile, the substrate conditions should meet the national standards.

4. Fertilization

After full nativity, pay attention to fertilizing the water and cultivating the beneficial biological communities again. Pour in the appropriate amount of photosynthetic bacteria and beneficial strains of bacteria to improve the speed of fertilization of the breeding pool, enhance the effect of fertilization. The effect of fertilization and the time needed for fertilization may vary depending on the local aquaculture environment, the target species and the fertilization method.

Generally, when the water temperature is lower than 20℃, it takes 15-30d to fertilize the water; when the water temperature reaches above 20℃, it takes at least 8d to fertilize the water. In order to strengthen the management of aquaculture process and the procedures of cleaning, disinfection and fertilization of aquaculture ponds, the following records should be kept for them: cleaning records, disinfection records, fertilization records, etc. These related documents and records shall be kept for more than 2 years.

5. Selection of seed ginseng

The fresh weight of seed ginseng should be more than 300g, and it is better to select the cultured individuals with more than 350g of vigor, good gonads, and no damage.

6, the seed ginseng temporary cultivation

Species of ginseng after entering the pool, usually need to go through 3-10d temporary cultivation period. If it is a short period of time, no bait can be put in, and all the water can be changed twice a day, and every night when the water is changed, a thorough cleaning of the bottom can be completed. If it takes a long time, you should put bait in the water, but the water temperature should be kept below 20℃, otherwise it will affect the feeding of the ginsengs.

Additionally, use a dark-colored plastic sheet to block out the light, and at the same time, pay attention to pick out the dirty individuals and those with ulcerated and broken skin. The density of temporary feeding is appropriately controlled within the range of 10-20 heads/m3, subject to not exceeding 30 heads/m3. Every morning, do suction bottom inspection to observe whether there are eggs. If there is only a small amount of spawning, it can be discarded.

7, artificial spawning technology

The stimulation method used to induce spawning includes shade drying, warming and water flow. Temporary rearing 5-7d, after 7:00 p.m. to catalyze the spawning. Continuously observe the spawning process and take care to record it. When the seawater in the pool is drained, let the ginseng dry for 40-60min, then shock the ginseng body with seawater for 30-45min, then inject the fresh seawater which has been filtered, so the ginsengs can generally spawn on the same day or on the second day.

Before the female ginseng spawns, it will be slowly put into the specific spawning box for fertilization. During the period, add artificial semen in appropriate amount, stir the culture water from time to time, and control the density of eggs at 80 grains/mL.

After fertilization, fish out the female ginsengs as soon as possible, and use filtered seawater to wash the eggs for 2-3min each time, to wash away the excess sperms and dirt until the pool water becomes clear. After ovulation, the female ginseng should be kept temporarily for 3-5d, waiting for the female ginseng to spawn naturally. During the period of temporary rearing, the parent ginseng will lay eggs several times.

8. Fertilization and incubation

Usually, farmers will adopt the method of mixed fertilization for large-scale broodstock production. The incubation water temperature of the fertilized eggs is about 20-22℃, and the incubation density is lower than 10/mL, and 6-8/mL is preferred. More than 10/mL, need to be divided into pools before incubation.

During the incubation period, turn the water up and down once every 0.5h with a stirring rake. Special attention should be paid to the fact that there should be no dead space when turning the water, and the water should not be stirred in only one direction, but should be prevented and controlled by rotating the embryos to the center of the pool. After the embryos hatch, give micro-aeration as needed.

9, selection and pooling

30-40h after hatching, the embryo development to the late protozoa or small auricular larvae in the early stage, the embryos are concentrated in the surface layer of the water, should be timely selection and pooling. Before selection and breeding, the measure of mirror inspection should be taken to observe whether the floated larvae are normal and robust. Adopt drag selection method for selection and breeding, according to the number of larvae needed in each breeding pool, the larvae collected by drag selection and concentration will be divided into each breeding pool after quantification.

10, planktonic larvae cultivation

Larvae cultivation conditions are water temperature 19-25 ℃, room temperature 27-30 ℃, salinity 2.7%-3.3%, dissolved oxygen control at 5-7.5 mg per liter, ammonia nitrogen less than 0.5 mg / L, pH value should be 7.8-8.3.

At the same time, the water quality should be in line with the requirements of the standard NY5052-2001. The density of the larvae pool should be controlled at 0.3-1.0/mL according to the actual situation.

The bait for the planktonic larval stage is mainly algae, such as whipple gold algae, salt algae, small crescent-shaped algae, etc. When feeding, a variety of bait can be used to feed the larvae. Feeding can be mixed with a variety of baits. According to the different stages of larval development, adjust the feeding amount.

11, young ginseng cultivation

In order to improve the growth rate of young ginseng, when the baby ginseng grows to about 1cm, it should try to add artificial bait, and with the bait inputs, in order to help make the young ginseng deepen the pigmentation in the body. When the body length of young ginseng reaches 2-3cm, the density should be 4000 heads/m3.

And increase the amount of oxygen and water exchange. At this time, we should pay attention to whether there are individuals with disease, timely injection of antimicrobial agents to control the spread of disease, if necessary, but also to the onset of individual drug bath treatment.

12, daily management and monitoring

Arrange personnel to observe the weather, water temperature, water quality changes every day, inspect the cage to observe the feeding and activity of the sea cucumber, ensure that the sea cucumber is cultivated in a clean and comfortable breeding environment, and fill in the breeding diary in time.

Baidu Encyclopedia - Sea Cucumber