Pretreatment method before oviposition of sea cucumber
I. Acquisition of sea cucumbers 1. Specifications The larger the individual body of sea cucumber, the more the amount of eggs, the better the maturation of eggs, so the larger individual should be selected as the pro-ginseng. Relevant reports indicate that individuals weighing 130-255 g have an average gonad weight of 34.7 g and an average gonadal index of 16.6%. Individuals weighing 115-200 g have an average gonad weight of 17.6 g and a body weight of 80 g. In 110 grams of individuals, the gonad averages 5.6 grams. Therefore, as a parent, choose a body length of 20 cm or more and a body weight of more than 200 g. 2. The acquisition time is to obtain the pro-growth of the gonads, and it is necessary to grasp the time of pro-acquisition. Many years of practical experience have shown that the collection of pro-ginseng should be from May to August before its spawning peak, that is, when the natural sea area water temperature reaches 15°C to 17°C, the specific collection time can be obtained by collecting a small amount of sea cucumbers for dissection and observation. Its gonad development is determined. Early harvesting, poor gonadal development, long storage time, easy to cause gonadal atrophy or spawning, and will increase management costs; late capture, sea cucumbers have been discharged in the natural sea area, will lose the opportunity to obtain eggs Even if eggs can be obtained, the amount of eggs will be reduced, and the quality is difficult to guarantee, making it more difficult to grow larvae. Due to the different recovery of water temperatures in different regions, the best time for catching is different in different regions. In general, the coastal areas of Dalian and the northern part of the Yellow Sea are from late June to early July. The coastal areas of the Bohai Sea are from late May to early June. The Qingdao area is suitable for the early June and late June and the northern coast of Shandong Province. . 3. Problems to pay attention to when collecting (1) Strictly avoiding the involvement of the sea in oil-polluting contact. Because the oil-polluting can make the paraginalized skin fester (body wall autolysis), special attention must be paid. Divers and operators should clean their hands before touching the sea cucumber. Do not use oily hands to directly touch the sea cucumber. The holding vessel on board and the temporary seawater shall not be stained with oil. (2) Try to avoid mechanical irritation and damage. The pro-species are usually collected by divers in order to prevent the pro-species from squeezing or spawning and spawning eggs. The number of captures should not be too large. The density of the pro-ginseng collected on the vessel should not be too high. The density should be controlled within 300 heads/cubic meter or less, and the water should be changed frequently during temporary maintenance. Also avoid exposure to high temperatures and direct light, cover it with a blind and place it in the shade. 4. Delivery of sea cucumbers The relatives collected should be shipped back to breeding sites in the shortest possible time. The density can be placed in a plastic bag with 2 heads/liter of water and kept in the incubator to maintain the temperature and return to the breeding site as soon as possible. There is no need to inflate during transportation to avoid contamination of the water by the foaming of seawater in the mixture of seawater and the parent compound. If the transportation time is too long, you need to change the water midway to ensure the water quality in the holding tank. In order to prevent filth due to squeezing each other, the containers used in the transportation are preferably delaminated. Second, the stocking of sea cucumber After the pro-recovery is collected, it usually takes a period of time to spawn and lay eggs. Before entering the culture pool, individuals with damaged organs and damaged skin should be sorted out so as not to continue to fester and affect other individuals in stocking. To control the stocking density, the density of the parent ginseng during storage should be controlled at about 20 heads per cubic meter, and the density is too high. Due to dissolved oxygen and other reasons, it will affect the development of gonads. Studies have shown that the dissolved oxygen in the ginseng stocking pool cannot be lower than 5 Mg/ml to 6 mg/ml. Stones, hollow bricks, black corrugated boards, etc. can be added to the bottom of the pool where the parents participate. During the period of stocking, the bait is generally not fed, and the water is changed once a day in the morning and evening. The amount of water exchanged is generally 1/2 or 1/3 of the water volume of the pool. When the water is changed, the bottom dirt and excrement and the dirty individual must be promptly removed. . Observe the activities of the pro-ginseng at any time. If there are signs of spawning, prepare for spawning in time. Third, the artificial warming up of the pro-ginseng promotes familiarity in the pro-constrained areas and in order to raise seedlings in advance, often using pro-ginseng indoor temperature, promote cooked method. In this way, the culturing of juveniles can be prolonged in the indoor incubation period, and large-sized seedlings can be cultivated in that year. In addition, due to the low temperature of natural seawater, there are fewer enemy predators in the water, which can reduce or avoid the harm to the larvae of sea cucumber. The pro-ginseng is generally collected from the pool 2 to 3 months in advance. During the ripening process, it is necessary to warm up the cultivation water in a planned way to promote the development of the progeny gonads, so that they mature earlier and spawn. Stichopus japonicus at 13 °C ~ 15 °C when the most food intake. Do not warm up in the first 3 days after entering the pool. When the life is stable, increase the temperature by 1°C per day. Must not be heated too fast to avoid excessive temperature rise, leading to filthy ginseng. When the temperature rises to 13 °C ~ 16 °C should be incubated at a constant temperature, do not continue to heat until 7 days to 10 days before spawning. Studies have shown that when the accumulated temperature reaches around 800°C, the gonads of the parental ginseng can mature and naturally release. During the whole ripening process, it is necessary to feed bait. The bait can use natural food or artificial compound feed. The daily feeding amount is 5% to 10% of the body weight of the sea cucumber. Feed the seaweed powder or seaweed powder daily and mix the bait containing organic sediment. The amount of feed depends on the quality of the water and the feeding conditions. In order to make sure that the familiar probiotics have normal day and night feeding habits, black cloth is used during the day to prevent them from squeezing in the corners of the pool during the daytime. In addition, feeds should be stopped one week before preparation for collecting gametes for artificial insemination. led spotlights Guangzhou Zhongzhinan Supply Chain Co.,Ltd. , https://www.gzzhongzhinan.com