I. Artificial breeding infrastructure for sea lice
1. Nursery room and nursery room The nursery room requires ventilation, and the light is dark, avoiding direct sunlight entering the room. There is no strict requirement on the size and shape of nursery ponds, and the depth should generally be more than 1 meter above the effective water level. Existing fish, shrimp and shellfish nursery ponds can double as jellyfish nursery ponds, and there are no bare metal pipes in the pool.
2. With a non-toxic polyethylene 1 mm ~ 2 mm thick, size 30 cm 40 cm, according to the spacing between the 4 cm ~ 5 cm horizontal composition with a seedling device, usually a set of seedlings with 8 to 20 pieces. Before putting on the seedlings, each corrugated board must be strictly disinfected and washed.
3. Artemia eggs hatching equipment 4 tentacles The best open bait of the larvae is the floating larvae, followed by the shellfish larvae; the other stages of the bait are mainly Artemia nauplii, so hatch Artemia nauplii The equipment is essential.
4. Requirements for water Sea larvae artificial seedlings seawater quality should meet the "fishery water quality standards", routine items to meet the following standards: dissolved oxygen> 5 mg / l, pH 7.8 ~ 8.3, specific gravity 1.013 ~ 1.022; should not be in the sea There are pesticides, heavy metals and other toxic substances, the surface of oil-free, foam, odor.
Second, pro-enlistment and holdings
1. Intimate gathering and pro-wrestling should choose umbrella diameter more than 30 cm, and the gonad maturity is good. The reproduction period of sea lice on the northern coast of China is from mid-August to early October. During a breeding season, the gonads have two or three discharge peaks. Coastal nursery farms in Shandong Province can collect pro-spawners in the first and second maturation peaks of the natural population, from the end of August to the beginning of September.
The intimacy of the harvested fish should be immediately restocked in a 0.5 cubic metre vat prepared on board and held for 4 to 5 barrels. During the transportation process, fresh seawater or long-flowing water must be constantly replenished. After landing, if you want to transport by truck, you can use a large plastic bag to store water, put one in each bag, and put it in a foam plastic box after oxygenation. Put 2 bags per carton and cool it with 4 frozen water bottles.
2. The gonads of innately mature and intimidating progenitors are milky white, and their male and female are difficult to distinguish accurately from the appearance or gonad color by using naked eyes, and a small piece of gonads can be taken out from the subgingival point by using tweezers, which is 20 to 40 times. Differentiate under the microscope. The eggs are spherical particles of unequal size, and the sperm is irregularly kidney-shaped. After entering the pool, the male-female ratio will be raised from 2 to 3:1.
The amount of oxygen consumed by the invertebrate is approximately 3000 mg/day to 4000 mg/day at 20°C to 26°C. During the stocking period, the water is changed twice a day, 100% in the morning and 50% in the evening. When the stocking density is high, the number of water changes should be increased and the air should not be inflated. If there are a large number of close relatives in the same batch, if you can end the harvest within one week, you do not need to feed it or you will have to feed it.
Third, spawning and hatching
1. Water storage and water treatment Brush the pond one afternoon before the nursery and inject about 100 cm of fresh filtered seawater. Add 4 ppm to 6 ppm of EDTA per cubic body of water and inflate for use.
2. Incubate at 2 o'clock in the morning to 3:00 o'clock in the spawning period. Move the intimacy to the spawning pool at a ratio of 3 to 1 in males and females. The spawning and intimacy density should be controlled between 1/m2 and 2/m2. Incubate spawning for about 1 hour after spawning into the spawning pool. About 3 hours after spawning, the relatives should be removed from the spawning pool. After the pond is left standing for 0.5 hours, the upper layer of 65 cm of water is discharged by siphon method, and the pool water is not agitated during the drainage so as to avoid a large loss of sperm and complete within 1 hour. After that, additional isothermal filtered seawater was added to the original position and replenished with EDTA and micro-inflated.
3. Incubating at a water temperature of 20°C to 24°C, the fertilized egg begins to crack at 0.5 hours, and when it develops into the blastocyst cavity, it gradually rises from the bottom of the tank. The fertilized eggs develop into floating larvae from 6 hours to 8 hours and are quantified using the volume method. The hatching process was sampled from the pool bottom every 30 minutes and the development of the embryos was observed under a microscope.
IV. Management of floating larvae
1. Properly placed attachment-based floating larvae are cultivated at natural water temperatures, have poor swimming capacity, and rotate left-handed, mostly at the bottom of the pool, and have increased swimming capacity in a few hours. To facilitate larval distribution, micro-aeration cultures are available. The fast-changing larvae metamorphose into zoea in 24 hours, most of them 2 days to 3 days, so when the floating larvae are cultivated to about 20 hours, the attachment base should be put in time. Attachment bases are suspended in the pool, 30 cm from the bottom of the pool, and the upper layer is just submerged under the surface of the water, and the amount is 3 groups/square meter. To ensure that the floating larvae are evenly distributed, inflation should be stopped at this time. Afterwards, appropriate amount of seawater should be added every 2 days to 3 days, and the water should be added 25 centimeters above the attachment base. Attachment of metamorphosis, the floating larvae attached to the front of the formation of the foot plate and shank, the rear end of the formation of the mouth and tentacles, such as metamorphosis did not encounter the attachment base, then in the floating state metamorphosis, the handle upside down floating in the water.
2. Repeated release of floating larvae If the number of floating larvae acquired for the first time is insufficient, newly hatched floating larvae may be pooled into the pool with 400-mesh cages several times in succession. This will not only increase the number of seedlings attached, but also serve as attached 4 Tentacle tentacles bait. When the average seedling density reaches 1/cm2 to 1.5/cm2, floating larvae are no longer collected, and water exchange and micro-inflation can be started.
Fifth, the training and management of zoea
1. Cultivation of zoea larvae The pupa larvae develop into tentacles four days after their attachment to the larvae and begin feeding. Individuals are very small at this time, if the feeding is not timely or the opening bait is unwell, it can cause a large number of deaths. The jellyfish floating larvae are the best bait for this stage, followed by shellfish larvae. Feeding time should be started 3 days to 4 days after the attachment of the substrate, feeding once a day, and the amount of feeding should be 5 to 6 times the seedling volume. After 5 days to 6 days, it can develop to 8 tentacles with body length of 0.5 mm to 0.8 mm. At this time, Artemia nauplii is started to feed, feeding once every 2 days, and feeding and inflating for 2 hours. Change the water, change the amount of water for the entire pool of 1/3 ~ 1/2; after 8 days to 10 days of cultivation, developed into a tentacles with 16 tentacles late larvae, body length 1 mm to 3 mm.
2. Management of zoea larvae The time for artificially cultivating zoea is from September to October in autumn. The time for larva rearing is from May to August in the summer of the following year. The interval is about 10 months, and there is a stage of overwintering. During this time, the management of the zoea is crucial.
1 Control the luminosity with black plastic film to block the doors and windows of the workshop so that the intensity of light in the workshop during the day does not exceed 500 lux. The prevention of the breeding of a large number of algae, etc., in the seedlings, thereby improving the survival rate of the juvenile larvae, is also conducive to the reproduction of the pods.
2 to maintain low temperature Zodiac larvae to adapt to low temperature life, with 0 °C ~ 10 °C appropriate. In winter, indoor insulation facilities should be provided to keep the pool from freezing. When the indoor water temperature in spring exceeds 10°C, temperature control measures should be taken, or the number of water changes should be increased so that the indoor water temperature gradually reaches the natural sea water temperature of 13°C to 15°C. In the summer, the juvenile larvae maintain seedlings, and there must be cooling equipment to keep the larvae at about 10°C.
2 Artemia nauplii was used as bait in timely feeding, and the frequency of feeding was dependent on water temperature, larval body color and amount of residual baits. Generally, it can be fed at 0°C to 2°C without feeding or 2 weeks, once at 3°C ​​to 5°C, once a week, and twice a week at 6°C to 8°C. The amount fed was 8 to 10 times the number of zoea. The juvenile larvae appear orange after satiation and pale when they are hungry. Therefore, the frequency of feeding and the amount of feeding can be increased or decreased according to the color of the zoea.
4 How much water is changed in time depends on the temperature of the water and the amount of water to be fed. The water temperature is high, and if the amount of water is large, the amount of water to be changed is large, and vice versa. During the winter, the water changes from 5 days to 7 days, and the water is changed by 1/3 to 1/2 after each feeding. Before the change of water, aspirate the dirt from the bottom of the tank and add the same amount of fresh seawater. The water temperature rose in the middle and late March of the following year, and the reproductive function of the zoea gradually recovered and entered a new stage of development. At this point, the black plastic film on the window should be removed to increase the indoor light intensity in order to increase the incidence of transverse fissure reproduction.
VI. Breeding of the zoea and the cultivation of the larvae
1. The larval reproduction of the larvae at the end of spring rises to about 13°C. The larvae begin to grow horizontally, that is, they form a transverse septum from the top to the bottom of the tentacles below the tentacles. When the crack is deep, it resembles a stack of plates and it is time to pour the pool. In order to cultivate young jellyfish in a short period of time (generally about two weeks), the temperature can be increased by about 2°C per day after the pool is poured. During this time, the juvenile larvae successively separated from the brood from top to bottom, resulting in a free-swimming dish-shaped larvae. The number of larvae released is directly proportional to the size of the larvae, and nutrition is the main factor affecting the growth of the larvae. Therefore, after the wintering of the zoea, special attention should be paid to the full supply of the bait. For each zoea, the first generation of horizontal larval reproduction of disc larvae, up to more than 20, at least 4, usually 5 to 10. After the last dish is detached, it returns to the state of zoea. After a period of growth and development, the larvae can reproduce again. However, the number of larvae forming a dish gradually decreases, and only one or two larvae are released at a time.
2. Management of dish larvae The nascent dish primordium is colorless and transparent, with a diameter of 2 mm to 4 mm. At 18°C ​​to 22°C, juveniles with a diameter of about 10 mm can be grown from 7 days to 10 days, and larvae with a diameter of about 20 cm can be grown from 15 days to 20 days. As the growth and development, oxygen consumption and ammonia excretion rose sharply. Therefore, it is very important to maintain fresh water quality in the process of cultivation of jellyfish jellyfish. The lower limit of dissolved oxygen in the water is 2 mg/l, the upper limit of ammonia nitrogen is 1.5 mg/l, and the pH range is 7.5-8.5. Lateral larval management.
The density of the butterfly larvae is preferably 10,000/m3, which is inflated. The survival rate of butterfly larvae to juvenile stages is generally more than 80%, and the survival rate to the stage of pups can reach 60% or more.
Wolfberry Juice Vermicelli Bag
Wolfberry Juice Vermicelli Bag,Wolfberry Juice Vermicelli Plastic Bag
Ningxia ZhaiXianSong Commercial and Trading Co.,Ltd. , https://www.nxupin.com