(B) Hatching methods and management
1. The hatching cylinder water hatching and incubating cylinder is composed of a cylinder body and a water filter cover (Fig. 2 to 5). The cylinder body can be made of ceramics, tin sheets, steel wire mesh concrete and other materials, and the bottom of the cylinder is in the form of a cone-shaped funnel, which should not be too deep. At the center of the bottom there is a water inlet pipe (water in the bottom of the cylinder), which is connected with the rubber pipe under the bottom. Higher pressure water flows through the controllable pipe and flows into the cylinder. The water flow is turned upside down in a fountain and filtered out of the filter bowl that is close to the edge of the cylinder. The water filter cover (generally four pieces of fan-shaped 40-50 mesh nylon screens are assembled together) is assembled 15 to 20 cm away from the cylinder port, so that the water filter cover has enough filtering area (area submerged in water) to achieve For the purpose of leaving eggs drained, the cover must be a circular table-like cover. To prevent fry from leaking at the cylinder cover, cotton or foam can be added. When the cylinder cover is in use, it must be straightened without creases to prevent seedlings. The hatching tank can also be reformed with a water tank with a smooth inner wall, as long as the bottom of the tank is opened, and a circle is filled with cement to form a funnel. The size of the hatching tank can be designed according to the need, generally about 150kg of water capacity is appropriate. The density of oviposition should be determined according to the water temperature and dissolved oxygen conditions. Generally, the water capacity is 150kg for the incubating tank of water, and each cylinder can put about 500,000 eggs of fertilized fish. Incubation cylinder water flow speed is adjusted so that the fish eggs rush to the center of the water surface, and the rear cylinder can be dispersed and sink around, usually 20-24 L/min. Prompt flow should be appropriate, and should be properly controlled according to the amount of dissolved oxygen in the water.
When the fish fry come out of the membrane, the management should be strengthened. The filter cover should be cleaned and washed to prevent the plugging of the cylinder cover due to the empty egg membrane blocking the mesh hole, causing spillage and escape of seedlings. The fry is filtered until the larvae swim in the flow hatching tank (usually 4-5 days), and the fry can be cultivated.
2. Incubation of cages Incubation of cages is a rectangular cage made of nylon mesh sieves of about 50-60 mesh. It is generally 40 cm high and has an area of ​​1 m2. It is placed in an outdoor pool with a draft of 30 cm. Egg density: Incubation in still water, preferably 25,000 grains per square meter. If water is flowing or inflated, the density can be doubled.
3. Cement pool or FRP sink The hatch cement pool or FRP sink is located indoors. The shape is rectangular, round or elliptical, with four corners arcing. The volume is about 5-20 cubic meters. Water depth is about 1.5 meters. Corresponding water supply, drainage, aeration and heating facilities should be set up. The air stone laid at the bottom keeps the water rolling continuously, which causes the egg to float up and down in the entire body of water. Each cubic meter of water can contain 100,000 to 150,000 fertilized eggs. Each day can be exchanged for temperature water 1/3-1/2. In addition to the above hatchery tools, there are also tanks, pots, buckets, and other containers used for indoor hydrostatic hatching and looping for running water. Hatching. Regardless of the form of hatchery used, whether it is running water or still water, there must be someone responsible for management. On-duty personnel should always observe and record the changes in water temperature, dissolved oxygen, embryo development, fertilization rate, hatching rate, and survival rate of fish in the pond.
(3) Calculation of fertilization rate and hatching rate of fish eggs When embryonic development enters the middle of the original intestine, fertility statistics can be calculated. First, use a small net to collect approximately 100 fish eggs and put them into a small white porcelain dish for inspection. Where the embryos are obviously shrunken, abnormal development or hollow eggs should be counted out, and then the number of eggs of the fertilized eggs (good eggs) is calculated. , Find the fertilization rate: fertilization rate (%) = the number of fertilized eggs (oval) / total number of eggs (good + bad eggs) 100 In order to raise the index of hatchery management, the hatching rate is generally calculated (calculated should be deducted Number of eggs not fertilized) Hatching rate (%) = Number of hatched fishes) / Number of fertilized eggs (total egg number fertilization rate) 100 Since it is difficult to calculate the actual hatching rate in production, the seedling rate is generally lower in production (below Pond rate) to indicate the fry hatching rate.
Fifth, fry cultivating from the larvae to swim in Pingyou, cultivating about 25-30 days, so that the body length of 2.5-3cm fry breeding process, known as fry cultivation. At present, in China, the cultivation of barnyard grass and barracuda seedlings is mostly done by using the traditional earth pond of freshwater fish to fertilize the seedlings with a little bait. This method is less investment, quicker, cheaper and suitable for mass production. However, due to the large body of water and the outdoors, the environmental conditions are difficult to control and the production is not stable enough. Overseas marine fish nursery uses indoor factory methods. Some units in China have begun to adopt.
(1) The area of ​​the fish nursery pond, the clear-cut fish ponds, and the fry fishery are 1-3 mu, and the water depth is preferably 1.2-1.5 m. The embankment should be larger, the bottom of the tank should be flat, and the sludge should be less (5-10 cm). There must be a certain amount of fresh brackish water (fish can be adapted in pure fresh water, and barracuda must be more than 4-5 mm long to fully adapt to fresh water).
The fry pool should be cleared before use, which is one of the effective measures to improve the environmental conditions of the pond and kill the enemy. Clearing work includes:
1. Pond dressing time is generally 20-30 days before planting, choose sunny. The method is to discharge the pool water, remove excessive silt, plug loopholes and cracks, remove the algae weeds at the bottom of the pond and the poolside, and level the bottom of the pond, exposing it for several days, and wait for clear ponds of drugs.
2. The drug clearing pond drug clear pond can be carried out about 10 days before the fry stocking. There are many kinds of drugs in Qingtang, commonly used are lime, croton, tea alum, fish fine, bleach, ammonia and so on.
(2) Shiji fertilizer can inject fresh seawater or brackish water (the salinity should be close to the incubating water) to about 40-60cm deep in the first week of the fish pond. When entering the water, filter the water with a sieve screen on the influent day to prevent wild fish and their eggs from flowing into the pool. After water injection, basal fertilizer was applied to the pond to reproduce plankton. In order to make small zooplankton baits appear in the pool at a suitable time for early fry feeding, fertilization should be carried out 4 to 5 days before the fry pond, so that the fry pond can eat enough palatable natural food. Early application of large-scale zooplankton to reproduce in large numbers was unfavorable to the growth of fry. The determination of the amount of basal fertilizer should take into account factors such as the climate, type of fertilizer, and the original fertility of the pool. Generally, about 250-500kg of manure can be applied per acre (people and livestock excrement), or about 5000-700kg of green grass (with leguminous or fungi plants). Or apply manure 100-150kg plus thiamine 5-10kg.
(3) Fish seedlings should be placed in the fry pond in time for fish rearing. Being too late will affect its growth and survival rate.
When determining the stocking density, it is generally based on the water quality of the pool, the quantity and quality of the bait, and the constitution of the fish. If the water quality is good, dissolved oxygen is adequate, and the feed is rich, it can be put in place. If the water quality is slightly poor or the feed supply is insufficient, it should be properly diluted.) The fry can have good constitution and the body can be thinner. The stocking density of the barracuda fish fry is better, with 80,000-150,000 fish fry per acre of water surface. When fish fry ponds should pay attention to: Clear ponds with drugs, fry ponds 1 to 2 days before the need to test the water, that is to take a pot of water into dozens of fish fry, observe whether the drug has disappeared to prevent the occurrence of dead fish accidents . At the same time, the species and quantity of food organisms in the pool must be checked to see if they are suitable for the feeding needs of the fry. Since the early larvae enter the pool, they need to pass through a “dangerous stage†of nutrient conversion (a few days before and after the yolk completely disappears). The pool must have a large number of small zooplankton diets such as copepods nauplii, copepods, or rotifers, which could easily cause a large number of larvae to die. The fish in the pond must be hatched in the same batch. If there are large or small, even if it is only one or two days, it will hinder the growth of the rear batch of fry and cause adverse consequences. When fish fry the pond, it should be noted that the incubation water temperature and the pool water temperature do not differ too much, generally does not exceed 3 °C. Keep the fish in the wind so that it will not be blown by the wind to the shore. The fish pond should be gently stirred after the pond to prevent the fry from getting together. Due to the young fry, special care must be taken during operation. When the number of fry is too large (available cup method), it should be carried out with water, and must not be concentrated after being overrun so as to avoid a large number of hypoxic deaths.
Pain Relief Patch for neck shoulder, lower back and leg.
[Name] Medical Cold Patch
[Package Dimension] 10cm×12cm 2pieces/box
The pain relief patch is composed of three layers, namely, backing lining, middle gel and protective film. It is free from pharmacological, immunological or metabolic ingredients.
[Scope of Application] For cold physiotherapy, closed soft tissue only.
[Indications]
The patches give fast acting pain relief for strains, sprains, cramp, bruises, swollen areas or joint stiffness.
[How To Use a Patch]
Tear off the packaging bag and remove the patch. Remove the protective film and apply the patch on the skin. One piece, one time. The curing effect of each piece can last for 8-12 hours.
[Attention]
Do not apply the patch on the problematic skin, such as wounds, eczema, dermatitis,or in the eyes. People allergic to herbs and the pregnant are advised not to use the medication. If swelling or irritation occurs, please stop using and if any of these effects persist or worsen.notify your doctor or pharmacist promptly. Children using the patch must be supervised by adults.
[Storage Conditions]
Store below 30c in a dry place away from heat and direct sunlight.
Pain Relief Patch For Neck Shoulder,Lower Back And Leg
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