Salmon culture

In the family of carps, they are known as crickets, and some are called crickets. They are collectively called crickets. It is called cold-water fish because it can be used for generations in low-temperature environments where other fish cannot breed. It is located in the vast sea and land areas north of 35 degrees north latitude, from the frigid zone to the temperate zone. For 200 years, people have developed salmonids, freshwater grazing and culture fisheries. Today, they have formed a world-famous cocoon fishery in more than 120 countries. In the 1950s, China started from the introduction of technology and developed rainbow trout farming. Since the 1980s, a single species of rainbow trout has developed into a breeding industry that breeds more than 20 provinces and regions, and people are beginning to realize the practical significance and development prospects of developing the breeding industry for the loss of cold water resources. First, the biological characteristics of carp Carp in the low temperature waters can only reproduce, grow, normal growth of the upper limit of the water temperature is very low, there is no obvious lower temperature biological characteristics than other fish. 1. The squid is a short-day-type fish, and it gradually matures in the autumn and winter in which the water temperature decreases day by day in natural light time. Gonadal development is sensitive to changes in light time, and changes in light can alter its maturation. People can use this feature to change their light to spawn at the desired time. 2. The breeding season is mostly from November to February of the following year, and the peak of reproduction is from December to January. In areas with long ice-sealing periods, some species breed in the spring when the stream begins to thaw the thawing food organisms. The breeding water temperature is below 8°C. 3. The upper limit water temperature for gonadal development, maturation, fertilization, embryonic development and juvenile hatching is 13°C. Over 13 °C gonadal development disorders, increased juvenile malformation rate. 4. There is no apparent minimum temperature for gonad maturation, fertilization, embryonic development, and juvenile hatching and development. At 0.5 °C water temperature, embryos can still develop and hatch normally. 5, after fertilization after embryonic development of up to 300 ~ 600 degrees, the completion of larvae development into the juvenile period after hatching film, just a hatching is juvenile fish, called hatching juvenile fish. 6. The optimum water temperature for growth is 8 to 20°C. Above 21°C, the metabolic intensity, feed efficiency, and disease resistance are reduced, and it will quickly die at 25°C. 7. There is no obvious minimum water temperature for growth, as long as the water does not turn into ice, it can feed and grow. 8. Lifelong inhabits the flowing water environment with high transparency and high dissolved oxygen. Due mainly to the above biological characteristics, Europe, the United States, and Japan have traditionally used carp as a cold-water fish. As a foreign language, China also quoted this term. In addition, squid also has the following biological characteristics. 9. There are two types of eco-groups, sea-fall and fresh-water, in most species. The seafall type is a sea freshwater migratory group. Freshwater species inhabit freshwater waters, but many species are also suitable for seawater life. Freshwater can also be implemented and mariculture can be implemented. 10. In addition to the humpback hemp hawa and the rock female salmon, the juvenile larvae of 0.2 to 15 grams of other bream fish have 7 to 12 larval ecchymosis (Parr?mark) marking the development of the juvenile fish. The residual groups of rivers in the Mashu haploid and the young females of the freshwater species will not disappear for a lifetime and will live forever in their naive form. 11. Carp fishes breed on the bottom of gravel rivers in freshwater streams. A few species spawn at the bottom of the gravel where the water flows. The large egg size, with a particle size of 4 to 6?, separates the eggs. 12. The squid is a ferocious fish, eating aquatic or near-water insects, shrimps, small fish, and frogs. Some large individuals feed on snakes and rodents. Sea-breeding species also feed on cephalopods, floating cavities, and intestines. After many species have been domesticated, artificial diets are preferred. Second, the type of catfish farming There are about 16 species of carp that can be completely artificially cultivated in the freshwater area of ​​the world. China's seawater breeding has achieved preliminary results, but it has not yet been promoted. At present, almost all of it is freshwater aquaculture. There are four kinds of supporting artificial culture techniques that have been generally cultivated or are being expanded. 1. Rainbow Trout: It is the first fish of the carps that was developed into aquaculture species. Up till now, there have been more than 130 years of breeding history. The breeding area has spread over 120 countries and regions. 2 years of sexual maturity, life can be repeated multiple times. The average annual water temperature of 12 °C, 2 kg of body weight up to 1 kg. The largest individual in the pond is 7 kg. Flowing pond culture, the output per square meter can reach more than 25 kg. The diseases that affect survival are mainly viral diseases and vibriosis. 2. Golden pheasant: Golden color system selected from the body color mutation of rainbow trout. Introduced from Japan in 1996, it has now become an excellent breed cultivated throughout the country. The biological characteristics, growth rate, and yield per unit area are similar to rainbow trout. Both food, fishing and ornamental value. Its golden body color is a dominant hereditary trait, which has important germplasm value for breeding scientific research. Because of its rich and elegant golden body color, the market price is higher than rainbow trout. 3, Yamagata: originated in Japan, was developed into a breeding species more than 50 years ago. It is one of the two most flavorful species of carp, and its market price is 3 to 8 times that of rainbow trout. Suitable for fishing in ponds and streams. 2 years of sexual maturity, breeding only once in life. The weight of the 2nd-instar fish is mostly 400-700g, and the largest individual is 900-1000g. Strong resistance to disease, generally not infected with viral diseases. At 22-25 °C water temperature, survival vigor and feeding intensity are better than rainbow trout. In 1996, the introduction of China, including full-scale human breeding, has matured and is currently expanding. 4, daylight white spotting: native to Japan, breeding history has been more than 50 years. 2 years of sexual maturity, life can be repeated multiple times. Suitable for fishing. Fish dishes are famous for sashimi, and the market price is 2 to 3 times that of rainbow trout. In 1996, China introduced an average annual water temperature of 12°C, 12-month-old body weight was 110-130 grams, and 2-year-old fish was 500-1,000 grams. The largest individual is more than 2000 grams. In the 0 ~ 4 °C environment, survival vigor, feeding intensity is better than rainbow trout. Eating artificial food that sinks, but also like to eat the bottom of the bait. Strong resistance to disease, basically no viral disease.

In addition, there are indigenous species of Fine-spotted pheasant, Far Eastern frog, red-spotted pheasant, and introduced species of river plover, Arctic erythrascus, silver pupa, Atlantic salmon, brown oysters, etc. are under experimental breeding.

Third, aquaculture environmental conditions Sturgeon fish should be cultured in an environment compatible with its biological characteristics, the most important is the physical and chemical conditions of the water environment. 1. Water temperature: Freshwater or mariculture requires a low-temperature water environment. Summer water temperature does not exceed 22 °C, the maximum does not exceed 24 °C, winter does not freeze or short-term ice, pollution, clear and transparent sea, fresh water can be used to farm catfish. Water temperature is an important factor affecting the breeding effect. In the optimum temperature range, the higher the water temperature, the faster the growth. Table 1 shows the growth of the pond-raised rainbow trout at different water temperatures. The higher the water temperature, the lower the dissolved oxygen. When the water temperature reaches 22°C, the dissolved oxygen in the water will drop to 5-6 mg/l. At this time, there are two unfavorable factors: high water temperature and low oxygen content in the water environment. The fish's metabolic intensity and feed efficiency will be reduced. If it continues, it will seriously affect growth and even cause death. Water temperatures below 18°C ​​are generally not affected by water temperature and dissolved oxygen. 2. Dissolved oxygen squid prefers high dissolved oxygen waters. Under normal circumstances, the critical value of dissolved oxygen in rainbow trout is 3.15 mg/L. For fish reared in a low-oxygen environment for a long time, the safety threshold is reduced to about 2.45 mg/L, and when the dissolved oxygen is less than 5 mg/L, The rainbow trout's respiratory rate is faster, swimming is slower than 4 mg/l, and when the fish clusters at the inlet and floats, the dissolved oxygen in the water has dropped below about 3 mg/l, and the fish’s life has been threatened. . In a quiet environment, fish oxygen consumption will decrease. Temperature, light, vibration and other stimulating factors of fish will increase the oxygen consumption and reduce the safety of dissolved oxygen environment. Stimulation of changes in water temperature can increase oxygen consumption by 30 to 70%. Illumination and vibration stimulation can increase oxygen consumption by 20 to 30% and 40 to 50%, respectively. A combination of multiple factors will cause oxygen consumption. More than 1 times more than in quiet state. Grasp the change law of dissolved oxygen in feeding water and adjust it timely to avoid stimulation of various factors. Maintaining a safe dissolved oxygen environment is the key to ensure the breeding effect. Feeding eel fish in the flow basin, the dissolved oxygen in the outlet should be kept above 4?/l. 3, water quality factors affecting the growth of carp water quality is very complex, mainly water acidity and ammonia nitrogen (NH3) concentration. The tolerance of rainbow trout to PH is 5.5 to 9.2, and the suitable range is 6.5 to 7.5. Acidity, particularly strong acidity, will have a detrimental effect on the growth of rainbow trout. The non-decomposing state of nitrogen derived from residual feces and other organic matter, particularly ammonia nitrogen and nitrite, is a toxic substance of salmon, which can affect the absorption of oxygen by hemoglobin, even if there is sufficient dissolved oxygen, the effect of ammonia in nitrogen It is also difficult to be used by fish to cause the same anorectic symptoms as hypoxia. Rainbow trout tolerance to ammonia nitrogen is 0.0125 mg/l. In the flow basin, if the pH is around 7, the tolerable concentration can reach 0.05 to 0.6 mg/l. In near-neutral water, ammonia nitrogen does not generally cause large harm. The higher the water temperature and pH, the stronger the toxicity of ammonia nitrogen. The higher the dissolved oxygen in the water, the stronger the tolerance to ammonia nitrogen. In an environment where the dissolved oxygen is more than 7 mg/L, when the amount of ammonia nitrogen reaches 0.8 to 0.1 mg/L, there will be no harm to the rainbow trout within 6 weeks. . In water with dissolved oxygen of 5 mg/l or less, when the amount of ammonia nitrogen is 0.5 mg/l or more, the growth of rainbow trout is slowed down, and the louse is vulnerable to damage and even kidney and liver tissue dysfunction. The turbidity of water quality is also an important factor affecting the growth of carp. Turbid water can impair the vision of the fish and affect feeding and growth. When building an eel farm, it is possible to fully understand the environmental conditions of the water source. In accordance with the water quality conditions indicated in Table 2, they can generally be used for trout farming. Farmers build small-scale farms, and can judge water quality according to whether there are wild animals in the water. If there are small fish, aquatic insects and other organisms in the water source, then this water source can generally be used to farm squid. Suitable for marine aquaculture such as rainbow trout, silver carp, etc., their childishness is spent in a freshwater environment. As the individual grows up, the salt tolerance gradually increases. The salinity of rainbow trout juvenile, current fish, first-instar fish, and adult fish can tolerate 0.5 to 0.8%, 1.2 to 1.4%, 2 to 2.5%, and 3.5 respectively. %. More than 35 grams of juvenile fish can adapt to seawater life after brackish water transition for about 10 days. Fourth, carp breeding facilities of various carp species, because of its common biological characteristics, aquaculture facilities, technology and management methods are generally the same, but also due to differences in biological characteristics and have their own characteristics. Sea, freshwater aquaculture, and aquaculture facilities must ensure that the water in the facility is being exchanged at all times. Mariculture is adopted in cage culture, freshwater aquaculture adopts flow-through culture, and lake cage culture is also implemented. Except for a few larval fish breeding sites, broodstock breeding and artificial breeding are implemented. The vast majority of culturing farms begin to purchase food fish by purchasing eggs or seeds for breeding. This article intends to introduce salmon breeding facilities and technologies from the purchase of oculo-eye eggs. 1. Hatching Eggs Egg hatching facilities The fertilized eggs, ovums, and juveniles of squid are sensitive to light in the early stages of development. Irradiation with direct light can severely affect the rate of rearing. Therefore, hatching eggs and juvenile rearing should be performed indoors or in facilities with shading conditions. Incubation of 100,000 eggs of the larvae and rearing of juveniles hatched by these eye-fed eggs requires incubation of a breeding room of 20 square meters. In the room, there should be a juvenile fish out of the hatching tank and a floating juvenile feeding and feeding trough. The film hatching tank is a facility that accommodates ovum eggs for hatching juveniles and for juveniles to eat and feed. Its structural feature is that it can ensure that the water flow continuously and evenly through each ovum in the tank. Under the irrigation of the water, the ovum will not oscillate, and it can always be evenly dispersed in the tank. According to this production requirement, people have created various forms of hatchery facilities. At present, domestically-used facilities that are more efficient and easier to manage are flat-row hatching tanks, which are made of fiberglass and consist of two parts, hatching trays and flat columns (Figure 1). The inner slot is 300 inches wide, 42 inches wide and 17 inches deep. The inner bottom is 300 inches long and 40 inches wide. One end of the slot is equipped with a drain pipe with an inner diameter of 5 inches. The hatchery was square, with an inner mouth of 42 inches wide, an inner bottom of 40 inches wide, and a depth of 14 inches. The bottom of the pan and the back wall are opened with a 2 mm diameter sieve. Below the back wall, there is a water deflector that extends 3 cm from the bottom of the pan. Four or five hatching trays are arranged in series in the trough. Eye eggs are placed in the hatchery tray. The water injected into the troughs passes through the sieve holes at the bottom of the hatching tray and flows upwards through the oculo-implanted eggs, and then flows out from the sieves in the back wall of the trays. Each hatchery can lay 8,000 to 10,000 eggs. Without a trough, you can hatch the eggs from a sink or a small pond fed with juvenile fish. Spread a small layer of river pebbles at the bottom of the trough, and place the ovum evenly between the pebbles. Keep the depth of the tank 10 to 15 cm. Per square meter can be hatched 10,000 eggs. It is also possible to make a simple hatchery plate by tapping the iron screen net at the bottom of the wooden frame and float it on the water surface of the flow pool. The ovum inside the plate will make the screen mesh below the surface of the water due to the gravity of the egg, making the ovum eggs Bathing in flowing pool water will not suffocate oxygen. 2. Juvenile fish and adult fish rearing facilities Juveniles will not float or feed during 30 days after hatching. During this period, the management of hatching and juveniles in the original hatchery trays and troughs can continue. After juveniles start to feed, they can also eat and feed in the original hatchery. After feeding for a period of time, according to the growth of juvenile fish, timely transfer into the juvenile breeding pond or breeding trough. After the juvenile grows, it will gradually move into larger juvenile fish ponds and adult fish ponds for breeding. Juveniles are weak in disease resistance. When rearing juveniles weighing 2 grams, the fish ponds are preferably arranged in parallel. The drainage of fish ponds is not used for rearing juveniles of the same size. This will help prevent the spread of diseases between fish ponds. The juvenile juveniles to adult fish breeding ponds generally use rectangular flow pools in the form of a terraced multi-pool upstream and downstream, a small pool suitable for juvenile and juvenile rearing at the upstream, and a large pool for rearing large fishes at the downstream. It is advisable to use 3 to 4 pools in series, with too many tandem pools. The water quality in the downstream pool is turbid, the dissolved oxygen is low, and the culture efficiency is not high. The ground slope of the upper and lower fish ponds should be above 1%, which can ensure the pool water is smooth and the pool water exchange is complete. According to the purpose of use, large and small fish ponds of different sizes should be set (Table 3). Table 3. Types of trout farming ponds

Fish pond species area (?) Depth of water (m) Function Upper larvae Juvenile fish pond Juvenile pond Juvenile pond Adult fish (bred broodstock) Pond 2~310~4060~100100~2000.2~0.30.3~0.40.3~0.60.6~0.8 Feeding After hatching Feeding of juveniles up to the time of feeding and feeding, feeding of juveniles up to 10 g, rearing of juveniles up to 10 g, juveniles rearing between 10 and 50 g, rearing more than 50 g of food fish or broodstock

Uprising juveniles and the fish of the year can be reared in a variety of sinks. The performance of the fish pond does not depend on the size of the fish pond, but depends on the amount of water injected per unit time. The more the pool water exchanges per unit time, the greater the stocking density and the higher the yield, so the fish pond area is not easy to oversize and is not suitable. Too deep. This facilitates management and facilitates observation of fish feeding and disease occurrence. The fish pond structure is suitable for cement stone, and the cement pool is convenient for cleaning and management. The ratio of length to width of the fish pond should be 4-6:1, and the fish pond should not be too long. If the pond is too long, the top stream of the pool fish will be concentrated at the inlet, and the rear half of the pond will be idled, wasting the space of the pond. The front and back of the fish pond should be equipped with injection and drainage outlets. The width of the outlet should ensure that the entire pond is filled with water, there is no dead angle, and the cross-section of water should occupy more than 3/4 of the width of the pool. Drainage gates shall be provided with water level control gates, bottom drain gates, and fish gate gates. In places where the soil is relatively solid, it is also possible to build earthen ponds for farming. The cost of earthen ponds is low, but pollution is inconvenient and the effect of breeding is not as good as that of cement ponds. Based on the amount of water available for use, the area of ​​fish ponds to be built and fish production can be determined (Table 4). In order to facilitate the feeding of large and small sub-pools, the number of fish ponds should not be less. Table 4. Water Supply and Available Fish Pond Area, Quantity, and Fish Production

Water Supply (L/S) Total Pool Area (?) Fish Pond Number (Units) Fish Production (Kg) 1015 to 2025 to 3560 to 8090 to 12010016533066090022 to 33 to 57 to 910 to 152000 to 30003000 to 50005000 to 1000015000 to 2500030000 to 40000

5. Technology and Management of Catfish Culture According to the growth and development stages, the production of carp aquaculture can be roughly divided into several stages of artificial breeding, fish rearing and adult fish breeding (Table 5). Table 5. Operational content of aquaculture production stages and stages of cultured fish development

Production stage Operation content Farming fish Development stage and its name Artificial reproduction Artificial collection of eggs, insemination Fertilized egg hatching Ophthalmic hatching hatching Juvenile rearing Floated juvenile Domestication-fed eggs Fertilized eggs Fertilized egg Hair Ovule hair Oocyte hatching Juvenile hatching Juvenile juvenile floating juvenile juvenile juvenile fish juvenile fish feed juvenile juvenile feeding juvenile 12-month-old fish (current fish) food fish cultured food fish breeding 12 months old 24 months old (adult fish) broodstock bred broodstock and Reserve broodstock breeds unripe broodstock

The name of each stage of development from the finished egg to the sexually mature fish is the common name adopted by the international cockroach farming industry, and adopting a unified name will help international technical exchanges. 1. The eye-catching purchases of squid farming at various stages of production are implemented under intensive water-flow culture methods under human control and operation. This type of farming is called fully artificial breeding abroad. This farming method requires a strong plan. Purchasing eyes must be based on the amount of fish pond water supply and food fish production to determine the amount of purchase. Table 4 and Table 6 can be used as a reference for purchasing quantity. Table 6. Feeding survival rate of rainbow trout If the water supply volume is 10 liters/second, refer to Table 4, food fish can produce 2000-3000 kg. Referring to Table 6, the fish with a tail weight of 770 g can be reared from the otophagocyte under normal conditions. The breeding rate can reach 68.6%. If 4942 ovum eggs are purchased, 339 grams of 3,392 kilogram tails of edible fish weighing 770 grams can be bred. If the purchased eye eggs are not good, the hatching rate and the juvenile rearing rate will be reduced to varying degrees, and the number of purchases can be appropriately increased according to the breeding experience in recent years. Most of the time to purchase eye eggs is from December to March of the following year. The purchased ovum should require the seedlings to provide the development of ovum. Developmental conditions are usually expressed as developmental accumulative temperatures. Developmental accumulative temperature is the product of the daily average water temperature and the number of development days, which means that the unit is “degree of day” or “°Cd”. The developmental accumulative temperature of different types of carp development to the same stage is different (Table 7). Table 7. Developmental accumulated temperature (days, °Cd) of fertile eggs after fertilization to various developmental stages

Stage of development Rainbow Trout Jinshan Mountain Nursing Daylight White Point Fenhe River Floats Hatching Float (open food) 160320600160320600200~250390~480690~880230~310460~620860~980230~310460~620860~980

The development of fertilized eggs to the early stage of the eye, visible in the egg membrane appears two pale black eyes, customarily called eye points, then the eye point is very small, only vaguely visible. Early eye eggs are still not vibrating and are not easy to sell or transport. After a few days, it develops to the middle of the eye, and the eye point becomes larger and more visible. Sometimes it is seen that the eye point turns and the vibration does not cause death. It is the best time for sale and transportation. In the following days, the hatching entered the late stage of the eye, and the egg color became red due to an increase in the blood volume of the juvenile fish in the egg. You can clearly see the juveniles that coiled in the eggs and sometimes you can see the movement of the juveniles. . Purely golden oyster eggs have no melanin in their eyes and body, so it is difficult to see the eggs of the ovum and juvenile fish. Judging from the developmental stage, besides observing the shape of the egg, it is also judged based on its developmental temperature. In the eyes of hybrids, their eyelids are pale black and most of them are pale pink and are not easily observed. Although the post-occurring ophthalmic eggs are resistant to vibrations, part of the juvenile fish hatch out of the membrane in the course of the sale, purchase, and transportation operations. The eggs are transported by dry method. The juveniles that are filmed during transportation will die because of no water, so they should not be sold or bought later. The most suitable for sale or purchase is a mid-term egg. For example, the most suitable purchase period for rainbow trout and golden trout is the ovum that develops at a temperature of 200–280°C. When purchasing the ovum, the developmental temperature of the eggs should be requested and the development stage should be aware of it for future management. Most of the ovary eggs are pale red, and the brood eggs fed from the astaxanthin are red. The egg diameter is mostly 4.2 to 6.5 millimeters, and the weight is 70 to 100 milligrams. Each 10,000 grains weighs about 0.8 to 1.0 kilograms. According to the egg's appearance and hatching condition, the quality of the eggs can be roughly judged. Large egg size, uniform size, translucency, bright color, less dead eggs, more concentrated filming time, hatching rate of more than 80% can be regarded as good quality. 2. The hatching eggs of the ophthalmia are purchased. The temperature of the eggs in the shipping box is usually 4 to 6°C. If the temperature of the incubating water and the temperature of the eggs do not differ by more than 4°C, the eggs can be immediately put into the hatchery. Plate, slot. When the temperature difference is too large, you must open the packing box so that the eggs can be placed in the room for a certain period of time or on the eggs, so that the egg temperature is close to the water temperature and then placed in the hatchery tray. White dead eggs were then counted and sorted out, and dead eggs were picked every 2 to 3 days thereafter. Pick out dead eggs to operate in a flowing environment and try to avoid vibrations. After hatching of all juveniles, the hatching rate was calculated based on the number of dead eggs and the egg quality was evaluated accordingly. Under normal circumstances, the higher the hatching rate, the lower the occurrence rate of malformation, and the better the juvenile constitution, the higher the bred rate. The ovum eggs placed in the incubator should be evenly distributed, and the water flow in the incubator should not have dead ends. Every 100,000 eggs should be injected with 12 liters per second. Dissolved oxygen in the incubator's drainage should be kept above 5 mg/l, below this standard will result in increased malformed fish. Water temperature should be kept below 13°C. Fertilized eggs, ovary eggs, and even hatched juveniles are all afraid of light. Irradiation of direct light will affect the breeding rate. The situation shown in Table 8 shows that even a faint light in a dark room will constitute a certain death rate. So hatching indoors should also cover the hatchery. When the juveniles are hatched into the eye, the oxygen consumption of the ovum increases, and the water injection volume is increased to more than 15 liters per 100,000 tablets per second. When it was found that there was a juvenile hatching on the first day, rainbow trout, golden pheasant, and mountain nymph were almost all hatched in about one week, and the days of daylight and sea trout hatched for about 10 days. . Under normal circumstances, the hatching rate of eggs of all kinds of squid can reach 70% or more, and the quality of eggs is good, and the management can achieve more than 80% without errors. Table 8. Lethal effects of light on rainbow trout eggs

Mortality after two weeks of light intensity (%) in a bright indoor, dark, indoor hatchery under direct sunlight (control) 15.45.40.850.650.55

3. Incubation and management of hatching juveniles Hatching juveniles can be reared in the original film hatching trays and in the troughs to open for food and feeding. The above-mentioned bottom 42 cm 42 cm water-based hatchery can stocked 8 million juvenile hatchlings, and the laid-out pebble hatching trough can be stocked 10 000 per square meter. Hatching juveniles are 12 to 18 mm in length and 70 to 100 mg in weight. The stellate melanocytes in the skin are few and the body is translucent. There are no melanocytes in the skin of the golden pheasant and the body is pale pink. The abdomen has a large yolk sac about 6 mm long and about 4 mm wide. The fins have not yet differentiated and are pleated and do not swim. If you are afraid of light, you will not eat. Relying on nutrients in the yolk sac to complete early development after hatching. Oxygen consumption increases after hatching, increasing the water supply per 100,000 to 20 liters/min. Management work is mainly to pick out and count dead fish in a timely manner to ensure adequate water supply, smooth water flow, avoid direct radiation, indoor brightness should remain dim. In addition to the shortage of water supply and light, the main reasons for affecting the rate of childbirth were yolk sac edema and deformity. Emitting eye eggs to avoid light can reduce the deformity rate. However, the cause of yolk sac edema, and its prevention and treatment methods are still unknown. 4. Feeding Management of Floating Juveniles From Table 8 it can be seen that hatching juveniles of rainbow trout and golden pheasant developed to 280 degrees day, and juvenile fishes of virgin calves hatched to 300 to 400 degrees days. Differentiation into their own independent fins, began to float to the water, upper swimmers become floating juvenile fish, and began feeding. Floating is the signal to start eating. When the daylight sunfishes and river leeks enter the start-up period after the development period of 400 degrees, they do not go up and there is no obvious signal for the start of eating. They can only be judged according to the developmental accumulated temperature and juvenile fish form and the situation of trial feeding. Whether you have already eaten. Floating juvenile or juvenile fish, yolk sac has been absorbed more than 3/5, from the original translucent light red to light black, due to increased skin melanocytes, dorsal side becomes black. The golden pheasant turns yellowish. Both the overall length and body weight were significantly greater than hatched juveniles. When feeding artificially-opened bait, you can eat food that is close to the mouth, and when about 30% of the juveniles have gone up, you need to start feeding. But do not float on the daylight and the juvenile river fish, do not eat artificial feed, and eat fresh liver or bovine liver paste. When about 20% of the juveniles eat liver paste, they must begin to feed. The purpose of domestication for rainbow trout, golden pheasant and mountain virgin is to make it a habit of eating food from the mouth of the mouth and actively eating artificial bait. The domestication of the white spotted pheasant and the river bream is to allow it to form the habit of feeding on artificial baits, and on this basis to form a habit of actively looting food. Tapping time is about 1 month. The length of floating juveniles is 18-28 mm and the weight is 90-180 mg. The first 10 days of training can be performed on the original hatching trays and tanks. The water injection volume should be increased to 30 liters per minute. The juveniles at this time still have to avoid direct light. The bait used for tame feeding is a rainbow trout with an opening diameter of 0.2 to 0.5 mm and is fed 6 to 8 times a day. At this time, the juveniles do not have the habit of feeding in groups, and evenly spread the bait throughout the entire pond. Spread a thin layer on the surface of the water. The amount of feeding should be such that each juvenile has the opportunity to feed on the bait and has a slight residual bait. The bait should be removed once a day to keep the fish ponds sanitary. After feeding for about 10 days, the juveniles can be transferred to the juvenile ponds or tanks for breeding. Small pools and sinks can stock 10,000 pigs per square meter, and a 20 square meter pool can store 0.5 thousand pigs per square meter. 100,000 liters of water per 100,000 liters per minute. Keep the water deeper than 30 cm. As the fish grows, the amount of water injected should be increased. After 2 weeks of feeding, juveniles began to form habits of active feeding. Training for one month can form a habit of active feeding of the colony. The number of feedings per day can be reduced to 4 times. The bait should have a particle size of 0.5 mm or more. Sunlight White Stork and River otters should be fed with pig or beef liver paste. Fingers of liver sauce into the water, a small number of juveniles will quickly swim from the bottom to the upper, feeding, feeding 6 to 8 times a day, every 10,000 fish 40 to 60 grams per day feeding. After a few days, almost all of the juveniles will actively eat liver paste, and after 1 to 2 weeks of training, we must add rainbow trout to the liver sauce, and then gradually increase artificial baits, reduce liver paste, and exercise for more than 20 days. Juveniles can form a complete habit of eating artificial baits. At a water temperature of 11°C and 14°C, the juveniles can weigh 200-300 mg and 600-900 mg, respectively, after a 1-month diet. After 1 month weight up to 1 to 2 grams. During the feeding period of floating juveniles, the main diseases affecting the breeding rate are bacterial rickets and viral diseases. Bacterial rickets are mainly harmful to sunlit whitefish, river fleas and mountain nymphs. Viral diseases mainly infect rainbow trout and golden trout, and the mortality rate often reaches 30~60%. To keep fish ponds and foods hygienically, a 1/2000 solution of formalin for 10 minutes can prevent bacterial rickets. The diseased fish is bathed with a 1/2000 solution of copper sulfate for 30 to 60 seconds. Repeatedly, it can receive therapeutic effects. Feeding juveniles above 2 grams at temperatures above 16 degrees or 6 degrees can reduce the risk of viral disease. 0.05% povidone iodine aqueous solution immersed in the eye for 15 minutes, tool sub-pool dedicated, diseased fish incineration treatment and other measures, have a certain preventive effect on viral diseases. The feeding and feeding of floating juveniles is the most difficult stage in the whole process of salmon farming. The quality of eye eggs, food and feeding environment, especially the health of the water environment, as well as technical and managerial mistakes can all lead to a reduction in the consumption of juveniles. What must be done well in management is to start feeding in due course, overfeeding, and fish pond hygiene. 5, when the feeding of juvenile fish reached about 1 gram, the food intake and disease resistance were significantly increased. At this time, the fish of the year can be started. Raising farms raise more than 2 grams of juveniles and will have a higher breeding rate. It is necessary to make a stocking plan based on the amount of water supply in advance. Water supply is 10 litres/second, and a fish farm with an area of ​​100 square meters can raise 3,000 kilograms of fish. If each weighs 750 grams, the number of fish tails is 2,000. Referring to Table 4, 2.74g of juvenile fish bred 770g of food fish, under normal circumstances, the breeding rate of up to 82.7%, bred 2000 770 grams of food fish, you need to purchase 2.24 grams of juvenile fish 2500. Considering the depletion in transportation and breeding, more than 3,000 can be purchased. One thousand stocks per square meter are stocked in small pools or sinks, with a water supply of 12-15 liters per minute, fed 4 times a day. According to the water temperature situation, refer to the feeding rate table (Table 9), and scientifically determine the daily feeding amount. Table 9: Feeding rate of rainbow trout The table is suitable for rainbow trout as well as other trout. For juvenile fish less than 12 grams, the amount of feeding on the table is too high and the amount of residual bait is too high. The amount of bait should be determined according to 80% of the number in the table. For juveniles weighing 2 grams, at a water temperature of 15 degrees, the daily feeding amount should be 3.9% of the fish's weight, and 80% should be 3.12% of the fish's weight. The total weight of 3000 tails is 6,720 grams, and the daily feeding amount should be 210 grams. After this, the management of fish ponds is mainly to test the growth of fish on a regular basis, and adjust the amount of feed as the body weight increases, increase the amount of water injected, adjust the stocking capacity per unit area, and expand the area of ​​the rearing pond. Table 10 can be used as a reference for adjusting the stocking amount. Table 10. Required pond area and water supply for 100,000 rainbow trout at different water temperatures The squid are fierce fish. When the size of the fish differs by about one time, fish will be eaten by large fish. In the course of feeding, it should be sieved in a timely manner and kept in size. Juveniles should be sieved 1 to 2 times before 5 g, and sieved once a month during 5 to 20 g. When the difference in individual sizes between 70 and 80 g is obvious, they should be sieved once more. Afterwards, proper screening can be performed according to the difference in fish size. At an average annual water temperature of 12°C, 2.24 g of juveniles are reared for 8 to 10 months. The average tail weight, rainbow trout and golden trout can reach 180 g, 150 g of mountain trout, daylight white trout and river trout. Up to 120 to 130 grams. If it is a rainbow trout, the rearing rate is 80% after 8 months of breeding. Then 2500 juvenile fishes can be bred with 2000 fish tails weighing 180 g each and the total weight is 360 kg. 6. The specifications for food fish in the fish farming market are more than 0.5 kg for rainbow trout and gold trout, more than 0.3 kg for mountain trout and 0.5 kg or more for daylight white trout. A total of 2,000 tails of whole juvenile juveniles weighing 120-180 grams were used as fingerlings for food fish culture. Within 10 months, they will gradually reach the market specifications. As the individual grows, 2000 fish of the first age will gradually occupy 100 square meters of fish ponds. During this period of breeding, the stocking and water supply per unit area can still be adjusted with reference to Table 10. Fish species with a tail weight of 150 grams can be stocked with 100 fish per square metre. At a water temperature of 10°C, 2000 fish should supply 2.64 liters of water per second. Food fish farming requires a large amount of feed, and feed costs account for about 60% of the cost of farming. Scientific adequate feeding is the basic guarantee for achieving the desired benefits. The daily feeding amount can be determined with reference to the feeding rate table. Feeding according to the amount specified in this table, the bait utilization (transformation) rate will be high, but it does not necessarily guarantee the fastest fish length. Feeding rate is higher than the feed rate table, the fish will grow quickly, but the feed efficiency is not necessarily the highest. Rainbow trout with a tail weight of 100 grams will have saturated food intake if the feed rate reaches 1.4 times the feed rate. In the beginning, the fish grew quickly, but anorexia soon appeared. The growth was affected and feed efficiency decreased. It is necessary to adjust the feeding amount according to the changes in food intake and water temperature. When the water temperature rises to 20°C, the metabolic capacity of the golden pheasant, rainbow trout, and daylight spotted quail decreased, and the feed amount at 21°C should be reduced to 3.5% at 20°C. Overfeeding at high temperatures can cause fish disease. In the environment above 21°C, the feeding condition of Shan Nu Wa was better than that of rainbow trout and daylight. Management of pool water is a must-do daily management, and a large number of feeding seasons are performed once a day. When the dissolved oxygen in the outlet drops to 4 mg/L, sufficient dissolved oxygen in the pool water is ensured by increasing the water injection amount, mechanically supplementing oxygen, or reducing the stocking density. At the time of fish and food fish breeding, the main fish disease affecting the breeding rate of rainbow trout and golden pheasant was vibriosis, and the high-rising season was from June to August. Most of the affected fish were larger than 200 g to several kilograms. The symptoms were mainly body cavities. Endometrial, liver, sputum, and cutaneous hyperemia can cause massive deaths and severe economic losses. The disease is characterized by repeated attacks over the years. After extensive spread, it is difficult to cure. In the early stage of disease, the daily injection of yellow amine drugs such as sulfamethoxazole (75-100 mg) or ofloxacin (10-50 mg) per kilogram of fish inhibits the spread of the disease. Eliminating the use of dead fish or fish guts can play a good preventive role. The ponds must be cleared and disinfected. The tools must be dedicated to the pool. The disease that affects the breeding rate of G. sinensis, G. sinensis, and Hess is mainly acne disease, which occurs most frequently in spring and autumn water temperatures of 9 to 13°C, and generally does not cause mass mortality. Yamagata who entered the mature period is prone to develop the disease. The condition is hemispherical hemorrhagic disease in the skin or muscle tissue. The treatment method is generally 70-100 mg of sulfa drugs per kilogram of fish per day, and the amount of drugs can be doubled on the first day.日光白点鲑与河鳟长到4克以后,一般很少发病,发病也不出现批量死亡的现象。六、养殖鲑鳟鱼的饲料养殖条件下,鲑鳟鱼完全依赖人工饲料发育、生长。这就要求必须投喂全价饲料。饲料营养不完全或组成不合理都会影响养殖效果,甚至会影响食用鱼的品质而阻塞销路。投喂颗粒饲料要考虑适口性,不同规格的鱼适于摄食的饲料粒径也不同(表11)。表11. 鱼体规格与适口饲料的粒径不同发育阶段要根据营养需求的特点投喂不同营养成分的饲料(表12)。表12. 虹鳟鱼各发育阶段饲料营养成分近几年的试验养殖表明虹鳟鱼用饲料基本上适于金鳟、山女鳟、日光白点鲑等鲑科鱼类的需求。当前的市售饲料都是虹鳟鱼饲料,也可以用于其他鲑科鱼类。饲料品质的优劣主要取决于蛋白质含量和种类。虹鳟鱼对饲料中蛋白质的需求量是40~55%。动物性蛋白中含有丰富的鱼类需求的必须氨基酸。饲料中的蛋白应主要来源于动物性蛋白。不同的蛋白,对鱼的味道有明显的影响,以蚕蛹蛋白投喂虹鳟鱼,鱼肉就会有蚕蛹味,投喂鱼粉蛋白,就会增加鱼味鲜度和浓度。饲料中的鱼粉蛋白应占蛋白含量的60%以上。饲料中的脂肪含量和种类也是影响鱼肉品质的重要因素。虹鳟鱼对饲料中脂肪量的要求是占饲料的10%。以脱脂鱼粉和大豆粕为主的饲料,脂肪含量为5%左右,这种饲料还应添加5%的豆油或鱼油。日本的研究表明用添加豆油的饲料喂鱼,鱼肉的鲜度好于鱼油。近几年,国内建成了几处生产虹鳟鱼饲料的专业厂家,饲料生产开始由养鳟场户家庭作坊式的饲料生产向着社会化专业生产的方向发展。这一发展趋势将会有力地促进养鳟业的发展。七、养鳟业的现状与发展前景我国的养鳟业,近20年来获得了迅速发展,全国26个省区已有800多养殖场户。虹鳟单一品种养殖已经发展成多品种养殖,年产量达7000~8000吨。经济发达地区在养殖的基础上初步形成了鲑鳟鱼游钓业。养殖和饲料加工技术的积累已经成为推动鲑鳟鱼养殖业持续发展的技术基础。 1、丰富的冷水资源为养鳟业展现了广阔的发展前景曾经任其白白流失的冷凉水,因养鳟业的开发成了可以为社会创造高档鱼蛋白的宝贵资源。人们开始知道身边的那股冷水,就是可以致富的源泉。东部的许多地方已经出现了争相占有那些从无人利用的冷凉水发展养鳟的局面。目前人们还不知道适合开发养鳟业的冷水资源到底有多少,但可以说资源是相当丰富的。现在全国26个省区已被开发养鳟的冷水资源,大体是每秒30立方米,而仅东北的长白山区就蕴藏着每秒200立方米的冷水。此外西部的雪山融水、高原山地的河湖水,大多是适于开发养鳟业的冷水资源。夏季水温超过22℃的水,秋、冬、春仍可用来养鳟。由此看来,内陆的冷水资源即可说是极其丰富的。试验养殖的结果已经表明,东部的大海也蕴藏着适于养殖鲑鳟鱼的冷水资源。大海为开发养鳟业展现了更为广阔的前景。 2、鲑鳟鱼的高档营养将会刺激社会需求量的大幅增长鲑鳟鱼是一类肌肉无刺、营养价值高、肉质鲜的高档鱼类,社会生活对鲑鳟鱼营养价值的认同将会导致对鲑鳟鱼需求的增长。从西方国家进口的所谓深海鱼油,就是从鲑科鱼提练出的高度不饱和脂肪酸20炭5烯酸和22炭6烯酸,是对心脑血管具有营养保健作用的保健食品。每100克虹鳟鱼22炭6烯酸和20炭5烯酸的含量分别达983毫克和247毫克,远远高于鲤科鱼、鸡肉等肉食品。可以说鲑鳟鱼具有营养心、脑血管的保健作用。鲑鳟鱼的鱼卵大如黄豆,内含丰富的不饱和脂肪酸和鱼卵蛋白,已经开始成为富裕人口的高级营养食品。随着社会经济生活的进步,鲑鳟鱼必将成为人们重要的蛋白来源。这一需求趋势必然会推动鲑鳟鱼养殖业的发展。 3、可观的经济效益是养鳟业持续发展的动力养鳟业是一项便于推广的高效益养殖业,一个劳动力利用每秒15升的冷水165平方米流水池养殖食用鱼年产可达0.3~0.5万公斤,按目前最低市价计算产值达4.8~8.0万元,盈利1.2~2.0万元。如果养鳟与鳟鱼游钓相结合经营,经济效益还要增加30%以上。在可观的经济效益的驱动下,近十余年来,黄河流域上下各省区的养鳟业获得了迅速发展。北京市远近郊地区已经形成了养鳟与鳟鱼游钓协调发展的养鳟业,为农民开出了一条新的致富之路,为社会生活提供了一项前所未有的新型休闲娱乐形式。

目前全国鲑鳟鱼消费量为2万多吨,其中三分之二是进口鲑鳟鱼,这一市场形势预示了鲑鳟鱼养殖业的发展潜力。开发冷水资源,发展养鳟业,前景是可观的。

Buckwheat Honey was traditionally produced in Northwest China, From the tiny white blossoms on the buckwheat plant (the same plant that produces the grain to make buckwheat flour for pancakes) comes one of the heartiest and robust honeys in the Buckwheat Honey is very dark in color. It is typically compared with black strap molasses, and it possesses a musty, earthy aroma. Buckwheat Honey has been demonstrated to have higher levels of antioxidants than other honeys and was featured as an effective cough soother in a research project completed by Penn State College of Medicine. Buckwheat Honey's hearty, full flavor has several unique applications. Drizzle over some blue cheese, use in a homemade wheat bread.

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